Influence of primary soil cultivation methods and systems on the dynamics of humus in drained soil

The research was carried out on the experimental fields of the All-Russian Research Institute of Reclaimed Lands (Tver Region). The purpose of the research is to study the influence of soil cultivation techniques and systems on the dynamics of humus in drained soil. The soils of the experimental plots are cultivated sod-podzolic, light loamy, gleyic, formed on a moraine or thin binomial. In 5 experiments in crop rotations, methods of minimizing and deepening the arable layer were studied (plowing and moldless loosening at 28–32 cm, three-tier plowing at 40–45 cm), agro-reclamation methods (reclamation loosening at 50–60 cm, volumetric slitting at a depth of 45–50 cm, ridge plowing at 20–22 cm), agro-reclamation and mixed-depth soil cultivation systems. It has been established that soil cultivation techniques and systems are an important factor influencing the speed and direction of changes in humus content in the soil. Their influence was determined, first of all, by the method, depth and frequency of tillage in crop rotation. Positive results on the dynamics of humus were obtained with ridge, combined and minimal tillage systems with volumetric slicing of the soil. Compared with traditional ridge tillage technology, the humus content in the arable layer increased by 0.23% over 7 years, with combined tillage – by 0.37 and minimum – by 0.46%. In soils on carbonated moraine, positive changes in the dynamics of humus were observed when plowing with a plow with cut-out bodies and during reclamation loosening of the soil. In conditions of complex soil cover, on soils formed on thin soil and moraine, the use of reclamation loosening caused additional difficulties in the formation of a deficit-free balance of organic matter. Reclamation loosening of such soils should be accompanied by liming and an increase in the application rates of organic fertilizers per hectare of crop rotation area, compared to the recommended ones.