SELECTION OF PREDECESSORS FOR CROPS OF PERIODICALLY IRRIGATED RICE ON LIGHT CHESTNUT SOILS

Abstract

The presented analysis of the of the All-Russian Research Institute of Irrigated Agriculture research results were obtained in 2014–2016 in the conditions of the southern slope of the Volga Upland allowed to enrich new knowledge the problem of rice cultivation using innovative water-saving technology on general-irrigation systems, including different agricultural crops as predecessor cultures. To estimate the preference choice of rice predecessor were selected the following crops: leguminous – soybean, tilled – potatoes and narrow-row crops – rice. These researches have shown that all predecessors of rice sowings with slight timing difference were completed vegetation and formed close to the planned yield without negative impact on the soil, that allow to recommend them for inclusion in rice rotations on general irrigation systems and use with periodic irrigation in the following rating order: soybean potato rice. The priority soybean place as a rice precursor is determined by its favorable impact on the agronomic properties of the soil: the plow-layer density - 0.6 m, pore space, water permeability and some others. The maximum rice yield (5.05 t of grain/ ha) was formed under soybean predecessor, under potato it was lower by 0.15 t / ha, and rice – by 0.29 t / ha. The highest water consumptive use of rice was summed under soybean precursor, the volume of which amounted to 5780 m3 / ha, in the variant where potato was predecessor it decreased to 5622 m3 / ha, and in rice planted after rice - 5521 m3 / ha.