Conservation agriculture (CA) can be defined by a statement given by the Food and Agriculture Organization of the United Nations as "Conservation Agriculture (CA) is a farming system that can prevent losses of arable land while regenerating degraded lands.It promotes minimum soil disturbance (i.e. no-till farming), maintenance of a permanent soil cover, and diversification of plant species. It enhances biodiversity and natural biological processes above and below the ground surface, which contribute to increased water and nutrient use efficiency and to improved and sustained crop production."[1]
Agriculture according to the New Standard Encyclopedia is "one of the most important sectors in the economies of most nations" (New Standard 1992). At the same time conservation is the use of resources in a manner that safely maintains a resource that can be used by humans. Conservation has become critical because the global population has increased over the years and more food needs to be produced every year (New Standard 1992). Sometimes referred to as "agricultural environmental management", conservation agriculture may be sanctioned and funded through conservation programs promulgated through agricultural legislation, such as the U.S. Farm Bill.
The first key principle in CA is practicing minimum soil disturbance which is essential to maintaining minerals within the soil, stopping erosion, and preventing water loss from occurring within the soil. In the past agriculture has looked at soil tillage as a main process in the introduction of new crops to an area. It was believed that tilling the soil would increase fertility within the soil through mineralization that takes place in the soil. Also tilling of soil can cause severe erosion and crusting which leads to a decrease in soil fertility. Today tillage is seen as destroying organic matter that can be found within the soil cover. No-till farming has caught on as a process that can save soil organic levels for a longer period and still allow the soil to be productive for longer periods (FAO 2007). Additionally, the process of tilling can increase time and labor for producing that crop. Minimum soil disturbance also reduce destruction of soil micro and macro-organism habitats that is common in conventional ploughing practices.[2]
When no-till practices are followed, the producer sees a reduction in production cost for a certain crop. Tillage of the ground requires more money in order to fuel tractors or to provide feed for the animals pulling the plough. The producer sees a reduction in labor because he or she does not have to be in the fields as long as a conventional farmer.
Key principles of CA
The second key principle in CA is much like the first in dealing with protecting the soil. The principle of managing the top soil to create a permanent organic soil cover can allow for growth of organisms within the soil structure. This growth will break down the mulch that is left on the soil surface.
2. Food Security Dilemma in SSA
Human population
• Increasing human
population
• Increasing demand for food
• Increasing pressure on
sustainable food security
Arable land area
• Declining arable land area
due to;
- Desertification
- Flooding
- Surface mining
- Accelerated urbanization
- Unfavorable farming
Practices
5. Which of these two fields when planted to maize
will give you a better yield and why?
Forest/fallow
land
Bare savannah
land
6. Conservation Agriculture Concept:
Under forest
Production and recycling of foliage results in biological activity,
humus formation and dark colored top soil with greater number of
soil organisms. Soil is productively active.
Continuously cropped fields
Biomass is largely removed, soil may be tilled several times and
soil is
much drier. Soil may be productively dead.
Traditionally, shifting cultivation has been used to simulate forest
land conditions to maintain the productivity of cropped fields.
7. Traditionally shifting
cultivation was used to
bring back such lands to
arable status
Shifting cultivation is no more
feasible because of increased
pressure on land due to:
- increased human population
and related factors
Q.How then can we improve
and sustain the productivity
of a field such as this one?
8. What is Conservation Agriculture?
Ecosystem approach to regenerative sustainable agriculture
and land use management.
CA is based on the practical application of context-specific and
locally adapted interlinked principles
Implemented along with other complementary good agricultural
and land management practices
Key considerations
- Sustainability
- Environmental friendliness
- Profitability
9. Principles of CA
Key principles
– Little or no soil
disturbance
– Permanent soil cover
– Diversified cropping
systems
– Crop-Livestock integration
10. Principles and practices.
1. Little or no soil disturbance
No soil inversion, no
incorporation of
residue
Direct seeding
through
crop/weed residue
12. Principles and practices.
3a. Practice Crop Rotations/associations
Soyabean to be replaced
with maize next season
Maize to be replaced with
soyabean next season
15. Summary of key features of CA
• No ploughing, disking or soil cultivation (no
turning over or mixing of the soil)
• Crop and cover crop residue stay on the
surface
• No burning of crop residue
• Permanent crop and weed residue mulch
protects the soil
• Crop rotations, intercropping and cover crops
are used to maximize biological controls
• Carefully planned crop-livestock integration
• The closed-nutrient recycling of the
forest is replicated
16. Paradigms of agricultural production
Derpsch 1999
Old
• Soil tillage is necessary to
produce a crop
• Crop residue is a waste product
and must be buried with tillage
implements
• Burning crop residue is allowed
• Bare soil is allowed for weeks
and months
• Strong emphasis on soil
chemical control
New
• Tillage is not necessary for
crop production
• Crop residue is a valuable product
and must remain on the soil
surface as mulch
• Burning of mulch is prohibited
• Permanent soil cover is
essential
• Strong emphasis on biological
soil processes and pest
control
• Strong emphasis on crop-
livestock integration
18. Disadvantages of CA
• Disadvantages mentioned by some
farmers:
– Lower grain yield during the first year
– Higher incidence of pest in the first year
– Too much mulch cover
• Difficult to work through, impedes germination
and emergence
19. Challenges of Introducing CA
• Change of mindset (tradition)
• Farmers, extension personnel, researchers,
government officials and all others involved in
agriculture
• Limited knowledge and capacity of
farmers to implement CA at certain
standards
• Lack of capacity to access print and on-line
information due to limited formal education amongst
smallholder farmers
• Lack of well established source of knowledge
and evidence of CA
• Learning by doing and believing by seeing
• Competition for crop residue
• Livestock feed, building, fuel wood etc.
20. On the hill side
Create contour lines using
simple tools such as the A-
Frame to guide where to
1. Dig canals
2. Establish vegetative
barriers
3. Align stones and trash
lines
4. Create contour bunds
Plant across the slope in-
between
two contour lines ensuring
1. Minimal soil disturbance
2. Soil cover
3. Diversified cropping system
