EFFICIENCY OF MINERAL FERTILIZERS ON PEAT SOILS OF NORTHERN TRANS-URAL REGION

Abstract

The paper presents the results of the longterm studies (1982-1995 and 2011-2014) on the effectiveness of mineral fertilizers (NPK) on medium-textured soils of the forest-steppe zone of the Northern Trans-Urals. The studies were conducted on the experimental land-reclamation system located in the central part of the Tarmansky bog land on the second lacustrine-alluvial terrace of the Tura river. The soils have a weakly acid medium reaction 5.2-5.9, relatively low hydrolytic acidity 28.1^10.8 mg - eq. /100 g of soil, a relatively low degree of base saturation 61.7-75.5%, high content of total nitrogen 3.1-3.9% and low content of phosphorus0.09-0.14%andpotassium0.02-0.05%. As a result of the research, it was revealed that there was a lack of nutrients both at the beginning of the growing season of perennial grasses during cold spring and permanently in the second half of the growing season. Therefore, without fertilization, perennial grasses form low hay yields (1.95 t/ha in two-time mowing on average in 14 years). It was noted that over the years, the yield of grass without fertilizers does not tend to increase. Yield fluctuations over the years are mainly due to weather conditions. Systematic application of complete mineral fertilizers in dressings increases the yield of hay of perennial grasses by 2.6-3.8 times. The maximum increase of hay by 32.2 kg on average in 14 years was achieved when applying N30P60K60. The increase in the fertilizer rate from 150 to 240 kg of the primary nutrient reduced the efficiency of each kilogram of the primary nutrient by 20%, whereas the increase up to 330 kg reduced the efficiency by 34%. The need of grasses in nitrogen is satisfied by mineral fertilizers by less than a half (41.4%). Formation of an adequate second mowing is possible only with the application of fertilizers. Fertilization provides a dominant position (87- 92%) of the awnless brome from the second year of using grasses. Annual fertilizer dressings applied to perennial grasses allow to obtain high-quality hay.