INFLUENCE OF DIFFERENT CONDITIONS OF MINERAL NUTRITION ON YIELD OF SWEET SORGHUM SEEDS IN THE CONDITIONS OF THE SOUTHERN FOREST-STEPPE OF WESTERN SIBERIA

Abstract

Sorghum occupies a significant place in world agriculture and is of particular value in intensive feed production. The selection of agricultural practices for increase of seed productivity is relevant and current, since the availability of own seeds is of decisive importance in reduction of feed production cost. The studies were carried out in Omsk region in 2013, 2015–2017 in a stationary field experiment in eight-field crop rotation. The aim of the work is to study the influence of mineral nutrition conditions on yield of sweet sorghum seeds, water and nutritional regimes of meadow-black soil in the conditions of the south of Western Siberia. The experiment included a three-factor scheme: the supply of soil with mobile phosphorus according to Chirikov (factor A) - average, 50-100 mg/kg (background 0); increased, 100-120 mg/kg (I) and 140-150 mg/kg (II); high, 150-200 mg/kg (III); phosphorus fertilizer (factor B) - P0, P60; nitrogen fertilizer (factor C) - N0, N30, N60. The field experiment was implemented by mutual method of pre-sowing application of mineral fertilizers and different levels of phosphorus in the soil. The soil is meadow-black soil, medium-thick, medium-humus, heavy loamy. The reaction of the soil environment in the arable layer is neutral, the depth of groundwater in spring is 2.86, in autumn - 3.09 m. The climate of the southern forest-steppe of Omsk region is suitable for sweet sorghum cultivation with insufficient moisture in some years and uneven distribution of precipitation during the growing season. The yield of sweet sorghum seeds ranged from 2.93 to 3.46 t/ha on average for 3 years, depending on the background, the largest yield increase was noted on 0 background (N60P60) with a natural level of mobile phosphorus and pre-sowing application of nitrogen and phosphorus fertilizers. It is possible to obtain seeds of sweet sorghum in the southern forest-steppe of Omsk region. To achieve high yields on soils with an average content of mobile phosphorus, it is necessary to use nitrogen and phosphorus fertilizers. It is also indispensable to select an early ripening variety capable of forming high quality seeds in the specific conditions of Siberia.