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Supplemental Irrigation

Value Chain
Annual Average Rainfall
Soils
Climatic Zone
Water Source
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Supplemental irrigation (SI) , also referred to as  Deficit Irrigation, is the application of water below full crop-water requirements, generally in drylands to assist crop growth in areas that experience low rainfall (300-500 mm/year). Supplemental irrigation involves adding limited amounts of water to rainfed crops to improve and stabilise yields when rainfall is insufficient for plant growth. Supplemental irrigation is a valuable and sustainable production strategy in dry regions or when experiencing irregular climatic conditions. This practice requires understanding of the yield response to water and the economic impact of loss in harvest. The aim of this technique is to ensure that the minimum amount of water is available during critical stages of crop growth.

Technical Application

To effectively undertake deficit irrigation:

  • Step 1: Determine critical growth cycle of desired crops.
  • Step 2: Experiment with SI strategies to determine critical watering times prior to upscaling.
  • Step 3: Strict management is required to determine the level of transpiration deficiency allowable without significant reduction in crop yields.
  • Step 4: Farmers capable of implementing deficit irrigation must have access to the minimum required water to implement deficit irrigation.
  • Step 5: Farmers must have access to a reliable water source, irrigation systems, including water distribution system, sprinklers and/or drip irrigation system.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Stabilises yield.
Increase Resilience
Adapts to real time rainfall conditions.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_23_SupplementalIrrigation_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Increase crop production in dry areas or those experiencing drought.
  • Assist farmers manage crops at optimal times (low rainfall).

Drawbacks

  • Farmers must have access to enough water to meet minimum water requirements.
  • Require water distribution system that is functional.
  • Close management of crops to ensure that SI is implemented at critical crop production moments.

Solar Irrigation

Value Chain
Annual Average Rainfall
Soils
Climatic Zone
Water Source
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Solar irrigation systems utilise solar energy to pump water to fields and distribute it through drip irrigation or other systems. Solar irrigation is a low-emission agricultural technology that replaces fossil fuel irrigation pumps reducing greenhouse gas emissions. This approach has the potential to reduce energy costs for irrigation and provide energy independence in rural areas. It provides opportunities to increase productivity by shifting from rainfed to irrigated agriculture in some areas. Solar irrigation systems require intensive management and regular monitoring to ensure the sustainable use of water resources. It requires maintenance of solar panels and irrigation equipment but can quickly yield a positive return on investment. Solar irrigation can be implemented for crop irrigation and livestock watering schemes and can improve food security, produce high value crops for sale, reduce energy costs and drive rural development. Although an expensive technology, solar irrigation can introduce significant operational savings if managed and maintained appropriately. It is considered a climate smart option as it can increase productivity, enable farms to adapt t climate changes and improve resilience, and the use of solar power reduces the use of on-grid, or diesel generator power, reducing emissions.

Technical Application

To effectively implement solar irrigation:

  • Step 1: To determine the solar pump system Crop water requirements, location, water sources etc. Do required research. Is water sourced from an above ground or below ground source?
  • Step 2: Source required materials to implement a solar irrigation system from regional or international suppliers including:
    • Photovoltaic (PV) panels to generate electricity (80-300 W system depending on context);
    • a structure to mount the panels;
    • a pump controller;
    • a surface or submersible water pump; and
    • a distribution system or storage tank for water.
  • Step 3: Identify funding sources as initial costs, as well as maintenance costs, must be considered and modelled prior to purchasing a system. There are regional and international solar irrigation producers.   These costs differ dramatically given the complexity of the context, starting at costs approximately USD $2,400 for equipment only. If drilling is necessary the cost increases significantly depending on depth, substrate etc.  Community-based investment, micro-leasing and rental services can be possible funding models to explore.
  • Step 4: Determine whether there is sufficient solar irradiation for the proposed area – consult and specialist; and/or the national meteorological service.
  • Step 5: Identify area suitable to install solar panels. The area should be easily accessible, and all trees/bush should be cleared. To determine most appropriate site and angle of panels, etc, consult an expert.
  • Step 6: The availability of technical expertise must be considered before implementation to ensure that any technical issues do not result in long period of service disruption.

