Cultivation of improved varieties, in combination with mulching, trenches and organic compost in Uganda Source FAO Strategic Objective 5 – Resilience, in FAO Keywords , mulching, trenches, organic composting, improved varieties, Uganda, climate change, disaster risk reduction, dry spells Country of first practice Uganda ID and publishing year 8947 and 2017 Sustainable Development Goals No poverty, climate action, and life on land

Summary This technology describes a combination a cost-benefit analysis of the combination of of good practices for soil and water the four good practices compared to usual conservation to enhance the resilience of practices. banana to increasing dry spells in the central corridor of Uganda, as part Description of the Global Climate Change Alliance (GCCA) 1. Step by step application of the technology project on Adaptation to Climate 1.1 Banana cultivation Change in Uganda Bananas are among the major cultural The combination of good practices include: food crops grown mainly in the southern, • mulching, a low cost practice that consists western and central Uganda and are in covering the soil with locally available becoming a major cash crop, mainly degradable plant materials to reduce cultivated by smallholders. water runoff and evapotranspiration as Banana cultivation is done through well as to improve soil quality; propagation of suckers, and they generally • digging contour trenches for harvesting flower between 8 to 16 months after sucker water during the rainy season while planting, and the first harvest matures three preserving soil quality; to four months later • preparation and application of organic (farmers must therefore wait 11 to compost to improve soil fertility at low 20 months from planting suckers until the costs; and first harvest of banana fruit). • the introduction of high-yielding, resistant Bananas should preferably be planted at banana varieties. the beginning of the rainy season so that This technology briefly introduces plants establish well before the concepts of mulching, trenches, the onset of dry weather organic compost and the introduction of conditions. Banana can be TECA high‑yielding banana varieties and presents spaced at 4.5 m x 3 m. TECHNOLOGIES and PRACTICES for SMALL AGRICULTURAL 1/6 PRODUCERS Crop Production

Bananas grow best under conditions in • reduce runoff and helps water seep into which relative humidity is greater than the soil; 60 percent and with an average annual • slow water evaporation; rainfall of 1 500 to 2 500 mm, but due to • prevent weeds from emerging; the increasing dry spells and delays in rainy • improve organic matter content and soil seasons in Uganda, the use of resistant nutrient status; varieties along with water conservation • provide a beneficial environment for practices, such as application of mulch soil organisms, such as worms and and dig of trenches along the is millipedes, that are important for helping to reduce the negative impacts on biological tillage; and banana yields and rural livelihoods. • regulate the temperature during warmer 1.2 Mulching and colder seasons. Mulch is defined as any material applied 1.2.2 Costs to the soil surface as cover. Mulching Usually, organic matters for mulching is a low cost practice that consists in are available on the as they mostly covering the soil with locally available consist in crop residues. Mulching degradable plant materials to help the therefore only involves some labor to cut soil-crop system to reduce water runoff and bring the crop residues on the soil, but and evapotranspiration, as well as for the in most cases no additional costs to buy mineralization of organic matter, while the mulch itself. counteracting the nutrient loss. 1.2.3 Side effects Figure 1: Mulching on a banana plantation Organic mulches decompose over time, improving soil structure and quality, and returning nutrients to the soil. Increased amounts of organic matter will improve soil tilth and drainage, increase soil moisture retention, reduce soil compaction and attract earthworms. Because organic mulches decompose, they need to be replaced. Depending on the type of mulch used, replacement intervals vary from one to four years.

© FAO/TECA 1.2.4 Major barriers 1.2.1 Socio economic benefits of mulching Organic mulching requires access to some Mulching allow to: crop residues, compost, grass, animal • conserve soil moisture, and therefore manure or leaves. reduce effects of rainfall variabilities and 1.2.5 General recommendations droughts; • improve soil fertility and health; • The general recommendation is to have • reduce direct raindrop impact and a mulching depth of 2 to 4 inches (5 to reduce soil erosion, for instance in case 10 cm). of intense rainfall; • Mulch should be kept at a minimum of

