Changes in the root mass and yield of rice depending on different water and food regimes drip irrigation in the lower Volga region

Abstract

The article reflects some results of long-term research conducted in 2013-2015 at the research field of VNIIOZ. After analyzing the research material, the following results were obtained on the influence of water or nutrient regimes of the soil on the formation of the mass of rice roots during drip irrigation. So, when maintaining the water regime of the soil 100-80% MWHC in the 0.6 m layer, the root mass was 4.96 m in the 0.4 m layer and 5.64 t/ha in the 0.6 m layer. In the variant where the soil moisture was maintained at 100-80% MWHC in this variant, the aboveground part of the plants was more developed, which contributed to an increase in the root mass of rice in the 0.4 m layer to 5.40, and in the 0.6 m layer – 6.14 t / ha. In the variant of the water regime of the soil with a humidity of 100-80% MWHC from sowing to the end of the tillering phase in the 0.4 m layer with subsequent increase to 0.6 m, and from waxy to full ripeness of the grain is not less than 70% MWHC, the number of roots in comparison with the second option for three years in the 0.4 m layer was less by 0.18 t/ha, and in the 0.6 – 0.20 t/ha layer, but more than the first in the 0.4 m layer by 0.26 and 0.6 m – 0.30 t/ha. The applied doses of fertilizers had a greater impact on the root system of rice than the water regime of the soil. As a result of the research, it was found that the maximum grain yield (6.95 t / ha) was obtained under the water regime of the soil 100-80% MWHC sequentially in layers of 0.4 and 0.6 m with the introduction of N137P90K108 (7 t/ha). The lowest yield, 4.88 t / ha, was obtained in the variant of the water regime of the soil 100-80% MWHC in a layer of 0.6 m with the addition of N95P62K75 (5 t / ha).