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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.

Erosion Control

Value Chain
Topography
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

Erosion control measures are practices designed to reduce runoff water and wind erosion that wash away top soil and nutrients, degrading soil biodiversity and reducing agricultural productivity. Erosion is a natural, biophysical process resulting from rainfall, water flows, wind, or storm runoff. Erosion is integral to the formation of soils, however human and animal activity, including agriculture and clearing of land, can accelerate erosive processes, drastically impacting landscapes, soils (e.g. quality) and watercourses. In addition, erosion control measures can contribute to reducing rainfall runoff, increased water infiltration into the soil, and attenuates flooding. The intensity of rainfall is directly correlated with the severity of soil erosion; hence, this is a significant problem across the Southern African region as much of the rainfall in the region is episodic, and intense. To prevent or reduce erosive processes control measures can be incorporated into farming systems to reduce or reverse degradation and potentially restore or improve soil quality. Erosion control measures aim to mitigate soil erosion and improve soil fertility by reducing flow and speed of run-off to avoid soil being washed away. Erosion control can be initiated through a number of interventions, including, but not limited to, intercropping (e.g. planting cover crops), mulch, conservation tillage and reforestation, as well as terracing, soil bunds, etc.. Example: Stone Bunds. Lessons learned from West Africa show that stone bunds constructed along contour lines in fields and in key run-off locations can significantly reduce run-off, particularly in steeper agricultural fields. The stone lines reinforce the soil structure in the field following the contours of the land, reducing the speed and volume of run-off, thereby reducing the likelihood of erosion. This is an appropriate technology to implement on slopes up to 15 to 20 degrees. This is considered a climate smart practice as it maintains soil structure and nutrients, in turn retaining carbon in soil, enabling farmers to adapt to climate changes and sustain agricultural productivity.

Technical Application

Without a topographic survey, this technology may require trial and error to begin with, to see how rainfall and run-off responds to the contouring. To effectively implement erosion control measures the following should be carried out:

  • Step 1: Perform a thorough local study of the landscape, soils, land use and erosive processes that most impact the area: steep slopes, flood plains, high winds etc.
  • Step 2: Source a large number of stones, preferably five to ten centimetres square blocks (from a quarry) or five to ten-centimetre diameter cobbles (from a river-bed). You will need 30 to 50 tonnes of stone per hectare for contour bunds approximately 300 metres long.
  • Step 3: Mark out contours, as discussed in Technical Brief 16 Contour Planting.
  • Step 4: In larger fields with shallower slopes, place stones in rows of two along contour line, interlocking alternately, burying the lower half. The bunds can be between 25 and 40 metres apart. On steeper slopes, stack and bury stones against or in vertical/near vertical walls of contours much closer together (five to ten metres apart) to reinforce them.
  • Step 5: Make sure that stone bunds follow the contours from one side of the field to the other, ensuring that no ‘pour’ points (larger gaps) exist along the way, lining the drainage channel or weir from one contour to the next with stones to avoid or reduce scouring in these locations.
  • Step 6: Following, and if possible, during rainfall events, check the stability of the slope, adjusting stone bunds where necessary.
  • Step 7: At the end of the rainy season and again following harvest, review the performance of the technology, and prepare for the next growing season.
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
Increased water infiltration can extend growing period and mitigates short dry spells. Can reduce flood risk downstream.
Increase Resilience
Increased production due to improved nutrient availability and higher nutrient use efficiency.
Mitigate Greenhouse Gas Emissions
Depending on practices used, may lock more carbon into the soil.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_11_ErosionControl_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Erosion control measures prevent the loss of top soils and nutrients.
  • Can help farmers adapt to changes in climate that have include increased rainfall amounts and intensity.
  • Can reduce the impact of wind erosion.

Drawbacks

  • Erosion is a natural process that can be increased due to human and animal activity.
  • Requires substantial labour inputs to construct bunds and other erosion control measures
  • Maintenance is also needed.

No Tillage

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

No-tillage or reduced-tillage farming involves growing crops without ploughing or reducing the use of machinery in preparing fields for planting. Excessive tillage can have major impacts on soils and the environment including loss of organic matter and soil organisms, increased soil erosion and pesticide runoff, reduced soil fertility, loss of soil structure, etc. Thus, implementing no- or reduced-tillage can help farmers in conserving soil quality and in many cases, increase crop production.

