Recycling of Chicken and Duck Litter Ash as a Nutrient Source for Japanese Mustard Spinach

ABSTRACT

Recycling combusted poultry litter ash as a soil amendment would potentially ameliorate problems normally associated with poultry waste management. We evaluated the effect of chicken litter ash (CLA) and duck litter ash (DLA) as nutrient sources for Japanese mustard spinach (Brassica rapa L. var. perviridis) grown on a sand dune soil. Chicken and duck litter were ashed at five temperatures: 200, 400, 600, 800, and 900°C and the resulting ash samples were applied at the rate of 100 kg phosphorus (P) ha^?1. Laboratory analysis showed the highest P extraction with citric acid from CLA and DLA obtained at 600°C. Chicken litter ash was richer in P and potassium (K) than DLA but the later contained more calcium (Ca) and magnesium (Mg). The amount of ammonium acetate soluble calcium (Ca), magnesium (Mg), and K recovered increased with increasing temperature except for Ca and Mg at the highest temperatures, 800 and 900°C. Plants grown in pots with the CLA and DLA obtained at 400°C had the highest P concentration, yielding significantly more biomass with dense green leaf color but on average, the DLA amended soil had greater biomass. However, the P level was higher in CLA treated plants than DLA due to the higher available P level (citric acid soluble). Increases in electrical conductivity and pH of the soil were noted after harvest due to litter ash application. Our experiment demonstrated that poultry litter is potential source of P and other nutrients for horticutural crops.