The influence of conventional and no-till technology on soil organic matter balance in various arable farming systems

The influence of two arable farming systems (low input and integrated one) with conjunction of catch crops sowing and nitrogen fertilization on the grain cereals production, total phytomass production (in dry matter), gross energy output and soil organic matter balance were observed in field experiment in 1999-2001. The experiment was founded on a very good chernozem soil in the water protected area (Borovce near Piestany, south-western part of the Slovak Republic). The territory has continental character of climate with average annual precipitation 593 m and 358 mm during vegetation period and average year temperature 9.2 degree C and 15.5 degree C during vegetation period. Two arable farming systems have been evaluated: LIS (low input arable farming system) - it represents cropping system with using of energy input (nitrogen limited); IS (integrated arable farming system) - it represents no-till crop production with crop residues management, fertilization with industrial compost and green manure, integrated nutrition and pest management. In both arable farming systems the four field crop rotation (pea-winter wheat - maize for grain - spring barley) were used. Two treatments of nitrogen fertilization in both arable farming systems have been used: N1 - 50% rate of nitrogen was used to the particular crops from the ratio of N2 treatment; N2 - to winter wheat 80 kg fertilizer, to maize 80 kg, to spring barley 30 kg (low-input system) or 50 kg (integrated system) and to pea 20 kg fertilizer per hectare. The dose of phosphorus and potassium fertilization represented a ratio for intended hectare yield 7 tons of winter wheat, 6 tons of barley, 4 tons of pea and 8 tons of maize. In the next years the rate of fertilizer was corrected according to the real grain yield into previous year. Thirty tons of industrial compost was applied to the maize and the catch crops (phacelia + white mustard was sowed following wheat and barley). The field experiment was situated in the water protected areas (degree II, outer band). The fertilization with inorganic (nitrogen from the industrial fertilizers is limited with maximum ration 80 kg/ha) and organic fertilizers and pesticides application was made according the special rules. The grain yield, carbon balance, total production of phytomass (specified by recomputation) and output of gross energy was spotted. From the results following: - Higher grain yield (about 10%), poverty-stricken higher total phytomass production and higher output of gross energy was obtained using of low-input system in comparison with integrated arable one. The soft deficit of organic matter was obtained in the low-input farming system, but this one was on the contrary positive in integrated arable one. From the point view of the organic matter resource, 64% of organic soil matter came from crop residues and 34% from compost in the low input farming system. The resources of organic matter were more differentiated in integrated arable farming system - 32% came from crop residues, 32% from straw, 20% from industrial compost and 16% from green manure. In term of cropping system the soil carbon balance was positive using low input farming system with winter wheat cropping and maize for grain and in integrated one using barley cropping, winter wheat and maize cropping