blog

Tissue sampling grapes at veraison – too late or getting in early for next season?

Mon, 16 Jan 2012 13:28:27 +0900

While petiole sampling of grapevines at full bloom is the most common method of tissue analysis employed by viticulturists and advisors, it is by no means the only time that tissue samples can be taken.

Sampling can also be carried out at veraison or berry colouring / softening.

There are several reasons why sampling could be carried out at veraison.

- Sampling was not carried out at full bloom (70-80% capfall) so there is no gauge as to how the vines are faring except for visual observation.

- Any nutrients which were in the low or just adequate range at flowering can be re-checked as can the response to any treatments applied to adjust for such situations.

- Potassium was low or borderline but not deficient at flowering and another check on tissue K is required. This will determine if K deficiency is developing at fruit ripening, a more common occurrence. Mg could also fall into this category.

- Other problems or symptoms may have manifested themselves between flowering and veraison and a check is warranted.

-If excess Na or Cl problems in the tissue are suspected.

There may still be time to apply corrective treatments for next season in the post-harvest period – this is the case for sub-tropical areas and there may be a small window of opportunity in temperate areas.

Having decided there is a need or benefit to be gained by tissue sampling at veraison, the next choice we have to make is which part to sample – the petiole or the leaf blade as calibration data exists for both.

Australian researchers, Weir and Cresswell, as well as many other researchers recommend petioles be used when checking K, Na or Cl levels. In the case of Na and Cl, these elements accumulate in the petioles even though the leaf blades may show the symptoms. If B toxicity is suspected, sampling leaf blades is recommended. For a general look at overall tissue levels either petiole of leaf blade analysis can be used.

Having decided on petiole or leaf blade, the next thing to consider is the position of plant part to sample as it differs depending on whether you choose petioles or leaf blades (different origins of the data meant different position of plant parts were selected by researchers).

Petioles - Sample petioles from recently mature, fully expanded leaves located 6 to 7 leaves from the shoot tip. Collect one or two petioles per vine. Sample from minimally shaded, normal growing shoots on both sides of the vine canopy. Collect 60 – 100 petioles per sample.

Leaf blades (without the petiole) - Leaf blades (lamina only) from leaves opposite bunch at base of shoot. One leaf per vine from a single variety x rootstock planting. Collect 50 leaves per sample.

Then of course there is trouble shooting when an unknown problem has shown symptoms. Here you may have to forget the good advice above and instead sample the affected plant part from affected vines and the matching plant part on non-affected vines for comparison. When there are no reasonable clues as to what the problem is, it is suggested both leaves and petioles be sampled and analysed separately, that is leaves and petioles of affected plant parts and leaves and petioles of matching plant parts from non-affected vines – four samples in all to give best chance of solving the problem. You do not have to wait until veraison in such situations – sample when the abnormal appearance is observed. Here you will be relying not so much on published standards but on the comparison between good and poor samples for the solution to the problem.

To avoid the need for trouble shooting, tissue sampling should be conducted regularly over a number of years as part of the management program.

So while it is true that sampling at veraison is too late for the current season, it could be argued it is getting in early for next season, much earlier than sampling at next season’s full bloom.

SoilMate ver 6.0 Available Now

Mon, 02 Jan 2012 15:34:32 +0900

Back Paddock is pleased to announce the release of SoilMate ver.6.0
The latest version, 6.0, of SoilMate is now easier and quicker to use. Back Paddock has made the program more intuitive and therefore quicker. The models that are used in SoilMate have been updated with the latest research information giving you confidence that the results from the models are meaningful.

SoilMate New Features
New CotN – Plant Model The new model incorporates the latest information to achieve the high cotton yields of today
Automatic creation of SoilMateWeb PO from pre-logging If the purchase order is entered whilst logging in there is no need to enter the PO when downloading tests
Improvements to In-Crop N When crop stages are selected from the drop down list the efficiencies are automatically adjusted
Printing Multiple SOF After creating the log in click on save changes. Click on form in the upper tool bar, click on Order Form, select the forms for printing and then click print
Improvements to Trend Analysis Inclusion of Lime rates, amongst other improvements
Selectable Title Page in report printing An option for a customised title page now appears automatically when a report is selected. There is also an option to include or not include the report page
New Sample Order Forms - multi farm & multi paddocks There are now three options: Single Depth, Same Farm-Multi Paddocks Single Depth, Multi Farm-Multi Paddocks Single Multiple Depths-Same Farm
Merging Trading Names Trading names, farms and paddocks can now be exported from Adviser into SoilMate. In Adviser go to File, click SoilMate Link and then click Export Details to SoilMate.
Grouping of lab tests by sample type Lab samples are now grouped by type ( soil,tissue,water)
New Calculations for Calcium % of CEC and Potassium % of CEC
Automatic Nutrient Status Report (Pre-Recommendation Phase 1) An automatic status report is now attached to the email that notifies samples are available. An evaluation table must be filled in during the log in process for this to occur.
Model Reports are now available in Report Tab When selecting types of reports a report for the Grain N Plan and Cot N Plan can now be selected.
Cotton Petiole Export Report It is now quick and easy to create a report and graph of petiole test results. After importing results click on Data. Click on Cotton Petiole report and then select the farm and field. Enter the nearest town and the day degrees. Click finish and save the file. The file will now download into an excel sheet.

For users currently using ver. 5.5 update to the latest version using the link below:

Call the Help Desk on 1800 557 166 for assistance with upgrading from older versions.

Download SoilMate ver 6.0 Here

click save and run the update.

A User Guide for SoilMate can be downloaded by clicking on the link below:

SoilMate User Guide

The Coming Famine

Sun, 01 Jan 2012 15:34:32 +0900

Abstract: Feeding 10 billion people sustainably in the late 21st century will be the greatest challenge humanity and science have ever faced. While food demand will double by 2060 there are emerging scarcities of all the main resources required to produce it – water, land, energy, nutrients, science, fish, finance and stable climates. These challenge us to rethink food itself, to develop new farming systems, diets and food products for the future that are healthy, creative, delicious and tread less heavily on the planet.

Make no mistake: we are facing the greatest challenge in human history – how to feed ten billion people sustainable for more than half a century.

In the first part of this talk I will outline the limitations we face – and you may well find this a bit confronting. In the second, however, I shall describe the enormous opportunities which recreating our food systems and diet holds for us – and I trust you will find this both inspiring and motivational.

Demand

Tonight there will be 242,000 more human beings to dinner than there were last night.

As we’re all aware there will be around 9 billion people in the world of 2050. However our numbers will keep on climbing as more babies are born and older people live longer, probably peaking at 10 or 11 billion in the mid-2060s.

The world economy, too, will continue to grow – as China, India, Brazil and other advancing economies seek massively more high protein food.

So global demand for food is likely to double in the coming half century.

By 2065 we will need 600 quadrillion calories every single day to feed us all.

My first point is that the central issue in the human destiny in the coming half century is not climate change, terrorism or the global financial crisis.

It is whether we can achieve and sustain such a vast supply of food.

Constraints

My second point is that our food systems face critical limitations. Not just one or two, but a whole constellation of them, playing into one another. And serious ones!!

There are looming scarcities of just about everything we need to produce good food – water, land, nutrients, oil, technology, skills, fish, finance and stable climates.

And it is very hard to solve one, without making the others worse.

So this isn’t a simple problem that we can just throw more technology or new policies at.

It is a wicked problem.

Water

By 2050, nearly 8 billion people will live in the world’s cities. They will use about 2800 cubic kilometres of fresh water every year – more than the whole of irrigation farming uses today. Many cities are already meeting their own needs by stealing the farmer’s water.

