Category

Agriculture

Jul 24
1

Plant nutrient detector breakthrough

By | Agriculture, News, Plant Science, Research

Findings from La Trobe University-led research could lead to less fertiliser wastage, saving millions of dollars for Australian farmers.

Published in the journal Plant Physiology, the findings provide a deeper understanding of the mechanisms whereby plants sense how much and when to take in the essential nutrient, phosphorus, for optimal growth.

Lead author Dr Ricarda Jost, from the Department of Plant, Animal and Soil Sciences at La Trobe University said the environmental and economic benefits to farmers could be significant.

“In countries like Australia where soils are phosphorus poor, farmers are using large amounts of expensive, non-renewable phosphorus fertiliser, such as superphosphate or diammonium phosphate (DAP), much of which is not being taken up effectively by crops at the right time for growth,” Dr Jost said.

“Our findings have shown that a protein called SPX4 senses the nutrient status – the ‘amount of fuel in the tank’ of a crop – and alters gene regulation to either switch off or turn on phosphorus acquisition, and to alter growth and flowering time.”

Using Arabidopsis thaliana (thale or mouse-ear cress) shoots, the research team conducted genetic testing by adding phosphorus fertiliser and observing the behaviour of the protein.

For the first time, the SPX4 protein was observed to have both a negative and a positive regulatory effect on phosphorus take-up and resulting plant growth.

“The protein senses when the plant has taken in enough phosphorus and tells the roots to stop taking it up,” Dr Jost said. “If the fuel pump is turned off too early, this can limit plant growth.

“On the other hand, SPX4 seems to have a ‘moonlighting’ activity and can activate beneficial processes of crop development such as initiation of flowering and seed production.”

This greater understanding of how SPX4 operates could lead to a more precise identification of the genes it regulates, and an opportunity to control the protein’s activity using genetic intervention – switching on the positive and switching off the negative responses.

La Trobe agronomist Dr James Hunt said the research findings sit well with the necessity for Australian farmers’ to be as efficient as possible with costly fertiliser inputs.

“In our no-till cropping systems, phosphorus gets stratified in the top layers of soil. When this layer gets dry, crops cannot access these reserves and enter what we a call a phosphorus drought,” Dr Hunt said.

“The phosphorus is there, but crops can’t access it in the dry soil. If we could manipulate crop species to take up more phosphorus when the top soil is wet, we’d be putting more fuel in the tank for later crop growth when the top soil dries out.”

The research team will now be investigating in more detail how SPX4 interacts with gene regulators around plant development and controlling flowering time.

The research was published in Plant Physiology with collaborators from Zhejiang University (China), Ghent University & VIB Center for Plant Systems Biology (Belgium), French Alternative Energies and Atomic Energy Commission (CEA) and the Australian Research Council Centre of Excellence in Plant Energy Biology.

Read the paper: Plant Physiology

Article source: La Trobe University

Image: Free-Photos / Pixabay

Jul 17
0

How much do climate fluctuations matter for global crop yields?

By | Agriculture, News

The El Niño-Southern Oscillation (ENSO) has been responsible for widespread, simultaneous crop failures in recent history, according to a new study from researchers at Columbia University’s International Research Institute for Climate and Society, the International Food Policy Research Institute (IFPRI) and other partners. This finding runs counter to a central pillar of the global agriculture system, which assumes that crop failures in geographically distant breadbasket regions such as the United States, China and Argentina are unrelated. The results also underscore the potential opportunity to manage such climate risks, which can be predicted using seasonal climate forecasts.

The study, published in Science Advances, is the first to provide estimates of the degree to which different modes of climate variability such as ENSO cause volatility in global and regional production of corn, wheat and soy. Such variability caused nearly 18 percent volatility in global corn production from 1980 to 2010, for example.

“Global agriculture counts on the strong likelihood that poor production in one part of the world will be made up for by good production elsewhere,” said Weston Anderson, a postdoctoral research scientist at the International Research Institute for Climate and Society and lead author on the study.

Of course, there’s always a chance—however small—that it won’t. The assumption until now has been that widespread crop failures would come from a set of random, adverse weather events, Anderson said.

He and his co-authors decided to test this idea by looking at the impact that the El Niño-Southern Oscillation, the Indian Ocean Dipole, and other well-understood climate patterns have had on global production of corn, soybeans and wheat. They analyzed how these modes of climate variability influenced drought and heat in major growing regions.

“We found that ENSO can, and has, forced multiple breadbasket failures, including a significant one in 1983,” said Anderson. “The problem with pooling our risk as a mitigating strategy is that it assumes failures are random. But we know that strong El Niño or La Niña events in effect organize which regions experience drought and extreme temperatures. For some crops, that reorganization forces poor yields in multiple major production regions simultaneously.”

How important is the influence of climate variability? The authors found that, on a global level, corn is the most susceptible to such crop failures. They found that 18% percent of the year-to-year changes in corn production were the result of climate variability. Soybeans and wheat were found to be less at risk for simultaneous failures, with climate variability accounting for 7% and 6% of the changes in global production, respectively.

“The bigger the uncertainty around climate drivers, the bigger the risk for those involved in the food systems,” said co-author Liangzhi You, a senior research fellow at the International Food Policy Research Institute. “The worst affected are poor farmers in developing countries whose livelihoods depend upon crop yields as they do not have an appetite for risks in absence of formal insurance products or other coping mechanisms.” The risk is further exacerbated by challenges posed by lack of infrastructure and resources in developing countries.

“ENSO may not be important in all years, but it is the only thing we know of that has forced simultaneous global-scale crop failures” said Anderson.

Within specific regions, the risk to agriculture by climate variability can be much higher. For example, across much of Africa and in Northeast Brazil, ENSO and other recurring climate phenomena accounted for 40-65% of the ups and downs of food production. In other regions, the number was as low as 10%.

While on the surface this may appear to mean that those areas more affected by ENSO and other climate patterns are more at risk to extreme events, the numbers actually reflect a link to climate patterns that can be monitored and predicted.

“What excites me about this work is that it shows how predictable modes of climate variability impact crop production in multiple regions and can scale up to influence global production, said co-author Richard Seager of Columbia’s Lamont Doherty Earth Observatory. “This should allow anticipation of shocks to global food prices and supplies and, hence, improve efforts to avoid food insecurity and provide emergency food assistance when needed.”

Read the paper: Science Advances

Article source: International Food Policy Research Institute IFPRI

Image: Laura Mendez / Pixabay