Organic matter decomposition and microarthropod community structure in corn fields under low input and intensive management in Guaíra (SP)

G.S Rodrigues,J.L De C Mineiro,M.A.V Ligo

doi:10.1590/s0103-90161997000100010

Abstract

The rate of organic matter decomposition and the structure of the communities of microarthropods were compared between two corn fields receiving contrasting agricultural management practices (low input and intensive farming). The rate of decomposition tended to be higher in the intensively managed field in the beginning of the growing season, but decreased to a level significantly lower than the observed in the low input field by the end of the growing season. This suggested that the biological community associated with the decomposition process could be negatively influenced in the intensively managed field. Analyses of the structure of microarthropod communities indicated differences between the two areas. The microarthropod populations present in the intensively managed field suffered abrupt decrease in numbers as the season progressed.

Highlights

A bstract: The rate of organic m atter decomposition and the structure of the communities of m icroarthropods were com pared between two corn fields receiving contrasting agricultural m anagem ent practices
Tests of significance for each comparison were performed for the following null hypothesis: Ho; The relative proportion of each microarthropod taxa is the same under low input and intensive agriculmral management
In the second monthly period the two means were no longer different, while in the third month the samples from the low input treatment showed a significantly higher decomposition rate. This result could be related to the increasing detrimental effects of the pesticides applied in the intensively managed field (Kajak, 1989)

Summary

Introduction

A bstract: The rate of organic m atter decomposition and the structure of the communities of m icroarthropods were com pared between two corn fields receiving contrasting agricultural m anagem ent practices (low input and intensive farm ing). In order to address the basic hypothesis that unbalances in the community structure of soil m icroarthropods and in the organic m atter decomposition process were being caused by the intensive m anagem ent in irrigated areas, a com parison between an intensively managed irrigated field and a low input field was carried out (El Titi & Ipach, 1989).

Results

Conclusion