The challenges of coffee cultivation in Africa – What is the major problem facing coffee farmers in East Africa?

The tropical environment fitting Arabica coffee production ranges from 1100 – 2100 meters above sea level, which perfectly fits the Kenyan coffee production zone. This elevation in the Kenyan highlands is characterized by deep volcanic soils in gentle and steep slopes where during heavy rainfall, the soils are subject to heavy soil erosion (Gachene et al., 1997). Kenya mainly produces Arabica coffee, which is considered an important cash crop for the country’scountry’s economy, with a global appeal due to its distinctive taste and deep aroma (Migwi et al., 2017). At introduction in the early 1930s, coffee was found to be well-suited to the climatic conditions, which features 2 rain seasons distributed between March-May (long rains) and October to December (short rains), helping in the coffee flowering and maturation (CRF, 2012). Coffee flowering is favored by the long rains in March to May, while the short rains favor coffee cherry maturation from October to December (CRF, 2012).

The rapid population growth has continued to put more pressure on available land for the crop (coffee) and livestock production, making synergistic adaptation to increase farmers’ resilience to the ever-increasing climate change impacts more urgent (Velmourougane & Bhat, 2017). The East African tropics have been facing increasing frequencies and duration of droughts which has further pushed farmers into poverty from missed cropping seasons and loss of livestock from lack of fodder (Agesa et al., 2019; Ayantunde et al., 2005). Concerning climate-smart land intensification that caters to crop and livestock production for smallholder farmers, there is a need for optimization while considering the land equivalent ratio (LER), where optimal land use includes space optimization using legume fodder cover crops (Amanullah, 2016).

Climate change challenges in East Africa

Varying rainfall patterns (impact of climate change) have affected the natural coffee production cycles associated with drastic and unpredictable rainfall shifts. This affects coffee flowering and maturation (Bunn et al., 2015). Delays in the onset of the rains delay flowering, while delays in the onset of the short rains interfere with cherry maturation, whereby inadequate rains cause the coffee berries to be subject to fruit abortion without maturing with consequent economic losses (Kabubo-Mariara & Mulwa, 2019). There is urgency in looking at the impacts of climate-smart agriculture practices in relation to coffee sustainability in the face of increasing climate change impacts (Abegunde & Obi, 2022).

Climate change impacts have heavily affected the climatic patterns previously enjoyed by coffee farmers, with rainfall shifting onset, cessation, intensity, and duration, with the worst consequences being faced during heavy rains at the onset of the rainy season (Quiroga et al., 2020). The months of January to March are often characterized by dry periods based on the weeding practices on the coffee, resulting in the loosening of the soils, making them highly prone to soil erosion if hand or herbicide weeding had been practiced (Jia et al., 2017). At the onset of the rains, when the soil from excessive exposure to the sun is greatly loosened, it suffers massive soil erosion from the heavy downpours since its ability to absorb the water is reduced (Jia et al., 2017).

Some case studies have found that over 21 tons per hectare (8.5 tons per acre) per year of topsoil are lost from soil erosion impacts in the Ethiopian highlands (Gao et al., 2016; Luo et al., 2020). This leads to a loss of organic matter and soil fertility resulting in poor crop yields and damaged soil structure (Rahn et al., 2014). The decrease in soil organic matter forces farmers to compensate with heavy synthetic fertilizer inputs to try and increase yields despite the vicious cycle repeating itself (Henault et al., 2012; Ires, 2021). On the other hand, many smallholder livestock farmers are already adversely affected by the impacts of climate change with the increasing scarcity of livestock feed resources in sustaining their dairy production, whereby the coping mechanism has been heavily negatively impacted (Tadesse, 2018).

Weed Challenges in Coffee production

Different weed species pose a significant challenge to coffee production due to their competition for nutrients, serving as hosts for some crop pests and reducing the speed of operations in coffee farms (CRF, 2012). Annual, semi-annual, and perennial weeds have been the dominant challenge in coffee plantations due to the wide spaces between the bushes planted at 2.7 x 2.7 meters (8.9 x 8.9 feet) apart that allows adequate photosynthetic radiation from the sun. This supports weed growth and thus comprises a significant cost implication for coffee farmers (Migwi et al., 2017).

Many smallholder farmers engage in intensive weed control practices using handheld tools such as hoes and machetes to control the weeds. Delayed weeding can result in coffee yield penalties (Shackelford et al., 2019; Shao et al., 2021). Additionally, if annuals and semi-annuals are left to produce seeds, the weed seed bank is enriched, and weed problems are expected for the following seasons (CRF, 2012). This continues the vicious cycle that makes the farmers face the cost implications season after season (Kinama et al., 2007). 