In implementing no-tillage processes, land is not or is minimally disturbed and crop residues are normally left on the soil surface with minimal use of implements. Reduced tillage practices include technological changes such as using more efficient ploughing tools and/or implementing strip-till, zone-till or ridge-till processes. Most reduced tillage systems are implemented in conjunction with cover crops and mulches to protect soil structure.  Tilling by hand or animal means are considered reduced tillage methods.

The adoption of no or reduced tillage practices reduces the amount of fossil fuels consumed by farmers and increases carbon sequestration as soil carbon is not exposed or released in the atmosphere and is thus a climate smart practice.

Technical Application

Switching to no-till or reduced tillage should be planned at least a year in advance so preparations can be made necessary implements can be obtained. Implements should match farm labour availability. You will also need to decide if no till or reduced tillage methods are appropriate based on farm area and desired crops, and start with a small area to determine feasibility. Cereal and legume crops are suitable for no tillage while vegetables and other crops often require some tillage – i.e. reduced tillage.

There are two forms of no-tillage, conventional and organic. Conventional no-tillage includes the application of herbicides to manage weeds, prior to and after planting. Organic no-tillage does not incorporate the use of herbicides, but includes other methods for controlling weeds, including cover crops, crop rotation and free-range livestock. Organic no-tillage is more suitable as it assists mitigate any climate change impacts on the farm.

No till

  • Step 1: Prepare fields using conventional (herbicide application) or organic processes include cover crop (Technical Brief 15) and crop rotation (Technical Brief 09).
  • Step 2: Test soils – aiming to balance nutrient and pH levels. In the case of acidic soils, add small amounts of lime each year.
  • Step 3: Avoid soils with bad drainage, as they become water-logged.
  • Step 4: Level the soil surface, removing uneven areas to assist even seed planting.
  • Step 5: Eliminate soil compaction.

Reduced Till

  • Step 1: This approach is similar to regular tillage, but with significantly less disturbance of the soil. Tilling is only done where needed, and the rest of the soil is undisturbed.
  • Step 2: Strip-tillage or zone-tillage involves tilling and seeding in 15 cm strips leaving areas in-between undisturbed.
  • Step 3: Ridge-tillage involves preparing ridges post-harvest and letting them settle over time to be planted the next seeding period; with ridges not more than 60 cm apart.

More information of each of these specific practices should be sought prior to implementation.

Crop rotation is a complimentary farming method when practicing no-tillage, as it promotes maximum biomass levels for permanent mulch cover, while controlling weeds (with pre- and post-emergent herbicides), pests, and diseases, as well as improving soil nutrition and fertility.

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
Improved soil structure and increased microbial and invertebrate activity in the soil makes nutrients more available to plants.
Increase Resilience
Increased water infiltration and soil biodiversity mitigates the effects of short-term dry spells.
Mitigate Greenhouse Gas Emissions
Locks more carbon in the soil. Reduced ‘passes’ in mechanised systems reduces fuel inputs required.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_12_No%20Tillage_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Increased soil fertility, organic matter and soil structure, and beneficial organisms (earthworms, etc).
  • Reduced compaction of soils.
  • Prevention of soil erosion.
  • Reduction in fossil fuel consumption.
  • Increased soil carbon sequestration.

Drawbacks

  • A positive response can be delayed for up to three years.
  • Effective weed management may require the application of herbicides.
  • Possible decreases in crop productivity if not carried out effectively.

Crop Diversification

Value Chain
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

Many farmers grow one crop repeatedly on the same field over-and-over again. Crop diversification is the cultivation of several crops of a different species or variety (of one crop) in one plot at any given point in time. The main advantage of implementing crop diversification is that it enhances household climate resilience through reducing risk of monocrop failure due to pests, disease, low rainfall and other climate risks.

Employing crop diversification may also provide opportunity of more diversified income sources and dietary diversity. Farmers can simultaneously grow both food crops, fodder and cash crops in an attempt to increase household food security and improve household incomes. There are also indications that crop diversification can increase crop productivity, which for poorer households can have significant positive impacts. For better capitalised farms, return on specialisation may be higher, and will likely not realise the desired returns.