Then there is the slice of farm water that climate change is stealing: rainfall over the world’s great grainbowls, evaporation from soil and dams, dwindling lakes, shrinking groundwater or the loss of icepack from mountain regions. The Himalayan glaciers are indeed disappearing. And the North China Plain is running out of water. Those two regions today feed 1.7 billion people now and must support twice as many in future.

By 2050 6 billion people will live in conditions of moderate to acute water scarcity, mainly in the regions shown in the map.

IWMI director general Colin Chartres warns “Current estimates indicate that we will not have enough water to feed ourselves in 25 years time.”

Lakes

Worldwide, groundwater levels and rivers are dropping as they are pumped dry. Immense waterbodies like Lake Chad are simply vanishing. America’s Colorado and Australia’s Murray River now rarely reach the sea, and there are many like them.

A recent study in the journal Nature reported that 80 per cent of the world’s major rivers are degraded.

Thirsty Race

Today, humanity uses about 7,450 cubic kilometres of water a year.

Each of us uses an Olympic swimming pool of water, every two and a half years. Three quarters of that water is used to produce our food.

The cup of coffee you enjoyed this morning took fourteen buckets of water just to grow the beans. The steak you might enjoy tonight takes 15 tonnes of water to grow two pounds of beef if grassfed, and 60 tonnes if grainfed.

To put our fresh water consumption in perspective, over a lifetime we each use enough water to float the USS Enterprise.

Land

Today, a quarter of the world’s farm land is degraded. (FAO 2008)

A recent satellite study has found that the world has been losing one per cent of its farmland every year – due to a combination of erosion, urban sprawl, mining, recreation, toxic pollution and rising sea levels. We are currently losing 750 tonnes of topsoil every second.

If we’ve already lost 24% of our food producing land and we lose around 1% a year from here on in, you can calculate for yourself how much land our grandkids will have left to double their food production on.

The world appears to have passed ‘peak land’ in 2001 – see the FAO graph.

Megacities

By 2050 the area of farm land buried under cities will exceed the total landmass of China, and the total area of land diverted to recreation and other non-food activities could rival that of the United States. This is nearly all prime farm land in river valleys and on coastal plains.

The word “development” must now be understood to mean the elimination of food potential. We need more laws to stop it.

Every hectare of good land lost near a city has to be replaced with four or five hectares of marginal country, at risk of drought or erosion, thousands of miles away – adding to global food insecurity, carbon emissions and land degradation.

Some of these mighty cities will have 20, 30 and even 40 million inhabitants. Yet they will grow little or none of their own food.

They are sustained by a mighty river of trucks that flows in every night to restock our shops and markets.

What would happen if - due to an oil crisis, a local war or natural disaster - that river of trucks failed to arrive, even for a few days?

Civilisation has designed its greatest cities as death-traps.

It is time for us to rethink them.

Nutrients

The world currently loses close to 90 per cent of its nutrients all along the chain from farm to fork.

On farm anything up to half of the fertiliser can be lost. Another half of our nourishment is lost in the food chain and waste disposal system.

This wastage is destroying lakes, rivers and coastal areas – as illustrated by China’s Olympic yachting course, overgrown with algae.

Modern civilization is largely dependent on finite mineral nutrients mined from rock or soil. There are no substitutes for these.

No phosphorus, no food.

Because these minerals are finite they will sooner or later become scarce. Just when is currently a fierce debate among scholars. But like peak oil, peak phosphorus is lying in wait for humanity, sometime this century.

When it happens, millions of farmers will be unable to afford fertiliser – and unless we have found new sources of nutrients, food prices will skyrocket.

Waste

In the developed world, we are the first generation in the whole of human history to throw away half our food. That picture shows the USDA’s estimate of the food trashed by the average American family every month.

Put another way, half of the hard work of the world’s farmers is going to landfill.

While a billion people go hungry and a child dies from malnutrition every five seconds, we waste food sufficient to feed 3 billion.

Our generation, it appears, has lost its respect for food – the very thing that keeps us all alive.

Our grandparents would say we were idiots. And they’d be right.

Peak Oil

Global peak oil happened in 2006, according to the International Energy Agency. It has certainly occurred 50 out of 65 of the world’s oil producing regions – including, possibly, Saudi Arabia.

Yet 60 million new cars will hit the world’s roads this year.

Whether the coming oil crisis happens next week or next decade, it is now a safe bet – and it will have a huge impact on the cost f farming and on both the price and availability of food worldwide

The modern food system is totally dependent on oil. Each of us consumes the distillate from 66 barrels, embodied in the food we eat.

Farm fuels are generally not a solution, as they drive up food prices. In theory you could grow enough fuel on farm to run all the tractors, but that would cut global food supplies by 10 per cent. And if you grew enough to run the trucks that supply out cities, it would cut global food by 30 per cent.

We need a crash worldwide program convert the whole of the world’s advanced farming systems to another energy source: algal biodiesel maybe. 2^nd generation biofuels. Or hydrogen. Or solar electrics.

But our governments are mostly asleep at the wheel on this looming crisis.

Fisheries

Fisheries scientists say a third of world fisheries have already collapsed and another third are in trouble. (Worm et al 2007). Whatever happens, we are not going to double the supply of wild-caught fish as world food demand doubles.

As FAO (2008) put it: “the maximum wild capture fishery potential from the world’s oceans has probably been reached”.

If we cannot double the fish catch, then we will have to get the extra 100 million tonnes of protein from land animals or fish farms. This will require us to grow a billion tonnes more grain.

In addition to this, FAO expects global meat demand to rise by 185mt by 2050.

Just to put the scale of the food production challenge in perspective for you, we’d need to discover three more North Americas to grow enough grain to feed all these livestock.

Climate

This is all happening in a time of climate change. “Our crops are adapted to climates which are about to become extinct,” is how Cary Fowler, who runs the Svalbard Seed Vault, sums it up.

The UK’s Hadley Centre thinks drought could regularly affect 40 per cent of the planet’s land area by the end of this century.

Their soil moisture projection suggests that regions once thought to have big farming potential, like Brazil, southern Africa and the Indian grain bowl, may prove unreliable.

The International Food Policy Research Institute warns of a 30% drop in irrigated wheat in Asia and 15% in rice due to climate factors. The World Bank thinks African productivity could halve and India’s drop by 30 per cent.

There general consensus is that global food production could drop 25%, right when we are trying to double it.

In the last few months drought and floods have smashed key food growing regions of China and the US. As we well know, nowhere is immune.

Challenge

This gives an idea of the challenge facing the world’s food industry in the next two generations.

We need to double the global food supply using half the water, less land, without fossil fuels, with scarce and costly fertiliser and chemicals, under the hammer of climate change.

This may seem like a massive task.

But it is also a magnificent opportunity for all those involved in food – and especially for good farmers and imaginative cooks.

It is the challenge of our Age.

It is a chance for Australia to pioneer novel farming and food systems and a truly sustainable, healthy and delicious new cuisine.

R&D

But we have put our farmers behind the eight ball.

On top of the scarcities of land, water, energy and nutrients agriculture is driving into a huge technology pothole.

This is because of decisions by national and regional governments worldwide, by aid donors and academic institutions, to slash funding for agricultural research over four decades.

In the year 2000 the rich countries spent just 1.8 cents in every research dollar on ag research, so unimportant has food become to them.

To give you a comparison: the world spends about $50 billion a year on food science.

And it spends $1500 billion a year on weapons.

To develop the sustainable eco-agriculture of the future, and the sustainable healthy diet that does not kill half its consumers, like our current one, we need massively more investment in food science and technology.

