Effect of Mineral Fertilizers and Vegetative Biomass on the Availability of Potassium in Grain Crops

The maximum effect of using vegetative biomass was achieved most steadily when it was plowed against the background of the use of mineral fertilizers N60P40K60. Under the influence of plant residues, the total yield of grain crops increased by 6%. The potassium content in the grain of cereals remained practically unchanged in the variants (often in the range of 0.4–0.6%), but varied significantly in the vegetative biomass (1.5–2.0%, respectively). To assess the state of the functioning potassium system, it is proposed to use the ratio of potassium absorbed from plant residues to its value absorbed from soil resources, or the potassium vegetative-soil coefficient (PVSC), varying within specific limits characteristic of a given environmental situation.