Soil Carbon Sequestration Methods Pros and Cons PDF

Preview

Summary

Pros and cons of each soil carbon sequestration method...

Description

Soil Carbon Sequestration Methods – Pros and Cons No Till Agriculture Pros      

Increases carbon sequestration Improves soil fertility Reduces emissions from fossil fuels from farming machinery Reduces run of Reduces soil erosion Reduced tilling agriculture is a compromise

Cons  Relies heavily on pesticide use  Can increase nitrous oxide production (280 more potent than carbon dioxide as a greenhouse gas)  Sequestration does not increase indefinitely  Can take 25-100 years for the soil to reach a new carbon equilibrium – until then crop yields may be decreased.  Wetter climates can rely on tilling to dry the soil out, farmers may have to wait longer to plant – detrimental to small farmers.

Breeding Plants with Deeper Roots Pros  

 



Increases carbon sequestration Increasing root length to more than 1m avoids the decomposing bacteria found in the top layers Often correlated with increased above surface biomass Could make crops more tolerant to drought and low nutrient concentrations Has an overall fertilising efect in the soil

Cons    

  

Nitrogen availability may act as a limiting factor May depends on heavy fertiliser use Use of GM can be controversial Deep roots may lead to the production of methane by anaerobic respiration May afect biodiversity May divert the plants energy belowground decreasing plant yields Deep roots may stimulate the activities of soil microbes causing mineralisation of organic carbon resulting in net carbon loss

Biochar Pros        

Increases carbon sequestration Biochar is stable and not easily broken down by microorganisms Works well in peatlands Improves soil fertility Improves water retention Improves soil structure Potentially helpful in degraded soils Potential use in replacing slash and burn

Cons   

Can cause a loss of humus in boreal forests Can stimulate organic matter decay May alter soil alkalinity which may afect fertility

Conversion to Species Rich Grasslands Pros  Increases carbon sequestration  Very productive ecosystem  Including legumes reduces limitation by nitrogen  Improves soil fertility  Improves soil structure  Low maintainence

Cons  Reduces land available for agriculture  Long term efects are not known

Biofuels Pros  Appropriate species and careful management can lead to carbon sequestration  Restores depleted soil organic pools  Reduces reliance on fossil fuels

Cons  Takes away land from food production  Converting land causes carbon release for up to 50 years to begin with

Optimisation of Grazing Pros  Extensive or rotational grazing can enhance soil carbon in some situations (depending on climate and soil conditions)

Cons  High intensity grazing leads to soil carbon depletion, reduces primary productivity and shifts the microbial community to enhance carbon turnover  Lots of variables

Afforestation Pros  Overall has one of the highest mitigation potentials  Can act as flood control in flood prone areas  Provides wildlife habitats  Increases timber and charcoal supply – more jobs  Prevents soil erosion  Increases oxygen content in the atmosphere

Cons  Can lead to carbon loss as the roots penetrate the soil and release carbon  Without proper management can lead to reduction in local biodiversity  Can introduce invasive species...