Presentation on theme: "The Great Hunger of 2008 Rioting in response to soaring food prices recently has broken out in Egypt, Cameroon, Ivory Coast, Senegal and Ethiopia. In."— Presentation transcript:
The Great Hunger of 2008
Rioting in response to soaring food prices recently has broken out in Egypt, Cameroon, Ivory Coast, Senegal and Ethiopia. In Pakistan and Thailand, army troops have been deployed to deter food theft from fields and warehouses.
Intensive tillage, soil erosion, and insufficient added residues Soil organic matter decreases Surface becomes compacted, crust forms Less soil water storage, less diversity of soil organism, fewer nutrients for plants Aggregates break down More soil organic matter is lost Crop yields are reduced Increased erosion by wind and water Hunger and malnutrition result Soil Degradation
… it is our work with living soil that provides sustainable alternatives to the triple crises of climate, energy, and food. No matter how many songs on your iPod, cars in your garage, or books on your shelf, it is plants’ ability to capture solar energy that is at the root of it all. Without fertile soil, what is life? —VANDANA SHIVA, 2008
Building Healthy Soils Fred Magdoff Building Healthy Soils Fred Magdoff
% of aggregates stable to 1.25cm rain/5mins: 2mm sieves Organic management ~70% - high Conventional management ~20% - low Aggregates after stability test
Add organic matter Increased biological activity (& diversity) Decomposition Nutrients released Aggregation increased Pore structure improved Humus and other growth promoting substances Reduced soil-borne diseases, parasitic nematodes Improved tilth and water storage HEALTHY PLANTS Harmful substances detoxified
crop harvest carbon dioxide (CO 2 ) (0.04% in the atmosphere ) erosion photosynthesis root respiration and soil organic matter decomposition carbon in soil organic matter respiratio n in stems and leaves crop and animal residues
a) create soil & above ground conditions for healthy plants with enhanced defenses b) stress pests c) enhance beneficials a) create soil & above ground conditions for healthy plants with enhanced defenses b) stress pests c) enhance beneficials Overall strategies of ecologically-based agriculture
Build internal strengths into agricultural ecosystem Prevention (of symptoms and consequences of weak ecosystem) Routine ecologically sound practices during season to keep plants healthy Reactive management
Preventive management pre-season through planting time (building internal strengths into the system) create soil & above ground conditions for healthy plants with enhanced defenses stress pests enhance beneficials 1. Crop/plant selection & planting management; habitat conservation & enhancement of field and surroundings 2. Build healthy soil (below ground habitat conservation & enhancement)
1. Add plentiful amounts of organic materials from crop residues (including cover crops) well as off- field organic materials such as animal manures and composts. Building Healthy Soil
2. Keep the soil covered with living vegetation and/or crop residue. Building Healthy Soils
Supplies food and habitat for maintaining biodiversity (helps beneficials at expense of pests) Suppresses weeds, insect, and disease cycles Helps grow healthier plants because: a) development of better soil tilth b) supplies nutrients and soil holds water better c) lessens compaction d) etc. Use cover crops or perennial sod cover routinely. Reduce tillage intensity.
3. Use better crop rotations. Building Healthy Soils
4. Reduce tillage intensity.
èMany different reduced till systems — conservation till, ridge till, zone-till, no-till. èBetter planters help. èCover crops can help. èMany different reduced till systems — conservation till, ridge till, zone-till, no-till. èBetter planters help. èCover crops can help.
Building Healthy Soils 5. Use other practices that reduce runoff and erosion.
6. Reduce severity of compaction. Building Healthy Soils
Don’t travel on wet soils. A lasting injury is done by ploughing land too wet. S.L. Dana, 1842 Don’t travel on wet soils. A lasting injury is done by ploughing land too wet. S.L. Dana, 1842
Use controlled traffic lanes (“permanent” beds). Better load distribution. Increase organic matter. Etc.
Building Healthy Soils 7. Use best management techniques to supply nutrients to plants without degrading the environment.
fertilizers, lime, organic amendment s leaching, runoff, and volatilizatio n crops farm-grown crops soil crop residues Farm boundary Nutrient Cycles vs. Nutrient Flows
Healthier Crops Better rotations Reduce compaction Add various sources of organic materials (crop residues, manures, composts, etc.) Cover crops Reduce tillage Control erosion Better nutrient timing, placement, and amounts Use Multiple Tactics