Reduction of Water Load on Rice Agrocenosis During Drip Irrigation
Year: 2021
Type: article
Abstract: Introduction.In the Russian Federation, rice is not one of the main food crops.But the Institute of Nutrition of the Russian Academy of Sciences, the recommended annual consumption rate of cereals per inhabitant should not be less than 6 kg.Hence, every year the required amount of raw rice in the country should be determined in the amount of 1.5 million tons.In 2020, a little more than 1.2 million tons of raw rice were produced, which is 26% lower than the demand.At the same time, irrigation water is spent on 1 ha of crops from 12 to 25 thousand m 3 /ha and more.Based on this, this is the most water-intensive crop that is cultivated on irrigated land.The recent shortage of fresh water leads to the need to search for new water-saving ecologically tolerant technologies for irrigation of rice.The search for a solution to this problem was based on the scientific hypothesis that rice belongs to the bluegrass family, the full development cycle of which proceeds not as an anaerobic, but an aerobic plant that forms root hairs and uses soil moisture for its water supply.Object.We studied the reaction rates of the early ripening rice cultivar «Volgogradsky» to the water and food regimes of the soil.The purpose of the research was to substantiate the possibility of rice cultivation during drip irrigation, different soil water regimes and fertilizer application rates, which will provide 5, 6 and 7 t / ha of grain.Materials and methods.The scheme included a two-factor experiment.The first factor: А 1 -permissible decrease in the moisture content of the active layer (0.6m) of the soil 80% of the lowest moisture capacity; А 2 -until the end of the tillering phase of rice according to option А 1 in a layer of 0.4 m, followed by an increase in the layer to 0.6 m; А 3 -water regime according to the А 2 option until the beginning of the wax ripeness of the grain, followed by a decrease in the pre-irrigation moisture content to 70% of the lowest moisture capacity.The second factor of the fertilizer application dose; B 1 for obtaining a yield of 5 t / ha of grain (N 95 P 62 K 75 ); B 2 -6 t / ha (N 114 P 74 K 90 ) and B 3 -7 t / ha (N 137 Р 90 К 108 ).The studies were accompanied by observations, counts and measurements carried out in compliance with the requirements of experimental techniques.Results and conclusions.Studies have established that the maximum leaf area, 36.78 thousand m2 / ha, was formed in the variant of the water regime 100-80% of the lowest moisture capacity, h = 0.4 and 0.6 m (A 2 ), which is 3.3 and 1% more than in options 100-80% of the lowest moisture capacity, h = 0.6 m (А 2 ) and 100-80% HB, h = 0.4 and 0.6 m (А 2 ).The application of mineral fertilizers, N 95 P 62 K 75 (5 t / ha -B 1 ), N 114 P 74 K 90 (6 t / ha -B 2 ) and N 137 Р 90 К 108 (7 t / ha -B 3 ), also had a stimulating effect on the main indicators of photosynthetic activity of plants.It was also determined that the planned yield at the level of 5 t / ha can be obtained on all variants of the water regime of the soil when applied with B 1 .But with a combination of А 3 + B 2 , calculated per ton of grain, the volume of water supplied to the rice field was the smallest.The yield of 6 t / ha of grain was obtained in all the studied variants of the water regime, but against the background of a higher dose of B 2 fertilizers.Here, the most preferred combination was А 3 + B 2 .Of all the studied factors, the minimum deviation of 0.71% from the planned level of 7 t / ha was obtained with a combination of А 2 + B 3 .But the combination А 3 + B 3 , which is less expensive per ton of grain and the cost of irrigation water (716 m 3 ).The calculation for economic efficiency showed that in all three variants of the water regime against the background of the introduction of B 1 , the yield was formed at the level of 5.0 t / ha with a profitability of 57.3 -92.6%.The introduction of B 2 , calculated to obtain 6.0 t / ha, contributed to its increase to 81.9 -92.6%, B 3 -7 t / ha to 104.1 -116.5%.
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W4205313434