Динаміка родючості чорнозему типового глибокого залежно від системи удобрення і ланки сівозміни

Abstract

The purpose. To determine rational alternatives of fertilizer system and rotation of crops of grain-tilling link of 10-field crop rotation for preserving soil fertility, restoring the content of humus and heightening values of agrochemical indexes of soil. Methods. Field test, physical and chemical, agrochemical. Results. Agrochemical researches were carried out in formation of fertility of typical deep chernozem in links of field crop rotation depending on system of fertilizing. Use during 40 years of organic-mineral systems of fertilizing in grain-beet crop rotation has not ensured restoration of the content of humus in typical chernozem up to the level of layland. At importation of decomposed manure in dose of 8,3 t/hectare + N29.3P45K36.7 the content of humus in arable layer on completion of 4 rotations made 4,59%; 16,7 t/hectare of decomposed manure + N29.3P45K36.7 — 4,72%, and in layland — 5,20%. Application of decomposed manure in dose of 8,3 t/hectare + N29,3P45K36,7 has ensured to the end of 4-th rotation the content of mineral nitrogen in arable layer in the link barley-pease-sugar beet — 19,1 mg/kg of soil; in the link vetch-oats-winter wheat-sugar beet — 16,4 mg / kg of soil. At increase of dose of fertilizers up to 8,3 t / hectare of decomposed manure + N36P85K76.7 — 21 mg / kg of soil. That exceeds initial indexes on 8,1; 5,4 and 10 mg/kg of soil. Resources saving fertilizer system (8,3 t/hectare of decomposed manure + N29,3P45K36,7) formed to the end of 4-th rotation the heightened content of mobile phosphorus in arable layer — 119,3 mg/kg of soil, at increase of dose of fertilizers up to 8,3 t / hectare of decomposed manure + N36P85K76.7 mg/kg of soil — its content reached 200 mg/kg of soil. At importation during 4 rotations of decomposed manure in dose of 8,3 t / hectares + N29.3P45K36.7 the content of mobile potassium in arable layer made 129,2 mg/kg of soil; 8,3 t/hectare of decomposed manure + N36P55K46.7 — 145,1 mg/kg of soil. That exceeded initial indexes accordingly on 18,9; 35 mg/kg of soil. Long use during 40 years of organic-mineral system of fertilizing caused acidification of soil solution. At importation of decomposed manure in dose of 8,3 t/hectares + N36P35K46.7 pHsalt in comparison with layland decreased on 1,0–1,2, Ng increased on 2,2–2,4 smol/kg of soil, at absolute values — accordingly on 5,2–5,3 and 4,0–3,6 smol/kg of soil. Conclusions. Use of organic-mineral system of fertilizing in dose of 8,3 t/hectare of decomposed manure + N29.3P45K36.7 on typical deep chernozem in the link of field crop rotation promotes optimization of agrochemical nature of soil and preserves its fertility.