Analysis of factors influencing rice productivity in conditions of water resources scarcity and man-made threats in the South of Russia

A strategic and vital task throughout the history of Russia has been to obtain stable yields of agricultural crops. The well-being of the country directly depends on ensuring food security by the country's agro-industrial complex. At all times, the implementation of this task has posed a difficult task for workers in the agro-industrial complex, the solution of which largely depends on many stochastic factors. In recent decades, such factors have become more and more numerous and it has become increasingly difficult to guarantee the receipt of guaranteed high yields of agricultural crops. Among the main factors, one can note climate change, the growing shortage of water resources and the growing risks of man-made threats in the water management complex of Russia. These factors are especially sharply noted in the South of Russia, where the main production of agricultural products is concentrated. The rice growing industry suffers from these factors to the greatest extent, since it is the most labor- and resource-intensive. Therefore, the purpose of our research was to analyze the factors affecting rice yields and find ways to optimize existing rice cultivation technologies, taking into account the negative factors affecting rice cultivation. Our research was carried out in the peasant farm "Golovin Grigory Nikolaevich" of the Kalininsky district of the Krasnodar region in 2021-2024. The relationships between the productivity of leaf surface photosynthesis, the accumulation of dry matter by the plant and the yield of intensive rice varieties Rapan and Patriot were studied and determined. Quantitative indicators in the formation of photosynthetic potential were established with various options for the applied doses of nitrogen, which made it possible to study the change in the net productivity of photosynthesis and the accumulation of biomass by plants of both varieties. It was found that the highest biological yield in the Rapan variety was obtained with a double (N50 main + N100 in 3 leaves) application of nitrogen, and in the Patriot variety it reached 1.18 kg/m2 when N100 was applied in 3 leaves, with a total dose of 200 kg/ha.