Seeding rates and mineral fertilizers influence on rice varieties yield and productivity elements

The purpose of research is to study the elements of the crop structure and productivity of rice at different seeding rates and doses of mineral fertilizers in the conditions of the Primorsky Region. The pronounced fluctuations in the weather conditions of the Primorsky Region impose special requirements on rice varieties, such as early maturity, resistance to low temperatures, diseases and pests, and suitability for mechanized cultivation. At soil temperatures of 12-13 °С, rice develops rapidly, intensively forms the root system and builds up a significant leaf surface. The study was conducted in 2018-2020 on the rice irrigation system. The effect of the main fertilizer N30P70K70 was studied with the addition of nitrogen fertilizers and the sowing rate on two varieties of rice that had a number of distinctive characteristics. The results showed that each variety responded differently to yield depending on seeding rate and fertilizer application rate. For example, the Karmelit variety showed higher yields at a seeding rate of 9 million germinating grains per 1 ha and a top-dressing dose of 60 kg of a.i. per 1 ha. For the Almaz variety, the optimal seeding rate was 7 million germinating grains per 1 ha, which were fertilized with urea at a dose of 90 kg of a.i. per 1 ha. The increase in grain yield was associated with the yield components and growth characteristics of the studied varieties.