Technical Application

To effectively undertake crop diversification:

  • Step 1: Identify potential market opportunities for alternative crops in local/sub-national/national area.
  • Step 2: Determine crops that farmer wishes to plant and the purpose whether it be household food stuff, cash crop or fodder crop.
  • Step 3:  Establish local demonstration plots at the local level growing non-traditional crops that have market demand and can be incorporated into local farming systems.
  • Step 4: Prepare smaller plot through clearing and weeding. CCARDESA recommends a no tillage approach (Technical Brief 12).
  • Step 5:  Secure seeds of desired crops and follow planting guidance if the crop has not been previously grown. Sow seeds on small plot.
  • Step 6: Track progress of crop and harvest and process as required.
  • Step 7: Discuss cost benefit of growing diversified crops with farmers.
  • Step 8: Farmers should gradually integrate a new crop(s) into their farming system to ensure that they are comfortable with diversifying at a greater scale.
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
Increased yields of rotated crops due to lower incidence of pests/ diseases.
Increase Resilience
Help reduce exposure to pests/diseases and drought/heat stresses and market fluctuations by having greater diversity.
Mitigate Greenhouse Gas Emissions
Potential to lock more carbon in the soil, especially if fallows or cover crops are incorporated.
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_10_Diversification_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Diversification provides opportunity to increase farmer resilience.
  • Substantial opportunity for increased crop productivity
  • Food security, farm income, household nutrient improvements.
  • Scaled up as farmers gain confidence.

Drawbacks

  • Farmer hesitation.
  • Require enough space to introduce additional crop.
  • Failure in diversified variety/species may dissuade farmers in the future.
  • Not encouraged for better capitalised farms, as returns to specialisation can be higher.

Crop Rotation

Value Chain
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

Monocropping in one field for many subsequent years will cause nutrient depletion in that field and lead to less productive returns. Crop Rotation is the process of planning the planting and harvesting of different crops planted on the same field over subsequent growing seasons, allowing less nutrient depletion and if applied effectively, increasing soil nutrients through nitrogen fixing etc. This farming practice also assists with weed control, prevents soil erosion, and is the most efficient and economical way to break the biological cycles of plant pests and diseases, mitigating the effects of pests/disease as they become more prevalent due to climate change and helping farmer diversify crop production.  Research has shown that rotation between nitrogen consuming crops such as maize and nitrogen depositing plants such as soybeans can provide a healthy balance of nutrients. This farming practice is advantageous for smallholder farmers who are less able to leave fields fallow for extended periods of time, as well as for commercial farmers wanting to reduce pesticide use. It is seen as climate smart as it breaks pest and disease cycles, returning nutrients to the soil, thereby supporting more predictable yields in times of climate pressure, and locking more carbon in the soil.

Technical Application

An example of crop rotation is maize, followed by a legume. Grain SA has reported a 12 % increase in maize production following rotation with legumes such as cowpea. Furthermore, the legume yields often increase following rotation with the grain crop, and sometimes responding differently to the crop type. For example, soybean yield has been measured at 20 % higher following sorghum than maize. To effectively undertake crop rotation:

  • Step 1: Determine which cereal crops and legumes are available in the area of interest.
  • Step 2: Prepare land through clearing, weeding. No-tillage approaches are preferable (Technical Brief 12).
  • Step 3: Plant a leafy cereal crop (maize or sorghum) and let the crop mature and harvest once ready. Once harvested, bend stalks over to increase biomass.
  • Step 4: If possible, allow field to fallow for a short period. If this is not possible, practice cover cropping (Technical Brief 15).
  • Step 5: Prepare land again, and sow second crop, usually a legume to improve soil structure and fertility. Harvest crop once ready.
  • Step 6: Repeat process. It is possible to include more than two crops into crop rotation if desired.

It is advisable to carefully monitor yield for demonstration purposes, run test plots if necessary.

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
Breaks pest and disease cycles. Returns nutrients to soil.
Increase Resilience
More predictable yields from each crop and a reduced risk of crop loss.
Mitigate Greenhouse Gas Emissions
Helps to lock more carbon into the soil if fallow/cover crops/green manure is included. Can reduce fertiliser requirements.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_09_CropRotation_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Improved soil fertility and protect soil.
  • Effect and cost-effective way to break pest/disease cycle.Food security/farm income increase.
  • Food security/farm income increase.
  • Nutrient fixing.

