Effect of vetch wheat mixture and broccoli as preceding crops on organic summer vegetables: on farm trial in western Turkey

摘要

Organic farming requires the use of practices such as crop rotation, green manure and compost application instead of chemical compounds to enhance farm productivity. In this study, effects of two pre-crops (vetch-wheat mixture and broccoli) and additional fertilization (AF) strategy (compost and commercial fertilizer) were tested on organic production of two main crops (tomato and zucchini) and on soil fertility. The main aim of this on-farm trial is to evaluate the applicability of the results obtained over four years study under experimental conditions. Pre-crops and AF strategy had no significant effect on zucchini yield; highest tomato yield was recorded after vetch-wheat mixture and AF. At the end of the cycle soil organic matter statistically increased in vetch-wheat mixture with AF plots. Soil nitrogen (N) levels increased slightly in all treatments but this increase was not significantly different from the initial level of N. Vetch-wheat mixture and tomato rotation with AF provided the highest gross-margin due to a higher yield.