Creating the sustainable food revolution is, today, humanity’s most urgent task and greatest scientific challenge.

Conflict

The reason is that, if we fail, the consequences will affect every person on the planet.

Modern wars are often driven by scarcities of food, land and water.

Dafour, Rwanda, Eritrea, the Balkans were all destabilized, at root, by squabbles over these resources. Going further back, the French and Russian civil wars both grew out of bread crises. We know that hunger breeds war.

The UK Ministry of Defence – which developed this threat map – America’s CIA, the US Center for Strategic and International Studies and the Oslo Peace Research Institute all identify food scarcity as a trigger for revolution, government collapse and wars, possibly even nuclear.

Food Prices

The riots that overthrew governments in Egypt and Tunisia this year both began with a public outcry over food prices.

Globally, as FAO points out, food prices are now at their highest level on record, peaking twice in three years.

But the good news, ladies and gentlemen, is that many wars can also be avoided – by successfully meeting the world’s need for sustenance.

Investing in food and farming science is, in other words, defence spending. It merits equal priority.

Refugees

Recent years have also witnessed a surge in the number of refugees and legal immigrants.

Future famines in any significant region – Africa, India, Central Asia, China, Indonesia, Middle East or any of the megacities – will confront the world with tidal waves of tens, even hundreds of millions of refugees, swamping their neighbouring countries.

In future, even places that think they are safe may face tidal movements of people in the millions or tens of millions, bringing profound change to society and impacting the whole world.

Let there be no doubt that solving global food insecurity is the great challenge of our time.

So what are the solutions?

Here are some of the most important – and exciting.

SOLUTIONS

We need to redouble the global investment in agricultural and food science. In my estimate we should lift the total agrifood R&D spend to at least $80 billion, twice what it is today.

Then, for every research dollar we need to spend another dollar getting the knowledge into the hands of the world’s 1.8 billion farmers.

We must generate the greatest knowledge sharing effort in history – to reach not only farmers, but also all cooks, food processors, restaurants and consumers

Using the internet and modern mass communication systems, I believe this to be completely achievable.

And where is the $160 billion to come from?

Food science IS defence spending.

Just ten per cent of the world’s current weapons budget would secure both a sustainable food supply – and enhance the prospects of peace everywhere.

An easy way to improve global food security is to reduce the colossal waste of half the food we currently produce.

However it means extensively redesigning our diets, our cities and the food production and distribution systems that satisfy them.

It means educating ten billion people with a new respect for food.

Vegies in Sky

It means greening our cities, mining and recycling the vast volumes of water and nutrients they presently collect, purifying them and designing entirely new urban-based food production systems.

These will turn what we now treat as waste back into food, fuel and a great many other essential things.

It will involve growing large quantities of fresh vegetables within urban areas by hydroponic, aquaponic and other intensive methods.

We will design this new urban permaculture and incorporate it into the buildings, landscapes and social milieu of our mighty cities.

Biocultures

It will involve creating new industries that use organic waste to produce vegetable, microbial, fungal and animal cells in biocultures and turn them into healthy and novel foods.

This may not sound very ‘gourmet’ – but remember that fine wines, cheeses, beers and salami are all the products of bio-processing. And these novel foods can be profiled to directly tackle conditions like diabetes, heart disease, cancer and obesity.

To do this, I here call for a World War on Waste.

Let us together design food systems that do not waste or, if they do, that then reuse.

We must refashion the world diet - to one that doesn’t actually kill half the people who eat it, as does our present one.

To one that treads more gently on our crowded planet.

Vegies

This diet will be lighter, fresher, healthier. It will be vastly more diverse, will contain far more plant foods, and less high-energy foods.

We are at the brink of a revolution in food diversity, the like of which we have never seen before.

A culinary and farming adventure like no other we have ever seen or imagined.

Australian scientist Dr Bruce French has compiled a database of 23,000 edible plants from all around the world – of which we currently eat only 1 or 2 per cent.

The richness of nature has scarcely been tapped.

Our menus, supermarkets, cookbooks and restaurants are poor in diversity compared with what they will become.

In Australia he lists 6132 edible plants, of which we actually farm about half a dozen.

This has the makings not only of a revolution in farming diversity but a grand culinary adventure and a breakthrough for health and sustainability.

Rangelands

Humans will still want to eat meat. But with the rise in grain and energy prices and the drying of the world’s grain bowls, I anticipate that livestock production will refocus in the world’s grasslands and rangelands - at lower stocking rates – while graingrowing will concentrate on producing food crops in the regions favoured by good soil and more consistent climate.

Future meat will be clean, healthy, natural and largely organic – by popular demand. But it will be very expensive, reflecting the true cost to the environment of producing it and giving a better return to the producer.

It will use advanced technologies like ‘precision pastoralism’ to ensure it is sustainable.

It will help to regenerate the world’s grasslands, rangelands and deserts along with their wildlife.

Because of the huge areas involved, it will lock up billions of tonnes of carbon.

We can also farm parts of the deserts, using novel systems that grow food, feed and fuel from sunlight and seawater.

But to achieve all this we need to reshape the attitudes and expectations of 8 billion urban consumers towards food and farming.

Food year

This calls for the world’s most ambitious educational campaign – to install one full year, a food year, in every junior school on the planet.

A year in which every subject – maths, language, geography, science, society and sport – is taught through the lens of food, how precious it is and how it is produced, where it comes from, how to eat safely, thriftily and healthily. How to help ensure it never fails.

Teaching food is acceptable in all cultures, races and creeds. Teaching respect for food and how it is produced is equally so. The means already exist to share these principles and educational courses universally.

I call on the farmers, chefs, food scientists and teachers of Australia to be leaders in this campaign, to engage the food processing industry, the supermarkets, the cookbook writers and nutritionists, the TV chefs and the health departments to promote the same universal messages.

Eat well but eat less. Eat more vegetables and less energy-intensive foods. Choose foods that spare our soil and water. Be happy to pay more for such good food, so our farmers can look after the precious environment that produces it.

Pay More

Current low prices paid by globalised supermarket chains risk destroying agriculture and its people.

If we underpay our farmers, they will go out of business, local industries will fail and landscapes will be damaged or ruined. And that will cause food prices to skyrocket.

Cheap food also kills a half of all consumers and adds massively to healthcare costs and taxation.

If food is too cheap, people do not respect it or the people who produce it. They waste it.

Conversely, paying just a little more and eating just a little less can secure the world’s food supply and enable farmers to safeguard its productive systems

Australia’s Role

Australia has a leading role to play in humanity’s next great food adventure.

To design new, healthier and more sustainable diets

To develop farming systems that use less water, energy and other inputs – but produce more.

And to pay a fair price to farmers, fishers and food producers so they can protect the environment that feeds us.

It is more than an inspiring challenge.

It is one on which depends the future prosperity, security, stability, peace and happiness of civilization.

It represents our great opportunity as a people to contribute meaningfully to the human destiny.

Let us be world leaders in avoiding and defeating the coming famine.

Back Paddock Reader

Sun, 01 Jan 2012 13:22:37 +0900

The Back Paddock Reader is bundled with Back Padddock Adviser Professional...you can distrirbute it freely to some or all of your customers and clients. The basis is simple, the farmer installs Back Paddock Reader on their computer, registers the software with Back Paddock Support, who setup the trust relationship between the farm (trading name) and the adviser. Back Paddock CornerPost then handles the data synchronisation, so that every time the adviser updates their production plan or associated files, the farmer can get those updates electronically...exactly the same as getting email from a mail server. Back Paddock Reader is actually a read-only version of Back Paddock Manager, so they have full functionality including mapping but just cant edit the data, albeit we've ensured full printing and email capability is turned on.

