Sweetpotato Yield and Quality as Influenced by Cropping Systems

Abstract

Producing safe and nutritious food for consumers and ensuring profitability and sustainability of farming enterprises through environmentally friendly agronomic practices are some of the major challenges facing agriculture today. Field studies were conducted in 2001 and 2002 to evaluate the effect of conventional (chemical-intensive) monocropping, transitional (reduced-synthetic input), and an organic (non-synthetic input) multiple cropping systems on sweet potato (Ipomoea batatas (L.) Lam) yield and quality, as well as soil properties. The studies were conducted on a Dexter silt loam soil in northern Mississippi. In both years No. I sweetpotato yield was greatest for the transitional and organic cropping systems and lowest for the conventional cropping system. In 2001, cropping system did not affect plant survival. In 2002, plant survival was greatest for the conventional cropping system and lowest for the organic cropping system. Soil extractable nutrient levels prior to planting (preplant soil fertility) were very high for Mg, high for P and Ca, medium for S, and low for K. Final post-harvest soil levels after the 2nd year: the content of Mg was very high for the three cropping systems, and high for P, K and Ca. Sulfur was high for the organic cropping system, and medium for the conventional and transitional cropping systems. In 2001, sweetpotato P content was greatest for the conventional cropping system and lowest for the transitional cropping system. Both Ca and Mg were greatest for the conventional cropping system but were not different from the transitional cropping system. Potassium was greatest for the organic cropping system and lowest for the transitional cropping system. Both N and S were not affected by cropping systems. In 2002, N content in roots was greatest for the conventional and organic cropping systems and lowest for the transitional cropping system. The other nutrients were not affected by cropping system. Sweetpotato roots under the conventional cropping system had the greatest protein, fat and ash contents, whereas crude fiber was the greatest for roots under the transitional cropping system. Root dry matter was greatest for the organic cropping system and lowest for the conventional cropping system. Data suggest that Beauregard sweetpotato cultivar can be successfully grown on a Delta silt loam soil in northern Mississippi. Where the production of No. 1 marketable sweetpotato roots are desired, both the transitional and organic cropping systems are recommended over the conventional cropping system. While the conventional cropping system will enhance root protein, fat and ash contents more than the transitional and organic cropping systems, both cropping systems will, respectively, enhance crude fiber and dry matter more than the conventional cropping system.