Modifying Land use changes

Question 1

Mitigation

Answer 1

One type of crop is replaced by another that has higher productivity and can absorb more co2 from the atmosphere

Change farming practices to increase amount of carbon going into soils

Question 2

Grasslands

Answer 2

Grasslands- Global greenhouse gas mitigation potential of 810 million tonnes of CO2. Most carbon would be sequestered in the soil. This can happen by:

Avoiding overstocking of grazing animals.

Revegetation- using legumes increases productivity and creates more plant litter and underground biomass, adding to soil organic content (SOC)

Irrigation and water management can improve plant productivity.

Question 3

Croplands

Answer 3

Mulching- adds organic matter. If crop residues are used, mulching also prevents carbon losses from the system. Some use of animal manure/ chemical fertilisers can increase plant productivity and thus SOC.

Reduce or no tillage (ploughing & harrowing) avoids accelerated decomposition of organic matter and depletion of soil carbon that can otherwise occur. Reduced tillage also prevents the break-up of soil aggregates that protect carbon.

Rotations of cash crops with pasture have the potential to increase biomass returned to the soil.

Using improved crop varieties can increase productivity above and below ground as well as increase crop residues, thereby enhancing SOC.

Question 4

evaluation

Answer 4

Requires reduction in demand for cattle

Good to increase storage of carbon/natural techniques