Effects of Biosolids Application on Pasture and Grape Vines in South-Eastern Australia

David Nash,Mike J Mclaughlin,Glenn Barry,Nancy Penny,Deb Pritchard,Mike Bell,Dianne Heemsbergen,Justine Cody,Craig Butler,Kris Broos,Michael St J Warne

doi:10.1155/2011/342916

Abstract

Biosolids were applied to a pasture and a vineyard in south-eastern Australia. At both sites, soil Cd, Cu, and Zn concentrations linearly increased with biosolids application rates although not to the extent of exceeding soil quality guidelines. Biosolids marginally increased soil C and N concentrations at the pasture site but significantly increased P concentrations. With lower overall soil fertility at the vineyard, biosolids increased C, N, and P concentrations. At neither site did biosolids application affect soil microbial endpoints. Biosolids increased pasture production compared to the unfertilised control but had little effect on grape production or quality. Interestingly, over the 3-year trial, there was no difference in pasture production between the biosolids treated plots and plots receiving inorganic fertiliser. These results suggest that biosolids could be used as a fertiliser to stimulate pasture production and as a soil conditioner to improve vineyard soils in this region.

Highlights

Biosolids are the solid or semisolid material produced from the biological treatment of sewage
The results from the Pakenham and Mildura sites suggest that biosolids can be applied to pastures and grape vines without adversely affecting soil or plant properties
Results from the Pakenham site suggest that biosolids can be used to stimulate pasture production

Summary

Introduction

Biosolids are the solid or semisolid material produced from the biological treatment of sewage. As biosolids contain pathogens and contaminants that can adversely affect flora and fauna (including humans), management of the increasing amounts generated is a major international issue [1, 2]. Given the organic nature of biosolids and the plant nutrients they contain, there is increasing emphasis on alternative disposal methods such as land application [6]. Composting can be used to reduce health risks from pathogenic organisms contained in biosolids [7, 8] prior to their application to land. Depending on the concentrations initially present in the biosolids, metals and organic pollutants (such as pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons) that remain after such treatments may adversely affect soil and human health [9, 10]. Studies examining changes in soil health following biosolids addition to soil have been somewhat equivocal, because the apparently negative effects of organic chemicals and metals on soil biota may be outweighed by the positive effects organic matter additions [11,12,13,14,15,16]

Methods

Results

Conclusion