What is the goal of Conservation Agriculture?
Conservation Agriculture (CA) aims to conserve, improve and make more efficient use of natural resources through integrated management of available soil, water and biological resources combined with external inputs. It contributes to environmental conservation as well as to enhanced and sustained agricultural production. It can also be referred to as resource-efficient / resource effective agriculture.
What are the characteristics of Conservation Agriculture?
Conservation Agriculture maintains a permanent or semi-permanent organic soil cover. This can be a growing crop or a dead mulch. Its function is to protect the soil physically from sun, rain and wind and to feed soil biota. The soil micro-organisms and soil fauna take over the tillage function and soil nutrient balancing. Mechanical tillage disturbs this process. Therefore, zero or minimum tillage and direct seeding are important elements of CA. A varied crop rotation is also important to avoid disease and pest problems.
Rather than incorporating biomass such as green manure crops, cover crops or crop residues, in CA this is left on the soil surface. The dead biomass serves as physical protection of the soil surface and as substrate for the soil fauna. In this way mineralization is reduced and suitable soil levels of organic matter are built up and maintained.
Is Conservation Agriculture compatible with IPM?
Conservation Agriculture is not only compatible but actually works on IPM principles. CA, like IPM, enhances biological processes. It expands the IPM practices from crop and pest management to land husbandry. Without the use of IPM practices the build up of soil biota for the biological tillage would not be possible.
What is the role of Animal Husbandry in Conservation Agriculture?
Livestock production can be fully integrated into conservation agriculture, by making use of the recycling of nutrients. This reduces the environmental problems caused by concentrated intensive livestock production.
Integration of livestock into agricultural production enables the farmer to introduce forage crops into the crop rotation, thus widening it and reducing pest problems.
Forage crops can often be used as dual purpose crops for fodder and soil cover.
Particularly in arid areas with low production of biomass, the conflicts between the use of organic matter to feed the animals or to cover the soil has still to be resolved.
What are the downsides of Conservation Agriculture?
Conservation Agriculture is generally a win-win situation. That does not mean that there are no problems.
CA may require the application of herbicides in the case of heavy weed infestation.
During the transition phase certain soil borne pests or pathogens might create new problems due to the change in the biological equilibrium. Once the Conservation Agriculture environment has stabilized it tends to be more stable than conventional agriculture. So far there has been no pest problem that could not be overcome in Conservation Agriculture.
What are the attractions of Conservation Agriculture?
Conservation Agriculture attracts different people for different reasons:
- Reduction in labour, time, farm power
- Reduction in cost
- More stable yields, particularly in dry years
- Gradually increasing yields with decreasing inputs
- Increased profit, in some cases from the beginning, in all cases after a few years.
- Better food security
- Practically no erosion (erosion is less than soil build up)
In case of mechanized farmers: longer lifetime and less repair of tractors, less power and fewer passes, hence much lower fuel consumption
Is Conservation Agriculture real?
Conservation Agriculture is being practised on about 45 million ha, mostly in South and North America. Its use is growing exponentially on small and large farms in South America, due to economic and environmental pressures. Farmers practising CA in South America are highly organized (in regional, national and local farmers organizations), and are supported by institutions from North and South America.
What are the issues?
Despite its advantages, CA has so far spread relatively slowly for a number of reasons. Firstly, there is greater pressure to adopt Conservation Agriculture in tropical, rather than temperate climates. Therefore in Latin America it is catching on. It has taken a long time, but over the past 20 years the establishment of a local knowledge base has ensured its spread. In some states of Brazil it is official policy, in Costa Rica the Ministry of Agriculture has a Department for Conservation Agriculture - so in these cases the policy makers have been convinced.
CA has great potential in Africa due to its propensity to control erosion, give more stable yields and reduce labour. There are a number of ongoing initiatives promoting different practices, from conservation tillage up to Conservation Agriculture.
Converting to Conservation Agriculture needs higher management skills, the first years might be very difficult for the farmer, therefore she/he might need moral support (from other farmers or from extension services) and perhaps even financial support (to invest into new machinery like zero-tillage planters). As it requires a complete change of understanding, the scientific and technical sectors often do not support Conservation Agriculture, fearing that they would contradict themselves.
Necessary technologies are often unavailable: in order to try CA, the minimum a farmer needs is a zero tillage planter, which might not be available in the neighbourhood. Buying one without knowing the system or even having seen it, is a risk that few farmers take. Machinery dealers might not wish to promote CA as long as it is not supported by extension. This is partly due to the cost of the equipment but more importantly because the widespread adoption of CA will reduce machinery sales, particularly of large tractors.
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