Ways of improving the use of photosynthetically active radiation in potato cultivation in the middle Volga steppe
The efficacy of using the calculated doses of fertilizers for upcoming harvests potatoes was studied. As a result of studies of the potato leaf area formation dynamics on gray forest soils of the Middle Volga steppe, its dependence on mineral nutrition level was revealed. Their impact on productivity and quality of potato tubers was identified. The efficacy of calculated doses of fertilizers for upcoming potato harvests were studied. Fertilizing crops by scheduled doses, counted by cash- balance method for upcoming yields of 25-40 tons per hectare, provided the formation of 90,5-98,0% of the target yield. The nitrate content in all versions of the experiment was below the maximum admissible concentration. However, with increasing fertilizers amount, their content was increased in 1,24-1,73 times (without fertilizers - 41 mg / kg of wet weight). As a result of studies of the dynamics of potato leaf area formation on gray forest soils of the Middle Volga steppe, we revealed its dependence on mineral nutrition level. The photosynthetic potential (PP) during the growing season of potato Udacha, was in the first version without fertilizers 2.173, the second 2.520, in the third 2.910, fourth 3.196 and fifth 3.575 million square meter per hectare * days, i.e. with an increase in fertilization rates, the photosynthetic potential increased accordingly to 0.347-1.402 million units, for every thousand units of photosynthetic potential we obtained from 7.2 to 10.8 kg potato tubers. A starch content varied from a few of fertilizers. The maximum starch content (14 %) was obtained in the second way, calculated on the tuber yield of 25 tons per hectare. A further increase in the background was led to some of its decline.