Zinc Sorption on Organic Treated Soils

摘要

FIVE COMPOST organic materials namely farm animal manure (AMC), farm different plant residues (PRC), mixture of AMC/PRC), farm poultry manure (PMC) and humic substance (HS) and an alluvial and calcareous soils were used in this study. Organic material/ soil system for each was prepared to evaluate Zn sorption by the different OM/soil systems. The data showed that Zn sorption by these OM/soil systems increased with pH increase up to pH 8 .The different systems showed marked variations in their capacity for Zn sorption. The relative increase or decreases for Zn sorption at pH 8 were 45.5, 36.4, 18.2, 9.1and 54.5% for AMC/soil, PRC/soil, AMPRC/soil, PMC/soil and IIS/soil with soil No.l (alluvial), respectively. In the case of soil No.2 (calcareous), these values were -7.6,-7.6, -18.47,-72.8 and 45.65 %, respectively. The data also showed that Zn adsorption isotherm followed the Langmiur equation especially at low Zn concentrations.The values of adsorption maximum (b) were higher with AMC/PRC and the least with PMCand PRC/soil systems for both the alluvial and calcareous soil. However, the bonding energy or affinity (a) of OM/soil systems to Zn were higher with PMC/soil systems than AMPRC/soil system for the two soils. These results suggest that applying PMC manure to both alluvial and calcareous soil would improve soil Zn supply to plants.