Maintenance costs and expertise should be considered before installing solar irrigation systems. A detailed cost benefit analysis is advisable. Other key technical considerations include: Legal permits to extract water from the source as water extraction may impact community watershed levels.

Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Plants get enough water. Potential for two or more cropping seasons per year.
Increase Resilience
Predictable yields. Higher production equals increased food security/income and resilience.
Mitigate Greenhouse Gas Emissions
Significant reductions in CO2 emissions compared to grid and diesel-fuelled systems.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_22_SolarIrrigation_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Energy independence will introduce significant cost savings for farmers.
  • Solar powered irrigation can significantly boost productivity, due to increased ability to sustainably irrigate crops.
  • Consistent irrigation can help to mitigate climate impacts, and aid adaptation.
  • Reduces operational costs for diesel or on-grid power to pump water.
  • Reduces greenhouse gas emissions.

Drawbacks

  • Solar irrigation is expensive to implement and there are costs for maintenance. Therefore, savings or access to credit will be required.
  • Access to solar equipment, spares and parts, and the transportation of the above may be complicated and/or expensive.
  • Over and above cost and access technology, other issues such as access to land and water sources are important factors.

Saving Seeds

Value Chain
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

The process of saving one’s own seed involves the collection of seeds from the best performing (most yield, largest size, early maturing or other desired traits, etc.) plants from one season to plant them in the next cropping season. The aim of this practice is to select seed from parent plants in the hope that desired characteristics are replicated in the next generation of plants. Seeds that have been selected will likely be adapted to local farming conditions including soil types and rainfall amounts. The seed most likely to carry intergenerational traits (size, colour, water use efficiency, and other biophysical traits) are open-pollinated (those plants pollinated by birds, insects, wind, etc.) seed varieties as they are cross-pollinated by the same type of crop. Different crops have different reproduction cycles with some species flowering or producing seeds annually, biennially or on a perennial basis. Thus, understanding seeding time is important for farmers aiming to save their own seeds. Almost as important as selecting the correct seeds is seed storage, which must be done correctly to avoid spoiling and losses. Seed saving is a cost-effective measure for farmers to employ and helps them avoid having to buy seeds at market on an annual basis. Seed trading or community seed banks provide a climate resilience strategy as they secure farmers access and availability of diverse, locally adapted crops and varieties while enhancing indigenous knowledge. Often crops from hybrid seeds or improved varieties do not generate viable seeds ensuring that seeds cannot be saved and must be purchased on an annual basis.

Technical Application

To effectively undertake seed saving:

  • Step 1: Communicate with national agricultural extension and local farmers regarding seed harvesting timing and practices for local crop species.
  • Step 2: Clear field and sow desired crop using climate smart agriculture practices.
  • Step 3: Monitor plant life cycle and ensure that seeds are extracted correctly and are not spoiled in the process. Employ local expertise to ensure seed harvesting is carried out correctly.
  • Step 4: Post-harvest, seeds should be adequately dried and then transferred to proper storage facilities.
  • Step 5: store seeds in dry, cool, and dark locations. This will prevent them from spoil. Different strategies for seed storage are implemented around the region so local expertise should be sought.
  • Step 6: Ensure that pests are excluded from storage areas to prevent loss or spoil (Technical Brief 61-65).
  • Step 7: Community seed banks or seed trading should be established to allow farmers to integrate different varieties into their farming system that are resilient to local climatic conditions
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Can reduce losses from pests and diseases.
Increase Resilience
More predictable yields.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_21_SavingSeeds_2019-10-17_0_0.pdf
Benefits and Drawbacks

Benefits

  • Climate resilient method for crop diversification.
  • Many farmers have been using this technique for generations and this should be encouraged.
  • Cost effective method for sustainable crop growth.

Drawbacks

  • Attention must be closely paid to plant lifecycle and seeds should be collected at appropriate time.
  • Storage methods should be employed to manage pests and rot.

