TY JOUR TI Optimization of the content of easily hydrolyzable nitrogen in the cultivation of narrow-leaved lupine on unproductive lands KW fertilizer system KW liquid effluents KW solid fraction of manure KW minimal tillage KW dump plowing KW sod-podzolic light loamy soils KW nitrogen balance and fixation JO INTERNATIONAL AGRICULTURAL JOURNAL AU Shevchenko, V.A. AU Popova, N.P. AU Bondareva, G.I. AU Solovyev, A.M. PY 2026 IS PB Electronic science