PLANT NUTRIENT RELEASE FROM POULTRY LITTER AND POULTRY LITTER ASH AMENDED SOILS BY VARIOUS EXTRACTION METHODS

Abstract

The present study aimed to assess the concentrations of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in poultry litter (PL) and poultry litter ash (PLA) using eight chemical solutions (acids, chelating agents, salts solution and water). The relationship of maize (Zea mays L.) growth to the P extractability by these extractants was determined. For this purpose, PL was ashed at 600°C. Both PL and PLA were applied to two types of soils at the rate of 100, 200 and 300 kg P ha−1. Poultry litter, PLA and amended soils were analyzed for extractable P, K, Ca, and Mg using 1M nitric acid (HNO3), 0.1M HNO3, 0.01M HNO3, ethylenediaminetetraacetate (EDTA), ammonium nitrate (NH4NO3), ammonium acetate (NH4OAc), calcium chloride (CaCl2) and deionized H2O extractions. For both PL and PLA, nutrients were varied in the order of P > Ca > K > Mg. Except water, all extractions released higher P in PLA than PL. The extractable nutrients seemed to have positive correlations with the application rate. Ashing of PL released higher concentrations of K, Ca, and Mg among all extractants. The extraction methods for P release differed in the order of 1M HNO3 > 0.1M HNO3 ≈ EDTA > 0.01M HNO3 > NH4NO3 ≈ NH4OAc > CaCl2 > H2O in PL and PLA amended soils. Soils amended with PLA produced higher maize biomass than PL treated soils. Plant growth increased under increasing applications of PL and PLA. Plants under PLA treatments exhibited higher concentration of nutrients. Phosphorus availability was highly correlated to P uptake and plant biomass.