Cotton Gin Trash, Rice Hulls, and Poultry Litter as Soil Amendments in Mid-south Vegetables
Soil fertility studies conducted in commercial vegetable fields to examine alternative uses of mid-south agricultural wastes as soil amendments included work with poultry litter, cotton gin trash, and rice hulls. Poultry litter applications ranging from 0.3 to 0.9 Mg·ha–1 resulted in significant increases in spinach, cabbage, turnip greens, and collard yields grown in soils damaged by precision leveling or in sandy soils with low organic matter; however, positive yield response to litter applied to undamaged soils was variable. Raw rice hulls applied at rates ranging from 2 to 44 Mg·ha–1 resulted in reduced cabbage yield. Trials with cotton gin trash and cover crops on yield of cabbage, broccoli, southern pea, snap bean, and cucumber indicate significant problems with weeds following use of raw gin trash. Composting alleviated most weed problems, but no yield response was apparent at composted gin trash rates ≤9.6 Mg·ha–1. High rates (60 Mg·ha–1) of composted gin trash on damaged soil significantly improved cabbage yield. There were increases in soil pH and Ca levels. Research was supported by a SAREIACE grant.