Influence of edaphic and management factors on soils aggregates stability under no-tillage in Mollisols and Vertisols of the Pampa Region, Argentina

In the highly fertile and productive soils of Pampa Region Argentina, constraints on soil water regime as a consequence decline in aggregates stability development platy structures, are observed. Most agricultural plots this region, even under no tillage, subjected to simplification crop sequences (low cropping intensity) with predominance soybean. On contrary, some farmers intensifying crops sequence avoid degradation equilibrate economical incomes. The aim work was evaluate effects intrinsic factors intensity surface horizon main region. Three Mollisols (an Entic Haplustoll two Typic Argiudolls) Vertisol (Hapludert) located across west-east transect northern part Argentinean Pampas were selected for study. each site management treatments no-till (GAP: Good Agricultural Practices –high intensity- PAP: Poor –low intensity-) without cultivation reference (NE: Natural Environment) compared. treatment, destruction mechanisms assessed by Le Bissonnais (1996) tests: slaking, microcraking cohesion loss. showed higher than Vertisol. Differences depended variables organic carbon contents both clay content-clay type Vertisol, revealing strong relationship aggregation taxonomic order. Mollisols, labile coarse particulate fraction (POCc) determined shifts slaking overall rather other fractions. studied, linked mainly variables, best reflected index (CI). More intensive managements (GAP treatments) resulted an enhancement stability; however, stronger Mollisols. Surface horizons from orders evidenced high fragility related process (FW10s FW tests). Thus, test discriminate between treatments. results obtained allow, one hand, understand stabilization structure and, highlight effect different NT practice aggregate stability, which affects health sustainability systems.