INFLUENCE OF ANNUAL GREEN MANURE CROPS ON POTATOES YIELD IN CROP ROTATION
The results of effective use of green manure mixtures in aftereffect on potatoes - in crop rotation (green manure fallow - potatoes - potatoes) are presented. A positive balance for the crop rotation was formed for all nutrients (nitrogen, phosphorus, potassium). The highest nitrogen balance was observed in two-component mixtures of spring rape + spring vetch and white mustard + spring vetch, respectively 109.92 and 121.62 kg / ha. In terms of nitrogen, the excess of the balance with green manure mixtures in comparison with single-species crops was 8.34–87.29, for phosphorus, 22.73 and 73.37, and potassium, 8.8–51.4 kg / ha. At the beginning of the crop rotation (green manure fallow), the arable soil layer was characterized by a low content of nitrate nitrogen (6.2 mg / kg) and mobile phosphorus (25.1 mg / kg), in the third field (potatoes) there was an increased content of these elements 60–66 and 150–195 mg / kg, which indicated the effectiveness of a longer mineralization of the green manure mass. The number of macroaggregates in the soil by the end of the crop rotation averaged 75.8–78.9%, which is 2.8–3.6% higher than the original (green manure fallow). The soil density of the arable horizon averaged 0.60 g / cm3, which was optimal for the growth and development of potatoes. Improvement of agrochemical and physical properties of the soil contributed to a significant increase in potato yield in the aftereffect of green manure against the background (NPK) 90: the increase in comparison with the direct action was 74.4–51.7%; the yield ranged from 26.4 to 30.7 t / ha. The coefficient of energy efficiency in the aftereffect of two-component mixtures was 2.00 and 2.06, in single-species crops – 1.8.