engleski

Some aspects of soil degradation in Croatia

Water erosion was recorded during the four-year period (1994-1998.) on Luvic stagnosol (pseudogley), in the Daruvar area (Central Croatia), in different crop development stages according USLE, under six tillage treatments in growing common arable crops and crop sequence. Much higher rate of erosion, higher than Soil loss tolerance (T value) was recorded in the growing of spring crops (row crops) than in winter crops of high plant density, where was below of T value. In the spring crops growing, critical period with maximal water erosion was the period of seedbed preparation (SB period according of USLE), the period just after sowing. In the growing of maize and soybean this is the period when over 80 % of the overall annual erosion occurs in all tillage variants. As we expected, the maximal rate of soil erosion, higher than T value was recorded in the standard plot according to USLE, followed by the variant of conventional up/down the slope tillage. Soil erosion was much smaller and below T value in the no-tillage variant and all variants with tillage across the slope. It means, those variants of soil tillage we can determine as conservation tillage in agroecological conditions of this part of Croatia. In the growing of winter crops of high density (wheat and oil rape), no critical periods were observed and erosion was much below of T value and uniformly distributed throughout the whole growing season. Following of results, to reduce soil erosion below T value on slopes of inclination higher than 9 % soil conservation tillage practices are all tillage operation across of slope and/or a reduced crop rotation, without row crops.

tillage; erosion; precipitation; crops

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