Drawbacks

  • Time should be allowed between harvest and planting of different crops.
  • Cultural shift away from traditional crops.
  • Limited market opportunities for non-traditional crops.

Relay Cropping

Value Chain
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

Relay cropping is a form of intercropping where two or more crops are grown simultaneously during part of their life cycles. Intercropping often involves maize and legumes, which increases nitrogen fixing in soils and increased biomass production. The second (or succeeding) crop is planted after the reproductive stage (flowering) of the existing crop but before harvesting. Some of the advantages of relay cropping include better erosion control due to crop cover, reduced spreading of pests and diseases, and crop diversification, plus general soil health. As an added benefit, it mitigates the emission of greenhouse gases through reducing nitrate leaching and increasing carbon sequestration. There is also potential socio-economic benefits for farmers as in many cases relay cropping increases crop productivity.

However, this form of intercropping is not easily implemented in large-scale agricultural systems due to complications in weed control and challenges associated with operating mechanised equipment on fields with relay cropping.

Technical Application

To effectively implement relay cropping, the following steps should be carried out:

  • Step 1: Test/experiment with locally available crops to determine if they are complementary and can grow concurrently - cereal crops and legumes are complementary and can generally grow concurrently.
  • Step 2: Prepare land through clearing, weeding and a no-tillage approach (Technical Brief 12).
  • Step 3: Plant cereal crop first according to normal planting season schedule –during rainy season. Space this cereal crop 70 cm by 50 cm apart.
  • Step 4: Prior to cereal harvest, plant the legume crop between cereal crop rows with spacing based on legume planting efficiencies (researched prior to planting for optimum growth).
  • Step 5: After cereal has been harvested, bend the dried stalks down to provide more ground cover.
  • Step 6: When legumes are ready for harvest, collect the productive pod/seed/bean/nut and leave the stalk uprooted in the field to maximise ground cover.
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
More efficient use of available resources. Increased yield from the same field.
Increase Resilience
If legume – maize/sorghum relays are employed the risk of crop loss is reduces and dietary diversity is enhanced.
Mitigate Greenhouse Gas Emissions
Helps lock more carbon in the soil.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_08_RelayCropping_2019-10-17_0_0.pdf
Benefits and Drawbacks

Benefits

  • Increased and diversified crop yield.
  • Improved soil quality preventing leaching, and introducing nutrients.
  • Increased land cover reducing erosion and improving carbon capturing.
  • Food security/farm income increase.

Drawbacks

  • Weeding makes this approach labour intensive, and planting and harvesting can become less efficient. This requires consideration, especially if women’s workload increases as a result.
  • Carried out precisely to ensure crops are compatible, planting is undertaken at correct times and harvesting is low impact to avoid crop damage.
  • Possible competition between plants for nutrients, water, space, etc.

Intercropping

Value Chain
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

Intercropping is a process of growing multiple crops either together or in proximity to each other on one piece of land, thereby improving crop production, reducing and preventing land degradation and increasing crop output.

There are different methods of intercropping:

  • Mixed intercropping – two or more crops are seeded together and harvested together.
  • Row/strip intercropping – two or more crops planted on the same field but planted in alternate rows.

Crops selected for intercropping should not have similar properties or compete but should be selected to complement one another and be mutually beneficial. For example, deep rooted crops can be intercropped with shallow rooted crops, so as to not compete for water or nutrients. Intercropping helps achieve ecological benefits not possible with monocropping systems. Intercropping is commonly practiced for maize-legume systems, where legumes introduce nitrogen into the soil benefiting maize production and improving soil fertility during crop growth. Furthermore, the legume crops can be utilised for fodder for livestock. This practice is particularly beneficial for smallholder farmers, who can grow multiple crops on small plots to receive multiple benefits including improving production/yields, and increasing household food security. Intercropping is also a climate-smart practice as it mitigates farmer risk to climate variations, through diversifying and increasing crop production, reduces threats of pests and disease, and increases carbon sequestration in soils and biomass production.

