What is Conservation Agriculture (CA)
It is an integrated agriculture system that aims to produce high crop yields while maintaining soil fertility as well as conserving water through minimum tillage. It is a way to achieve sustainable agriculture and improve livelihoods.
Why Conservation Agriculture (CA)
- Climate changes are forcing farmers to seek new agronomic practices/approaches to ensure crop yields
- Food security is at risk from changing climate patterns. Traditionally, where I live in northern Uganda, the onset of the first season rainfall was between 15th to 20th of March each year and onset of second season rainfall was around 15th to 20thof July each year. Regrettably this has not been the case for several years. Rainfall is no longer predictable. People are trying to farm
without accurate weather information
- Soil erosion by water and wind can result from poor soil management practices such as conventional tillage, burning of crop residues, overgrazing, deforestation and other causes.
- Greenhouse gas emissions from human activities like burning crop residues, transportation and tractors contribute to climate change.
What to do then?
Minimum soil disturbance or Minimum Tillage have been recognized and recommended as one of the fundamental principle/intervention in an attempt to address climate changes in crop farming system
Minimum Tillage refers to reducing the tillage operations to the minimum soil disturbance of 10-12% actually required to plant a crop. This is achieved through the use of hand dug basins, ripping by animal power, tractors and other means.
Basins are semi-permanent/permanent planting stations dug by hand using a hand hoe and allow for targeted application of manure, fertilizer and water. Usually they are 35cm from one hole to the other and 35cm in between the rows. The basin size is 35cm long x 15cm deep x 12-15cm wide. The number of seeds placed in each basin varies from crop to crop. For example, beans can be planted with 7 seeds in each basin while maize is planted with only 3 seeds per basin. In steeply sloped areas the basins should be dug in a zigzag pattern to increase the retention of water run-off and control soil erosion.
Ripping is a method of soil preparation that opens a trench just wide enough for planting and fertilizing. The design of the ripping tool allows the farmer to reach below the hard, compacted soil produced by years of plowing at the same depth. This loosening of the soil below the hard pan allows better water and root infiltration.
Minimum Tillage alone is not enough. Conservation Agriculture also involves the use of soil covers such as mulching using dry mulch materials to avoid transportation of weeds or the use of cover crops to control soil erosion, suppress weeds as well as regulating the water evaporation rate and soil temperature. Practicing crop rotation to improve soil fertility, discourage total burning of crop residue and grass, and encouraging the use of soil and water conservation techniques such as use of stone/grass bands, contouring and other methods are all part of making Conservation Agriculture successful.
Ripping is done in two stages; First ripping is done with just the chisel shaped ripper before the rain. This breaks up the hard pan and also targets the onset of rainfall allowing rain water to more easily enter the soil. The Second ripping is done with the ripper wings attached. This opens up a furrow wide enough for fertilizer and seed application and this is done when you are ready to plant the seeds. It is important to get the “ripping standards” correct. This means that the field is ripped to the right depth, the right spacing and is consistent with the topography. “Never rip along the slope“. Ripping along the slope would promote rapid run off of water instead of minimizing it and could result in soil erosion.
Benefits of Minimum Soil disturbance/Minimum Tillage
- It helps to reduce soil erosion due to water and wind as they are trapped in the basin or along the rip line
- Breaking the soil hard pan will facilitate roots and water penetration. Usually the hard pan becomes a barrier to water and root penetration
- Since the basin/rip lines are done before the rain onset, they facilitate better harvesting of rainwater
- CA practices ensure proper row and plant spacing and correct plant population
- The physical and chemical properties of the soil around the planting areas gradually improve due to accumulation of nutrients
- Facilitate timely planting of crops
- Higher, more reliable crop yields
Challenges
- Digging of basins is labor intensive
- Lack of appropriate tools and equipment. Conservation agriculture requires a certain level of precision so the tools such as rippers, planters, high residue weeders are difficult find
- Crop residues are often fed to animals rather than being left as soil covers and used to enrich soil nutrition
- Lack of technical knowledge among the farmers about Conservation agriculture
- Insufficient resources (Human and materials) to sensitize the community about the benefits of CA
Recommendations
- Training of more trainers in CA
- Support local artisans with training and tools to enable them provide timely repair and maintenance services for the CA tools in the community
- Training of ripping services providers to benefit people who cannot dig the hand basins
Okumu Boniface is the Managing Director of Oxen Clinic Uganda, a company in northern Uganda, that provides training and trainers to help farmers improve crop production through the use of Conservation Agriculture, Draft Animal Power, and the sale of tools and equipment designed for local conditions. Artisan and manufacturing training is also available. Learn more at https://www.oxenclinicuganda.com/