Of course, if the farm wishes to be involved in changing information, especially being able to records 'actuals' they simply upgarde their license to either Back Paddock Premium or Standard, with out losing or having to re-enter any data. The system then becomes really powerful, as CornerPost manages the synchronisation of data from both, or even multiple parties, so that all remain up-to-date.

Key points:

Bundled with Adviser license – freely distributed.

Requires User registration; will setup self-registration when able.

Works exactly the same as Manager, but data is read-only.

Connects to CornerPost to synch data.

Can print all reports. Can email.

Our future world relies on wheat research today

Sun, 01 Jan 2012 10:21:15 +0900

After decades of stagnating investment in its agricultural R&D program the International Maize and Wheat Improvement Centre (CIMMYT ) has seen its budget nearly double in the past three years as food security concerns escalate worldwide.

With the renewed financial support has come a bold new agenda that includes productivity goals that move well beyond previous strategic thinking. CIMMYT is responding to the unprecedented intensity of the stresses bearing down on farmers from the combined effects of population growth, climate change and diminishing natural resources, especially water.

CIMMYT’s director general Dr Thomas Lumpkin says that generous funding is now coming from non-traditional sources. Mexico for example is now CIMMYT’s biggest donor nation and India has provided 500 hectares and funds to create the Borlaug Institute for South Asia, a new focal point for agricultural research and development in the region.

The centre is also engaged in strategic alliances with several large agribusinesses including Sygenta, Pioneer and Monsanto – which will donate their advanced technology to benefit smallholder farmers in Africa and Asia.

Amid all the new activity and growth Dr Lumpkin says CIMMYT is grateful for the sustained investment provided by Australia from the GRDC, which has supported projects to import and evaluate CIMMYT wheat germplasm for use in Australia since 1994, and through ACIAR. Australia’s support is especially well received for many reasons – for the budget, the consistency of support and for the mentality. We share similar attitudes to many things with Australia, especially in wheat breeding and development.

Between GRDC and ACIAR, Australia in 2010 provided US$6.7 million towards CIMMYT’s US$65.5 million budget. Because of shared interest there is close collaboration with Australia on a range of products including:

Breeding for drought tolerance – this includes crossing Australian lines noted for their drought tolerance with elite CIMMYT lines known for their yield stability, disease resistance and high yield potential.
Provision and evaluation of rust-resistant wheat germplasm throught the Australian Cereal Rust Control Program
Breeding for resistance to soil-borne diseases, especially cereal cyst, root lesion nematodes and crown rot
Transferring karnal bunt resistance genes into adapting Australian wheat lines in preparation for an incursion
Transfer of new dwarfing genes identified in Australia

Past investment has been beneficial to Australian farmers. More than 90% of the wheat grown in Australia has ancestry that traces back to CIMMYT’s genebank. The value of these resources has been estimated at nearly $150 million a year.

Dr Lumpkin believes wheat production systems are coming under intensifying pressure from a combination of stresses. Prime concerns are heat stress, rising transportation costs, dwindling groundwater resources and disease pressure.

He says impacts are already discernible, with subsistence farmers shifting from wheat to more heat-tolerant maize, even in regions where there is no tradition of eating maize

In a recently published study researchers found significant climate change effects already for crops like wheat. Climate shift over the past three decades have been linked to a 5.5% decline in global wheat production. Based on models it is reasonable to assume that by 2050 higher temperatures will cut wheat yields by 20-30% in developing countries if no mitigating measures are taken.

Innovation, foresight and collaboration can make a big difference and is highlighted in an impact study published in Science. It found that without the improved varieties developed by the international centres such as CIMMYT, crop yields in 2000 would have been about 20% lower, prices as much as 66% higher, caloric intake 14% lower in the developing world.

The next Green Revolution, however comes with the added need of gains in sustainability, not just productivity.

“Every day at CIMMYT we think about 2050, about the farming conditions we face,” he says. “It takes scientists 15 to 20 years to get innovation into farmer’s fields. So we must use foresight now to prepare for a very challenging future.”

Fertcare B

Wed, 16 Nov 2011 14:41:27 +0900

In a business if the staff are up to date and know what they are talking about the efficiency and sales improve dramatically. It is often thought that the sales person is the agronomist in the field but often a sale is closed or initiated by a member of the staff in the branch office.

If everybody at a branch has the knowledge and confidence of the products being sold it increases the sales capacity of the business. This is especially true with fertiliser sales. Often a farmer will walk into a branch looking to buy fertiliser either on the recommendation of his agronomist or on the strength of what was used last season. This is the first step in the sale, but the sale is not completed until the order is placed and settled. There is potential for losing the sale if the staff member attending the farmer does not know what he or she is talking about.

So how does a staff member in a branch get the knowledge of fertilisers to be confident in dealing with a customer?

Knowledge can be gained in several ways:

a) Experience

b) Formal Training

c) A combination of a and b

The Fertcare B course is designed to give staff members in a branch this formal knowledge. It is a course for staff requiring an awareness of fertiliser products and it covers the following:

Soil properties that can lead to production problems.
Nutrients needed by crops and animals
The role of soil amendments
The five nutrient management risk categories
Fertiliser application methods
How to take soil, water and plant tissue samples
Regulations, security and OHS issues

It makes sense to equip all the staff in a branch with knowledge be it fertiliser knowledge or general product knowledge so that clients are dealt with efficiently and potential sales are not lost due to ignorance of a product.

Cotton Petiole Testing

Tue, 15 Nov 2011 13:58:49 +0900

It is now generally recognized that an appropriate way of monitoring and managing the effectiveness of a plant nutrition programme for high yield potential cotton is to track the concentration of nutrients in plant tissue over time. At any sampling time the concentration of nutrient in the tissue reflects the interaction of growing conditions such as water, light and heat availability and nutrient concentration available from soil. Therefore, if growing conditions are not standardised as much as possible, measurement of the adequacy of a crop nutrition programme may be masked by variability introduced from differences in growing conditions between sampling times.

Much of the inconsistency experienced in the past appears to have resulted from a lack of precision and clarity in protocols for sample collection rather than incorrect critical nutrient concentration ranges. Lack of precision and clarity in sampling protocols leads to large variations in plant tissue nutrient concentration. These reflected the variability within a field than the more valuable change in concentration as a result of supply and demand across time.

The absolute value of plant tissue nutrient concentrations and the rate and direction of its change are all valuable information making good nutrient management decisions for cotton. Single measurements of plant tissue nutrient concentration increase the need to ensure growing conditions are optimal and therefore increase the risk of a poor decision. Multiple measurements over time provide more data, therefore multiplying the information with which management decisions can be made.

LOCATING SAMPLING REFERENCE POINTS

The Field

Select a location or locations in the field that are easy to relocate and preferably related to some features of the performance of past crops e.g. high or low vigour area, high yield area and\ or where other observations such as soil moisture and soil chemistry are being made. The combination of soil nutrient and water information, and plant tissue analysis provide a useful platform on which to make decisions.

Avoid areas of the field such as areas affected by head ditches or tail drains or leaking channels that may be atypical. This is unless the aim of the sampling programme is to monitor these areas.

Once the sampling reference point is located then a samples should be collected in a repeatable pattern within a specified radius of the reference point. A radius of 10 metres should provide low variability due to soil factors and an adequate number of plants (2000 – 5000) from which to obtain samples

The Plant

To reduce variability, standardisation of location on plants for collecting tissue is advisable particularly for N, P, K as these nutrients are highly mobile in the plant and generally have a large gradient in nutrient concentration between leaves from upper to lower leaves. Ideally leaves should be at the same developmental age and undamaged; standardisation in cotton is commonly for the “youngest mature blade” (YMB) on the main stem. Under different growing conditions this may occur at the third to the fifth leaf below the terminal.

