Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2009
Publication Date: 8/29/2009
Citation: Tewolde, H., Shankle, M., Adeli, A., Sistani, K.R., Rowe, D.E. 2009. Macronutrient concentration in plant parts of cotton fertilized with broiler Litter in a marginal upland Soil. Soil & Tillage Research. 105(1):1-11.
Interpretive Summary: Cotton in the southeastern states is increasingly grown without tillage to help conserve soil and reduce cost. Whether poultry litter, which is generated in abundance in the southeastern US, is an effective fertilizer for cotton grown without tillage has not been adequately investigated particularly in highly erodible and marginal upland soils. This research was conducted to test the effectiveness of fertilizing no-till cotton with broiler litter in contrast to fertilization with conventional fertilizers in a Mississippi upland soil. This research tested if broiler litter improves cotton plant nutrition – specifically nitrogen, phosphorus, potassium, calcium, and magnesium – relative to conventional inorganic fertilizers. It also tested if incorporating the litter with the top soil improves cotton nutrition in a marginal upland soil. Concentration of nitrogen, phosphorus, potassium, calcium, and magnesium were measured in leaves, stems, and fruits of cotton on three or four separate dates between flowering and maturity. The result showed cotton fertilized with broiler litter always had less nitrogen concentration but greater phosphorus and potassium concentration in leaves, stems, and fruits than cotton that received conventional inorganic fertilization. Lightly incorporating litter into the top 5 mm soil layer, relative to leaving it on the soil surface, resulted in greater nitrogen concentration in nearly all plant parts at all growth stages, suggesting incorporation conserved litter-derived nitrogen from loss. Incorporation also increased Mg concentration in leaves and stems, but this increase seemed to be due to its increasing effect on nitrogen concentration. Unlike nitrogen and magnesium, incorporating litter with soil did not consistently affect concentrations of phosphorus, potassium, or calcium in all plant parts. These results show surface-applied broiler litter improves phosphorus and potassium but not nitrogen nutrition of cotton above that of conventional inorganic fertilization. However, litter supplied adequate nitrogen to support yield that exceeded that of the conventional fertilization as reported earlier.
Technical Abstract: Effectiveness of surface-applied unincorporated litter relative to conventional inorganic fertilizers under no-till or conventional-till cotton (Gossypium hirsutum L.) production systems and the magnitude of litter benefit reduction associated with lack of incorporation in the upland soils of the southern and southeastern USA is not well documented. The objectives of this research were to (1) test if broiler litter improves plant macronutrient (N, P, K, Mg, and Ca) nutrition of cotton above that of cotton fertilized with conventional inorganic fertilizers and (2) determine if incorporating litter increases macronutrient concentration in cotton plant parts under no-till and conventional-till systems in a marginal upland soil. Six treatments of an unfertilized control, a fertilized standard (STD), litter-only, and litter plus inorganic N as urea-ammonium nitrate solution (UAN) were tested in adjacent fields, one under no-till (NT) and the other under conventional-till (CT) systems. Concentration of N, P, K, Mg, and Ca were measured in leaves, stems, and reproductive parts on three or four dates between early flowering and maturity. Based on data pooled across tillage and years, cotton fertilized with the litter-only treatments, despite receiving an equivalent amount of plant-available N as the STD, always had less N concentration but greater P and K concentration in leaves, stems, and reproductive parts than cotton that received the STD treatment. Litter affected Mg concentration by its effect on N nutrition because Mg concentration in leaves and stems seems to depend on the N concentration in these plant parts. Litter had no consistent effect on Ca concentration in any of the plant parts. Lightly incorporating litter into the top 0.05 m soil layer, relative to no incorporation, resulted in greater N concentration in nearly all plant parts at all growth stages, suggesting incorporation conserved litter-derived N from loss. Incorporation also increased leaf and stem Mg concentration, but this increase seemed to be due to its increasing effect on N concentration. Unlike N and Mg, incorporation did not consistently affect concentrations of P, K, and Ca in all plant parts. These results show surface-applied broiler litter improves the P and K but not N nutrition of cotton above that of conventional inorganic fertilization. However, litter supplied adequate N to support yield that exceeded that of the STD as reported earlier. Soil incorporation of litter improves the N and possibly Mg nutrition of cotton.