Correlation analysis of crop rotation productivity depending on physicochemical, agrochemical parameters of light grey forest surface-gleyed soil under long-term agricultural impact

Abstract

The level of soil fertility is determined by a set of properties, including agrophysical, physicochemical, agrochemical, etc. Indicators that characterize the agrochemical component of the soil change under the impact of organic and mineral fertilizers. Fertilizers transform, while interacting with the soil, significantly affect conditions of plant nutrition and, as a consequence, the productivity of crops.

The results of research show that organo-mineral fertilizer with liming improve physical and chemical properties in the light gray forest surface-gleyed soil under periodically leaching water regime. The pH_KCl increases to 5.25, Ah decreases to 2.30 mg-eq/100 g of soil, and the amount of absorbed bases increases to 10.7 mg-eq/100 g of soil. The content of mobile aluminum is 4.15 mg/kg of soil.

Under such conditions, the content of N in HEglarable. and HEglsub layers is 96.6–102.9 mg/kg of soil, P₂O₅ – 204.7–184.5 mg/kg of soil, K₂O – 159.4–
182.5 mg/kg of soil against 86.8; 37.2 and 45.0 mg/kg in the variant without fertilizer application.

In many agronomic studies it is very important to find out the relationship between two or more traits, to establish their relationship. Such relations between variables are more common, when each value of the attribute X corresponds to not one, but many possible values of the attribute Y. Such connections appear only in the mass study of attributes and, unlike functional ones, are called probabilistic or correlation.

The correlation analysis revealed certain trends in the relationship between physicochemical, agrochemical parameters of the soil and crop rotation productivity. There is a tendency of close connection of crop rotation productivity with physicochemical and agrochemical indicators, except for nitrogen, where the level of connection was average (r = 0.571–0.661).

The inverse dependence of productivity on hydrolytic acidity and mobile aluminum is revealed, which leads to a decrease in productivity on the experimental soil.

Correlation coefficients indicate that pH, hydrolytic acidity and mobile aluminum significantly affect the increase in the content of humus (r = 0.771) and phosphorus (r = 0.629) in the soil layer 0-20 cm, the closeness of the relationship between these indicators was inverted.