engleski

Run off and soil loss on different tillage systems in growing of arable crops

Our objectives were to quantify water erosion (referred as a runoff and soil loss) during the 14-year investigation cycle (1994-2008) on Stagnic Luvisols, in central Croatia, under common agricultural crops grown in six tillage treatments. This paper presents the results relating to the total soil loss, with special reference to the time occurrence of soil loss per crop and development stages of the crops grown: Maize (Zea mays L.) ; Soybean (Glycine hyspida L.) ; Oil-seed rape (Brassica napus var. oleifera L.) ; Winter wheat (Triticum aestivum L.) and Spring barley (Hordeum vulgare L.). The largest erosion in the 14-year period was recorded in the standard variant (black fallow). Following variant was the variant that involves ploughing up and down the slope. Much smaller soil losses were recorded in no-tillage and treatments with ploughing across the slope. Much higher soil losses were recorded in growing of the spring row crops (Maize and Soybean) than in the winter crops (Winter wheat, Spring barley and Oil-seed rape). In growing of spring row crops, soil losses were not evenly distributed during crop growing, quite contrary. The period of seedbed preparation, or the period immediately after sowing spring crops (May and first decade of June) is the most critical period with the highest risk of erosion. In the period of growing the spring crops over 80% of the overall annual soil loss occurs in all tillage treatments. The period from May to mid-June is the riskiest period for water erosion in the agroecological conditions of central Croatia if low-density spring row crops (Maize, Soybean, Potato, Tobacco, Sugar beet, Sunflower) are grown in the field. The trend of increasing participation of low-density spring crops compared to high-density winter and fodder crops on the arable areas in the Republic of Croatia indicates that the problem of water erosion on sloping terrains will be increasingly present. During the winter crops growing (wheat, barley, oil-seed rape) crops of high density, no critical periods were observed and water erosion was insignificant. We are recommending no-tillage (or some other reduced tillage) and ploughing across the slope due to the all advantages and drawbacks of studied tillage methods in 14 years investigation for a wide application in crop growing on this soil type, . And the last but not the least, we find that erosion control in the future requires a new, integral approach. Instead of the so far individual (personal) scientific attitudes to the problems of soil protection from erosion, an integral approach to erosion control should be adopted. Relevant work should include teams of specialists from various fields, such as agronomists, civil engineeringist, geologists, hydrologists, foresters, etc. The so far isolated and scattered activities in agriculture, forestry, water management, energetics, traffic and similar disciplines aimed at fighting the soil erosion and torrential watercourses were not governed by a unique conception of managing torrential watersheds and erosion areas. The ultimate aim is to preserve the environment for the coming generations.

water erosion; crops; tillage treatments; runoff; soil loss

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