The influence of the agricultural crops-phytoameliorants on changes in fertility and productivity of eroded chernozems of the Western Ciscaucasus

The ameliorative efficiency of crops-phytoameliorants was studied in stationary crop rotation on common chernozem at Armavirskaya experimental station of VNIIMK in 1991-2011. The research was conducted in three 13-field crop rotations: with grain crops, with grain and grasses and esparcet (holy clover), with application of two systems of the primary soil treatment: traditional and soil protective. Depending on the crops the depth of the primary soil treatment in control was 22-30 cm. The soil treatments due to soil protective technology were as following: surface disk treatment on depth 8-10 cm under the winter wheat after spring forecrops, shallow moldboard treatment on depth 14-16 cm after cereal forecrops. These researches and analysis of the obtained results showed that factors of fertility (moistening, density, content of the mobile forms of the main nutrients in soil) are influenced mostly by biological features of cultivated crops in the different types of crop rotations and less - by cultivation technology. For twenty years after the beginning of the research, humus content in soil decreased in average to crop rotations on 0.17% at traditional cultivation and on 0.06% at soil protective cultivation. Humus content in crop rotation with alfalfa was at the initial level (4.05%).