Longerenong Cropping Challenge

Thirteen groups participated in this agronomy challenge, where advisors were asked to provide crop management plans for the production of a wheat crop on the same plots used for canola in 2010. The management plans allowed agronomists to select variety, sowing time, seeding rate, crop protection strategies and nutrient management plans, as well as marketing plans for the grain. More important than the winning or losing was the sharing of information and experiences among the agronomists as they try out new strategies.

Best yields were over 5 t/ha and modelled yield suggested 6 t/ha so there could have been some unmet potential still on the site. Maybe the very dry September was a problem in achieving this yield potential (YP). The highest wheat yields were for Tylers/Agwise and IPL (no significant difference). Three other groups grew better than 4.5 t/ha. Tylers/Agwise also achieved the highest gross margin of AUD 564/ha, and four other groups got gross margins over AUD 500/ha. There were no “silver bullets” in the plans, the results here are the consequence of the whole package.

Nitrogen was generally not a limiting factor over the whole this season. The two top yielding groups exceeded the predicted N limit maybe because the crops exploited N deeper than the soil test went. Nitrogen fertilizer recovery in the grain was higher for the higher yielding crops were around 50% and less than 40% for the lower yielding crops.

Up front, N was probably associated with lower grain protein, but yields were generally good. 2011 was a tough year to make decent grain protein—even the high N users tended to stimulate yield more than protein. Lower yields tended to have higher proteins. Phosphorus was generally well supplied, and on average across the site, the P off-take was the same as the amount of P applied. Stripe rust was the main disease; present at varying levels depending on variety susceptibility and use of fungicides. In determining final gross margin, yield seemed more important than price. Keeping costs down was more important than forcing up quality. ANZ-11