Soil physical quality changes under different management systems after 10 years in the Argentine humid pampa

J L Costa,V Aparicio,A Cerdà

doi:10.5194/se-6-361-2015

Abstract

Abstract. South American countries with the highest surface of land under no-tillage (NT) management are Brazil, Argentina and Chile. In Argentina, 78.5% of the agricultural land is cropped under NT management. Several experiments have confirmed the improvements in soil aggregation and infiltration achieved by NT management in dry-land farming areas associated with increases of bulk density (δb) under NT management. An increase in bulk density implies a reduction of the macro and mesoporosity that is in contradiction with the increased infiltration that occurs at macro and mesopores. We hypothesize that the increase of bulk density in NT management mainly affects the mesopores. We evaluated the evolution of the soil physical parameters in three management systems in four farmers' fields. We found that the reduction in total porosity under NT management is mainly a product of a reduction in the percentage of mesopores in the soil. In this work, the results indicate a modification of some soil physical parameters (porosity, near-saturated hydraulic conductivity, soil structure) due to uninterrupted agricultural production, but the management system did not affect the yields of crop.

Highlights

Sustainable soil management in agricultural land is needed for a sustainable world
Several experiments have confirmed the improvements in soil aggregation and infiltration achieved by NT management in dry-land farming areas associated with increases of bulk density under NT management
We aimed to evaluate the following: (i) δb, the change in weighted average diameter, the hydraulic conductivity and organic carbon content on wheat–corn–sunflower crop sequence in three management systems; (ii) whether pore size is affecting the differences in bulk density observed in three management systems and its relation to the soil hydraulic conductivity; (iii) yields of the crop sequence over 10 years

Summary

Introduction

Sustainable soil management in agricultural land is needed for a sustainable world. Efforts to achieve a sustainable management can be found in developed and developing countries (Perkins et al, 2013; Mekuria and Aynekulu, 2013). South American countries with the highest surface of land under NT management are Brazil, Argentina and Chile (Lal et al, 2007). In Argentina, with 33 million hectares cultivated with grain, 78.5 % is cropped under NT management (Aapresid, 2012). The southeast section of the humid pampa, spanning 6 million hectares, 90 % of which are agricultural lands, does not reflect this situation, because most of the crops are managed with tillage practices. NT management is becoming more popular, and little is known about the effects of this practice on soil properties

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