Effectiveness of environmental soil management systems in the Forest-steppe of Ukraine
The article outlines the methodological support for evaluating the feasibility of specific soil management systems. The criteria of such evaluation are the indicators of economic, industrial and environmental efficiency of the industry. The economic efficiency of agriculture is estimated by the adequacy of the actual productivity of the arable land (Pa) with its resource-secured value (Pr) by the share Ca = Pa: Pr (if Ca = 0.9, then the adequacy is high, ca = 0.7-0.8 - average, Ca <0.7 - low) and its stability. Industry stability is estimated by means of the stability coefficient Sc, determined through variation analysis, and its gradations: Sc≥90 % - high, Sc = 89-80 - average, SC <80 - low [6]. Intensity and profitability have become the indicators of economic efficiency of agriculture. The intensity factor (Ic) is calculated by the ratio of the value of gross output (Go) to the price of anthropogenic costs for its production (Ac, UAH/hectare). Intensity is considered high for Ic≥1,5; the average Ic = 1.1-1.4, the low - Ic-1.1 [7]. The profitability of production is estimated to be high for the indicator P = 50, the average - p = 10-49, low - P <10. Soil management energy efficiency is calculated by dividing the energy efficiency of the grown products Еn by the costs of non-renewable energy for its production Ec, GJ/ha, referred to as the energy efficiency coefficient Ceе = Еn/Еc. Energy efficiency is estimated to be high in Cee> 5, medium - > 4-6 and low - <2 [8]. In order to assess the level of environmentalization of soil management, ecology index Ei is used, which is the fraction of the division of the amount of active substances of the introduced mineral fertilizers Σ NPK, kg/ha to the sum of organic substances introduced into the soil in the form of fertilizers and surface and root plant residues, Σ0, t/ha. There is an inverse relation between the module of the index Ei and the level of soil management ecologization: for maximal ecologization the value of Ei = 0, its level increase Ei = 15 - > 0, Ei decrease = 16-25, and low Ei => 25. Among the ecological criteria, the carbon-nitrogen ratio in the soil environment is especially important, which becomes a code for assessing the conditions for humus reproduction. The ratio C:N = 20-30 is optimal for humification. Increased or decreased value of this criterion from the specified interval is caused by the increase of mineralization and the weakening of the humification of plant residues. An additional criterion for ecological examination of soil management is the agroecotoxicological index of AETI, calculated on the arguments of pesticide application safety level [10]. The article also describes the results of the three years of ecologization: industrial (control), ecological and biological, with its coefficients, 25; 6.2 and 0 respectively, in the stationary field experiment of the comparative evaluation of the effectiveness of soil management system options for the Law-Banking Forest-steppe of Ukraine during 2002-2012. The evaluation is carried out using the above-mentioned test of the criteria of the branch system efficiency..According to the results of these researches, the criteria for rationality on low-humus medium-gravel chornozem of the Right-bank Forest-steppe of Ukraine corresponds to crop rotated intensive model of the system of ecological soil management with saturation of a hectare of the crop rotation with organic fertilizers at the rate of 24 tons and mineral ones at the rate of 150 kg (N<sub>46</sub>P<sub>49</sub>K<sub>55</sub>) against the background of mold basic cultivation of soil in crop rotation with alternating organic matter once in 4-5 years under cultivated crops and non-field measures in the interval between plows. The reality of the specified resource of organic fertilizers is due to the adequate development of livestock breeding and the full use of vegetable residues, non-consumable parts of crops, seed crops, compost, for the fertilization of soil. On average, over 11 years, the system received the following indicators: arable land productivity - 10.7 t/ha of feed units with its adequacy to the bioclimatic potential of 1.18; intensity factor 1.9; productivity stability 83 %; coefficient of energy efficiency 6,3; profitability 96 %; high quality and environmentally friendly products; positive annual balance of humus + 0.36 t/ha and elements of mineral nutrition in the ratio of C: N to 0-10 cm in the soil layer 18-20. The system of biological farming is associated with a 20 % reduction in arable productivity due to the shortage of available nutrients and a significant deterioration of the phytosanitary state of the fields.