Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 11/14/2002
Publication Date: 11/14/2002
Citation: KOVAR, J.L., SAUER, T.J., MOORMAN, T.B. TURKEY LITTER AS A PHOSPHORUS SOURCE FOR CORN. AMERICAN SOCIETY OF AGRONOMY MEETINGS. 2002. CD-ROM. MADISON, WI. Interpretive Summary:
Technical Abstract: Turkey production in Iowa is an important industry, with more than 7.1 million birds raised in 2001. Given the current focus on nutrient management, an understanding of soil and plant processes affecting nutrient availability is necessary to effectively utilize the litter produced. The purpose of our study was to compare the effectiveness of turkey litter and commercial fertilizer as a phosphorus (P) source for corn (Zea mays L.) production in Iowa. Samples of soil and litter were collected from four sites in the turkey-producing areas of the state. Four treatments (control; common litter on all soils; source litter on each soil; and commercial fertilizer) were imposed. A single P rate of 56 kg/ha was used. Available P (Bray 1), labile inorganic P (exchange resin), and phosphatase activity were determined at weeks 0, 3, and 7 during incubation at -33 kPa water content and 23C. After incubation, corn seedlings were planted in pots in a controlled-climate chamber. After 17 days, plants were harvested, shoot and root fresh and dry weights, as well as N and P content, recorded. To evaluate depletion of available soil P in litter-amended soils under intensive cropping, the cycle was repeated three times. Phosphorus availability tended to increase during 7 weeks following application, regardless of source. Available P in all soils was adequate for optimum growth of corn, although levels were lower in litter-amended soils. This suggests that only part of the P in the applied litter was plant available. Nutrient addition had little effect on early growth of corn during the first cycle due to variability among seedlings. Plant P was below sufficiency level (0.25%) for all treatments in 3 of 4 soil areas in subsequent cycles. Nevertheless, results suggest that the residual value of litter may be its greatest benefit.