Enhancement of Vegetable Crop Growth with Biosolids and Yard-Waste Compost on a Calcareous Clay Soil

Research is needed to determine if organic matter residuals available near urban centers will benefit vegetable crops when incorporated into calcareous clay soil common to the Southern Great Plains of the United States.  Therefore, a field plot study was conducted on a Houston Black clay in north Texas where organic matter amendments were incorporated into the soil in the late summer of 2001 and the early fall of 2002.  Cumulative application rates for the two years were 26 tons ac-1 for waste water residuals (biosolids) and 31 or 93 tons ac-1 for a low and high rate of municipal yard waste compost (MYWC), respectively. An untreated check that received no chemical fertilizer treatment was included as a control.  The sequence of crops consisted of soybean (spring-summer 2002), turnip and beet (fall-winter 2003), and sweet corn (spring 2003).  The yield of the edible portion of all four crops increased when soil was treated with biosolids as compared to untreated soil and was followed in rank by the high rate of MYWC, the low rate of MYWC, and finally the check.  These findings suggest that biosolids and MYWC applied to this clay soil has yield-enhancing potential worth further investigation.