Soil Quality and SustainableAgriculturePresented by :MAISHNAM ANAND SINGHDepartment of Soil Science & Agricultural Chemistry.
Contents• 1. Introduction• 2. Soil Degradation a global crisis• 3. Concept of Soil quality and Sustainable Agriculture• 4. Soil quality Index• 5. Alternative Agriculture : The strategy• 6. Sustainable Agriculture- The Goal• 7. Research needs and Priorities.
India’s Population Tops the World in 2035India’s Population Tops the World in 2035
Shrinking Land AvailabilityShrinking Land AvailabilityRamesh Kumar(2011)
Nutrient Deficiency - AlarmingNutrient Deficiency - Alarming%ofSoilsEssential NutrientsTiwari ( 2008)020406080100N P K S Zn B
Soil degradation at a glance. (from 1 : 250,000 soil map (1985–1995)Classes Area (in M ha)Water ErosionLoss of top-soil 83.31Terrain deformation 10.37Wind ErosionLoss of top-soil 4.35Loss of top-soil/terrain deformation 3.24Terrain deformation/overblowing 1.89Chemical DeteriorationSalinization 5.89Loss of nutrients (En) – (Acid soils) 16.03Physical DeteriorationWaterlogging 14.29OthersIce caps/Rock outcrops/Arid mountain 8.38Total 147.75 Source : NBSS & LUP,2004
What is Soil Quality and Sustainable Agriculture?• Concise definitions for soil quality include “fitness for use” and “the capacity of a soilto function”.Combining these, soil quality is the ability of a soil to perform the functions necessary forits intended use.Sustainable agriculture is the act of farming using principles of ecology, the study ofrelationships between organisms and their environment.It has been defined as "an integrated system of plant and animal production practiceshaving a site-specific application that will last over the long term:• Satisfy human food and fiber needs• Enhance environmental quality and the natural resource base upon which theagricultural economy depends• Make the most efficient use of non-renewable resources and on-farm resources.• Sustain the economic viability of farm operations• Enhance the quality of life for farmers and society as a whole."
Role of soil in the environmentSoil functions include:•sustaining biological Diversity, activity, and•productivity• regulating Water and solute flow• filtering, buffering, degrading organic and inorganic•materials•storing and cycling Nutrients and carbon• providing physical Stability and support
Soil Quality• The ability of a soil tofunction within ecosystemboundaries to supporthealthy plants and animals,maintain or enhance air andwater quality, and supporthuman health and habitation• Soil quality integrates thephysical, chemical andbiological condition of thesoilBiologicalChemicalPhysicalSoil Properties
In 1 teaspoon of healthy soil thereIn 1 teaspoon of healthy soil thereareare…… Bacteria 100 million to 1 billion Fungi 6-9 fungal strands put end to end Protozoa Several thousand flagellates & amoebaOne to several hundred ciliates Nematodes 10 to 20 bacterial feeders and a few fungal feeders Arthropods Up to 100 Earthworms 5 or moreTravis & Gugino -
Ecosystem Services Provided by SoilEcosystem Services Provided by SoilOrganismsOrganisms• Decomposition andmineralization• Contribute to plant nutrition(Rhizobia, Mycorrhizae)• Soil aggregation,aggregate stability, andporosity• Infect, compete with orantagonize pestsActinomycetesPredatory MiteGround and rove beetlesInsect-parasitic FungusEarthworms and otherecosystem engineers
Ecosystem Service:Mineralization and ImmobilizationOrganisms consume SOM and otherorganisms and excrete inorganic wastesInorganicnutrients areusable byplants, and aremobile in soilOrganic nutrientsare stored in soilorganisms andorganic matterOrganisms take up andretain nutrients as theygrow
Soil Disturbance in AgricultureFull tillageMoldboard plow basedMinimum tillageChisel plow/Cultivator
Some Effects Associated with Tillage• Soil organisms moreabundant and more diverse insystems that reduce soildisturbance• Organisms vary in sensitivity• Tillage increases fluctuationsin:– Soil Moisture– Soil Temperature– Crop Residue and SOM• Soil Mixing• Disruption of soil structure• Erosion risk
Soil Organic MatterSoil Organic MatterManagementManagementas a Balancing Actas a Balancing Act•RootsRoots•LeavesLeaves•MulchesMulches•ManuresManures•CompostsComposts•HarvestHarvest•OxidationOxidation•ErosionErosionEquilibrium levelEquilibrium levelof SOM attainedof SOM attainedTillageSoilOrganic MatterGainsLosses
• Such a relationship could take the following form:Soil Quality Index = f (SP, P, E, H, ER, BD, FQ, MI)where;Soil Quality IndexSP = Soil PropertiesP = Potential ProductivityE = Environmental FactorsH = Health (Human/Animal)ER = ErodibilityBD = Biological DiversityFQ = Food Quality/SafetyMI = Management InputsSource: J. F. Parr,.et alAgricultural Research ServiceUS. Department ofAgriculture
• Crop rotations instead of monocultures• Integrated crop/livestock systems• Nitrogen fixing legumes• Integrated pest management• Conservation tillage• Integrated nutrient management• Recycling of on-farm wastes as soil conditioners andbiofertilizers.Alternative Agriculture: The Strategy
• Sustainable agriculture is increasingly viewed as a long-term goal that seeks toovercome prob-lems and constraints that confront the economic viability,environmental soundness, and social acceptance of agricultural production systemsworldwide.Soil Quality: The LinkageStrategy Linkage GoalSustainable Agriculture: The GoalAlternative Agriculture•Skilled Management•Crop RotationsOrganic RecyclingReduced ChemicalInput Crop/LivestockSystems Integrated PestManagementSustainable Agriculture•Productive/Profitable•Energy Conserving•Environmentally Sound•Economically Viable•Conserved Natural•Resources Improved Health/•Food Quality/Safety
Research Needs and Priorities• There is a strong consensus that the establishment of a global network for monitoring,assessing, improving, and restoring the quality of degraded soils is a logical andappropriate goal.• Re-search is needed to quantify the indicators or attributes of soil quality into indexesthat can accurately and reliably characterize the relative state of soil quality asaffected by management practices and environmental stresses.• The best indicator of soil quality probably will differ according to agro ecologicalzones, agro climatic factors, and farming systems.• A high priority for future research is to identify and quantify reliable and meaningfulbiological/ecological indicators of soil quality, including total species diversity andgenetic diversity of beneficial soil microorganisms.• We need to know how these indicators are affected by management practices, andhow they relate to the productivity, stability and sustainability of farming systems.