Medium-sized and large coffee estates have been using herbicides to control weeds (Migwi et al., 2017). The most dominant herbicide is glyphosate which clears all weeds and leaves the soil bare with little weed competition (Lopez-Vicente et al., 2020). Continuous use and reliance on glyphosate have already been documented to cause resistance of specific weed species, with farmers using even higher herbicide dosages in their hope of eradicating these weeds (Migwi et al., 2017).

Glyphosate has already been indicated to have deleterious impacts on both humans and beneficial species, such as bees, creating the need to evaluate alternatives for reducing these negative impacts (Gunstone et al., 2021). Glyphosate breakdown has been studied and been found that some carrier molecules, such as MCPA and surfactants, do not breakdown entirely and are susceptible to being carried by water during rainfall which is accelerated by soil erosion (Ndiritu et al., 2021).  

Herbicide usage and the negative impacts on the ecosystem and farmer’s health

Herbicide application in many areas affects, among others, the workers’ welfare. While there are some subscribed protective clothing, most herbicide applicators do not use them (Gunstone et al., 2021; Motta et al., 2018). This leaves them exposed to dangerous chemicals that affect their health systems sometimes, even without observing them (Motta & Moran, 2020). Many cases of diseases associated with herbicides are being regularly documented, whereby a small fraction comprising some illiterate applicators get affected, and these cases mainly comprise unreported incidences (Mertens et al., 2018).

Coffee production depends on bee pollination for the successful setting of flowers due to its nature of being only 5% self-pollinated (Farina et al., 2019a). The presence of some flowering plants, including some weed species, is an important source of bee forage when coffee is not flowering (Klein et al., 2003). The need for pollinators such as bees is therefore essential for the successful fruit setting of coffee production, considering that coffee berries are the end product that farmers desire (Fikadu, 2020).

Excessive herbicides have been attributed to the elimination of several weed species that serve as a source of bee forage, thereby reducing their food sources (Medeiros et al., 2019). Some ground-dwelling bees rely on shade and protection from vegetation; therefore, bare grounds or excessive soil disturbance results in the loss of their habitat (Klein et al., 2003). Aquatic life has also been documented to be affected by glyphosate resulting from runoff from the farms during heavy rains (Gunstone et al., 2021).

Coffee production land practices and greenhouse gas emissions

The IPCC has attributed the greenhouse gas emissions from agriculture at 30%, mainly comprising the use of synthetic fertilizers, bare soils, and methane emissions from livestock production practices (IPCC, 2022). The increasing impacts associated with the emissions from agricultural production will therefore require the development of practices that reduce the overall greenhouse gas emissions as part of the adaption process of agricultural production systems (Delgado et al., 2021; Elhakeem et al., 2019).

The reduction of synthetic fertilizers application in coffee, especially as a source of nitrogen, requires reorientation and the reduction in activities that leave the soil bare, which are the main areas that have been seen as possibly reducing these land-based emissions are urgently needed (Acharya et al., 2008). Ecological practices such as the adoption of legume cover crops have been shown to increase farmers’ adaptation capacity and improve their ability to cope with climate change (Acosta-Alba et al., 2020).

References.

Abdalla M., Hastings, A., Cheng, K., Yue, Q., Chadwick, D., Espenberg, M., … Smith, P. (2019). A critical review of the impacts of cover crops on nitrogen leaching, net greenhouse gas balance and crop productivity. Global Change Biology, 25(8), 2530–2543. doi: 10.1111/gcb.14644.

Abegunde, V. O., and  Obi, A. (2022). The Role and Perspective of Climate Smart Agriculture in Africa: A Scientific Review. Sustainability, 14(4), 2317. doi: 10.3390/su14042317.

Acharya G. P., Tripathi, B. P., Gardner, R. M., Mawdesley, K. J., and  Mcdonald, M. A. (2008). Sustainability of sloping land cultivation systems in the mid-hills of Nepal. Land Degradation and  Development, 19(5), 530–541. doi: 10.1002/ldr.858.

Acosta-Alba I., Boissy, J., Chia, E., and  Andrieu, N. (2020). Integrating diversity of smallholder coffee cropping systems in environmental analysis. The International Journal of Life Cycle Assessment, 25(2), 252–266. doi: 10.1007/s11367-019-01689-5.

