Chapter 11 - Strategies To Increase Agricultural Sustainability

Question 1

Describe the problems with pest control and the sustainable strategies

Answer 1

Problem:
- use of some pesticides have been banned or restricted due to their impacts on non target species
- many pests have developed resistance to pesticides

Strategy:
- cultural pest control = mulching, weeding, crop rotation, barrier crops, culling, biological control, predator habitats
- reduced use of antibiotics

Question 2

Describe the problems with nutrient supplies and the sustainable strategies

Answer 2

Problem:
- current supplies of rock phosphates to produce phosphate fertilisers are non-renewable

Strategies:
- increased use of natural processes to supply nutrients
- recycling of organic matter
- crop rotation
- cultivation of legumes
- conservation of soil biota

Question 3

Describe the problems with energy inputs and the sustainable strategies

Answer 3

Problems:
- manufacture of nitrate fertilisers require large energy inputs from fossil fuels

Strategies:
- reduced use of artificial fertilisers, especially nitrates
- low tillage techniques
- low food miles

Question 4

Describe the problems with water supplies and the sustainable strategies

Answer 4

Problems:
- over exploitation of rivers and groundwater reserves
- soil salinisation caused by using saline irrigation water

Strategies:
- cultivation of low water use crops
- maintenance of soil and soil organic matter
- use of reservoirs and aquifers recharge
- drip irrigation rather than overhead sprays

Question 5

Describe the problems with methane releases and the sustainable strategies

Answer 5

Problems:
- methane produced by anaerobic microbes in rice pads fields and the digestive system of livestock

Strategies
- cultivation of rice varieties that can tolerate drier conditions so fields can be drained earlier
- feeding cattle a high carbohydrate diet and grinding their food first releases methane production

Question 6

Describe the problems with wildlife biodiversity and the sustainable strategies

Answer 6

Problems:
- loss of species that provide important ecosystem services such as lest control, nutrient provision, and pollination

Strategies:
- retain natural and semi-natural existent mrs such as hedgerows, ditches, ponds, woodlands.
- maintinence of soil biota