Farm Table says:
Row spacing of winter crops in broad scale agriculture in southern Australia
What is the problem?
This research reviews the claimed advantages and disadvantages of wide rows and, in Australia, quantifies the effects of widening rows on yields in wheat, barley, canola, and lupins. Widening of row spacing has accompanied the adoption of conservation cropping systems with no-till and stubble retention. Row space widening has allowed sowing machinery to operate in stubble with minimal blockages caused by the retained stubble.
What did the research involve?
This paper examines the claims of advantages and disadvantages of wide rows, including effects on weed competition and control, harvestability, seed size and grain quality. The authors have sought to capture as much data as possible in Australia in order to quantify the effects of wide rows on yield in wheat, barley, canola and narrow-leaf lupins.
General conclusions have been drawn based on the data.
What were the key findings?
The major driver of interest in wide row spacings is the need to sow through stubble in no-till and retained stubble systems. Further interest relates to compatibility of sowing rows and machinery in the northern NSW and Queensland systems that produce both summer and winter crops, and to the improved yield of lupins at wide row sowings in WA.
The conclusion for wheat, barley and canola was that narrow row spacings were associated with higher grain yield, except in situations of low yield for wheat and barley. This general loss of yield with wider rows also applies to other crops
The scope for overcoming the yield penalties of wide row sowing of wheat by agronomic means or appropriate cultivar choice seem limited. The most appropriate action seems to be sound agronomy and cultivar selection aimed at maximising grain yield. In the reviewed data, this approach generally gave highest yield irrespective of
row spacing in the reported experiment.