The aim of the research is to reveal the influence of green manure crops on the productivity of irrigated lands by the example of summer planting potatoes resowing. Pea, lupine, buckwheat, rapeseed, mustard were chosen as green manure crops. During the years of research green manure crops sowing was carried out from late April to early May. During the field experiments the methods by B. A. Dospekhov, V. F. Moiseychenko and other generally accepted methods for setting and conducting field experiments were used. Studies have shown that with summer planting potatoes growing after green manure crops, its yield increases by 8–23 %, and it becomes possible to obtain additional products from an irrigated hectare by crops compaction and thereby land resources are utilized more completely. At the same time, obtaining the additional products from the green manure crop cultivation allows not only to preserve, but to increase the fertility of soils. The usage of green manure crops before summer planting potatoes raises the photosynthetic potential of irrigated lands by 24.3–30.3 %. The maximum indicator of photosynthetic potential was obtained in the variant when sarepta mustard was cultivated as a green manure crop and it reached 3.7 million square meters days/ ha, against 2.1 million square meters days/ha in the control variant “without green manure crop”. Studies have shown that the total yield of dry biomass by using green manure crops before summer planting potatoes is 11.2–13.9 t/ha, which is 49–85 % higher than in the variant without green manure crops, depending on the type of green manure crop used. The net productivity of photosynthesis by using green manure crop increases and reaches 7.6 g/square meter per day in experiment with mustard. In the control variant, the net productivity of photosynthesis was 3.6 g/square meter.
Key words: photosynthetic potential, net productivity of photosynthesis, leaf area duration, green manure crops, summer planting potatoes.