Technical Application

To implement intercropping practices:

  • Step 1: Consider soil properties - has the soil been mono-cropped and/or is it leached?
  • Step 2: Consider crop characteristics – will crops be competing for nutrients, water space, sunlight or will they be mutually beneficial adding nutrients
  • Step 3: Prepare land through clearing and weeding. A no-tillage approach is recommended – see Technical Brief 12.
  • Step 4: Select whether the farmer should undertake Mixed Intercropping (Good for smaller plots however plants compete) or Row/Strip Intercropping (crops less likely to compete). See also KP07 – Climate Smart Planting Options for Maize and Sorghum.
  • Step 5: If mixed intercropping is selected, sow two crops simultaneously mixing seeds to together while planting. Harvesting may not be a simultaneous process as different crops have different growth rates and seasons.
  • Step 6: If row/strip intercropping plant two or more crops in the same field but in separate rows patterns. Rows should be spaced 50 cm apart and can have a row of 1:1 or 2:1 ratio of cereal crop to legume.
  • Step 7: Harvest as individual crops require, be careful not to disrupt other crops that have not yet matured.
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
Higher levels of production from the same area of land, due to healthier soils.
Increase Resilience
Reduces losses due to pests and diseases and can mitigate losses due to drought as they increase organic matter, with increased water holding capacity and stimulated bacterial growth.
Mitigate Greenhouse Gas Emissions
Helps lock more carbon in the soil and plants.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_07_Intercropping_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Increased and diversified crop yield.
  • Food security/farm income increase.
  • Nutrient fixing.
  • Food security/farm income increase.

Drawbacks

  • Competition between plants for nutrients, water, space, etc.
  • Increase farmer workload as weeding, planting and harvesting are less efficient. Requires consideration especially if women’s workload increases as a result.

Integrated Soil Fertility Management (ISFM)

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

Integrated Soil Fertility Management (ISFM) refers to a set of agricultural practices that can be applied simultaneously to improve agricultural productivity through increasing soil nutrients and improving crop water use. ISFM includes a broad range of agricultural practices that have all been adapted to local conditions to improve soil nutrients and include the combined application of the following approaches:

  1. Utilisation of organic fertilisers such as green manure, compost and crop residues.
  2. Application of locally available soil amendment methods, such as lime and biochar.
  3. Implementation of techniques like germplasm, agroforestry, crop rotation, intercropping etc.
  4. Limited use of inorganic or mineral fertilisers – seen as the last option in ISFM, when other interventions are not achieving optimal results.

ISFM can be successful for most arable farmers and has been known to double productivity and increase farm-level incomes by 20 to 50 percent if implemented correctly. It focuses on a series of practical approaches to sustainable farm productivity through locally available and affordable options for maintaining soil fertility and productivity, and is seen as a viable approach to reduce over-reliance on inorganic fertiliser. ISFM permits short- and long-term increases in productivity of cash crops and food security, and is considered climate smart as the combined ISFM approach maximises fertiliser uptake and sequestration of carbon in soil, allowing sustainable agricultural intensification driven by improved soil structure and fertility.

Technical Application

In addition to agricultural inputs and the following technical implementation steps, ISFM requires the farmer to consider farm size (land area), and property rights (land tenure) to ensure that investments are efficient and sustainable.

To implement ISFM approaches, the following should be considered:

  • Step 1: Prepare a needs assessment based on understanding of farm challenges – low or declining productivity, soil fertility, low organic content, etc
  • Step 2: Measure fields that require attention to understand volumes of inputs required.
  • Step 3: Develop (or update) an agricultural calendar to use as a platform for discussion between farmer(s) extension officer(s).
  • Step 4: Develop plan and schedule/programme of locally appropriate ISFM interventions between farmer(s) and extension officer(s), obtaining guidance from agricultural suppliers where necessary (lime application, etc). As ISFM is a blended approach, the plan should consider short and medium to long term interventions and outcomes.
  • Step 5: Examine cost implications of the plan, revising where necessary based upon available resources, and if necessary/available apply for credit to fund investments.
  • Step 6: Assess labour requirements within the ISFM plan to ensure that they can be fulfilled, and considerations of gender and youth have been accommodated – women are not expected to do the majority of work, and children are not missing school.
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
Improves soil structure. Increases soil fertility.
Increase Resilience
Aims at sustainable intensification, increasing resilience through more predictable production.
Mitigate Greenhouse Gas Emissions
ISFM has the potential to reduce greenhouse gas emissions owing to greater uptake of Nitrogen-based fertilisers by crops and soil carbon sequestration.
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_06_ISFM_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Applying an ISFM approach can be a sustainable way to improve/rehabilitate soil fertility.
  • ISFM is intended to optimise a combination of CSA strategies to achieve maximum outcomes.
  • The focus should be on leveraging locally available materials and resources to improve productivity.
  • ISFM should be seen as a scalable approach, involving a range of interventions that match available inputs and financial and human resources.

