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Biological Properties of Soil, Mr P Reynolds - Coggle Diagram
Biological Properties of Soil
Humification - Process by which soil organic matter (Slurry,FYM) is converted to humus (Improves Soil Sturture)
Humus - Fibrous organic matter in soil, formed from decomposed plant/animal remains. Binds soil together and makes it dark
Rhizosphere - Zone of soil surrounding a plant root where the biology and chemistry of the soil are influenced by the plant root
Soil biomass -Total mass of living organisms in the soil
Microbiome - A community of micro-organisms that inhabit a particular environment
Soil Bacteria
Convert Organic Matter (OM) into Humus (Humification) - Hairy Bacteria – Actinomycetes
Converting (Air) Nitrogen (N2) into Usable forms (Nitrate, NO3 ) for plant growth
Convert Unusable Nitrogen (NH3) into atmospheric (Air) Nitrogen (N2)
Symbiotic relationship:
Where different organisms live in close relationship, both organisms benefit from the relationship (mutualistic relationship)
Bacteria – Plant Symbiosis (Rhizobcteria)
Bacteria supply hard found nutrients to the plant from the soil
They trade these nutrients (N,P,K) for carbon sugars (Glucose) - made by photosynthesis
How - They convert nutrients into more usable forms.
Rhizobacteria form a protection barrier around the root
Happens in the rhizosphere.
Mycorrhizal Fungi – Plant Symbiosis
ncrease absorption of nutrients that are out of reach by rhizobacteria/roots
Fungal threads (hyphae) reach through micropores in soil
Hyphae create a network of nutrient/water absorption
Hyphae penetrate roots to extend the root absorption System
Benefit
Increased Nutrients available to plants
Increased water available to plants (Drought Resistance)
Increased Grass/Crop Growth
Increase feed for animals
Increase LWG/ Milk Production of animals
Increase profit
How to increase Bacteria/Mycrhizzial
Increase Aeration - Drainage– allows oxygen and heat
Correct pH – the pH allows for nutrients to become available
Increase Organic Matter – Nutrient source for bacteria
Plant Diversity – Increases nutrient transfer
Less chemical fertilizer – Kills or reduces bacterial growth
Clover
Science
Rhizobium bacteria lives in the root nodules of clover
The bacteria fixes atmospheric nitrogen into nitrates NO3
The plant produces excess Nitrate which is released into the soil
The grass plant using Mycorrhizal Fungus/Rhizobacteria absorb the nitrate
The plant uses these to make protein and increase grass growth.
Benefit
ncrease Grass Growth (50%) = Increase Milk/LWG
Decrease fertiliser Use – Cost Save
Decrease fertiliser use – Less harm to Environment
Increase Palatability – How Tasty the Grass is
Increase Protein – Clover is high in protein
Earthworms
Convert organic matter into humus = improves fertility by releasing nutrients
Create channels = improve and aid aeration and drainage by burrowing (improve soil structure)
Reduce Compaction – Improve soil structure
Mix layers of soil = organic matter brought into deeper soil levels increasing overall fertility
How to increase Earthworms
Correct pH (6.5 ideal) - Worms do not tolerate acidic soil – add lime
Less Chemical Fertiliser – Fertiiliser is Acidic
Increase drainage - worms prefer drier soil as its warmer
Increase aeration/less compaction – allows worms travel easily
Less ploughing/harrowing – allows worm create a biome
Increase Organic Matter – Add slurry/FYM but do not overapply
Organic Manure
Slurry
Liquid
Low Organic matter - (Silage)
Lower Nutrient Value of N,P,K
Quickly available to plants
High water %
High Leaching/Emissions
Produce gas
FYM
Solid
High Organic Matter – Straw/Silage
High Nutrient Value of N,P,K
Slow Release to plants
Low Water %
Less leaching/emissions
No gas Produced
Importance of soil organic matter
Biological
Biodiversity
Nutrient reservoir
Chemical
pH Buffering (Stay Same)
Cation Exchange
Biological
Soil Structure/Compaction
Water Retention
Factors that affect the organic matter
Soil type
Climate
Topography
Vegetation
Land management practices
How farming affects OM level?
Continuous tillage
Soil bare during winter – OC released to atmosphere
Regular cultivation - Ploughing releases OM and OC
All vegetation harvested
Lower level of plant manures' returned to land - Lower organic matter
Permanent grassland
Grass cover – No Erosion
Minimal cultivation - Less OM/OC to the air
Higher manure levels Animal Manure – Increase OM
How to increase OM/OC in Soils
Grow catch crops
Animals graze – Increase manure – Increase OM
Plant remaining is ploughed into ground – Green Manure – Increase OM
Crop rotation
Increase Green Manure – Increase OM
Add FYM/fertilisers - Increase OM
Plough in straw
Increases Green Manure – Increase OM
Min-till – less intense than ploughing
Decrease loss of OM/OC to atmosphere
Return to permanent pasture
Increase manure from cow manure
Organic Carbon
Soil organic matter contains 58% organic carbon
Carbon sequestration is the capturing, removal and storage of carbon dioxide (CO2) from the earth's atmosphere.
Carbon Cycle
Plants take in CO2 (photosynthesis) and respire (producing CO2)
Animals eat plants, respire (producing CO2 and animal manure)
Microorganisms in soil produce CO2 when they break down manures
Carbon sugars are produced by roots and microorganisms
Some CO2 produced in soil diffuses back into the atmosphere
Soil Capping
reduces aeration – prevents bacteria/earthworms function
increases run-off from surface - increase water pollution
prevents seedlings emerging – decrease growth
Cause
Soil Compaction – Heavy Machinery
Low Organic Matter –
Nitrogen Cycle
Aim: Convert or "Fix" all forms of Nitrogen to Nitrate
Why: Plants can only use Nitrate to grow (Produce Protein)
How: Nitrification - The conversion/fixing of urea and ammonia into nitrates
Science
Nitrifying Bacteria
Nitrosomonas – convert ammonium into nitrite
Nitrobacter – convert nitrite into nitrate
Nitrogen Cycle Steps
Fertiliser (Urea,Ammonia,Nitrite) added to soil
Nitrification by Nitrosomonas/Nitrobacter
Release Nitrate
Atmospheric Nitrogen added to soil
Nitrogen Fixation by Clover Rhizobium
Release Nitrate
Slurry/FYM added to soil -
Mineralisation to ammonia
Nitrification by Nitrosomonas/Nitrobacter
Release Nitrate
Immobilisation – Earthworms/Bacteria use nitrate themselves to grow and keep the nitrates until they die
Excess Nitrogen
Leached into surface water
Denitrification – Nitrate Released Back to Air
Mineralisation – Release of Ammonium as Organic Matter is being Broke down by bacteria
If This Doesn’t Happen:
Denitrification - The conversion of nitrates to nitrogen gas (Air)
Volatilisation – The Quick conversion of urea/ammonia to nitrogen gas (Air)
Mr P Reynolds