CONDITIONS

To get the earliest indication of a crop unable to meet peak nutrient demand it is important to ensure that samples are taken under conditions where the growth rate is unlikely to be limited by any other factor other than nutrients. Hence, it is important that moisture availability and light intensity are similar at each sampling i.e. photosynthesis and transpiration are at or near maximum for the irrigation cycle. To achieve this standardisation of factors such as soil moisture (deficit), time of day and light conditions (cloud cover) should be specified and strictly adhered to for each sampling time. Allowable variance from these conditions should be set so that sampling can be rescheduled if prevailing conditions are outside those where reliable results may be gained.

PLANT PARTS

Leaf Blade (minus petiole)

Leaf blades are most commonly used where a full range of nutrients are to be analyses early and late in the season. There is a large body of interpretation data for leaf tissue analysis with critical concentrations or concentration ranges derived from crop productivity response but because leaves are storage organs for nutrients they may be slower to indicate a deficit in supply to the leaf than petioles.

Petiole

Petiole analysis is most useful for monitoring N and K across time. Water soluble nitrate-N and K are measured hence petioles are more responsive to changes in nutrient availability. This is because they are conduits for the movements of nutrients from the soil and lower leaves to meet current growth needs and therefore usually provide earlier indication of nutrient trends than leaves. Conversely petioles are also more likely to change rapidly in response to adverse sampling conditions. Petiole analysis is most useful in managing major nutrients just prior and during flowering and boll filling. There are few published interpretation studies that have developed critical concentrations or concentration ranges from field responses for nutrients other than N, P and K.

NOTE - It is vital that the petiole is removed from the leaf blade immediately after picking.

TIMING

When monitoring the progress of the cotton crop it is important to develop a sampling plan just prior to or immediately after sowing. This will allow planning of sampling activities around a known sowing data and estimated crop development

It is important for interpretation that crop growth stage at sampling is correctly identified by either calculating Accumulated Growing Day Degrees or closely defining phenological development stages.

The following suggested timings are a guide to sampling that is most useful in managing crop nutrition. Early leaf analysis timed to detect underlying nutrient issues that may limit ability to closely manage N and K during peak demand (80 – 90 days post emergence) whereas the later sample is suggested to assess the crops’ ability to maintain its nutrient status under maximum boll load. Petiole analysis is timed to span the start of and peak N and K demand to ensure tactical N and K applications decisions can be made in an informed and timely manner.

SAMPLE TIMING GUIDE

At a minimum it is suggested that sampling be conducted as follows

Sample Type	BPC Product Code	Growth Stage	Day Degrees
Leaf (YMB only)	PAA-01	Late Vegetative -Early Squaring	400-650
Petiole (from YMB)	PAA-10	Early Flowering	750 -800
Petiole (from YMB)	PAA-10		900-950
Petiole (from YMB)	PAA-10	First Max Size Boll	1000 - 1050
Leaf (YMB only)	PAA-01	First Open Boll	1450 – 1700

OPTIONAL

2 samples between 1100 and 1700 DD

The “optional” sampling times are less likely to provide timely information for tactical in crop management of nutrients in the current crop but may help in fine tuning the entire crop nutrition program in the following season.

We'll Do it...

Tue, 08 Nov 2011 13:08:23 +0900

Back Paddock Company has developed the Back Paddock System as a means of providing agronomic consulting firms and rural merchandise businesses with a system to enable them to develop and manage the on-farm relationship with their clients and customers.

Assessing sulfur adequacy in winter cereals

Mon, 10 Oct 2011 15:36:48 +0900

The incidence of low sulfur rates in grain and sulfur deficiency in winter cereal plants seems to have increased in the northern cereal belt in recent years.

The problem first appeared in barley crops on the southern Darling Downs in the early 1980s, usually as yellow, stunted, heavily diseased patches of barley in otherwise normal crops in late winter and early spring.

More recently, the hint of a more widespread sulfur problem has come from wheat grain N:S results and reponses to inclusion of sulfur in fertiliser programmes .

One of the first signs of sulfur problems is a reduction in grain sulfur levels and a widening of the grain nitrogen : sulfur ratio.

The sulfur content of the grain is particularly important in bread and durum wheats because low grain sulfur (or nitrogen) can significantly reduce dough quality (elasiticity).

Along with this problem, affected crops also appear to be more susceptible to diseases, because the nitrate and sugar levels in the plant are raised by the inability of the plant to synthesis some amino acids, providing ideal conditions for spreading fungal diseases.

The risk of sulfur problems arises mainly where:

double cropping is practiced
crops are planted on shallow upland soils
where the depth to a significant subsoil sulfur layer is 40 cm or greater
in soils with low orgainic matter
following dry summers when mineralisation of organic matter have been limited

At the moment, there is a limited amount of data to interpret soil tests for sulfur in cereal crops. Of the two methods currently available (MCP and KCl40), both appears to be useable for northern grain crops the most important point being testing needs to include sampling to at least 50 cm.

If you suspect a sulfur problem in your crops, it is not too late to confirm or dismiss your suspicions by grain analysis this season or soil anlayisis next autumn before starting out on a big sulfur fertilizer program.

New Potato Evaluations

Wed, 28 Sep 2011 14:11:22 +0900

Back Paddock has been developing a range of potato evaluations based on the tuber size. The evaluations that are available are:

POTATO - petiole of 5th leaf, 10 - 30 mm tuber

POTATO - petiole of 5th leaf, 30 - 50 mm tuber

POTATO - petiole of 5th leaf, 50 - 70 mm tuber

POTATO - petiole of 5th leaf, > 70 mm tuber

POTATO - petiole of 5th leaf, cv generic, tuber bulking

POTATO - petiole of 5th leaf, cv generic, tuber initiation (SR)

POTATO - petiole of 5th leaf, cv Rus. Burbank, tuber bulking

POTATO - petiole of 5th leaf, cv Rus. Burbank, tuber initiation (SR)

POTATO - petiole of 5th leaf, cv Kennebec, tuber bulking

POTATO - petiole of 5th leaf, cv Kennebec, tuber initiation (SR)

POTATO - petiole of 5th leaf, cv Atlantic, tuber bulking

POTATO - petiole of 5th leaf, cv Atlantic, tuber initiation (SR)

POTATO - petiole of 5th leaf, 10 mm tuber + 10 weeks

POTATO - petiole of 5th leaf, 10 mm tuber + 8 weeks

POTATO - petiole of 5th leaf, 10 mm tuber + 6 weeks

POTATO - petiole of 5th leaf, 10 mm tuber + 4 weeks

POTATO - petiole of 5th leaf, 10 mm tuber + 2 weeks

POTATO - petiole of 5th leaf, 10 mm tuber

POTATO - MRM leaf plus petiole, first flower

POTATO - MRM leaf plus petiole, tubers half grown

POTATO - MRM leaf plus petiole, plants 20 to 25 cm tall

Some of the references that have been used to construct these tables are:

Walworth and Muniz 1993 A compendium of tissue nutrient concentrations for field-grown potatoes American Journal of Potato Research Volume 70, Number 8, 579-597.

Weir and Creswell Plant Nutrient Disorders 3 - Vegetable Crops. Inkata press

Reuter D J and Robinson J B (1997) Plant Analysis - an interpretation manual. CSIRO Publishing.

