Content and Balance of Trace Elements (Co, Mn, Zn) in Agroecosystems of the Central Chernozemic Region of Russia

Abstract

This work is devoted to the study of the provision of arable soils with mobile forms of the most important trace elements (cobalt, manganese, and zinc). In modern Russian agriculture, the low provision of soils with trace elements is one of the reasons leading to lower yields and the deteriorating quality of most crops. The materials of the regional and local agroecological monitoring of soils in Belgorod region, which is part of the Central Black Earth region of Russia, were used in this work. The results of the local agroecological monitoring showed that the average gross contents of manganese, zinc, and cobalt in arable chernozems in the typical forest-steppe zone were respectively 345, 36.5, and 8.48 mg/kg, and in chernozems common in the steppe zone the contents were 397, 42.9, and 9.51 mg/kg. In the distribution of the gross contents of the studied trace elements in the profile of arable chernozems, a tendency of a gradual decrease in their concentrations with increasing depth was revealed. According to the results of the regional agroecological monitoring of arable soils in the Belgorod region for 2015–2018, it was found that the proportion of soils with a low content of mobile compounds of zinc (<2 mg/kg) was 90.3%; for cobalt (<0.2 mg/kg) and manganese (<10 mg/kg), the proportions were 99.3% and 38.6%, respectively. In these soils, it is advisable to introduce microfertilizers containing trace elements that are in deficit. The main sources of the manganese, zinc, and cobalt input to agroecosystems are organic fertilizers, which account for 79.3%, 86.3%, and 66.6% of the total amounts, respectively. Losses of manganese and cobalt from agroecosystems mainly occur as a result of the washing away of arable soils—82.8% and 96.8% of total losses, respectively—and 60.5% of zinc losses are due to alienation by the marketable part of the crop. A positive balance had been a feature of zinc, with an intensity of 106%, while manganese and cobalt had a negative balance, with intensities of 61.3% and 25.3%, respectively.