Addis Tadesse, Endale Taye, Alemseged Yelma, and  Sisay Eshetu. (2016). Management of Desmodium for efficient Weed control and soil moisture conservation to improve production of Coffee arabica at Gera, Southwest Ethiopia. World Journal of Biology and Medical Sciences, 3(1), 93–100.

Adugna Tolera and Aster Abebe. (2007). Livestock production in pastoral and agro-pastoral production systems of southern Ethiopia. Livestock Research for Rural Development, 19(177), 12.

Agesa B., Onyango, C., Kathumo, V., Onwonga, R., and Karuku, G. (2019). Climate Change Effects on Crop Production in Kenya: Farmer Perceptions and Adaptation Strategies. African Journal of Food, Agriculture, Nutrition and Development, 19(01), 14010–14042. doi: 10.18697/ajfand.84.BLFB1017.

Aktar, W., Sengupta, D., and Chowdhury, A. (2009). Impact of pesticides use in agriculture: Their benefits and hazards. Interdisciplinary Toxicology, 2(1), 1–12. doi: 10.2478/v10102-009-0001-7.

Alvarez, A., del Corral, J., Solís, D., and Pérez, J. A. (2008). Does Intensification Improve the Economic Efficiency of Dairy Farms? Journal of Dairy Science, 91(9), 3693–3698. doi: 10.3168/jds.2008-1123.

Alyokhin, A., Nault, B., and Brown, B. (2020). Soil conservation practices for insect pest management in highly disturbed agroecosystems – a review. Entomologia Experimentalis et Applicata, 168(1), 7–27. doi: 10.1111/eea.12863.

Amanullah, D. (2016). Land equivalent ratio, growth, yield and yield components response of mono-cropped vs. Inter-cropped common bean and maize with and without compost application. Agric. Biol. J. North America, 7, 40–49.

Anantasook, N., Wanapat, M., Cherdthong, A., and Gunun, P. (2015). Effect of tannins and saponins in Samanea saman on rumen environment, milk yield and milk composition in lactating dairy cows. Journal of Animal Physiology and Animal Nutrition, 99(2), 335–344. doi: 10.1111/jpn.12198.

Andrews, M., James, E. K., Sprent, J. I., Boddey, R. M., Gross, E., and dos Reis, F. B. (2011). Nitrogen fixation in legumes and actinorhizal plants in natural ecosystems: Values obtained using ¹⁵ N natural abundance. Plant Ecology and Diversity, 4(2–3), 131–140. doi: 10.1080/17550874.2011.644343.

Animut, G., Puchala, R., Goetsch, A. L., Patra, A. K., Sahlu, T., Varel, V. H., and Wells, J. (2008). Methane emission by goats consuming diets with different levels of condensed tannins from lespedeza. Animal Feed Science and Technology, 144(3–4), 212–227. doi: 10.1016/j.anifeedsci.2007.10.014.

Archimède, H., Eugène, M., Marie Magdeleine, C., Boval, M., Martin, C., Morgavi, D. P., … Doreau, M. (2011). Comparison of methane production between C3 and C4 grasses and legumes. Animal Feed Science and Technology, 166–167, 59–64. doi: 10.1016/j.anifeedsci.2011.04.003.

Ayantunde, A. A., Fernnadez-Rivera, S., McCrabb, G., and International Livestock Research Institute. (2005). Coping with feed scarcity in smallholder livestock systems in developing countries. Nairobi, Kenya. International Livestock Research Institute.

Bain, C., Selfa, T., Dandachi, T., and Velardi, S. (2017). ‘Superweeds’ or ‘survivors’? Framing the problem of glyphosate resistant weeds and genetically engineered crops. Journal of Rural Studies, 51, 211–221. doi: 10.1016/j.jrurstud.2017.03.003.

Baloyi, J. J., Hamudikuwanda, H., and Ngongoni, N. T. (2009). Estimation of true intestinal digestibility of dry matter, nitrogen and amino acids of cowpea and silverleaf desmodium forage legumes and Brachystegia spiciformis (musasa) browse legume. African Journal of Range and Forage Science, 26(2), 51–57. doi: 10.2989/AJRFS.2009.26.2.1.844.

Boadi D. A. and K. M. Wittenberg. (2012). Methane production from dairy and beef heifers fed forages differing in nutrient density using the sulphur hexafluoride (SF6) tracer gas technique. Canadian Journal of Animal Science, 82, 201–206.

Beauchemin, K. A. (2009). Dietary mitigation of enteric methane from cattle. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, 4(035). doi: 10.1079/PAVSNNR20094035.