Maier N and Shepherd K, Plant Analysis and Interpretation Manual for Potato SARDI & HRDC ISBN 0-7308-6027-2

Understanding Variations in Wheat Grain Protein

Tue, 27 Sep 2011 15:11:44 +0900

Take Home Message There are numerous factors both manageable and uncontrolled that significantly influence the grain yield and protein outcome of crops. To be able to increase the probability of reaching a grain yield and protein target it is important to have and understanding of processes important to the final outcome. This may provide the ability to respond appropriately to those factors that are manageable and minimise the risk of the uncontrolled having significant influence.

Grain Development

To understand the likely causes of season to season and paddock to paddock variations in wheat grain protein, it is important to have an overview of the process that constitute grain development and the factors that influence it. Grain development consists of two overlapping phases; grain enlargement and grain filling. Grain enlargement commences at anthesis and continues for about 20 days consisting of increase in number and expansion of structural cells. Grain filling commences 10 to 15 days after anthesis, lasting 20 to 30 days until the grain ripens.

Deposition of both starch and protein take place during this period, starch deposition beginning about 1 week after anthesis with storage proteins first appearing in the endosperm about 10 days after anthesis.

Grain fill has two components, rate and duration, both under genetic and environmental controls.

Starch deposited in grain is mostly derived from CO₂ fixed during grain fill whereas grain protein is largely derived from nitrogen (N) absorbed and assimilated in earlier stages of growth and stored throughout the plant in a soluble form or as protein that is subsequently re-mobilised for deposition in grain. Stems and leaves are the most important reserves of N. Each may contribute 30 % of the protein deposited in the grain. Environmental events (hail, frost, insect damage, disease) that reduce and cause traumatic death of stem and leaf tissue may significantly affect the N supply for grain fill. Contribution from the root is small, about 10 %. The glumes may contribute 15 % but more importantly act as a temporary site for deposition of N in early grain fill. Diseases such as head blights and melanism may also impact on grain N thought a reduction in function of the glumes.

Environmental Influences

Grain fill is considerably affected by environmental factors, N nutrition and water balance being the most important. Depending on the nature and timing of the stress starch deposition and /or protein deposition may be affected.

Elevated temperature (>30 ^oC) post-anthesis may cause premature cessation of starch deposition in the endosperm even with adequate water supply (pinched grain). Protein deposition is largely unaffected by temperature. Water stress will cause similar poor deposition, starch deposition being more sensitive than protein.

Protein and starch deposition are not always synchronous, the rate and duration being mostly independent events. The rate of protein deposition may reach its peak earlier than starch, explaining higher protein in grain when grain fill is shortened.

Every season presents us with a different set of environmental and biological circumstances that culminate in a grain yield and protein outcome that can largely be explained by events that affect the processes described above. In relation to the amount of N available for synthesis in to protein the following are some prime factors influencing availability, uptake and utilisation of soil N.

Soil Nitrogen

Quantity available not matched to the yield potential.

- inadequate information about soil N status - overestimation

- seasonal influences increase yield potential (in-crop rainfall) - amount or efficiency

- soil sample depth appropriate

- over-estimate of mineralisation contribution

Sufficient soil N available but not available to the crop.

- dislocation from soil moisture during critical growth stages

- co-located with soil moisture but distance from root interception during critical growth stage.

- soil based restriction to uptake - salinity, chloride, pH, density

Plant Nitrogen

Adequate nitrogen available to crop but poor crop uptake.

- poor root development due to physiological condition - P deficiency, root disease.

- periodic unavailability - anaerobic soil conditions, compaction

Nitrogen taken up but not transferred to grain.

- N locked in damaged tissue and unavailable for re-mobilisation - leaf disease, disease affecting glumes, frost, hail

NEW WATER TEST

Tue, 20 Sep 2011 07:46:49 +0900

Are you interested in what’s happening to the Nitrogen that you are putting into your irrigation water? If so this new test will give you the answers.

Our new water test allows you to measure the Nitrate N, Ammonium N and the Urea N. These measurements enables you to measure and monitor the amount of N in the head ditch before application, the N in the tail drain and the N in the dam thus giving you some idea of the efficiency of your water run nitrogen.

Our new water test will also allow the measurement of nitrogen in water running off the property and thus avoiding any potential environmental problems.

The test code for the new water test is:

SG-WAT-03

For interpretation use the evaluation table Water-Irrigation-Nitrate, Ammonium and Urea N. The test is available from SGS laboratories and you will need to do a SoilMate reference data update to take advantage of this test.

If you have any questions please ring the helpdesk on:

1800 557 166

NEW !! Potato Skin Test

Mon, 19 Sep 2011 08:12:37 +0900

Potatoes store better and are less subject to bacterial soft rot when the peel of the potato contains sufficient calcium. In trials it has been found that there is a correlation between a reduction in bacterial soft rot and an increase of calcium in the peel of a potato tuber.

In response to this and requests from clients Back Paddock has set up a test for calcium in the potato peel. The new test codes are:

SG-POT-01

AP-POT-01

These tests are available from the SGS and APAL laboratory.

When sending samples choose 2kg of tubers at random. If you can rinse the tubers before sending it will speed up the process. Take care when cleaning the tubers not to remove any skin.

For interpretation use the new evaluation table ‘ POTATO – peel for calcium analysis’. Note: interpretation is given for calcium only when using this evaluation table. You will need to take a SoilMate reference data update to get access to this new evaluation table.

If you have any questions please ring the helpdesk on:

1800 557 166

Upcoming Fertcare Training

Tue, 13 Sep 2011 11:15:32 +0900

The latest round of Fertcare training has now been scheduled. For those requiring Fertcare training it is suggested that you book into a course as soon as possible to ensure that you secure your place.

To book into a course go to, fill in the booking form and you will be placed on a course. At Back Paddock we do our best to fill all the courses scheduled but we do need a minimum of people to run a course. If by any chance we are unable to meet the minimum number we will transfer your name to another course if you so wish or transfer your name to the next round of courses.

The latest training schedule is:

NEW SOUTH WALES – WAGGA WAGGA
Course	Date	Trainer
Better Soils Management	14-16 November 2011	D Harbison
FertCare C	17 November 2011	D Harbison
FertCare B	18 November 2011	D Harbison

QUEENSLAND – TOOWOOMBA
Course	Date	Trainer
Better Soils Management	14-16 November 2011	G Fullerton
FertCare C	17 November 2011	G Fullerton
FertCare B	18 November 2011	G Fullerton

SOUTH AUSTRALIA – ADELAIDE
Course	Date	Trainer
Better Soils Management	28-30 November 2011	A Spiers
FertCare C	1 December 2011	A Spiers
FertCare B	2 December 2011	A Spiers

VICTORIA - BENDIGO
Course	Date	Trainer
Better Soils Management	28-30 November 2011	D Harbison
FertCare C	1 December 2011	D Harbison
FertCare B	2 December 2011	D Harbison

WESTERN AUSTRALIA - PERTH
Course	Date	Trainer
FertCare B	6 December 2011	G Fullerton
FertCare C	7 December 2011	G Fullerton

NEW SOUTH WALES - DUBBO
Course	Date	Trainer
Better Soils Management	12-14 December 2011	D Harbison
FertCare C	15 December 2011	D Harbison
FertCare B	16 December 2011	D Harbison

Soil nutrient puzzle examined

Tue, 13 Sep 2011 10:25:40 +0900

Farmers from varied backgrounds learnt about soil health, management and testing at a series of seminars organised by I K Caldwell last week.

The object was to arm the farmers with enough information to make better decisions and to ask relevant questions, not turn them into experts, workshop presenter Chris Dowling said.

