FAO SOILS BULLETIN 80 The importance by and José Benites |
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FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 2005 |
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Cover photographs:
Background: Honduras.
FAO/18884/G. Bizzarri.
Inset: Honduras. FAO/18907/G. Bizzarri.
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ISBN 92-5-105366-9
ISSN 0253-2050
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© FAO 2005
2. Organic matter decomposition and the soil food web
Soil organic matter
The soil food web
Decomposition processNon-humic substances: significance and function
Compounds and function of humus
3. Natural factors influencing the amount of organic matter
Temperature
Soil moisture and water saturation
Soil texture
Topography
Salinity and acidity
Vegetation and biomass production
4. Practices that influence the amount of organic matter
Human interventions that influence soil organic matter
Decrease in biomass production
Replacement of perennial vegetation
Replacement of mixed vegetation with monoculture of crops and pastures
High harvest index
Use of bare fallowDecrease in organic matter supply
Burning of natural vegetation and crop residues
Overgrazing
Removal of crop residuesPractices that increase soil organic matter
Increased biomass productionIncreased water availability for plants: water harvesting and irrigation
Balanced fertilization
Cover crops
Improved vegetative stands
Agroforestry and alley cropping
Reforestation and afforestation
Regeneration of natural vegetationIncreased organic matter supply
Protection from fire
Crop residue management
Utilizing forage by grazing rather than by harvesting
Integrated pest management
Applying animal manure or other carbon-rich wastes
Compost
Mulch or permanent soil cover
5. Creating drought-resistant soil
Effect of soil organic matter on soil properties
Inefficient use of rainwater
Increased soil moisture
Reduced soil erosion and improved water quality
6. Key factors in sustained food production
Increased plant productivity
Increased fertilizer efficiency
Reduced waterlogging
Increased yields
Reduced herbicide and pesticide use
Increased biodiversity
Resilience
7. The role of conservation agriculture in organic matter deposition and carbon sequestration
Principles of conservation agriculture
Organic matter deposition
Increased carbon sequestration
Annex 1. Soil organisms
Annex 2. Effects of organic matter on soil properties