|BUEHRING, NORMIE - Mississippi State University|
|Way, Thomas - Tom|
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2021
Publication Date: N/A
Interpretive Summary: Poultry litter, a byproduct of the poultry production industry, has increasingly been used as a fertilizer for row crop production in the southeastern US where much of the industry in the US is concentrated. Research has shown that repeating poultry litter application to the same soil for as few as two to five years leads to accumulation of phosphorus and other mineral elements in the soil which is a concern environmentally. Applying just enough litter to meet the phosphorus need of the crop, often referred to as phosphorus-based application, is currently the best and most recommended litter application strategy to prevent soil nutrient buildup but may not always be the most efficient strategy. This study explored whether rotating fertilizers and crops or a combination of the two can be used to increase yield, enhance the export of mineral nutrients with harvested seed, and prevent litter-derived nutrient buildup in the soil when poultry litter is repeatedly applied as a fertilizer. The study has identified a new strategy as a viable alternative to phosphorus-based litter management. This new strategy involves applying poultry litter at a relatively high rate for two years to meet the nitrogen need of cotton followed by a cessation of litter application for two or three years during which only synthetic nitrogen fertilizers are applied. Not only did this strategy prevent nutrient buildup in the soil, it also improved the economic yield of all three crops in the study which included cotton, corn, and soybean. The best strategy of managing litter where the three crops are grown in rotation is to fertilize cotton or corn with poultry litter to supply the full nitrogen need of cotton followed by growing soybean without applying any fertilization in the subsequent two to three years.
Technical Abstract: Exporting excess mineral nutrients from soils that receive repeated poultry litter (PL) applications may be enhanced by rotating crops and fertilizers that increase crop yield. The objective of this study was to determine the impact of rotating crops and fertilizers on cotton, corn, and soybean yield and on mineral nutrient removal at harvest. Cotton, corn, and soybean were grown in rotation for 5 yr with five fertility treatments which included an unfertilized control (UTC), a standard fertilization with synthetic fertilizers (Std), P-based PL application every year for 5 yr (P5L), N-based PL application for 5 yr (N5L), and N-based PL application for 2 yr followed by synthetic N fertilization for 3 yr (N2L). Yield of the three crops and the amount of nine mineral nutrients removed were measured at the end of each season. The results showed that the N2L treatment increased the yield of all three crops and enhanced nutrient mining and removal in the last 3 yr. All treatments that involved PL (N5L, N2L, P5L) increased soybean yield by as much as 12% over the Std, but this increase with the high PL rate may not be economical. Cotton and corn yields were reduced by the PL treatments if the plant available N fell below the target. Rotation did not affect the yield of any of the three crops. Continuous cotton removed the least amount of nutrients among four rotation treatments. Rotations that included two soybean crops in the 5 yr removed the most amount of nutrients. The best strategy of managing PL where the three crops are grown in rotation is to fertilize cotton with PL to supply 100% of its N need followed by growing soybean without applying any fertilization in the subsequent 2 or 3 yr.