"It's not teaching people to be soil nutrionists or plant specialists; it's giving background knowledge so they can ask relevant questions and sort out who is going to be able to do the right job for them," Mr Dowling said.

"Today was about saying: where does it all fit?; and challenging farmers to think about where they want their soils to be in the future, compared to where they are now."

Mr Dowling said during the past few years fertiliser prices had encouraged farmers to become more careful about what they spent, and more precise about soil nutrition.

He said technology was helping soil nutrition become more targeted, but farmer experience and observation should not be dismissed.

"A lot of stuff you can do is to confirm what the farmer would tell you anyway - but we apply technology so we can quantify it and manage it better," Mr Dowling said.

"Most farmers sitting on a header will be able to tell you where the thin patches are every year and how it changes from year to year.

"All the technology does is place it on the paddock, put in on a map, quantify it. Then we go back and investigate with soil testing technology to find out why it is happening."

Mr Dowling, who is the technology services manager for the Back Paddock company, said soil nutrients might have built up in soils during the drought.

He suspects many farmers will have continued to supply phosphorous to their soils despite the poor prospects, and some underutilised nutrients will have remained.

"If it hasn't been lost or used, then it's there somewhere," he said.

I K Caldwell agronomist Scott Bartlett said he was frequently asked about nitrogen availability.

"Because of the past droughts, we are coming into a spring that is looking favourable and then are looking at when and how much nitrogen to apply for protein and yield."

Adviser & SoilMate - The Perfect Match

Thu, 01 Sep 2011 15:54:01 +0900

In the past users of Adviser and SoilMate had to use both programs separately and information could not flow between both programs.

This is now a thing of the past with the development of SoilMate Link. SoilMate Link now allows you to access soil analysis results straight into Adviser giving you the ability to store all your information on one program. Having results from SoilMate in your Adviser program gives you more information to make those important decisions on crop production.

To find out more about the SoilMate Link and how it can positively help your business contact us .

Why would you be interested in SoilMate Link?

Exchange the farm and paddock structure between both programs

No more double entering of the farm and paddock structure. What’s entered in one program is exported into the other

The Import wizard allows you to create farms and paddocks from SoilMate to a new client file in Adviser

One entry populates both programs saving time

Import laboratory test results and recommendations which can be filtered by date

Laboratory test results can be seen at the click of a button for each field enabling better decision support for nutrition programs

Laboratory test results are stored by field and by test type ( soil, plant tissue, water etc)

It’s easy to find different test types.

Selected recommendations can be copied to the fertiliser plan at a click of a button

Fertiliser plans can be created quickly and easily

Map layers of Lab test data

Soil data can be visually displayed as a map and therefore easily understood at a glance

GPS points of lab tests displayed on maps

Can easily see if the lab test was taken at the correct spot in the paddock.

SoilMate video tutorials

Wed, 31 Aug 2011 11:34:32 +0900

A set of "How to" video tutorials to assist with using Back Paddock SoilMate

Coming Soon

Which fertilizer? MAP or DAP?

Tue, 07 Jun 2011 13:43:46 +0900

The relative merits of different phosphorus fertilizers for crops can be easily misunderstood. Most confusion surrounds monoammonium phosphate (MAP) and diammonium phosphate (DAP), especially when technical information is used to promote one of these fertilizers over the other.

Sales pitches of the benefits of MAP and DAP tend to focus on their different pH of dissolutions. pH of dissolution refers to the pH of the solution in and immediately around fertilizer granules. The pH (water) of dissolutions for MAP and DAP are approximately 4 to 5 and 7 to 8 respectively (http://frec.cropsci.illinois.edu/1990/report7/index.htm).

Any theoretical benefits of MAP or DAP based on different pH of dissolution are rarely transferred to consistent performance in the field. At best, only small differences in phosphorus efficiency have been measured across most experimental conditions and crops. The exception is highly calcareous soils where it is now widely recognized that acidic phosphorus sources from MAP generally out performs phosphorus from DAP .

In the field it tends to be other differences in chemical and physical properties that determine whether MAP or DAP produces the better plant response in any given set of conditions. The key property differences are:

- nitrogen content: usually 10 to 11% for MAP and 18% for DAP.

- salt index: compares the increase in osmotic potential brought about by addition of a fertilizer compared to the increase when an equivalent weight of sodium nitrate is added to water. Depending on source, the salt index for MAP is normally about 30 and DAP is more salty at about 34 but at similar product rates the difference is negligible.

- potential to cause ammonia toxicity: primarily related to ammonium concentration, pH of the reaction product with the soil solution and product solubility. High ammonium concentration, high pH and high product solubility can all create conditions in the area of application that are favorable for the generation and maintenance of concentrations of ammonia that are toxic to germinating seeds.

- product solubility: an important characteristic, not only in relation to nutrient availability to plants, but also on the rate of chemical reactions that can be detrimental to plants. Higher solubility increases salt index and potential for ammonia toxicity. The solubility (at 20^oC) of MAP is approximately 35 to 40 kg/100L while DAP is 65 to 70 kg/100L (National Fertiliser Solutions Association: Liquids Manual 1986)

Differences between MAP and DAP are smallest and mostly nonexistent when the fertilizers are broadcast and incorporated into the soil, and when they are drilled preplanting into neutral to acid soils. However because DAP contains about twice as much ammonium-nitrogen as MAP, and because its pH of dissolution is more alkaline than MAP, DAP has greater potential for nitrogen loss through ammonia volatilization when broadcast onto neutral to alkaline soils. Nitrogen losses from DAP can be 0 – 20% higher than MAP when broadcast on neutral to alkaline soils.

Differences in the key properties listed above are much more important when MAP and DAP are applied with or near the seed, or in close contact with living plants.

Applied at the same rate, DAP is more likely than MAP to reduce germination and restrict root growth through ammonia toxicity because of its higher potential to release free ammonia. In laboratory conditions, release of free ammonia from DAP has been measured as 300% higher than from MAP.

The decision on whether to drill MAP or DAP with or near seed is largely determined by the likelihood of crop establishment damage, which in turn is influenced by crop susceptibility and type and setup of application equipment. Crops like canola, soybean and linseed are more sensitive to establishment damage that is more likely with DAP than MAP. Changes to application equipment, like wider row spacing and narrower tines, will exacerbate any establishment problems caused by fertilizer. In this case professional advise should be sought to ascertain whether current rates are appropriate for the new sowing equipment.

Trace elements are sometimes included in or on granules during manufacture of MAP and DAP so the fertilizers can be carriers for the trace elements and even to differentiate otherwise fairly generic products. Research suggests that trace elements are likely to be more effective in MAP based fertilizers than DAP based fertilizers, and that for the best response to trace elements in the year of application, water solubility of trace elements in compounded products should be at least 40%.

In summary, there is little agronomic difference between MAP and DAP as sources of phosphorus. However caution should be exercised when using DAP under some soil and environmental conditions to avoid establishment damage.

PHOSPHORUS RESPONSE IN VERTOSOLS STILL A MYSTERY?

Wed, 25 May 2011 14:23:45 +0900

In recent years there has been renewed interest in reliably predicting situations where phosphorus increases crop yield and profitability.

Static phosphorus measurements in soils with low phosphorus and large net negative balance, combined with lack of phosphorus responses suggest that the current Colwell extraction methods may not be universally effective.

Greater understanding of the chemistry of phosphorus in vertosols is indicating the need for a different approach to predicting responsiveness. This approach may include resurrecting the Whitehouse dual index for phosphorus responsiveness (developed in the late 1960’s and early 1970s) that was refined and promoted by Chisholm and Strong (1984). The different approach may also include more emphasis on phosphorus in deeper soil layers with indications of around 30 % of the P taken up by crops being drawn from the 10 – 30 cm layer. This layer may be more important in season that are dry between sowing and the start of head initiation and in more western areas.

