Mariano Cossani, Andrew Ware and Victor Sadras (SARDI)
|Contributor||SARDI Minnipa Agricultural Centre|
Site 6, Minnipa Agricultural Centre, SA
Within Eyre Peninsula, as in other Mediterranean environments, grain yields of cereal crops are variable, and in many cases, this is due to under-fertilization. Previous modelling and field experiments showed the need for higher rates of fertilization in south-eastern Australia. Research into interactions between water and N, with simulation models and empirical data, has proved that yield, as well as water-use efficiency, is positively related to the degree of co-limitation between water and N [1, 2] . In other words, yield and water use efficiency increase when the stress produced by water has similar intensity than the stress produced by N. The understanding of how resources co-limit and its genotypic variability in wheat crops of Eyre Peninsula is a key step for improving the water use efficiency and to reduce yield gaps.
This trial is part of a new project which addresses research and development gaps on the interactions between water and nitrogen in Australian cropping systems identified in GRDC scoping study DAS00157. The novelty of this project is a new tool to estimate the actual water and nitrogen stress and co-limitation in the season. The new tool will complement existing tools and provide opportunities to adjust N availability in the season, thereby reducing farmers’ risk and increasing chances of capturing the benefits of wetter seasons. Results are expected to be applicable to the medium to low rainfall areas of south-eastern and western Australia. The current project is focused on management of nitrogen fertilizer under uncertain conditions as related to variable rainfall and changing agronomic practices.
The aim of the current trial was to evaluate the impact of water and N co-limitation on grain yield of wheat under different N and water availability and to assess the genotypic variability in the main parameters.
|Lead research organisation||
South Australian Research and Development Institute
|Host research organisation||N/A|
|Trial funding source||GRDC DAS00165-BA|
The present project is co-funded by SARDI and GRDC. Special thanks to Leigh Davis, Brenton Spriggs and Sue Budarick for their collaboration with field and lab activities, and to Dr. Alan McKay and his team for advice with the root sampling.
|Other trial partners||Not specified|
|Sow rate or Target density||The sowing density was targeted at 180 plants/m2, and rows spaced at 27 cm.|
|Sow date||13 May 2016|
|Harvest date||30 October 2016|
|Plot size||1.6m x 10m|
|Paddock history||2015: Legume pasture 2014: Barley 2013: Wheat|
|Fertiliser||<p>Prior to sowing we applied MAP at a rate of 120 kg/ha. Weeds, pests, and diseases were controlled following the practices used for National Variety Trials (NVT).</p>|
|Rainfall avg ann (mm)||325mm|
|Rainfall avg gsr (mm)||241mm|
|Rainfall trial total (mm)||391mm|
|Rainfall trial gsr (mm)||268mm|
SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.