Equipment was developed and tested for injection and broadcast application of municipal solid waste (MSW) compost at selected rates to agricultural land for cotton production. Replicated tests were conducted to determine the effects of injected vs. broadcast applied compost on soil parameters (organic matter, soil compaction, and soil fertility) and plant growth.

All broadcast application rates of compost significantly reduced hardpan formation in the top 6-in. of soil compared to no compost application. In addition, all rates of injected material significantly reduced soil compaction in the E- and B-horizons (6-18 in.). Injected applications did not affect compaction in the top 6-in. of soil. Broadcast application of compost significantly increased soil organic matter content 6- and 12-weeks-after planting proportional to the compost application rate. In addition, soil nitrogen content was significantly higher in the broadcast application plots 6-weeks-after planting. 12-weeks-after planting, only application of 12-tons/acre compost (broadcast) statistically increased soil nitrogen content averaged over the top 8 in. of the soil.

MSW compost (broadcast or injected) significantly increased plant N, P, and K contents compared to no compost application. Increases in plant nitrogen were proportional to application rates. In addition, injected application increased plant sulfur compared to no compost application. All rates of compost (injected or broadcast applications) significantly increased cotton lint yield compared to no compost application. Yield increase was proportional to application rates. For the 12 tons/acre injected application treatment, yield increases were 23%, 24%, and 44% in 1997, 98 and 99, respectively compared to no compost application. Compost significantly increased plant height. Height increase was proportional to application rate.

Vitazyme increased plant N, P, and K contents with no effects on Ca, Mg, and S. Vitazyme increased cotton lint yield 31 lb/acre or 3%. In addition, soil nitrogen content 6-weeks-after planting in plots treated with Vitazyme was 12% higher than no-Vitazyme plots.