Dr Mike Bell’s (DEEDI) approach to predicting phosphorus responsiveness, based on similar principles, is funded by GRDC (DAQ00148) and is attracting considerable interest from industry. The project is now working with a substantial data set from over 70 summer and winter sites. The team is collaborating with laboratories and fertilizer companies to develop new phosphorus testing and fertilizing strategies. Preliminary data supports a strategy of soil testing for phosphorus every 3 - 5 years in 0 - 10 cm and 10 - 30 cm increments, and requesting both Colwell and BSES phosphorus soil tests.

The guidelines suggested by this project have been incorporated into the Backpaddock SoilMate Soil Test Analysis product range. This ensures SoilMate users are in a position to act quickly on new findings.

For those who want to get to the bottom of the phosphorus “mystery”, complete soil test (SNB-26) should be conducted on soil at the surface (0 - 10 cm) to assess any factors that may interact with phosphorus uptake e.g. trace element limitation and calcium carbonate %. For the 10 – 30 cm layer, a soil test with a smaller range of analyses, including phosphorus (BSES) has been developed (SNB-27). For those wanting to completely solve the mystery by checking nitrogen further down the profile, there are three soil tests available (SNB-03, SNB-04 and SNB-05).

While still awaiting firm guidelines for interpretation from a new GRDC funded project, Back Paddock has included the latest information on phosphorus responsiveness, including interpretation of phosphorus (BSES) and calcium carbonate %, in SoilMate evaluation tables for winter crops. The information is for wheat grown on vertosols in the northern wheatbelt and includes the guidelines suggested by Chisholm and Strong in 1984.

Further reading:

Chisholm R.H., Strong W.M. 1984. Improved field methods of soil analysis interpretation. Australasian Field Crops Newsletter 19, 83–86.

NEW CALCULATIONS EXPAND UNDERSTANDING

Tue, 03 May 2011 14:07:43 +0900

At Back Paddock Company we endeavor to keep our customers up to date with the latest tools and information to be able to better service the end-users of our technology. Periodically this means adding in new analyses and calculations that help improve productivity, profitability, sustainability, and minimize risk and the offsite impacts of added nutrients.

In the latest release of the software there are three new calculations that will appear in laboratory results, in the evaluation tab and on reports when they are relevant. They are Phosphorus Environment Risk Index, Grass Tetany Risk Index – Soil, Grass Tetany Risk Index – Plant T and soil Sodium: Potassium ratio

PHOSPHORUS ENVIRONMENTAL RISK INDEX (PERI)

Phosphorus (P), with nitrogen, are the two main environmentally harmful nutrients where they escape from the intended location to water bodies. Movement of P from the site of soil application generally occurs as a result of water movement of organic and mineral sediment to which the P is attached, or dissolved in moving water. The PERI is a calculation that provides some indication of the potential for P to move through the soil in the solution phase. It is calculated from the available P and the Phosphorus Buffer Index (PBI). As the available P to PBI ratio rises, so to does the probability of the P buffer capacity of the soil being exceeded. Once the critical value (>2) is exceeded the risk of movement of P in the soil increases.

Validation of the PERI is still in progress but sufficiently advanced to provide confidence that it will provide worthwhile comment to defining the line between sufficient P for high productivity and where environmental risk is increases.

In the future is appears that agronomic advisers are going to be ask to not only comment on nutrient management practices that improve productivity but also highlight and help avoid potential environmental impacts.

GRASS TETANY – GRASS STAGGERS - HYPOMAGNESIA

In most pasture situations, magnesium is present in adequate quantities for plant growth. However, the level of magnesium in the grass may be too low to meet the animals’ requirements and may lead to a condition known as grass tetany (cattle) and grass staggers (sheep) or hypomagnesia - blood magnesium levels fall below a critical level. Pasture magnesium levels are highest in summer and lowest in late winter and early spring. Grasses, which contain less magnesium than clovers do over most of the year, are usually dominant in late winter and early spring. Thus, grass tetany has typically occurred in late winter and early spring. Also, low temperatures and wet soils can reduce magnesium levels in forage. It can cause significant losses in production, even when there are no signs of illness.

However, high application rates of potassium fertilisers or dairy shed effluent can result in a luxury consumption of potassium (in other words, the plant takes up more soluble K than it requires and no yield increase occurs). This high concentration of plant potassium can often result in a lower proportion of other nutrient cations in the plant, such as calcium, sodium and, in particular, magnesium. These low magnesium levels may induce hypomagnesaemia, or grass tetany, in cattle. With more farmers applying more potassium and potassium blends in early spring, there appears to be anecdotal evidence that grass tetany is becoming more prevalent in the following autumn.

Grass tetany may also be caused by applying high rates of nitrogenous and potassium fertilisers, thus releasing ammonium ions and potassium ions together. The ammonium and potassium ions both compete with the uptake of magnesium ions at the plant root, thus resulting in a lower magnesium concentration the plants. The use of nitrogenous fertilisers alone generally does not cause this problem. Also, animals consuming pasture or fodder high in potassium concentration can often upset the magnesium movement through the rumen and intestinal walls, consequently inducing a magnesium deficiency leading to grass tetany.

Symptoms of the disease include restlessness, staggers, an over-alert appearance, being excitable and in some cases, aggressiveness. In severe cases, animals may fall down and go into convulsions or just die without warning.

There are some common factors that are always present with grass tetany.

Heavy use of nitrogen and/or potash fertiliser on pasture.

Animals are usually grazing grass dominant pasture or lush cereal crops, often without any hay supplementation.

Cold and wet windy weather with little or no shelter, resulting in short periods of fasting.

Animals are either fat and losing condition, or very thin.

Animals recently moved to a different paddock.

Dairy cows in peak lactation are most commonly affected, but dry cows and, under certain conditions, beef steers, may also suffer.

Grass tetany can be prevented by including a magnesium supplement in the diet to provide each cow with 10 15 g of magnesium per day.

GRASS TETANY RISK INDEX – SOIL (GTRIs)

The risk of grass tetany increases as magnesium decreases as a proportion of the total soil cations. This is particularly the case where high rates potassium has been applied in late winter or spring. GTRIs is a calculation that takes into account the balance between the soil cations and indicates a higher risk (>0.07) of grass tetany. Where the GTRI exceeds the critical level, advice from a animal nutrition specialist or veterinarian should be sought.

GRASS TETANY RISK INDEX – PLANT (GTRIp)

The risk of grass tetany increases as magnesium decreases as a proportion of the cations in the forage consumed. This is particularly the case where high rates potassium has been applied in late winter or spring. GTRIp is a calculation that takes into account the balance between the plant tissue cations and indicates a higher risk (>2.2) of grass tetany, in which case advice from a veterinarian or animal nutrition specialist should be sought.

SODIUM: POTASSIUM RATIO – SOIL (Na/K)

Findings of a recent research, conducted as a part GRDC Nutrient Management Initiative in Nthn NSW and Queensland, has highlighted a potential yield limiting affects of soil sodium concentration on the availability of potassium. Similar evidence of this direct interaction has also been highlighted in a recent PhD in the cotton industry.

Current evidence is when Na/K exceeds 5 there can be a significant impact of K uptake and dry matter production. As this ratio is still in its early days as a universal indicator of the sodium x potassium interaction, it is suggested further investigation be undertaken where the ratio exceeds the critical level of 5 and there is suspicion of poor production.

Note: It is suggested that Na/K ratio be only used for grain and cotton crops until there is further validation for other crops and pastures