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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.

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.

Organic Fertilisers

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 fertility is one of the most critical factors needs to be maintained so farmers can continue to grow productive and nutritious crops, especially in southern Africa where soils are often fragile and lacking in plant nutrients. Soils are often quickly depleted if mismanaged, further exacerbated by natural biophysical processes such as rain, wind and/or heat. The use of organic fertiliser can help farmers to improve soil fertility, as they improve absorption of water and add nutrients into the soil, drastically improving crop production. Organic fertilisers are plant (crop residues) or animal-based materials, such as green manure, worm mouldings, compost, animal waste, and sewage residues, many of which may be readily available on the farm, or within a farming community. These products are potential counters to inorganic fertilisers - artificially manufactured chemicals (synthetic) mined from mineral deposits comprising minerals such as nitrogen, phosphorus and magnesium - which are often costly when few farmers can access credit needed to sustainably access such materials. Organic fertilisers are considered climate smart as they utilise (recycle) readily available organic materials to feed soil and crops simultaneously as they add nutrients into the soil and condition it, and thus increase productivity and resilience, while inorganic fertilisers add nutrients to the soil only, and are often expensive.

Technical Application

Organic fertilisers can be produced at the household level or purchased. On-farm production includes stock-piling animal manure, crop residues, and other organic waste, following appropriate guidance for processing and usage.

To apply organic fertilisers the following should be considered:

  • Step 1: Assess field area where fertiliser is to be applied, and fertiliser needs – poor crop performance, low organic matter content, etc.
  • Step 2: Ensure that fertiliser is available in sufficient quantities for application in all target or priority fields.
  • Step 3: Ensure organic fertiliser – especially green manure/crop residues – are broken-down/chopped to aid breakdown/integration with soil.
  • Step 4: Monitor soil nutrient levels and crop performance (in the light of prevailing climatic conditions) to determine success of organic fertilisers.
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
Improves efficiency and crop yields.
Increase Resilience
Greater production and efficiency results in increased food security and resilience.
Mitigate Greenhouse Gas Emissions
Locks more carbon in the soil and reduces need for inorganic fertilisers.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_04_OrganicFertilisers_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • Fertilisers can help restore soil nutrients, improve soil conditions and improve crop production if applied correctly.
  • Organic fertilisers are plant or animal materials that can be produced locally or purchased for application.
  • An appropriate strategy in rural and low-income communities with small holder farmers that can generally not afford synthetic pesticides and inorganic fertilisers.
  • Collective action can minimise the financial cost of implementing organic fertilisers, in terms of shared transportation and storage costs, as well as bulk purchasing power.
  • Use of organic fertilisers can help avoids the leaching of inorganic fertilisers into waterways, which can result in eutrophication.
  • Where farmers do have access to financial resources and/or credit, organic fertilisers should be used in combinate with inorganic application.

Drawbacks

  • Manure and other types of organic fertilisers require management, and relevant storage mechanisms. If not stored correctly, investment can be lost as nutrients can be lost due to exposure to the elements.
  • It can be costly to transport if sourcing from off-farm
  • Weed seeds can be present in manure, increasing labour requirements for weeding.
  • If not produced on-farm, organic fertilisers, while beneficial can require access to sustainable financial resources or credit to implement correctly.
  • Requires extension support to ensure that fertiliser requirements are being met.

Biochar

Value Chain
Annual Average Rainfall
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

