SOIL FERTILITY AND FERTILIZERS EFFICIENCY IN A GRAIN AND HERB CROP ROTATION OF ZAVOLZHJE
The paper analyzes the contemporary State of the soil fertility of Samara region from with 1-6 cycle studies. Found that leaving the agricultural use of arable land, declining soil fertility, reduced stocks of humus, mobile forms of nitrogen, phosphorus and potassium, deteriorating soil properties agrophysical. The main reason for this-in sharp fall in the level of application of organic fertilizer (compared to 1987-1988, when nutrient balance was positive and manure technology volume amounted to 7.7 million tonnes) decreased in 2015 year 9 times and amounted to 0.85 million tons. In 1987 year volume of mineral fertilizers was 180 thousand tons of d.v., and in 2015 year-38 tons of d.v. noted that currently almost non-existent activities on reclamation of sodic soils.