Long-Term Irrigation and Fertilization of Typical Chernozem on the Bălţi Steppe of Moldova

Abstract

Irrigation and fertilization are key factors of agricultural intensification. Their influence on crop yield and soil fertility has been studied in an experimental six-field crop rotation on Typical chernozem at Selectia Research Institute of Field Crops on the Bălţi Steppe begun in 1968. The yields of both winter wheat and sugar beet are increased by application of farmyard manure and mineral fertilizers and, also, by irrigation. But, in the case of winter wheat, the extra yield does not cover the extra costs. Corn-for-grain does not respond to irrigation or to fertilization. Without addition of farmyard manure and mineral fertilizers, even a crop rotation that includes 50% of perennial legumes cannot compensate for the annual losses of soil organic matter by mineralization. Irrigation increases these losses and, at the same time, changes the quality of soil organic matter.