Drawbacks

  • Lack of knowledge of applying the different strategies individually or in combination.
  • Potentially high transaction costs as the process involves multiple interventions.
  • Lack of credit facilities.
  • Availability of labour.

Lime Treatment of Soil

Value Chain
Soils
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

Soil acidification is a widespread problem across southern Africa, often driven by monocropping with cereals and occurring as a result of erosion, compost decomposition and soil leaching. Applying lime to soil is regarded as a key management practice in agriculture to balance pH, enhancing crop productivity, water penetration and absorption of major nutrients by crops. Most crops grow best in soils with a pH between 6.5 and 6.8. Acidity constrains crop growth below pH levels of 5.5. Agricultural lime is limestone mined as a rock that is crushed into various particle sizes ranging from course to fine particles and can be applied in areas where there is high soil-acidity due to high levels of manganese and iron. Lime texture also determines the speed of absorption in the soil; that is, fine-lime reacts more quickly than more granular lime. However, the use of lime must be managed appropriately to avoid losing other nutrients in the soil. This practice is considered climate smart as it assists with adaptation strategies through improvement of soil fertility, whilst improving productivity at modest application rates, noting that annual application is not recommended.

Technical Application

Before applying lime to increase lower soil pH the following should be considered. Equipment required: soil pH testing kit, protective goggles and mask, agricultural lime, shovels/forks/hoes, and disk harrow, drag harrow or hoe if available.

  • Step 1: Use a pH testing strip to determine soil pH levels, making sure to test surface and sub-surface acidity.
  • Step 2: Measure area of land to be treated in order to determine amount of lime for purchase. Application should be calculated as metric tonne per hectare, depending on soil pH and crop. Lime requirements will differ depending on soil type and level of acidity in the soil. Application volumes can be guided by suppliers.
  • Step 3: Purchase lime according to requirements from agricultural supplier. Savings could be realised if purchasing as a group of farmers.
  • Step 4: Apply lime to the soils at least two months prior to planting directly after harvesting to allow the lime to react with the soil, and positively impact the pH.
  • Step 5: Mix lime and soil well in order to reduce soil acidity. This is normally achieved through disk tilling but can be done manually using a drag harrow or hoe. However, this can be an intensive process.
  • Step 6: Test pH prior to planting to ensure amendments have improved soil pH.
  • Step 7: Plant crops. Monitor crop performance, and harvest results with a view to understanding impact of lime treatment.
  • Step 8: Following harvest, test soil pH again.

Application of lime can be part of an Integrated Soil Fertility Management (ISFM) practices.

While a practical solution, this soil amendment should be informed by research and discussion with extension officers and lime suppliers. On-farm storage and management of lime should be included in this dialogue.

Return on Investment Realisation Period
Crop Production
Fodder Production
Farm Income
Household Workload
Food Security
Soil Quality/Cover
Biological Diversity
Crop/Livestock Water Availability
Wind Protection
Erosion Control
Increase Production
Significant increases in productivity.
Increase Resilience
Sustainable improvements to soil fertility. Application is not required every year.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_05_AddingLime_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Lime treatment can assist farmers to balance pH in acidic soils, optimising water and nutrient use for crop plant growth.
  • A practical and effective way to combat the negative effects of erosion, compost decomposition and leaching on soil.
  • Lime does not need to applied to soil every year.

Drawbacks

  • Adding lime to soils is laborious and should not be considered a short-term solution to balancing soil pH.
  • Over-application or overuse of lime can negatively affect soil quality.
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4.61M

Beneficiaries Reached

97000

Farmers Trained

3720

Number of Value Chain Actors Accessing CSA

41300

Lead Farmers Supported