Mineral fertilizers, lime and green manuring in crop rotation under conditions of the Baikal region

Abstract

The results of research on the effect of long-term application of mineral fertilizers, lime and green manuring on soil acidity and crop productivity are presented. The experiment was conducted in a long-term (2017-2020) stationary field experiment in the fifth rotation of a four-field crop rotation: corn, barley + clover, clover, spring wheat. The soil of the experimental plot is gray forest heavy loam. The following variants were studied: without fertilizers, N90Р60, Р60К90, N90К90, N90Р60К90 on two backgrounds - without liming and with the introduction of 0.5 Ng of lime (5.7 t/ha). It was found that 5 times use of ameliorant helped to decrease acidity of gray forest soil: рНKCl increased by 0,9-1,5 in comparison with the initial indicator (4,5-4,9), hydrolytic acidity decreased by 6,1-8,3 mg-eq./100 g, the degree of base saturation increased by 20,0-25,5%. Due to the use of green manuring in the crop rotation, рНKCl grew by 0.4-0.6; hydrolytic acidity fell by 2.3-4.1 mg-eq./100 g of soil, the degree of base saturation raised by 9.2-13.3%. The mineral fertilizers at the applied rates had no effect on changing the soil acidity, both on non-lime- and lime-fertilized backgrounds. The productivity of crop rotations by experiment variants increased by 0.23-0.69 tons of grain units per hectare (tgru/ha) (7-21%) and was the greatest with the combined effect of total mineral fertilizer (N90P60K90) and lime. The recoupment of 1 kg rate of application of mineral fertilizers to agricultural products was 6.1-11.5 kg of grain, 1 ton of lime - 2.5-3.2 kg of grain.