Benchaar C., C. Pomar, and J. Chiquette. (2001). Evaluation of dietary strategies to reduce methane production in ruminants: A modelling approach. Canadian Journal Of Animal Science, (Reduction Of Methane Emissions From Ruminants), 563–574.

Bergtold, J. S., Ramsey, S., Maddy, L., and Williams, J. R. (2019). A review of economic considerations for cover crops as a conservation practice. Renewable Agriculture and Food Systems, 34(1), 62–76. doi: 10.1017/S1742170517000278.

Blanco‐Canqui, H., Claassen, M. M., and Presley, D. R. (2012). Summer Cover Crops Fix Nitrogen, Increase Crop Yield, and Improve Soil–Crop Relationships. Agronomy Journal, 104(1), 137–147. doi: 10.2134/agronj2011.0240.

Blanco‐Canqui, H., and Ruis, S. J. (2020). Cover crop impacts on soil physical properties: A review. Soil Science Society of America Journal, 84(5), 1527–1576. doi: 10.1002/saj2.20129

Blanco‐Canqui, H., Ruis, S. J., Proctor, C. A., Creech, C. F., Drewnoski, M. E., and  Redfearn, D. D. (2020). Harvesting cover crops for biofuel and livestock production: Another ecosystem service? Agronomy Journal, 112(4), 2373–2400. doi: 10.1002/agj2.20165.

Bracken, P., Burgess, P. J., and  Girkin, N. T. (2021). Enhancing the climate resilience of coffee production. [Preprint]. AgriRxiv. doi: 10.31220/agriRxiv.2021.00106.

Bunn, C., Läderach, P., Ovalle Rivera, O., and Kirschke, D. (2015). A bitter cup: Climate change profile of global production of Arabica and Robusta coffee. Climatic Change, 129(1–2), 89–101. doi: 10.1007/s10584-014-1306-x.

Camargo, M. B. P. de. (2010). The impact of climatic variability and climate change on arabica coffee crop in Brazil. Bragantia, 69(1), 239–247. doi: 10.1590/S0006-87052010000100030.

Chen, L., Bao, X., Guo, G., Huo, W., Xu, Q., Wang, C. … Liu, Q. (2021). Effects of Hydrolysable Tannin with or without Condensed Tannin on Alfalfa Silage Fermentation Characteristics and In Vitro Ruminal Methane Production, Fermentation Patterns, and Microbiota. Animals, 11(7), 1967. doi: 10.3390/ani11071967.

Coffee Research Foundation, Kenya. (2012). History of Kenyan Coffee. Coffee Research Foundation, Kenya. Retrieved from www.crf.co.ke (Accesed 22.5.2022)

Craparo, A. C. W., Van Asten, P. J. A., Läderach, P., Jassogne, L. T. P., and  Grab, S. W. (2015). Coffea arabica yields decline in Tanzania due to climate change: Global implications. Agricultural and Forest Meteorology, 207, 1–10. doi: 10.1016/j.agrformet.2015.03.005.

DaMatta, F. M., Avila, R. T., Cardoso, A. A., Martins, S. C. V., and  Ramalho, J. C. (2018). Physiological and Agronomic Performance of the Coffee Crop in the Context of Climate Change and Global Warming: A Review. Journal of Agricultural and Food Chemistry, 66(21), 5264–5274. doi: 10.1021/acs.jafc.7b04537.

Daramola S. O., (2020). Timing of weed management and yield penalty due to delayed weed management in soybean. Planta Daninha, 38, e020236046. doi: 10.1590/s0100-83582020380100072.

Delgado, J. A., Barrera Mosquera, V. H., Alwang, J. R., Villacis-Aveiga, A., Cartagena Ayala, Y. E., Neer, D., … Escudero López, L. O. (2021a). Potential use of cover crops for soil and water conservation, nutrient management, and climate change adaptation across the tropics. In Advances in Agronomy (Vol. 165, pp. 175–247). Elsevier. doi: 10.1016/bs.agron.2020.09.003.

Didier Snoeck , Federico Zapata , Anne-Marie Domenach. (2000). Isotopic evidence of the transfer of nitrogen fixed by legumes to coffee trees. Biotechnology, Agronomy and Society and Environment open Access, 4(2), 95–100.

Elhakeem, A., van der Werf, W., Ajal, J., Lucà, D., Claus, S., Vico, R. A., and Bastiaans, L. (2019). Cover crop mixtures result in a positive net biodiversity effect irrespective of seeding configuration. Agriculture, Ecosystems and Environment, 285, 106627. doi: 10.1016/j.agee.2019.106627.

