Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2011
Publication Date: 9/20/2011
Citation: Tewolde, H., Adeli, A., Sistani, K.R., Rowe, D.E. 2011. Mineral nutrition of cotton fertilized with poultry litter versus ammonium nitrate. Agronomy Journal. 103:1704-1711.
Interpretive Summary: Poultry litter which is a mixture of chicken manure and bedding material has proven to be a superior fertilizer for cotton and other row crops in certain soils. In this research we investigated whether this superiority is related with the ability of litter to supply multiple mineral nutrients. A field research was conducted in northern Mississippi where cotton was fertilized with several rates of broiler chicken litter or the synthetic fertilizer ammonium nitrate in a marginally productive upland soil. The results show the superiority of litter may be associated mostly with maintaining a more ideal soil acidity and concentration of the micronutrient manganese although better nutrition of certain nutrients such as potassium and boron may also be involved. Fertilizing cotton with even the smallest amount of ammonium nitrate increased soil acidity, elevated manganese concentration in aboveground plant parts, and reduced cotton lint yield. Exceeding the minimum rate of ammonium nitrate application required for maximum yield further exacerbated the problem of elevated plant manganese concentration and soil acidity in addition to being wasteful. Applying lime most likely would have prevented the soil acidity increase brought about by fertilizing with the synthetic ammonium nitrate fertilizer, but the results clearly show that fertilizing with litter would make liming an unnecessary additional step for a more profitable cotton production in this soil with marginal soil acidity and productivity. Fertilizing with broiler litter maintained or reduced acidity of this soil and prevented the increase of manganese concentration in aboveground plant parts as was the case with ammonium nitrate-fertilized soil. Many farmers and other practitioners wonder and ask whether litter can correct soil acidity issues. Several studies have shown that litter may reduce soil acidity, but the reduction is slow and gradual and may not be immediate enough for many farmers. Overall, the results from this research show broiler litter, unlike the synthetic fertilizer ammonium nitrate which reduced cotton yield, maintained soil chemical and physical conditions ideal for optimal cotton mineral nutrition and lint yield.
Technical Abstract: Poultry litter is a superior fertilizer for cotton production in some soils, but whether this superiority is related with its ability to supply multiple mineral nutrients has not been well investigated in the field. The objective of this research was to describe the mineral nutrient profile of litter-fertilized cotton and determine if the yield increasing effect of litter relative to inorganic N fertilizers may be related with better mineral nutrition. Cotton was fertilized with six broiler litter rates ranging between 2.2 and 13.4 Mg ha-1 or six NH4NO3-N rates ranging between 34 and 168 kg ha-1 plus an unfertilized control (UTC) in northern Mississippi in a silt loam upland soil. Litter resulted in greater concentration of extractable soil P, K, Ca, Mg, Cu, Zn, and Na NH4NO3, but this did not always translate to greater concentration in aboveground plant parts. Only concentrations of K, B, and Na were increased by litter in plant parts. The two fertilizers had the same effect on soil Mn concentration, but NH4NO3 elevated Mn concentration in plant parts, sometimes by as much as two-fold, which seemed to be related to soil pH decline.The greater lint yield of cotton fertilized with broiler litter than NH4NO3-N likely was not associated with greater nutrition of N, P, Ca, Mg, Fe, or Cu. The results suggest that the better yield performance of litter than NH4NO3-N in this soil may have been due to a more ideal soil pH and tissue Mn concentration and better K and B nutrition.