Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2016
Publication Date: 7/11/2016
Publication URL: http://handle.nal.usda.gov/10113/5454514
Citation: Tewolde, H., Sistani, K.R., McLaughlin, M.R. 2016. Residual effect of poultry litter applications on no-till cotton lint yield. Agronomy Journal. 108:1405-1414.
Interpretive Summary: Poultry litter is known to be a superior cotton fertilizer in the growing season that it is applied, but potential benefits to cotton production in subsequent years are not well known. This study investigated yields of no-till cotton grown with a conventional synthetic fertilizer in soils with and without litter applications in prior years. The lint yield of an on-farm no-till cotton planted in a soil that had received 2 or 3 tons/acre litter in the previous 3 or 6 years was compared to lint yield of cotton fertilized with synthetic fertilizers for the same length of time. The results showed that, in the first year after stopping litter application, cotton produced 10 to 25% more lint yield in the soil with 3 or 6 year histories of litter application. The benefit persisted up to 5 years but was largest in the first year and diminished in subsequent years. The results also showed that additions of potash, phosphate, and other less-frequently applied nutrients was not necessary in soil that had received litter in previous years, reducing the cost of no-till cotton production. The yield-boosting benefit shown in this research along with the apparent cost-cutting benefit should encourage growers to include poultry litter as an integral component of no-till cotton production systems in regions such as the southeastern US, where poultry litter is generated in abundance.
Technical Abstract: In no-till cotton production systems, the potential residual benefits from prior years of poultry litter application are not well known. This study investigated the productivity of no-till cotton fertilized or unfertilized with synthetic N in years subsequent to the last application of suboptimal poultry litter rates. Treatments included 3- or 6-yr histories of 0, 2.2, 4.5, or 6.7 Mg ha-1 yr-1 litter; 4.5 Mg ha-1 yr-1 litter plus 67 kg ha-1 yr-1 N (as urea-ammonium nitrate solution, UAN); and 118 or 135 kg ha-1 yr-1 UAN-N plus synthetic P and K as needed. In subsequent years, cotton was grown with residuals from these treatments or with the residuals plus 135 kg ha-1 yr-1 UAN-N. Cotton produced up to 25% more lint yield in the first year from the residuals of 3- or 6-yr litter applications of 4.5 or 6.7 Mg ha-1 yr-1. The benefit of a 6-yr history of 4.5 or 6.7 Mg ha-1 litter application, when followed by fertilization with 135 kg ha-1 UAN-N, was 10% in the first year. The residual benefit persisted up to 5 yr but was largest in the first year and diminished with time. Results showed that the residual from 3 to 6 yr of 4.5 or 6.7 Mg ha-1 yr-1 litter applications improved lint yield for several years after litter application stopped. Fertilizing cotton in this soil with 4.5 Mg ha-1 yr-1 litter supplemented by 67 kg ha-1 yr-1 UAN-N was optimal for lint yield and had a yield-boosting effect for up to 5 yr.