Changes in the density of chernozem in crope rotation with minimization of basic tillage

The results of a field experiment to study the influence of basic processing techniques on the density of chernozem in the Krasnoyarsk forest–steppe are presented. The research was carried out in a field of fallow and grain crops in a five–field field crop rotation (fallow – wheat – rapeseed – barley – oats). The experimental design included basic tillage techniques: 1 – moldboard tillage to a depth of 20–22 cm; 2 – minimal processing (disc peeling to a depth of 10–12 cm); 3 – zero tillage (direct sowing on the stubble of the predecessor). It was shown that ordinary chernozem of the Krasnoyarsk forest–steppe under the conditions of basic cultivation was characterized by a loose and normal composition of the 0–20 cm layer with a seasonal rhythm not exceeding 18 %. The density of the 0–20 cm layer of chernozem depended 19–28 % on the nature of the agrocenosis. This influence is most pronounced in the 10–20 cm layer (26–37 %). Crop rotation fields according to the density of the crop on all backgrounds of the main cultivation were located in the following increasing series: fallow (0.90–0.96 g/ cm 3 ) – wheat (0.95–1.02 g/cm3) – barley (0.97–1.00 g/cm 3 ) – oats (0.98–1.05 g/cm 3 ). It was established that the cultivation of agricultural crops and fallowing the field against the background of moldboard plowing formed a density at the level of 0.94–0.98 g/cm 3 . Tilling the soil with a discor in crops of grain crops increased the soil density to 0.97–1.01 g/cm 3 ; zero sowing – up to 1.00–1.05 g/cm 3 . At the same time, the value of the studied parameter did not go beyond the optimal values.