Effect of Straw and Fertilizer Nitrogen Management for Spring Barley on Soil Nitrogen Supply to a Subsequent Potato Crop

The effect of straw management (straw removed or retained) and fertilizer N rate (0, 80 or 160 kg N ha(-1)) on a preceding barley rotation crop on N availability to the subsequent potato crop was evaluated in two years. Nitrogen fertilizer application increased barley grain and straw yield and N uptake, and generally decreased straw C:N ratio. Barley N rate increased residual soil nitrate at harvest in one year, but not in the subsequent spring. Barley management had no effect on assays of soil N supply or on total tuber yield, tuber specific gravity, plant dry matter accumulation or petiole nitrate concentration for an unfertilized potato crop. However, straw retention reduced potato plant N accumulation in both years, and reduced soil nitrate content in vegetation-free plots in one year, compared with straw removal. In this cool, humid environment, management of a barley rotation crop has limited short-term effects on N supply to a subsequent potato crop.