Evaluation of soil fertility agricultural areas in the Central-Tuva Depression

In the article, the fertility of a soil cover of the agricultural territory of Tuva is considered. The structure of agricultural grounds of the region where the share of an arable land makes 5% is considered. The main share of an arable land is in Central Tuva basin. More than 60% of acreage in the republic are concentrated in the central part of the region (Tandinsky, Kaa–Hemsky, Pius–Hemsky and Sut-Holsky areas). The reasons for reduction of arable land during the considered period are analysed. The maintenance of a humus in an arable layer of zone soils is defined. Chestnut soils have the low maintenance of a humus, chernozem soils — an average. For the last 35 years in soils of an arable land of Tuva, the maintenance of a humus almost by 1,3 times has decreased. It is revealed that during this period in arable soils process of a degasification continues. Soil index of aerosols of Tuva very low. The annual deficiency of a humus in soils of agricultural use is 845 kg/hectare. It is established that organic fertilizers have a positive effect on the increase in fertility of aerosols (desiderata, manure). The Tributary on green fertilizer leaves the crop residue and root remains in a number of 6,3 t/hectare, peas — 5,0 t/hectare, and the greatest number of organic substance comes to the soil with manure (12 t/hectare).