Background and methodology:
Vegetable farmers and consumers are increasingly concerned about the association between crops and human health. Consequently, consumers are requesting more organically grown products. The objectives of this paper were to compare the production, mineral and vitamin contents of four vegetables grown conventionally and organically. Field experiments were conducted in different plot areas from 1990 to 1992 in a Pugwash sandy loam in Lowe Onslow, Nova Scotia using five replicates/treatments.
Analysis of the three years of data showed that the yield and vitamin C content of the potatoes was not affected by treatments. The conventionally grown treatment out-produced the organically grown treatment for two corn cultivars but there was no difference between treatments in the yield of one cultivar or the vitamin C or E contents of the kernels in any year. At p<0.11, four elements in potato tubers ( P, Mg, Na and Mn) and four elements in potato leaves (N, Mg, Fe and B) were influenced by treatment, but only leaf CU was affected in the sweet corn. Extractable P, Ca, Mg and Cu were higher in organically fertilized potato plots. Leafy P and K were significantly positively correlated with extractable P (r=0.70) and K (r=0.73) in the potato plots, while leaf Cu and kernel S were positively correlated with extractable CU (r=0.56) and S (r=0.62) in the sweet corn plots.
Warman, P. R. & Havard, K. A. (1998). Yield, vitamin and mineral contents of organically and conventionally grown potatoes and sweet corn. Agriculture, Ecosystems and Environment 68:207-216.