Crop Yield and Plant Density under Diff erent Tillage Systems

To determine the optimal ploughing depth and to make tillage simpler and less costly, but also taking account of edaphic and climatic conditions as well as biological and agrotechnical requirements of crops grown, long-term investigations (1994-2009) have been carried out on Stagnic Luvisol of sloping terrains in central Croatia near Daruvar. Th e paper presents the results relating to plant density and yields of maize (Zea mays L.), soybean (Glycine max L.), oilseed rape (Brassica napus L.), winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.). Investigation results point to the conclusion that high density crops (winter wheat, spring barley and oilseed rape) are suitable for growing under reduced tillage systems. Yields of low density spring crops (maize and soybean) obtained under the no-tillage system are not satisfactory, especially in climatically extreme years.