Regime of nitrate nitrogen in chernozem during the cultivation of perennial grasses

Abstract

The article presents the results of field experiments to study the dynamics of nitrate nitrogen in ordinary chernozem of the forest-steppe zone of the Krasnoyarsk Territory. The studies were carried out in 2017-2019 years in three-field grain-steam and 8 grain-grass crop rotations. Melilot and sainfoin were cultivated neat and under the cover of barley, incl. with seed treatment with Rizotorfin inoculant. Winter rye was sown in 2018 in a field of clean fallow in a grain-fallow crop rotation and after mowing the second cut of perennial grasses of the 2nd year of use in grain-grass crop rotations with a stubble seeder SZS-2.1 without preliminary tillage.It has been established that a high supply of nitrate nitrogen is characteristic of a steam field in a 0-20 cm layer of chernozem (19 mg/kg). The average supply of chernozem with nitrate nitrogen was formed by coverless crops of sweet clover and sainfoin and cover crops of sweet clover (9-10 mg/kg). In the crops of winter rye, according to various predecessors, an intensive consumption of mineral nitrogen by plants and a very low supply of soil with nitrate nitrogen (2-5 mg/kg) were noted. Grain-grass crop rotation with the cultivation of winter rye on binary and pure crops of sweet clover created the best conditions for the accumulation of nitrate nitrogen in the 0-40 cm layer of chernozem (6-8 mg/kg). The treatment of sweet clover and sainfoin seeds with the inoculant Rizotorfin determined a more intensive absorption of nitrate nitrogen from the soil and a low supply of nitrate nitrogen to the soil (4-6 mg/kg) in the crop rotation.