Effects of Broiler Litter Ash on Nitrogen Uptake By Soybean.

The effects of broiler litter ash (BLA) on nitrogen uptake when applied to low fertility soils have not been investigated. Objective of this study was to determine the effects of BLA on nitrogen uptake by soybean (Glycine max) grown on low fertility soils. Beltsville and Fort Mott soils low in phosphorus and nitrogen were collected, sieved to < 4.0 mm. pH was adjusted to 7.0 using calcium and magnesium carbonate (5/1) ratio. Phosphorus as BLA or super-phosphate was added at 56, 168 and 336 kg P ha^-1to 1.75 kg^-1 of the pH adjusted soil and incubated for three weeks. Each treatment was replicated three times. Six inoculated soybean seeds were planted in each pot and later thinned to three plants per pot. Plants were harvested before grain filling stage of growth (stage 4), and separated into leaves, stems, pods and roots. Plants parts were rinsed with deionized water and oven dried. Shoot and root yields were higher in the plants grown on the SP treatment. Yields were higher in plants grown on the Fort Mott soil. No significant difference in soil, stem and root N was observed between P sources. Pods and leaves N was significantly higher in the SP treatment compared to the BLA. Soil and plant P concentrations were higher in the SP treatments. The lower P and N in plant tissue grown on the BLA treatments may have resulted from the lower available P in the BLA. The rate of P used in this experiment from BLA was based on the total P in the material. Further studies are needed to determine the precise percentage of plant available P that is in BLA.