Effects of Reduced Tillage on Growth, Yield and Fruit Quality of Organic Eggplant.

Tillage is widely used for organic production for many purposes. However, tillage has been reported to have many negative impacts on soil health and the environment. The aim of this study was to investigate the efficacy of using reduced tillage following winter cover crops for organic vegetable production. The experiment was conducted on an Annapolis fine sandy loam at CMREC (Central Maryland Research and Education Center) Upper Marlboro Facility, Upper Marlboro, Maryland. The four treatments used in the study were: conventional tillage with bare ground (BG), conventional tillage with black plastic mulch (BP), strip-tillage (ST), and no-tillage (NT). Winter cover crops (a mix of rye, crimson clover and forage radish) were planted in late August in all plots and flail-mowed in late April prior to applying the treatments. Besides nitrogen provided by the cover crop, mixed organic fertilizers (chicken manure and feather meal) were hand spread along the plant rows at preplanting at 84 N kg/ha in the BP plots and at preplanting and sidedressing in the plots of BG, NT and ST at rates of 45 and 39 N kg/ha, respectively. Eggplant seedlings were machine transplanted in late May at a population density of 24,000 plants/ha. Surface drip irrigation was used during eggplant growing season when water supply from rainfall was insufficient. Eggplant plants exhibited faster early growth in the BP treatment plots but growth in ST treatment plots caught up by 4 weeks after transplanting. Yield was slightly less in the NT plots in the first year but there was no difference among treatments in the second year. Fruit quality was best in the NT treatment plots in both years.