Crop Variety Selection

Value Chain
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Selecting crop varieties is a key resilience strategy for farmers facing changing climatic conditions. There are two types of seed varieties: traditional varieties and improved varieties. Traditional varieties have been selected by farmers for their special characteristics and due to many years of selecting the strongest seeds over generations, they are generally adapted to local natural conditions. In some respects, these seeds increase the chance of getting a return on investment in stable environments, but are less likely to mitigate GHG emissions. Traditional crop varieties are usually selected by small scale farmers due to their relatively low cost and availability and can be saved and replanted for further growing seasons. Improved varieties are seeds that have been altered by scientific processes to incorporate desired characteristics using techniques such as following pure line breeding, classical breeding, hybridisation and molecular breeding. Desirable characteristics include higher yields, shorter growing seasons, drought resistance, salt tolerance, etc. Improved varieties are selected when facing adverse conditions such as higher temperatures and/or less predictable rainfall and normally result in the efficient use of water reducing use of energy for irrigation systems. While these seeds offer improvements they are usually commercial products and as a result can be expensive. Furthermore, as they are sold by seed companies availability is driven by demand. Most seed companies protect enhancements using  intellectual property rights that legally limit seed saving and replanting of seeds. In fact, many of these seed varieties have been designed to prevent plants to be reseeded. Thus, seed varieties afford farmers the opportunity to incorporate crops that can be planted to exploit their unique characteristics – traditional or improved, assisting farmers to grow crops that are resilient to changing climates to produce crops that are market-appropriate.

Technical Application

To effectively undertake leverage traditional seed characteristics, or improved crop varieties  the following should be carried out:

  • Step 1: Prior to selecting seed varieties, perform a Cost Benefit Analysis (CBA) to identify how crops will perform and their benefits compared to the costs of the seed, considering the following:
    • Local  farming system(s): land availability per household, crops traditionally grown, access to inputs such as fertilisers,
    • Local environmental conditions: soil conditions, disease, pests, climatic conditions, occurrence of flooding/droughts and other natural disasters.
    • How climate change has impacted or will impact the farming system and how crop variety selection can be a climate- smart practice.
    • Local access to seeds – is seed collected at the householder level, do neighbours exchange seeds, do farmers have access to commercially produced seeds?  Are the costs for accessing commercial, improved seeds manageable or prohibitive? The CBA should weigh the benefits of a new seed against perceived actual or transactional costs for selecting a new seed.
  • Step 2: Obtain information and guidance from local experts, lead farmers, and government regarding best varieties to grow.
  • Step 3: Evaluate results of the CBA and select appropriate seeds that match the farm system/requirements, and available financial resources/access to credit.
  • Step 4: Plant test plots of selected seeds to understand if benefits are realised and demonstrate outcomes with farmers, showing possible alternatives and discuss implementation.
  • Step 5: Following full demonstration and discussion with farmers, implement at farm level – planting the first crop in accordance with guidance provided by seed provider, or traditional knowledge.

Consider in-country seed sources to access different varieties through local extension or research services. When buying seeds ensure that the seeds are adequately dry and look for seed that is certified by a national seed laboratory to ensure that the variety is the highest quality possible. Seeds should be properly stored to avoid high temperatures and humid air to reduce chances of early germination.

Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Selecting improved seed varieties allows the farmer to maintain agricultural productivity as the climate changes.
Increase Resilience
Selection of improved varieties may assist farmers adapt agricultural production to assist adaptation to climate change.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_20_CropVarietySelection_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Exploring crop variety is a key way for farmers to grow more resilient crops within the context of changing climatic conditions. Drought resistant or faster maturing varieties, for example, allow you to respond to reduced rainfall conditions.
  • Improved crop varieties have been altered by scientific processes to incorporate desired characteristics.
  • Understanding local context is important when researching the best crop variety for the area.

Drawbacks

  • Improved crop varieties are commercially sold and can be expensive as they often require additional inputs (inorganic fertilisers etc.)
  • Traditional crops have generally adapted to local climatic and landscape conditions, are widely available and are cost effective for local populations; however, these varieties may not be resilient to climatic changes, and are less likely to mitigate GHG emissions.

