Wheat stubble height effects on subsequent corn and grain sorghum crops.

For sustainable productivity, a winter wheat (Triticum aestivum L.)–summer crop (corn [Zea mays L.] or grain sorghum [Sorghum bicolor L.])–fallow (W‐SC‐F) cropping system could benefit from optimal wheat stubble cutting height management, but only limited information is available. The objective of this study was to evaluate the effect of wheat stubble height on subsequent corn and grain sorghum yields, available soil water, crop water use, and precipitation storage efficiency in a W‐C‐F and W‐S‐F cropping system. This study was conducted from 2006 through 2020 at the Kansas State University Southwest Research‐Extension Center near Tribune, KS. The experimental design was a randomized complete block with three wheat stubble heights (high, low, and strip). Average across all years, there was a 9%–10% corn yield and 7%–11% corn biomass advantage from high and stripper harvested wheat stubble compared with low cut stubble, and a 5% sorghum yield advantage from high cut stubble compared with low cut stubble. Kernel weight of corn was the only yield component that significantly differed among stubble height treatments. Water productivity of corn in the high and stripper harvested stubble treatments (15.3 kg ha−1 mm−1) was significantly greater compared with the low cut stubble (14 kg ha−1 mm−1). Water productivity of sorghum in the high cut stubble treatment (18.9 kg ha−1 mm−1) was also significantly greater compared with low cut stubble (17.7 kg ha−1 mm−1). Total available soil water at planting (ASWP) and available soil water at harvest (ASWH) of corn were both greater for high cut stubble compared with stripper harvested stubble but total ASWP and ASWH of grain sorghum were not significantly different among stubble height treatments. We concluded that low cut wheat stubble decreased subsequent corn and grain sorghum yields in a W‐C/S‐F cropping system. Core ideas: There was a 9%–10% corn yield and 7%–11% biomass advantage from high and stripper harvested compared with low cut wheat stubble.There was a 5% sorghum yield increase from high cut stubble compared with low cut wheat stubble.Kernel weight of corn was the only yield component that significantly differed in response to wheat stubble height.Water productivity of corn and sorghum in the high and stripper harvested was significantly greater compared with low cut wheat stubble. [ABSTRACT FROM AUTHOR]