The influence of field crop rotation on the accumulation of stubble and root residues in the arable layer of sod-podzolic soil

The purpose of the work is to conduct a comparative assessment of the amount of smelted plant residues in various field crop rotations in the conditions of the Mari El Republic. The work was completed in 2013-2018 on a stationary site in a two-factor experiment. The first factor is types of crop rotation and crop rotation. Four crop rotation with a different set of crops. Cereal crops occupy 83% in the first. The share of cereals was 67% in the second and third. Cereals occupy 50% and perennial grasses and potatoes 50% in the fourth crop rotation. The second factor is mineral fertilizers: 1) without fertilizers: 2) N 60 P 60 K 60 . On average, 3.02 ± 0.06 t / ha of stubble and root residues was received per year according to the results of studies in the control grain-grass crop rotation with a one-year use of clover. There are no perennial herbs, but there are potatoes in the first fruit-bearing. Here, plant residues entered the soil by 41% less than in the first crop rotation. The accumulation of stubble and root residues was 2.91 ± 0.07 t / ha in the second crop rotation. The decrease is due to the cultivation of potatoes, which does not leave plant residues after harvesting. The largest number of stubble and root residues was formed in the third crop rotation (3.37 ± 0.07 t / ha). The use of mineral fertilizers increased the mass of stubble and root residues in all crop rotations by 0.16 t/ha.