Weed Control

Value Chain
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Weeds are any unwanted plant species that compete with crops for sunlight, water, nutrients, air and space, hindering crop growth and in some cases are even toxic to crop plants. Weed control measures can be applied in an integrated manner to help prevent the growth and spread of weeds in agricultural systems. An integrated weed management approach aims to restrict weed growth until a crop is well established and can outcompete weeds. This integrated approach includes biological, chemical, cultural and/or physical tactics to combat weed spread and growth and these practices can be more cost effective than herbicide applications. Integrated weed management is climate smart as it combines multiple climate smart practices that increase farmers resilience, limits GHG releases and increases productivity. Options for weed control include crop rotation, intercropping, cover crops (which can be used as green manure or mulch), mulching, seed-bed preparation, livestock grazing, seed/variety selection, mowing, and hand-weeding.

The application of integrated weed control is climate smart as it reduces herbicide application and reduction in machinery usage (i.e. through no-tillage practices).

Technical Application

To effectively undertake weed control measures:

  • Step 1: Review weed control measures - crop rotation, intercropping, cover crops, mulching, seed-bed preparation, livestock grazing, seed/variety selection, mowing, hand-weeding and adjustments to tillage practices - and determine which methods are available and appropriate for the farming system and farmer. Two or more of these techniques can be applied to assist in ensuring farmers have more chance of success. Understand possible negative impacts of each weed control method.
  • Step 2: Improve weed identification knowledge in specific areas.
  • Step 3: Prevent weeds from spreading – clean clothes, animals, machinery, vehicles to limit weed transport; use only well stored/rotted manure (4-5 months) (Knowledge Product 16), include fencing, irrigation and other farm ‘breaks’ where possible
  • Step 4: Apply a combination of weed control methods including – cover crops (Technical Brief 15), mulching, intercropping (Technical Brief 07), crop rotation (Technical Brief 09), livestock grazing, seed selection (Technical Brief 20), mowing, hand-weeding. Try to avoid the application of herbicides, tillage and burning.
  • Step 5: monitor and document most effective weed management strategies for each farmer, and use lessons learned from the area with other farmers where applicable.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Weed control supports agricultural productivity by removing competition while reducing the need for herbicides.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_19_WeedControl_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Integrated weed management involves employing two or more climate smart practices.
  • Reduced consumption of chemicals
  • Cost effective methods that do not require additional inputs.

Drawbacks

  • More time consuming than applying herbicides or other more destructive methods.
  • Strategy requires careful planning.
  • May not be 100% effective.

Terracing

Value Chain
Annual Average Rainfall
Soils
Topography
Climatic Zone
Water Source
Altitudinal Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Terraces are cross-slope barriers that have been cut into slopes offering surfaces that are flat or slightly sloped. Terraces are designed to minimise erosion and increase the infiltration of runoff water. In addition, terracing allows for a maximum of area for farming and cropping by cutting into slopes, creating steps on a hillside. Riser walls are retained by growing trees or grasses, using stones or compacted soil to manage runoff and ensure stability. Terracing involves significant planning and labour to implement and maintain. Labour should be coordinated and planned to ensure that terracing is not carried out in an ad hoc manner, and labour to maintain the terraces is available annually. Terracing is suited to areas with severe erosion hazards, deep soils, on slopes that do not exceed 25 degrees and are not too stony. Community action is often required, as terracing is a landscape-level solution that can only be implemented if all parties agree and convert slopes together. Implementing individual terraces or terraced sections can negatively impact the entire hillside.

Technical Application

To effectively approach to terracing construction:

  • Step 1: Measure slope angle – should not exceed 25 degrees and soils should be at least 0.5 metres deep.
  • Step 2: Plot the contours – see Technical Brief 16 Contour Planting for instructions for staking-out contours, and the diagram below for use of a t-stick to measure the distance between contours.
  • Step 3: Start at the lowest terrace. Dig a trench vertically below the next contour, and then dig outwards to the lowest contour. Remove soil and place downhill below the lowest contour.
  • Step 4: Compact soil on constructed terrace.
  • Step 5: Work should then progress upslope, emptying top-soil on to the terrace below to provide soil for planting.
  • Step 6: Strengthen riser buttress walls (back-walls) with stones, compacted soil, or by planting grass or trees.
  • Step 7: Terrace-end drainage should also be considered, so water does not pool too heavily. The down-field gutters can be lined with stones to reduce erosion

Detailed diagrams and tables for calculating terrace dimensions are provided in Peace Corps 1986, Soil conservation techniques for hillside farming.

