Injected and broadcast application of composted municipal solid waste in cotton

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 versus 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 15 cm of soil compared to no compost application. In addition, all rates of injected material significantly reduced soil compaction in the E- and B-horizons (15 to 45 cm). 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. 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 26.9-Mg/ha injected application treatment, yield increases were 23, 24, and 44% in 1997, 1998, and 1999, respectively, compared to no compost application. Vitazyme increased plant N, P, and K contents with no effects on Ca, Mg, and S. Vitazyme increased cotton lint yield 35 kg/ha or 3%. In addition, soil nitrogen content 6 weeks after planting in plots treated with Vitayme was 12% higher than no-Vitazyme plots.