CONCENTRATION OF NITRATE NITROGEN IN THE SOIL AND PRODUCTIVITY OF CROPS WHEN LONG-TERM MINIMIZING OF TILLAGE ACCORDING TO VARIOUS FORECROPS

Abstract

In a multifactor stationary field experiment on the area of the Elitnoye Holding in the Novosibirsk region (central forest-steppe subzone) in 2002-2018 the seasonal dynamics of nitrate nitrogen in the fields of four full grain-steam crop rotation by steam and grain predecessors against an extensive background (without chemical means) in four versions of the main mechanical treatment of leached black soil was investigated. Along with this, the productivity of grain crops was studied with long-term minimization of the main tillage on extensive and intensive backgrounds. The authors found out that in the central forest-steppe of the Ob river region before sowing grain crops according to the various methods of steam preparation most of all in the meter layer of nitrate soil was found in black steam with plowing (150 kg / ha) and less in variants with soil-protective treatments (132-141 kg / ha ). The lowest level of this element in the soil (124 kg / ha) in spring was noted by the early minimum steam. Before sowing the second wheat after steam, the nitrate nitrogen content in the meter soil layer for plowing (79 kg / ha) was slightly higher than in the options with soil treatment (61-64 kg / ha). In the final field of crop rotation, regardless of the studied soil cultivation systems, the minimum initial amount of nitrogen (56-57 kg / ha) was noted. By the end of the growing season of crops, the nitrate content in the soil was sharply reduced. Before harvesting wheat by steam, the nitrogen content in the upper meter profile was 41-55 kg / ha, for grain precursors even less - 27-33 kg / ha. The steam yield of grain crops on extensive and intensive backgrounds was 3.09-3.21 and 3.96-4.02 t / ha, respectively, and practically did not depend on the methods of its preparation. On repeated sowing the wheat yield in comparison with an extensive background in plowing (1.26-1.79 t / ha) was significantly higher than in the studied options for minimizing the main tillage (1.02-1.55 t / ha). When optimizing the mineral nutrition of plants and the phytosanitary situation of crops, wheat productivity by grain predecessors in crop rotation fields increased 2.0-2.9 times without significant differences in soil treatment options.