Productivity of fodder crop rotations depending on the nitrogen fertilizers

Abstract

Legumes in the structure of fodder crop rotations can cause reducing the efficiency of nitrogen fertilizer application on sod-podzolic soil. A comparative assessment of the productivity of six-field fodder crop rotations with different field number of legume-cereal grasses was carried out on the background of mineral nitrogen application (Р60К60, Ж0Р60К60). The research was carried out in 2013-2017 in crop rotations with 16%, 33% and 50 % legume-cereal grasses saturation in the Mari El Republic. It was noted that one-year extension of period for using perennial legume-cereal grasses in the fodder crop rotations under study was followed by increase in dry matter collection by 1.1-2.1 t/ha, exchange energy - by 6.7-16.5 GJ/ha, and crude protein - by about 2.3-3.7 C/ha. Continuous application of mineral nitrogen led to increasing the productivity of fodder crop rotations with legume-cereal grasses by 9-21%. In crop rotations, target annual and winter crops ensured a significant increase in productivity, with the exception of annual grasses with perennial grasses undersowing in 2013. The greatest increase in productivity was noted in the first crop rotation, where a long-term agrocenosis had been used for 1 year only. The ammonium nitrate application resulted in increase in crude protein collection more than in other productivity indicators of fodder crop rotations target crops.