Steep

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.