Unit 5B Flashcards
Modern Agro-Ecosystems Differ From Natural Ecosystems
- Maintained at an early community (successional) stage and tremendous energy input required to keep it that way
- Monoculture/low biodiversity is preferred over biological diversity
- Crops generally planted in rows and lacking spatial complexity or differences
- Intensive tillage reduces soil community function and soil structure, while increasing erosion and water logging
- Use of genetically modified organisms with unknown ecosystem community influences is a concerning outcome
Agricultural Approaches Tend to Contribute to Loss of Soil Physical Properties and Fertility
- Soil erosion
- Enter the waterways
- Little water infiltration
- Too many animals
Tillage activities (plowing)
- can accelerate breakdown of organic matter/decomposition rates; separate and disrupt aggregate complexes that are existing or reduce success in them forming
- 1.7 billion tons lost in USA in one year!
Bare and exposed soils
at risk to erosional processes from rainfall or wind
loss of soil organic matter
arises through burning and removal of crop residue
Poor nutrient cycling
results in the loss of a rich soil community
Pesticides
affect beneficial as well as intended microorganisms
Poor water infiltration and water storage
the aggregate mixture is disrupted and leads to greater dependency on irrigation and risks of pesticide/fertilizer runoff
5 Steps to Soil health
- Cover crop – “armour” on the soil to minimize erosional processes with living roots in the ground as long as possible
- Improve nutrient cycling so that inorganic fertilizer application can be reduced
- Use biological processes to “feed the soils”
- Diversity of plants leads to diversity in the soil community – improving SOM and infiltration
- Crop rotation; polyculture cropping
- Domesticated animals mimic the natural disturbance of grazers historically and with healthier soils the stocking rate can be much greater
- Rotational grazing schedules
Integrated Pest Management
- Use current, comprehensive information on the life cycles of pests and their interaction with the environment.
- This information, in combination with available pest control methods, is used to manage pest damage by the most economical means, and with the least possible hazard to people, property, and the environment.
- Management rather than eradication
- Requires education and effective decision-making
Slash and Burn Agriculture
- Tropical forests are cut and burned to remove debris and use ash as fertilizer to grow crops
- Productive soils last for a short period of time before the farmer is forced to abandon the location
- Forest regrowth fails due to poor soil development
- Use trees to anchor soils, making terrace and alleyway terrains
Apply Intercropping or Alley Cropping Strategies
- Plant a variety of crops in same field
- These may mature at different times or offer shade so less evaporation
- Green litter serves as mulch to suppress weeds and to decompose back into soils
- Microclimate due to shading effect of trees
- Retain, recycle, replenish
Reducing Desertification Through Soil Reclamation
- Reduce soil erosion by terracing and shelter belts of trees and shrubs to improve productivity
- Restore of agriculture activity of plants and crops (reduced the farming and grazing of animals)
- Restore wetlands to improve watershed management
- Build soil organic matter by planting nitrogen fixing licorice to develop soil matrix
- Focus on three pillars of sustainability to ensure the efforts are viable and likely to be adopted by farmers and local stakeholders
- The regeneration of the vegetation lead to lessening of carbon emissions and help to reduce the climate change
The “Green Wall of China”
- the largest ecological project ever undertaken by authorities
- was launched in 1978, aiming to increase human-made tree cover from five per cent to 15 per cent of the country’s vast landmass
- These forests are envisioned to stretch across four million square kilometres of the country’s north by the year 2050
Livestock in Africa Are A Key to Ecosystem Restoration Efforts
- By using livestock and carefully planned rotational grazing, degraded regions in
- Africa are being restored and agricultural activities again productive
