|Dryland Corn in Colorado 16" annual rain|
In July 2009 I headed around the world on a Nuffield Scholarship to study "Soil Structure and Fertility in Arable Farming Systems". One of my key findings was the importance of growing a variety of crop types to build up organic matter and improve soil structure. I spent some time in the great plains of the USA. In these areas I saw farmers successfully growing corn on 16" annual rainfall. Although they had dry winters, they had similar summer rain to Bairnsdale, Sale and Toongabbie. They were also slightly hotter in the summer and were covered in snow in the winter. Basically they didn't have any advantage over us. The exciting thing is that these guys were averaging 70 or 80 bushels (4.4 - 5.0t/ha). The other good news was that when they started growng corn, their wheat yields went up! They would double crop field peas after corn, then plant winter wheat into the pea stubble. It sounds a lot like the sorghum, chickpea, spring wheat rotation of northern NSW. The photo above is a 70 bushel corn crop in Colorado.