Effects of mineral fertilizer and organic management on soil nitrate and barley production in semi-arid conditions

Abstract

In a long-term experiment performed in a semi-arid area of the Province of Toledo (Spain), plots were used over two years to raise barl ey either continuously with applicatons of mineral fertiliser (CC) or under three forms of organic management: continuous cultivat ion with no fertiliser input (Ca), barley raised in rotat ion with a c1ean fall ow period (CF), and barley raised in rotation with vetch (CV). The CC treatment was associated with higher autumn soil nitrate contents as we ll as higher and more stable crop yields than the CO treatment. In the CF plots, the summer accumulation of soil nitrate was favoured during the c1ean fallow year, and was greater than that seen in the CV plots. Barley productivity in the different treatments followed the order CF > CC > CV > CO. Productivity was related to the soil nitrate content before sowing.