K.E. Sokaev, V.V. Bestaev
Station of Agrochemical Service «Severo-Osetinskaya», ul. Sadonskaya 36, Vladikavkaz, 362013, Russian Federation
Summary. The article presents the results of an agro-ecological survey, carried out in the Republic of North Ossetia-Alania, during the last 50 years. During the first years of observation (1965-1987) the volumes of application of organic and mineral fertilizers increased, the saturation of arable land by organic fertilizers reached 3.37-4.6 t/ha, by mineral ones – 129.5-178.4 kg/ha. Due to this process the yield of crops also grew. The balance of nutrients in the agriculture of the republic was simultaneously improved. In 1984 the positive balance of nitrogen was obtained for the first time with the intensity of 105.3 %; and in 1987 the zero balance of potassium was also noted for the first time. Since 1988 the balance of all elements became negative due to the decrease in the volumes of application of organic and mineral fertilizers and the absence of liming of acid soils. These processes negatively influenced the content of organic matter (humus) in soils. It decreased from 4.8 to 3.7 % for the last 25 years. The areas of arable lands low-provided by humus increased up to 107,000 ha, or 58.3 % of the inspected area. During 50 years the content of mobile forms of phosphorus and potassium did not change significantly. During the first six cycles of the survey (1965-1990) the area of soils with low content of mobile phosphorus and exchange potassium reduced to 15.9 and 1.2 %, respectively, in comparison with 59.8 and 9.3 % in the years of the first cycle (1965-1968). After that the area of soils with the low content of these elements expanded and was 21.2 and 6.7 %, correspondingly, at the end of the 10th cycle (2006-2012). Today arable lands of the republic are, mainly, medium provided by mobile sulfur and microelements. The content of heavy metals (Cu, Zn, Pb, Cd, Ni) does not exceed the maximum permissible concentration.
Keywords: soil fertility, humus, organic matter, mobile phosphorus, exchange potassium, cycle of the survey, monitoring, organic, mineral fertilizers, liming, yield, balance of plant nutrients, microelements.
Author Details: K.E. Sokaev, D. Sc. (Agr.), deputy director (e-mail: agrohim_15@ mail.ru); V.V. Bestaev, Cand. Sc. (Agr.), director.
For citation: Sokaev K.E., Bestaev V.V. Dynamics of Soil Fertility in the Republic of North Ossetia-Alania. Dostizheniya nauki i tekhniki APK. 2016. V.30. No. 12. Pp. 56-60 (in Russ.).