Effect of mineral fertilizers, forecrops and soil-climatic conditions on millet productivity in steppe zone of the Southern Urals

The research was carried out on southern chernozems in arid conditions of the Orenburg Urals in 2002-2021. The influence of agrometeorological conditions of the growing season, spring reserves of soil moisture and nutrients, cellulolytic activity of microorganisms, content of organic matter, humus and acidity in the soil after applying mineral fertilizers on increasing productivity of millet (Panicum miliaceum L.) cv. ‘Orenburg 9’ were studied. The soil and millet crops were selected as the object of research. The work uses field, thermastatic-weight, ionometric, Machigin, application-weight, Tyurin, dispersion and statistical methods of research. Field experiments were performed in four-field, two-field crop rotations and continuous cropping according to the following scheme: 1) Sowing after durum wheat in the aftereffect of black fallow (control); 2) Sowing after common wheat in the aftereffect of black fallow; 3) Sowing after common wheat in the aftereffect of soil-protective fallow; 4) Sowing after common wheat in the aftereffect of sideral fallow; 5) Sowing after durum wheat; 6) Millet continuous cropping. It was revealed that the studied factors in the experiment increased millet productivity under two-field crop rotation with durum wheat after fertilizers application. Compared to the control, the maximum increase of grain yield was after using ammophos complex fertilizer (N40P40) - by 0.45 tons; feed units - 0.44; energy units - 0.26 and feed protein units - 0.24 t/ha. The best effect on increasing productivity was provided by: July precipitation - 28.05 %, spring reserves of productive moisture in 0-30 cm soil layer -- 25.96 %; in 0-100 cm - 20.86 %, nitrate content - 71.80 %, phosphorus - 38.05 %, potassium - 33.07 %, microbial activity (cellulose decomposition) - 62.32 % (p < 0.05) compared to the control. The highest organic matter content (17.6 %) and humus (3.5 %) in soil and neutral acidity (pH = 7.0) create favorable conditions for growing millet after durum wheat. As a result of research on other crops, it was found that these factors do not affect yield increase. Positive results of the influence of factors can be useful in increasing millet productivity.