Effect of Multiple Stresses, Organic Amendment and Compaction, on the Fate and Impact of Isoproturon in Soil

Laure Mamy,Pierre Benoit,Ghislaine Delarue,Agathe Brault,Nathalie Cheviron,Sabine Houot,Valérie Dumeny,Christian Mougin,Laure Vieublé-Gonod

doi:10.3390/environments7100079

Abstract

Organic matter decline and compaction are two major processes of soil degradation. Organic amendment is a current practice to compensate the loss of organic matter, which could in addition contribute to increase soil aggregate stability and limit compaction. Therefore, the objective of this work was to study the effect of multiple physico-chemical stresses, organic amendment (compost of sewage sludge and green waste) addition and soil compaction, on the fate and impact (measured through the urease enzyme activity) of isoproturon. Compost addition and compaction did not significantly affect the fate and impact of isoproturon. The lack of effect of compost can be due to the delay between soil sampling and soil amendment. Compaction had no effect probably because the porosity reduction does not affect the habitable pore space accessible to degrading microorganisms. Nevertheless, isoproturon significantly increased the urease enzyme activity in compacted and not compacted unamended soils contrary to the amended ones. It seems that the organic amendment could act as a buffer with regards to the impact of isoproturon. The results obtained in this work suggest that, in general, the fate and impact of isoproturon in soils will not change following compaction and/or organic amendment addition, neither the corresponding risks for the environment.

Highlights

Soil is essentially a non-renewable resource which delivers services vital to human activities and ecosystems survival [1,2]
The balances between the mineralised, CaCl2 and CH3 OH extractable and non-extractable fractions ranged from 85.8% to 134.7% of the initial 14 C. Both organic amendment and compaction did not affect the fate of isoproturon in soil (p > 0.05)
The effect of multiple stresses, organic amendment addition and compaction, on the fate and impact of isoproturon in soil was studied under laboratory conditions

Summary

Introduction

Soil is essentially a non-renewable resource which delivers services vital to human activities and ecosystems survival [1,2]. Soils suffer from the increasing environmental pressure, driven or exacerbated by human activity, such as inappropriate agricultural practices, industrial activities or urban development. These activities are damaging the capacity of soil to continue to perform in full its broad variety of crucial functions. Soil degradation has strong impacts on water resources, human health, climate change, nature and biodiversity protection and food safety. Commission identified the main eight threats to which soils are confronted: contamination, organic matter decline, compaction, erosion, salinisation, soil biodiversity loss, sealing, landslides and Environments 2020, 7, 79; doi:10.3390/environments7100079 www.mdpi.com/journal/environments. Some of themcontents directly result agricultural practices such as

Objectives

Methods

Results

Conclusion