Changes in the Parameters of Soil Adsorption Complex and Humus State of Leached Chernozem under the Conditions of the Long-Term Application of Fertilizers and Lime Treatment
Gasanova, E.S.; Kozhokina, A.N.; Myazin, N.G.; Stekolnikov, K.E.
Vestnik of Voronezh State Agrarian University 2018(4): 13-21
The studies of changes in chernozem soils during lime treatment have been performed since the establishment and confirmation of the undoubted positive role of this technique in maintaining the soil fertility. However, the mechanism of action of this method on the parameters of soil adsorption complex and humus state always has its own peculiarities that depend on the soil and climatic conditions and the applied fertilizers. In order to study the effect of fertilizers and lime treatment on the fertility of leached chernozem and yield of agricultural crops in the conditions of the forest steppe of the Central Chernozem Region (on the territory of Voronezh Oblast) a long-term stationary field experiment was laid in 1986. This experiment utilized a six-field crop rotation. The experimental design includes 15 variants. Seven of them were selected for studies in 2014 and 2018. The obtained results showed that the application of mineral fertilizers on the background of aftereffect of organic fertilizers caused the acidification of soil; the value of exchange acidity decreased by 0.6-0.8 points, and the value of hydrolytic acidity increased by 0.4 mg-eq per 100 g of soil compared to the period before the experiment initiation. Also there was a simultaneous depletion of soil bases. At the same time the experimental variants differed from each other. The most favorable parameters of soil acidity were provided by the aftereffect of manure and defecate without the application of mineral fertilizers, as well as by the co-use of mineral and organic fertilizers and ameliorant. The content of exchangeable calcium varied within the range of 19.4-22.8 mg-eq per 100 g of soil with the minimum value in the variants with mineral fertilizers applied on the background of the aftereffect of manure only. Lime treatment of soil led to an increase in humus content and its reserves by 0.2-1.0% and 155-250 t/ha, respectively. Moreover, the maximum content of calcium-associated humic acid fractions was found in the defected variants. The variants where mineral fertilizers were applied exhibited an increase in the share of fulvic acids in humus composition.