Additional guidance can be sought from videos provided by Access Agriculture: SLM02 Fanya Juu terraces. The Kenyan example provided is also up-slope terrace construction but using a different method where a trench is dug, and the loose topsoil is thrown up-hill (fanya juu in Kiswahili) which forms a ridge that flattens over time.

Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Stable slopes are a critical element of maintaining agricultural productivity.
Increase Resilience
Terraces enhance slope stability and reduce soil erosion in the face of changing climates, with changing temperature and rainfall regimes.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_18_Terracing_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Terracing prevents erosion and can act as a rainfed irrigation system.
  • Terracing is a labourious process to implement and takes significant effort to maintain.

Drawbacks

  • Requires professional advice on implementing terracing.
  • If implemented incorrectly, can have negative impacts including more erosion than without terracing.

Contour Planting

Value Chain
Annual Average Rainfall
Soils
Climatic Zone
Water Source
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Contour Planting is a planting strategy for sloping fields, where crop rows follow slope contours rather than planting in rows up- and down-slope. The primary aim of this strategy is to slow the downhill flow of water and encourage the infiltration of water into the soil. Slowing the flow of runoff water reduces soil erosion and therefore also nutrient loss.

Contour Ridges are created by tilling, ploughing or hoeing soil to establish ridges along contour lines, acting as a barrier to downhill water runoff and other erosive processes - the higher the ridge height, the more effective the barrier is to preventing soil erosion.

Contour Strips involves use of vegetative barriers e.g. planting of strips of grass or hedges and other species to secure soil and further prevent erosion. These practices are labour intense and require extension support, especially as contour lines are not straight but follow slope characteristics, correctly identifying contour lines is important and can be done using the ‘low-technology’ options that are identified in the Technical Application section of this Technical Brief.

Technical Application

To effectively undertake contour planting:

  • Step 1: Construct an A-frame that has a plumb-line with a rock hanging down the centre. The base of the A-frame should be 90 cm.
  • Step 2: Calibrate the A-frame on flat ground. Ensure that both legs are on the ground. Mark where the plumb line meets the cross bar.
  • Step 3: On a slope, working perpendicular to the slope, plant one leg of the A-frame and swing the other leg around until the plumb line meets the mark on the cross bar. Drive a stake into the ground where the first ‘planted’ leg is and continue the process across the slope.
  • Step 4: Once the extent of the contour has been staked, tie a string from post-to-post across the slope; this identifies the contour to be planted.
  • Step 5: Plant selected crops, develop contour ridges or plant contour strips along the contour line.
  • Step 6: Subsequent contours should be spaced 3-5 m up or downhill of the preceding contour line. To determine the length between contour lines, measure off the top of each stake to a stake up or downhill with a tape measure or accurately measured third stick.
  • Step 7: Contour ridges can be implemented like Water Spreading Bunds (Technical Brief 28) to form ridges of soil that are formed by tilling or ploughing and can be left after land preparation to further prevent erosive forces. Crops can be planted between these ridges.
  • Step 8: The planting of contour strips can be implemented by planting grasses or hedges 20 m (shallow slopes) to 10 m (steeper slopes) apart up or downhill, similar to Trash Lines (Technical Brief 14). This intercropping allows for erosion control and can be used as fodder for livestock.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Retaining soil structure enables farmers, particularly those planting on sloping fields to maintain productivity.
Increase Resilience
This land management practice aid farmers to maintain soil structure in the face of changing climates and shifting rainfall patterns.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_16_ContourPlanting_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Contour planting prevents erosion on sloped fields and efficiently trap runoff water.
  • Contour planting improved water infiltration and contour ridges improve water retention.
  • Contour planting can be integrated with intercropping contour strips of grass or hedges to help maintain soil structure.

