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Browsing by Author "Dendooven, L."

Now showing 1 - 5 of 5
  • Conservation agriculture and soil carbon sequestration: Between myth and farmer reality
    Govaerts, Bram; Verhulst, N.; Castellanos-Navarrete, A.; Sayre, Ken D.; Dixon, John; Dendooven, L. (Taylor & Francis, 2009)
    Improving food security, environmental preservation and enhancing livelihood should be the main targets of the innovators of today's farming systems. Conservation agriculture (CA), based on minimum tillage, crop residue retention, and crop rotations, has been proposed as an alternative system combining benefits for the farmer with advantages for the society. This paper reviews the potential impact of CA on C sequestration by synthesizing the knowledge of carbon and nitrogen cycling in agriculture; summarizing the influence of tillage, residue management, and crop rotation on soil organic carbon stocks; and compiling the existing case study information. To evaluate the C sequestration capacity of farming practices, their influence on emissions from farming activities should be considered together with their influence on soil C stocks. The largest contribution of CA to reducing emissions from farming activities is made by the reduction of tillage operations. The soil C case study results are not conclusive. In 7 of the 78 cases withheld, the soil C stock was lower in zero compared to conventional tillage, in 40 cases it was higher, and in 31 of the cases there was no significant difference. The mechanisms that govern the balance between increased or no sequestration after conversion to zero tillage are not clear, although some factors that play a role can be distinguished, e.g., root development and rhizodeposits, baseline soil C content, bulk density and porosity, climate, landscape position, and erosion/deposition history. Altering crop rotation can influence soil C stocks by changing quantity and quality of organic matter input. More research is needed, especially in the tropical areas where good quantitative information is lacking. However, even if C sequestration is questionable in some areas and cropping systems, CA remains an important technology that improves soil processes, controls soil erosion and reduces production cost. (CabAbstracts)
  • Conventionally tilled and permanent raised beds with different crop residue management: Effects on soil C and N dynamics
    Govaerts, Bram; Sayre, Ken D.; Ceballos-Ramirez, J. M.; Luna-Guido, M. L.; Limon-Ortega, A.; Deckers, Jozef; Dendooven, L. (2006)
    This article compares levels of soil carbon and soil nitrogen in conventionally tilled and conservation agriculture production systems in Mexico. It is found that conservation agriculture systems have much higher carbon and nitrogen levels over time.
  • Influence of permanent raised bed planting and residue management on physical and chemical soil quality in rain fed maize/wheat systems
    Sayre, Ken D.; Govaerts, Bram; Lichter, K.; Dendooven, L.; Deckers, Jozef (2007)
    Using a long range field trial, this research examines the impact of conservation agriculture practices in permanent raised beds on soil quality and soil organic matter in Central Mexico
  • Influence of tillage, residue management, and crop rotation on soil microbial biomass and catabolic diversity
    Govaerts, Bram; Mezzalama, M.; Unno, Y.; Sayre, Ken D.; Luna-Guido, M. L.; Vanherck, K.; Dendooven, L.; Deckers, Jozef (Elsevier, B.V., 2007)
    This article examines the impact of no till systems in a 12 year trial in the central highlands of Mexico, specifically focusing on effects on microbial biomass and catabolic diversity in rainfed smallholder agricultural systems. A significant finding of the study is that zero till without residue retention is an unsustainable production practice.
  • Using NDVI and soil quality analysis to assess influence of agronomic management on within-plot spatial variability and factors limiting production
    Verhulst, N.; Govaerts, Bram; Sayre, Ken D.; Deckers, Jozef; François, I. M.; Dendooven, L. (2008)
    This study uses remote sensing technology to map the spatial variability of crop performance within trial fields using conservation agriculture practices. Using zero tillage and residue removal, it is discovered that crop performance is unevenly distributed within the field with lower elevations offering higher performance. However, retaining soil cover allows for uniform distribution of crop performance. Subsequently, the article concludes that maintaining soil moisture is the most important element of the production system and recommends retention of cover for best performance throughout the field.