Investigating the potential effects of the broiler industry's rapid regional growth on the phosphorus and trace element status of the agricultural soil.

摘要

The main objective of this study was to investigate the potential P and trace element accumulation in the agricultural soil of a region experiencing strong growth of the broiler feeding industry (Bolu, Turkey). The broiler density increased from 40 to 140 head ha-1 of the utilized agricultural area within a decade (1998-2007). The OECD P balance and scenario analysis methods were used to assess the potential impact of the broiler industry's expansion on the P and trace element accumulation in the agricultural soil, respectively. The physicochemical characteristics (mainly N, P, As, Se, and metal composition) of fresh and stockpiled broiler litter were also determined and are presented with globally compiled data. The stockpiling practice significantly decreased the N content and increased the P, Ca, Mg, and Mn content of the broiler litter. In general, the Co, Mo, As, Se, Ag, Cd, Cr, Ni, and V concentrations were found to be less than 12 mg kg-1. The scenario results indicated that Zn and Cd could be the leading metals of environmental concern, since their projected loading rates and soil concentrations could exceed the guidelines relatively faster than the other elements. The relative time period required to reach the guideline soil concentrations was Zn ~ Cd < Cu < Pb < Cr < Ni. The P imbalance almost doubled within a decade by increasing from 12 to 20 kg P ha-1. A linear equation (r2=0.81) relating the P imbalance to the broiler density was developed. This study highlights the need for the simultaneous implementation of effective agricultural nutrient management with the rapid growth of the animal feeding industry.