Drawbacks

  • Contour lines are extremely labour intensive and take a significant amount of time to implement.
  • During contour measuring and development, land may be exposed to erosive forces.

Cover Crops

Value Chain
Annual Average Rainfall
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Cover Crops are incorporated into farming systems and planted in between growing seasons with the primary purpose of preventing soil erosion and improving nutrient content, and promoting soil quality in general, rather than being planted as a regular food or cash crop. Cover crops can also be utilised for food stuff, fodder or cash crops; but these outcomes are usually secondary to the main aim of improving/retaining soil quality. An additional benefit from growing cover crops is reduction in weed growth, and pests and diseases; increases in water availability in the soil; and increased soil biodiversity. Additional benefits are recognised from cover crops in areas with steep slopes, as the retained plant cover contributes to reducing erosion. Cover crops can be combined with other practices including intercropping practices and erosion control measures to further enhance soil quality and structure. Incorporating cover crops into farming systems increases farmers resilience to climate impacts through improving soils, reducing fossil fuel consumption, and increasing soil carbon sequestering. Extension guidance can be beneficial when selecting relevant cover crops to achieve the above outcomes.

Technical Application

To effectively implement cover crops:

  • Step 1:  Research whether locally available crops (especially legumes) provide potential options for cover crops.
  • Step 2: Establish a demonstration plot could provide farmers with an example of how cover crops function.
  • Step 3: Plant cover crops between primary crop growing systems to improve soil fertility, quality and nutrients.
  • Step 4: Monitor soil structure, nutrient levels, and field integrity to ensure efficacy.
  • Step 5: Incorporate cover crops with other climate smart practices enhance soil, including: Intercropping (Technical Brief 07), Crop Rotations (Technical Brief 09) Reduced/No-tillage Options (Technical Brief 12) etc
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Cover crops improve soil conditions, providing an enabling environment for agricultural productivity.
Increase Resilience
In changing climates, cover crops can contribute to adaptation strategies, improving soil health.
Mitigate Greenhouse Gas Emissions
Retains and improves soil quality, including carbon sequestration.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_15_CoverCrops_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Cover crops protect soils from erosion and prevent soil nutrient loss.
  • Preventing weed growth, control pests and disease, increase water availability in the soil and increase soil biodiversity.
  • Cover crops may be non-traditional food crops, fodder and/or cash crops.
  • Low cost option for protecting soils and improving soil fertility.

Drawbacks

  • May take time to determine suitable to improve soils.
  • May increase labour demands as new or unfamiliar crops are incorporated into farming systems.

Trash Lines

Value Chain
Annual Average Rainfall
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Trash lines are the incorporation of lines of organic materials spread across contours of hilly agricultural fields - strips of heaped straw or weed materials that have been collected during primary cultivation of the land. Trash lines have been found to direct runoff in field and act as an erosion control method. Through decomposition, the trash line material acts as a type of compost adding nutrients to the soil, adding more organic material year on year, should the farmer continue to build this line. This is a climate smart approach as it contributes to soil health, capturing more nutrients and carbon in the soil, and in turn promoting sustainable agricultural productivity. In changing climates, implementation of this practice can contribute to adaptation strategies.

Technical Application

To effectively undertake trash lines:

  • Step 1: Collect straw, stalks, picked weed or other organic materials from field or surrounding area.
  • Step 2: Establish contour lines using method identified in contour planting (Technical Brief 16).
  • Step 3: Contour lines for trash lines should be spaced between 5 to 10 m apart.
  • Step 4: Heap straw along contour lines on hilly or sloped fields to be approximately 0.5 m wide and up to 0.3 m in height.
  • Step 5: Trash should be piled on annually or as the field is prepared. Lines can be maintained for a few years and then decomposed materials can be mixed into the soil.
Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Contribute to soil health and therefore agricultural productivity.
Increase Resilience
In changing climates, strategies such as this can contribute to retain and improving soil health.
Mitigate Greenhouse Gas Emissions
Helps retain carbon in soil.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_14_Trashlines_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Low cost option for soil and water conservation on sloped fields.
  • Increase of organic materials in fields.
  • Green manure (Technical Brief 02) production in the field.

