Articles
CAN SOIL NEMATODE COMMUNITY STRUCTURE BE USED TO INDICATE SOIL CARBON DYNAMICS IN HORTICULTURAL SYSTEMS?
Article number
1018_46
Pages
425 – 433
Language
English
Abstract
There is a need to develop indicators that relate the dynamics of soil organic carbon (SOC) with changes in land management of horticultural production systems.
Soil nematode communities have been shown to be sensitive to land management changes, but often do not include plant-parasites in the calculation of soil nematode community indices.
The concept of nematode functional guilds was used to estimate the proportion of carbon entering the soil ecosystem through different channels, such as through decomposition of organic material, the detrital channel, through the roots of plants, the root channel or recycled through the activity of predators, a predation channel.
Calculations of the indices were developed and validated using case studies in the north Queensland banana industry.
Firstly, a survey of organic and conventional banana farms found a greater proportion of C entering the soil ecosystem through the detrital channel and a reduced proportion of C originating through the root channel at the organic sites relative to conventional sites.
Secondly, a field experiment comparing compost amendments, found application of fresh compost significantly increased the proportion of C entering the soil ecosystem through the detrital channel and decreased proportion of C originating from the root channel.
Thirdly, a field experiment comparing conventional banana production to an alternative system which incorporated organic matter, found the proportion of C entering the soil ecosystem through the root channel was significantly greater in the conventional systems relative to the alternative system.
This research demonstrates that nematode indices can be used to assess horticultural systems, by indicating the origins of SOC.
Soil nematode communities have been shown to be sensitive to land management changes, but often do not include plant-parasites in the calculation of soil nematode community indices.
The concept of nematode functional guilds was used to estimate the proportion of carbon entering the soil ecosystem through different channels, such as through decomposition of organic material, the detrital channel, through the roots of plants, the root channel or recycled through the activity of predators, a predation channel.
Calculations of the indices were developed and validated using case studies in the north Queensland banana industry.
Firstly, a survey of organic and conventional banana farms found a greater proportion of C entering the soil ecosystem through the detrital channel and a reduced proportion of C originating through the root channel at the organic sites relative to conventional sites.
Secondly, a field experiment comparing compost amendments, found application of fresh compost significantly increased the proportion of C entering the soil ecosystem through the detrital channel and decreased proportion of C originating from the root channel.
Thirdly, a field experiment comparing conventional banana production to an alternative system which incorporated organic matter, found the proportion of C entering the soil ecosystem through the root channel was significantly greater in the conventional systems relative to the alternative system.
This research demonstrates that nematode indices can be used to assess horticultural systems, by indicating the origins of SOC.
Authors
A. Pattison, T. Kukulies, L. Forsyth, P. Geense
Keywords
banana production systems, bioindicators, detrital channel, energy channels, Musa sp., predation channel, root channel, soil ecosystems, soil organic carbon
Online Articles (76)