2/6 20 cm away from the trunk of the plant. 1.3.4 Major barriers This space will allow for air circulation • It requires work from farmers to dig and around the base of the plant and help maintain the trenches. avoid potential disease problems that • Less land might be available for can arise from excessive moisture against cultivation. the trunk. 1.3.5 General recommendations 1.2.6 Synergies with other good practices • Sediments should be removed from the • Cover crops. trenches and reapplied to the field. • Minimum tillage. 1.3.6 Synergies with other good practices • Improved varieties. • Organic . • Mulching. • Cover crops. 1.3 Trenches • Minimum tillage. Trenches are dug along the contours of the • Improved varieties. plantation, with the aim of harvesting water • Organic fertilizers. during the rainy season and by keeping it • . around the agricultural land, infiltration and 1.4 Organic composting soil moisture are enhanced. In addition, trenches slow down rainwater runoff and Compost is decomposed organic matter, as a consequence soil moisture is improved such as crop residues and/or animal and soil quality is preserved. This technique manure. Composting contributes to soil is particularly useful in areas where rainfall fertility and soil structure in the long term is sparse, and their applicability fits all kinds due to the increase of organic matter of soils and rain conditions. content of the soil. 1.3.1 Socio economic benefits of trenches Adding compost to sandy soils increases the Trenches allow to: water retention capacity. This means that water remains longer in the soil and thus • harvest water; remains available to plants for a longer time • prevents soil degradation and erosion, in periods of drought. hence, preserving soil quality; and • enhance surface water infiltration. Compost is an organic that can be made on the farm at very low cost, since 1.3.2 Costs most of its ingredients (natural materials This technique only involves labor of either plant or animal origin, including (depending on the soil conditions) to manure, green manures, crop dig the trenches along the contours of residues, household waste and woodland the plantation, which could be the most litter) can be easily found around the farm, expensive input, in addition to the cost of being the farmer’s labor the most important basic construction materials for digging input. the trenches. 1.4.1 Socio economic benefits of organic 1.3.3 Side effects composting No side effects were identified regarding Continued use of organic fertilizers the use the trenches. results in increased soil organic matter,

3/6 reduced erosion, better water infiltration Estimating the cost of the technology can and aeration, higher soil biological be difficult because most of the necessary activity as the materials decompose resources are found within the farm. Labor in soil, and increased yields after the for constructing compost pits is the most year of application. Crops with fertilizer expensive input. Depending on the size, application perform better (better yields) it can be estimated to be equivalent to than the plots with inorganic fertilizers. one person working for a day. Collecting During production of compost manure, organic material and then applying the large amounts of vegetation such as crop compost constitute the additional costs. remains, garden weeds, kitchen and 1.4.3 Side effects household waste, hedge cuttings, and No side effects were identified regarding garbage are put to good use. Benefits the use organic fertilizers. include: 1.4.4 Major barriers • when properly made, compost is It requires work from farmers to create immediately available as plant food; their own compost, prior to its application • compost does not cause excessive weed to the field. Organic composting growth; limitations: • good crop yields can be obtained without the need for extra chemical • Composting is labor intensive and inputs; requires a lot of organic materials. Some • all farmers regardless of their financial have to be gotten outside the farm; abilities, can make and use compost; • The outputs of using compost are not • compost manure can be used in all soils immediate, results appear only after with low fertility; some seasons. • compost manure is especially good in 1.4.5 General recommendations areas that receive low rainfall. in such • If the quantity of organic fertilizer is areas, artificial fertilizers cannot be used limited, it may be banded along furrows effectively because of limited moisture. or spot applied, but the seed needs to be in addition, compost will maintain soil placed away from the fertilizer. moisture, which artificial fertilizers do • The outputs of using compost are not not do; immediate, results appear only after • compost manure is also useful in sandy some seasons and it requires some soils which have poor water holding labor. Farmers see immediate results capacity. with inorganic fertilizers, but these have 1.4.2 Costs adverse impacts at the difference of Compost is made by farmers or bought. organic ones. The challenge is to teach They are usually available on or near the farmers to be patient and consistently farm at very little or no cost other than use compost for six years without labor costs of handling, transportation, or switching if they don’t see immediate opportunity costs of land used for their results. production.

