PRODUCTIVITY OF OATS DEPENDING ON COMBINATIONS OF MINERAL FERTILIZERS IN GRAIN/FALLOW CROP ROTATIONS
There was determined a degree of influence of mineral fertilizers in various combinations on productivity of oats for seven rotations of long-term stationary experiment in four-course grain/fallow rotation under conditions of the Republic of Buryatia. Over 28 years, owing to paired combinations of nitrogen to phosphorus (N40P40), the increase in yields made up 7.9 centners per ha on the average as compared with the yield in the control (without fertilizers). When N40P40K40-compound was applied, the increase in yields amounted to 8.7 centners per ha. The application of potash fertilizers in an N40K40 combination gave 14.1% lesser increase in yields than that of N40P40, and 20.8% lesser as compared with N40P40K40. Calculations of fertilizers payback by an increase in yields show an advantage of N40P40 combination applied to oat for grain. During seven rotations, the humus content in the arable layer decreased by 0.21 % (with 1.17 % of initial content) in the control and by 0.06 % in the N40P40K40 variant.