Biochar refers to a fine-grained charcoal, rich in organic carbon compounds, used to improve soil quality through enhanced nutrient and water holding capacity of soil, reducing total fertiliser needs. Biochar is a stable solid produced from the controlled burning of plant and waste feedstock, including wood chips and pellets, tree bark, crop residues (straw, maize stovers, nut shells and rice hulls), grain, sugarcane bagasse, chicken litter, diary manure, sewage and paper sludge. Biochar is used as a soil conditioner as part of soil amendment strategies, improving the workability of soil, particularly those with heavy clay components.. The application of biochar to soil is a strategy to minimise the climate and environmental impact of cropland systems, such as the application of synthetic fertilisers, and improve soil quality through enhancing its physical-chemical characteristics. This agricultural practice improves soil structure, nutrient cycling and water retention, and the high stability of biochar carbon compounds contributes to the reduction of green-house gas emissions by increasing carbon sequestering in soils. Biochar is shown to be effective in improving soil conditions in acidic, sandy and clay-rich soils, improving the physical characteristics, and is classified by the FAO classifies as an adaptation strategy and contributes to mitigation of climate change as the processes captures and stores carbon in soils create other secondary socio-economic benefits, through additional fuel sources, and economic opportunities for production. Biochar can either be purchased or produced on-farm on a small or large scale. Collective action may benefit communities, so discussion with neighbours and community leadership may be necessary, especially if a biochar.

Technical Application

To effectively implement biochar the following should be carried out. Tools required – shovel and a metal sieve.

  • Step 1: Acquire charcoal from local vendor, and sieve or grate the charcoal into fine material in a pile. Biochar should not be applied to soil directly after production. It should be allowed to ‘rest’ for one to two months.
  • Step 2: Rotate the pile every 2-days for a period of up to 10-days (total).
  • Step 3: Prior to application, aim to wet (but not waterlog) biochar stock with water or preferably urine. If done when still warm, it will fracture the charcoal, increasing surface area for absorption.
  • Step 4: Spread the biochar evenly across soil prior to planting and let it settle or mix with the top layer of soil. One to three kg/m2 is recommended, depending on the degree of soil required.
  • Step 5: Regularly monitor soil pH, water retention and soil texture, keeping records if relevant to ensure that improvements are realised, and negative impacts do not arise.

Biochar can be produced on-farm, but will require collection of plant and waste feedstock (see above). Biochar can be produced on-farm using a trench. A biochar trench is a dug recess where crop residues are burned to create charcoal. Tools required are a shovel and one or more roofing sheets (one-metre long).

  • Step 1: Dig trench 50 to 70 cm deep, and one to two metres long, ensuring that roofing sheets fully cover the trench void.
  • Step 2: Start a fire in one end of the trench, throwing in loose crop residue or other organic waste, keeping the fire under control (not creating large flames and smoke).
  • Step 3: Keep fire burning until trench is full of char.
  • Step 4: When the trench is full, and flames have burned-out, cover the trench with the roofing sheet, sealing edges with loose soil, trampling it down to ensure closure.
  • Step 5: Leave the covered trench for five to six hours to extinguish.
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
Makes nutrients more available to plants and increases water retention. Can increase pH.
Increase Resilience
Improves water retention. Remains in the soil for a long time.
Mitigate Greenhouse Gas Emissions
Capturing carbon in soils thereby reducing emissions.
Additional Information
PDF File
/sites/secondsite/files/tb/CCARDESATechnicalBrief_03_Biochar_2019-10-17_0.pdf
Benefits and Drawbacks

Benefits

  • The production and application of biochar reduces GHG emissions of cropland systems due to the properties of the biochar itself, and reduction in the application of synthetic fertiliser.
  • Can improve physical and chemical composition of soil, especially in acidic, sandy and clay-rich soils; soil nutrient cycling and water retention.
  • Can reduce fertiliser and irrigation requirements.
  • Potential socio-economic opportunities for biochar producers, if not produced on-farm.
  • Improved food security from production of secondary fuel source.
  • Provides an appropriate and sustainable mechanism for dealing with crop residues and biomass.
  • Can be mixed with compost during application to increase performance of soil amendments.

Drawbacks

  • Requires sustainable non-wood supply of organic matter for production so as not to increase deforestation.
  • Long-term impacts not fully understood.
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Funding Partners

4.61M

Beneficiaries Reached

97000

Farmers Trained

3720

Number of Value Chain Actors Accessing CSA

41300

Lead Farmers Supported