engleski

Tillage erosion in growing arable crops

Our objectives were to quantify tillage erosion ( referred as soil loss) during the 14 year investigation cycle ( 1994- 2008) on Stagnic Luvisols, in central Croatia, under common agricultural grown crops 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 grown crops: Maize (Zea mays L.) ; Soybean (Glycine hypsida L.) ; Oil- seed rape (Brassica napus var.olefera L.) ; Winter wheat ( Triticum aestivum L.) and Spring barley ( Hordeum vulgare L.). The largest erosion in the 14-year period was recorded in the check treatment. Following variant was the variant that involves ploughing across the slope. Much higher soil losses were recorded in the growing of spring row crops (maize and soybean) than in the growing of winter crops ( winter wheat, spring barley and oil-seed rape). In the growing of spring row crops, soil losses were not evenly distributed, quite contrary. The period of seebed preparation, or the period immediately after sowing spring crops (last decade of April, May and first decade of June) is the most critical period with the highest risk of erosion. In that time in growing spring row crops over 70% of the overall annual soil loss ocurs in all tillage treatments. From that reason 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 and sunflower) are grown in the field. The trend of increasing participation of low-density spring crops compared to a high-density winter and fodder crops on the arable areas of Republic of Croatia indicates that the problem of tillage erosion on slopping terrains will be increasingly present. One of the reasons for more row spring crops in crop rotation is production of bio fuels. Durint the winter crops growing (wheat, barley, oil-seed rape- crops of high density), no critical periods were observed and water erosion was insignificant. According to 14-years of investigation 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 growing crop on this soil type. And the last but not least, we find that erosion control in the future requires a new, integral approach. Instead of the so far individual (personal) scientific 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, geologist, hydrologists, foresters, etc. The so far isolated and scattered activities in agriculture, forestry, water managment, energeticst, 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 enviroment for the future generations.

tillage erosion, crops, runoff, soil loss

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