Crop rotation effects on sweet potato yield and quality.

摘要

In 1985 a study was initiated in central Alabama to evaluate the effect of various crop rotations on sweet potato (Ipomoea batatas) yield and quality. Specific rotations were: (i) continuous sweet potatoes, (ii) sweetcorn and sweet potatoes, (iii) soyabeans and sweet potatoes, (iv) 2 years sweetcorn and one year sweet potatoes, (v) 2 years bahiagrass (Paspalum notatum) and 1 year sweet potatoes, and, (vi) soyabeans, sweetcorn and sweet potatoes. Two complete cycles (1988-90 and 1991-93) of the rotations were analysed. The crop rotation producing the largest annual yield (4.70 tons/acre) and one of the largest cumulative (11.35 tons/acre) sweet potato yields was 2 years of bahiagrass followed by sweet potatoes. Continuous sweet potatoes produced the lowest annual (2.12 tons/acre) and one of the highest total marketable cumulative yields (11.39 tons/acre) during the 6 years. In general, a rotation containing a grass (bahiagrass, sweetcorn) produced higher annual sweet potato yields than those without.