Effect of liming and fertilisation systems on the physico-chemical properties of leached chernozem (black soil)

Abstract

Long-term agricultural use of chernozems (black soils) leads to a decline in their effective fertility. The depletion of the arable and subsoil horizons in calcium can occur under the influence of natural and anthropogenic factors. The strongest anthropogenic impact on physico-chemical properties is caused by varying levels of fertilizer application. Average annual rate of pHkcl decrease on unfertilized variant was 0.008-0.01 units per year. At the same time in the grain-fallow crop rotation the decrease of pHkcl is more intensive than in the grain-grass crop rotation. Under the influence of mineral fertilizers the growth rate of acidity increased by 1.8-2.1 times. After 12 years after application of organic fertilizers the value of acidity increased by 0.13-0.15 units after carrying out the experiment with pHkcl in comparison with initial values. The application of dolomite flour contributed to the increase of pHkcl by 0.41-0.53 units as early as one year after application of the ameliorant, the maximum shift was observed on the 4th-5th years. The application of organic and mineral fertilizers contributed to the trend of increasing the content of available phosphorus in the soil, compared with the unfertilized variant in both crop rotations. The content of mobile forms of phosphorus increased in the variants where green manure crops were sown. The application of manure and mineral fertilizers had no significant effect on the content of potassium in the soil. When using organo-mineral fertilizer system, as well as its combination with crop-sideration, there was a tendency of some increase in potassium content in the arable layer. The minimum additional yield was obtained for all crops with the application of 8 tonnes of manure per hectare of crop rotation land, and the maximum was obtained with the organo-mineral fertilisation system and its combination with crop-sideration. Liming increased the productivity of all crops.