Drawbacks

  • Increased workload to implement trash lines but low effort to maintain.

Mulching

Value Chain
Annual Average Rainfall
Climatic Zone
Decision Making
Farming Characteristics
Mechanisation
Labour Intensity
Initial Investment
Maintenance Costs
Access to Finance/Credit
Extension Support Required
Access to Inputs
Access to Markets
Gender/Youth Smart
Description

Mulching is the process of introducing vegetative material to the surface of soil in fields to provide soil cover, reduce evaporation, maintaining an even soil temperature and ultimately improve organic content in soil. These materials can include grasses, crop residues, tree bark and other plant materials, even including seaweed if it is available. These materials should be well decomposed, and mixed well into the top soil when the growing season is over. Mulching improves soil fertility by creating a positive soil environment favouring microbial activity and other promoting beneficial organisms such as earthworms, increases moisture retention, stabilises soil temperatures (protecting soils from both heat and cold), reduces soil erosion and restricts weeds. The temperature control keeps roots and plant bulbs cool in the summer and warm in the winter. It can be utilised on all scales of farm, depending upon the availability of input mulch materials. It is considered a climate smart approach as it sequesters carbon in the soil and promotes soil health which in turn maintains agricultural productivity and the ability of a farmer to adapt to climate changes. In some cases, shredded plastic is sometimes used as a synthetic soil cover, but this is not considered climate smart, as it does not integrate organic matter to the soil, instead introducing plastics.

Technical Application

To effectively undertake mulching the following should be carried out. Tools required: shovel, scissors or shears.

  • Step 1: Gather organic materials from the farm and other external sources if possible. grasses, crop residues, wood chips, tree backs and other plant materials.
  • Step 2: Prepare a location to stock-pile mulch material. A large farm will need a substantial area or pit to achieve this. For smaller operations, mulch can be stored in open-topped barrels and bags punctured for air holes. Storage must allow moisture to contribute to the decomposition process, but no become waterlogged.
  • Step 3: Chop/shred organic material and add to the stock-pile. With larger amounts of material, a motorised, or pedal driven chopper/shredder is useful.
  • Step 4: Allow materials to decompose, but do not leave for extended periods as nutrients and minerals will be lost.
  • Step 5: At the end of the growing season, remove any remaining weeds from the soil surface.
  • Step 6: Spread mulch material over the surface approximately two centimetres deep.
  • Step 7: In firmer or more compacted top soils, lightly work the mulch into the upper soil.
  • Step 8: Lightly water area where mulch has been applied.

Mulch should be applied annually as mulching materials will decompose.

Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Flooding
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Improving soil health through practices such as mulching promotes productivity.
Increase Resilience
In changing climates, with shifting rain patterns, and increasing temperatures, practices such as mulching help retain soil health.
Mitigate Greenhouse Gas Emissions
Mulching provides soil cover, promoting retention of carbon in the soil, and also introducing organic content to the soil itself.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_13_Mulching_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Mulching improves soil structure, fertility and quality, stabilising soil temperature and retaining moisture.
  • Mulching can increase nutrient content in the soil.
  • Mulch can contribute to reducing soil erosion.
  • Mulching contributes to preventing weeds from growing.
  • If not used, mulch can be sold to other farmers.

Drawbacks

  • Despite positive benefits, requires substantial labour inputs, hence the need for on-farm labour resources, or the ability to hire.
  • Mulch can spoil if not managed correctly.
  • Considerable quantities of mulch are needed to cover fields.
  • Again, if not managed correctly, can harbour pests, diseases and weeds (seeds).
  • If over-applied, can result in a toxic environment.
Subscribe to to 750mm

Funding Partners

4.61M

Beneficiaries Reached

97000

Farmers Trained

3720

Number of Value Chain Actors Accessing CSA

41300

Lead Farmers Supported