The Effect of Tillage on Organic Carbon Stabilization in Microaggregates in Different Climatic Zones of European Russia

Zinaida Artemyeva,Boris Kogut

doi:10.3390/agriculture6040063

Abstract

Tillage may affect the microstructural organization of soil, including the distribution of microaggregates with different mechanical strengths. We quantified the impact of tillage treatment on the amount and distribution of free organic matter, microaggregates (unstable and stable under low intensity sonification) and their components, in the upper horizons of zonal soils of the Center of the Russian Plain. Under plowing, the carbon content decreases, both in unstable and stable microaggregates. The loss of carbon in unstable microaggregates was ~24%, whereas in stable microaggregates, it was ~37%, relative to native soils. The carbon content of organic (LFoc) and organo-clay (Clayrd) fractions in unstable microaggregates (CLFoc/CClayrd) was almost identical in the upper horizons of native soils: the ratio of these components is for Albeluvisols (1.1), Phaeozem (0.8) and Chernozems (1.0). Under plowing, these decrease to: Albeluvisols and Chernozems (0.6) and Phaeozem (0.5). The shares of carbon accumulated within the unstable and stable microaggregates (Cunstable/Cstable) are constant under equilibrium conditions and show a tendency to decrease from north to south on the order of: Albeluvisols and Phaeozem (2.2) > Chernozems (1.0). Under plowing, they increase to: Albeluvisols (3.0) and Phaeozem (3.2) > Chernozems (1.5).

Highlights

Soil organic matter (SOM) is one of the most important components of soil, which determines most of the soil quality [1], and reflects the balance between humification and mineralization processes in soil [2,3,4,5]
The ratio between carbon in the unstable and stable microaggregates (Cunstable /Cstable ) in the studied native soils shows a tendency to decrease from north to south and follows the order of Albeluvisols (2.2 ± 0.4) and Phaeozem (2.2 ± 0.7) > Chernozems (1.0 ± 0.1) (Table 9)
The variations in organic matter content related to the change of land use depend on OM

Summary

Introduction

Soil organic matter (SOM) is one of the most important components of soil, which determines most of the soil quality [1], and reflects the balance between humification and mineralization processes in soil [2,3,4,5]. Some reports have pointed out that the chemical composition of organic matter is less important for C dynamics in soils than the location and physical protection of soil C [6,7,8]. The stabilization of organic matter (OM) in soil (protection of OM against microbial decomposition) can mainly be attributed to three general mechanisms: spatial inaccessibility, biochemical recalcitrance and organo-mineral association [7]. The importance of these mechanisms can differ for each soil horizon and depends on several factors, such as soil type and texture, mineralogical composition and land use [11]

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Conclusion