The effect of minimum tillage with weed cover mulching on organic daikon (Raphanus sativus var. longipinnatus cv. Taibyousoufutori) yield and quality and on soil carbon and nitrogen dynamics

Minimum tillage with weed cover mulching (MT) could be one alternative practice for root vegetable production because of soil erosion control and energy savings. This study compared the effects of MT and conventional tillage with weed removal (CT) on daikon yield and quality, soil carbon and nitrogen dynamics, and physical properties under organic farming practices. Root yields of daikon were 77% higher on average in MT than in CT although weed biomass was higher in MT than in CT in both years. Organic fertilizer application also significantly increased daikon yield. Nitrate-N content in daikon root was lower in MT than in CT. Soil total C and N at 0-2.5cm soil depth were significantly higher in MT than in CT in both years but organic fertilizer application did not increase soil total C and N. Soil bulk density at 0-7.5cm soil depth was significantly lower in MT than in CT. Penetration resistance between daikon rows was also significantly lower in MT than in CT at 0-4cm soil depth, although this relationship was reversed in between 11 and 17cm soil depth. These results suggest that MT is a beneficial approach for root vegetable production, given that it produces excellent crop yields and increased soil total C and N with minimum disturbance to agro-ecosystems.