4/6 1.4.6 Synergies with other good practices The CBA calculates the cumulative net • Improved varieties. benefits obtained from 1 hectare of banana • Mulching. over a period of 11 years, as well as the • Minimum tillage. benefit-cost ratio (BCR), which is the ratio • Cover crops. between total discounted benefits and total discounted costs over the appraisal 1.5 Improved varieties period. A 10 percent discount rate is applied 1.5.1 Synergies with other good practices to express the future value of costs and • Mulching. benefits in present terms. • Trenches. Figure 2 provides an overview of the • Organic composting. outcome of the CBA. In particular, it shows • Intercropping. that: 2. Benefits • In affected by dry spell, the All farmers but one said they would replicate cumulative net benefits over 11 years the good practice in the coming seasons from 1 hectare of banana where mulching, since it resulted in higher yields and positive trenches, organic composting and high- impact on income and food security. One yielding varieties were implemented are farmer said replication would depend on almost 10 times higher in farms that adopt income levels. 85 percent of farmers found the good practice package, as compared to that the good practice brought higher non-adopters. The good practice requires banana yields, and about 70 percent of additional labour and some farmers farmers said that their income has increased hired agricultural workers to help with due to the good practice. On a 1 to 5 plantation management activities. On the scale, farmers assigned a 4.4 score to the other hand, the overwhelming increase performance of this good practice in the face in yields due to the crops’ enhanced of dry spell. resistance to dry spells more than One farmer noticed an increase in pests compensated the additional input cost. after the introduction of the good practice. • The benefit cost ratio (BCR) of the good All farmers stated that their knowledge of practice is 2.16, as compared to 1.16 for resilient practices has increased, and most of the existing local practice. them recommended to conduct additional • The low-cost, high-returns features of trainings on banana plantation management. this good practice package make it very suitable for this agro-ecological zone of 2.1 Cost-benefit analysis Uganda. Cost-benefit analyses were conducted 2.2 Added benefits based on quantitative data collected during the monitoring period in in the 2016 dry Added benefits under non-hazard season (Jun-Aug). Data collected from conditions could not be analysed since all good practice plots were compared with farms were affected by dry spell. data collected from control plots within 2.3 Avoided losses the same farms, or from neighboring farms In farms affected by dry spells, the good where the good practice had not been practice package brought net benefits about implemented yet.

5/6 10 times higher than that of the existing temperatures were 3 to 7 °C above local practice. This was largely due to average, causing a reduction in water enhanced drought resilience. availability. The results of the qualitative Figure 2: Cumulative Net Benefits and Benefit Cost Ratios and quantitative analyses conducted of Good Practice and Local Practice (USD per acre per year) based on field demonstration data are 2016 Dry Season (Jun-Aug) summarized hereafter. 3.2.2 Economic (Livelihood strategy) and Social (target group) context Banana producers of the central cattle corridor of Uganda. 4. Necessary basic conditions for a successful implementation • Bananas should preferably be planted at the beginning of the rainy season so that plants establish well before the onset of dry weather conditions.

© FAO/TECA • Banana can be spaced at 4.5 m x 3 m. • Constrains (limiting factors) for the 2.4 Co-benefits implementation of the technology According to farmers interviewed, soil • The implementation of the good practice quality has improved considerably since the implies high capital and running costs. implementation of the good practice. • The good practice requires additional 3. Validation of the practice labor and capital costs (i.e. purchase of 3.1 Geographical area of practice validation improved varieties of banana suckers and materials for digging trenches). Sixteen farms in Kiboga (5), Mubende (2) • Time: farmers will have to wait almost two and Sembabule (9) districts in the central years to have the first harvest of bananas. cattle corridor of Uganda. 5. Further reading 3.2 Context of implementation • Le Groupe-Conseil Baastel. 2016. 3.2.1 Environmental and climatic (period/ Cost Benefit Analysis (CBA) of Climate season) context Change Adaptation and Prioritization During the 2016 dry season, in Agriculture, Environment and Water comprehending the months of June, Sectors in Uganda – Case Studies Report. July and August, the performance of this FAO. good practice package was monitored in 6. Agro-ecological zones 16 farms in Kiboga (5), Mubende (2) and Sembabule (9) districts. • Tropics, warm All the farms were affected by dry spell during the monitoring period. In particular, rainfall was between 50 to 100 percent TECA below normal in August, and land surface TECHNOLOGIES and PRACTICES for SMALL AGRICULTURAL 6/6 PRODUCERS