COMPARISON OF SEVERAL ORGANIC AMENDMENTS WITH A CHEMICAL FERTILIZER FOR VEGETABLE PRODUCTION

Field research was conducted for seven seasons (1983-89) on three soil types comparing several organic amendments (dry and liquid fish silage, fish bone meal, blood meal, meat meal, seaweed meal, seaweed extract) with a chemical fertilizer (17-17-17) applied to seeded beans, carrots, peas and sweet corn, and transplanted broccoli, Brussels sprouts, cabbage, cauliflower and lettuce. In most instances, amendments were compared singly with a chemical fertilizer with different rates of nitrogen (N) and methods of application studied each season. In the last season (1989), combinations of fish bone meal, blood meal, meat meal and a seaweed concentrate were compared with pelleted fish silage (ground fish and herring), fish bone meal and a chemical fertilizer. For the cropping seasons 1983-88, in the majority of comparisons, plants receiving the organic amendments produced crops of comparable yield and size to those from plants receiving the chemical fertilizer. In 1989, plants receiving the chemical fertilizer had significantly higher yields than plants receiving any of the organic treatments. Soil and leaf nutrient values were not consistently affected by the soil type, fertilizer material, rate of N or method of application.