Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil...
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Transcript of Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil...
![Page 1: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/1.jpg)
Soil health and fertility
![Page 2: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/2.jpg)
Two statements:
“tillage reduces soil productivity”
“conservation agriculture benefits the soil”
![Page 3: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/3.jpg)
Conventional tillageAdvantages
Machinery is presentIncorporates fertilizersNeeds less managementSuppresses weedsEliminates soil compaction
Disadvantages
Uses more fuelNeeds more labourNeeds more tractorsProvokes more compactionCauses more erosion
![Page 4: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/4.jpg)
Conservation AgricultureAdvantages
Conserves soil humidityUses less fuelRequires less timeNeeds less machineryProvokes less compactionSaves money
Disadvantages
Difficult in clayey soil with bad drainageRequires specialized equipmentRequires high management levelPossibly increases pests in monocrop
![Page 5: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/5.jpg)
Crop yield Soil productivity
Following factors need to be in optimum condition:
Water retention capacitySoil densitySoil porosityCompactionHealth
![Page 6: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/6.jpg)
Main objectives to conserve soil
To reduce soil lossIncrease natural fertilityImprove soil structureLeave the soil in same or improved condition to next generations
![Page 7: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/7.jpg)
Soil basics
m
m
m
m
m
m
Soilparticle
Microbes
Space forH2O & air
m
m
m
m
Humicacid
m
m
Polysaccharides
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Soil problems that occur in conventional systems
CompactionSurface crustingErosionLow water holding capacity
All are caused through a reduction in soil organic matter
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Effects of conservation agriculture on soil properties
Biological properties: organic matter, macro and micro-organisms
Physical properties: water, temperature, porosity, density
Chemical properties: nutrients and acidity
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Carbon cycleCrop
residues
Humus
Immobilization
Proteins andpolysaccharides
Mineralization
Nutrients
Crop
Soilstructure
Microorganismsand soil biota
CO2 + H2O
Decomposition
Soil tillage activities
![Page 11: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/11.jpg)
Organic matter
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Soil depth (cm)
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Micro-organisms
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Harvest Sowing Flowering Harvest Sowing Flowering Harvest
Numb
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Root nodule bacteria
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Mycorrhizal fungi
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![Page 15: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/15.jpg)
Earthworm activity
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![Page 16: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/16.jpg)
Nutrient concentration through insect activity
Soil depth(cm)
Organicmatter (%)
pH Al (me/100g) Ca(me/100g)
Mg(me/100g)
P(ppm)
K(ppm)
0- 5 5.8 5.1 0.18 5.7 2.2 8.9 >2005-10 3.8 5.2 0.17 5.5 2.0 8.5 164
10-15 3.3 4.9 0.49 2.2 1.2 1.4 16215-20 2.7 4.8 0.51 1.2 0.7 1.2 10420-25 2.4 4.8 0.48 1.0 0.7 0.7 8425-30 2.2 4.8 0.43 1.0 0.6 0.5 66
Bothynus sp.chambers
>9.4 5.3 0.17 9.3 3.7 7.6 >200
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Physical properties
Aggregate stabilityBulk density and macroporesWater infiltrationWater storageTemperature
![Page 18: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/18.jpg)
Higher aggregate stability
Mulch layer protects the soil against impact of raindropsNo soil disturbanceOrganic matter induces aggregationIncreased soil densityHigher concentration of calcium and magnesium
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Bulk density and macroporosity
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![Page 20: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/20.jpg)
Water infiltration
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1 2 3 4 5 6 7Time (hours)
Rainw
ater in
filtra
tion (
mm)
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![Page 21: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/21.jpg)
Water storage
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![Page 22: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/22.jpg)
Soil temperature
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Time of the day (hours)
Soil t
empe
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![Page 23: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/23.jpg)
Chemical properties
Ability of the soil to exchange nutrientsAddition of plant nutrientsIncrease in organic matter
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Soil acidity - pH
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![Page 25: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/25.jpg)
Phosphorus content
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![Page 26: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/26.jpg)
Calcium and magnesium levels
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![Page 27: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/27.jpg)
Soil fertility management
Is different in CA systems, because reduction of land preparation may lead to:
accumulation of immobile nutrients reduction of mineralization of nitrogendecomposition of residues may lead to immobilization of nitrogensuperficial application of ammonia fertilizers can acidify the soil surface
![Page 28: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/28.jpg)
Accumulation of immobile nutrients
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![Page 29: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/29.jpg)
Practices to avoid accumulation of nutrients in surface layers
Start with correct nutrient levelsApply part of the fertilizer in bandsAssess nutrient levels at different soil depthsGuard nutrient levels during first 2-3 yearsKeep surface homogeneously covered with residues
![Page 30: Soil health and fertility - Food and Agriculture · PDF fileMain objectives to conserve soil To reduce soil loss Increase natural fertility ... Polysaccharides. Soil problems that](https://reader031.fdocuments.us/reader031/viewer/2022030410/5a9cc7537f8b9aba4a8e6d3f/html5/thumbnails/30.jpg)
Nitrogen management
Three factors can hinder the availability of nitrogen for plants:
immobilizationmineralizationvolatilization
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Practices to avoid lack of nitrogen for plant growth
Allow some time for organic matter to be decomposed before sowingApplication of N-fertilizer before sowingApply N-fertilizer as band placement during sowingUse nitrate fertilizers, because they dissolve easier
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Acidification of soil surface through ammonium fertilizers
Acid formation
NH4
NO2-
Immobilization
Mineralization
Nitrification
O2
Nitrification
H+ + H2O
NO3-
O2
Ammonium fertilizer
Absorbed bycrops
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Lime applicationUsually lime is incorporated into the soil
In CA this is not possible and thus lime is broadcast over the soil coverCover releases organic acids that bring lime to deeper soil layers