Abstract

The Hungarian vetch (Vicia pannonica L.) planted to prevent erosion with setting the green cover on the soil surface and to produce forages for animal feed. The cover crop was cut twice as early and late cutting in the spring. The nitrogen doses were 0-5-10-15 kg per da before sunflower planting to determine of the optimum nitrogen rate. The sunflower (Helianthus annuus L.) yield was decreased due to cover crop planting and the seed yield decreased when harvest being late. Due to soil water uses, sunflower yield was lower than ploughed plots. However; these yield losses were compensated from forage crops production with getting extra income based on economical analysis. There were no significant difference between nitrogen doses and any positive increase on seed yield in normal rainy winter season. On the other hand, high sunflower yields were obtained from early cover crop harvesting so early sunflower planting in the experiment. Based on economical analysis results of the research; cover crop planting before sunflower production in the wheat-sunflower rotation system were found as profitable method especially in rainy winter seasons in Trakya region.