Balance of the main elements of mineral nutrition in different agroecosystems of Tersko-Sulakskaya low-land

The dynamics of main elements content of mineral nutrition (nitrogen, phosphorus, potassium) of plants was studied in agroecosystems of rice and winter wheat and natural ecosystem on Tersko-Sulakskaya low-land for the purpose of evaluation of these elements balance. It was shown, that quantitative evaluation of balance of nitrogen, phosphorus and potassium in ecosystems of rice, winter wheat and herbal-gramineous group makes a significant contribution on conceptions about these systems functioning. The application of nitrogen-potassium fertilizers in the mentioned ratio (1:1) and the proportion of mineral elements in soil of rice-growing plantations on Tersko-Sulakskaya low-land permit to maintain the positive balance of nitrogen and phosphorus in investigated agrocenosis. The negative balance of potassium in agroecosystems suggests a necessity of the development of new approaches to fertilizers application for the purpose of a more detail study of the influence of potassium fertilizers on productivity of agricultural crops.