Sustained Vegetable Production for Three Years Using Composted Animal Manures

Intensive vegetable production trials were conducted for three years at Windsor (sandy terrace soil) and Mt. Carmel Connecticut (loamy upland soil) following yearly applications of spent mushroom compost (SMC) and chicken manure compost (CMC) applied at two rates (56 or 112 t/ha) as the sole source of nutrients. Yields of seven crops from these amended plots were compared to yields from control plots fertilized with NPK fertilizer. Yields of all vegetables increased as the rate of compost increased. Average yields of tomatoes (Lycopersicon esculentum Mill.), peppers (Capsicum annuum L.), and spring and fall broccoli (Brassica oleracea L.) on all CMC-amended plots at both rates and sites in all years equaled or were greater than fertilized controls. Yields of eggplant (Solanum melongena L.) from all compost-amended plots at both sites in all years equaled or were greater than fertilized controls. Cauliflower (spring and fall) (Brassica oleracea L.) yields from CMC-amended plots (both rates) equaled or exceeded the fertilized control in all years with one exception. Spent mushroom compost added to plots at 112 t/ha produced yields of eggplant, tomatoes, and spring cauliflower equal to the fertilized control at both sites in all years. After three consecutive years of application, there appears to be a negative cumulative effect to compost additions for eggplant and peppers and a modest positive effect for cauliflower at rates applied in this study.