Farina, W. M., Balbuena, M. S., Herbert, L. T., Mengoni Goñalons, C., and Vázquez, D. E. (2019a). Effects of the Herbicide Glyphosate on Honey Bee Sensory and Cognitive Abilities: Individual Impairments with Implications for the Hive. Insects, 10(10), 354. doi: 10.3390/insects10100354.

Fikadu, Z. (2020). Pesticides use, practice and its effect on honeybee in Ethiopia: A review. International Journal of Tropical Insect Science, 40(3), 473–481. doi: 10.1007/s42690-020-00114-x.

Gachene, C. K. K., Mbuvi, J. P., Jarvis, N. J., and Linner, H. (1997). Soil Erosion Effects on Soil Properties in a Highland Area of Central Kenya. Soil Science Society of America Journal, 61(2), 559. doi: 10.2136/sssaj1997.03615995006100020027x.

Gao, Yong, Yu, Yi; Li, Yubao, and Dang, Xiaohong; (2016). Effects of Tillage Methods on Soil Carbon and Wind Erosion. Land Degradation and Development- John Wiley and  Sons, 27(3), 583–591.

Gomes, L. C., Bianchi, F. J. J. A., Cardoso, I. M., Fernandes, R. B. A., Filho, E. I. F., and Schulte, R. P. O. (2020). Agroforestry systems can mitigate the impacts of climate change on coffee production: A spatially explicit assessment in Brazil. Agriculture, Ecosystems and  Environment, 294, 106858. doi: 10.1016/j.agee.2020.106858.

Gunstone, T., Cornelisse, T., Klein, K., Dubey, A., and Donley, N. (2021). Pesticides and Soil Invertebrates: A Hazard Assessment. Frontiers in Environmental Science, 9, 643847. doi: 10.3389/fenvs.2021.643847.

Henault, C., Grossel, A., Mary, B., Roussel, M., and Léonard, J. (2012). Nitrous Oxide Emission by Agricultural Soils: A Review of Spatial and Temporal Variability for Mitigation. Pedosphere, 22(4), 426–433. doi: 10.1016/S1002-0160(12)60029-0.

Heuzé V., Tran G., Hassoun P.,. (2017). Greenleaf desmodium (Desmodium intortum) :Feedipedia, a programme by INRAE, CIRAD, AFZ and FAO.Animal feed resources information system. FAO / CIRAD. Retrieved from https://www.feedipedia.org/node/303.

IPCC: (2022). Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Washington, D.C: IPCC. (Accessed 2.6.2022).

Ires, I. (2021). Intensive Agriculture as Climate Change Adaptation? Economic and Environmental Tradeoffs in Securing Rural Livelihoods in Tanzanian River Basins. Frontiers in Environmental Science, 9, 674363. doi: 10.3389/fenvs.2021.674363.

Jia, L. Z., Zhang, J. H., Wang, Y., Zhang, Z. H., and Li, B. (2017). Effect of tillage erosion on the distribution of CaCO3, phosphorus and the ratio of CaCO3/available phosphorus in the slope landscape. Soil Research, 55(7), 630. doi: 10.1071/SR16077.

Kabubo-Mariara, J., and Mulwa, R. (2019). Adaptation to climate change and climate variability and its implications for household food security in Kenya. Food Security, 11(6), 1289–1304. doi: 10.1007/s12571-019-00965-4.

Kaye, J. P., and Quemada, M. (2017). Using cover crops to mitigate and adapt to climate change. A review. Agronomy for Sustainable Development, 37(1), 4. doi: 10.1007/s13593-016-0410-x.

Kelln, B. M., Penner, G. B., Acharya, S. N., McAllister, T. A., and Lardner, H. A. (2021). Impact of condensed tannin-containing legumes on ruminal fermentation, nutrition, and performance in ruminants: A review. Canadian Journal of Animal Science, 101(2), 210–223. doi: 10.1139/cjas-2020-0096.

Kinama, J. M., Stigter, C. J., Ong, C. K., Ng’ang’a, J. K., and Gichuki, F. N. (2007). Contour Hedgerows and Grass Strips in Erosion and Runoff Control on Sloping Land in Semi-Arid Kenya. Arid Land Research and Management, 21(1), 1–19. doi: 10.1080/15324980601074545.

Klein, A.-M., Steffan-Dewenter, I., and Tscharntke, T. (2003). Bee pollination and fruit set of Coffea arabica and C. canephora (Rubiaceae). American Journal of Botany, 90(1), 153–157. doi: 10.3732/ajb.90.1.153.

Lopez-Vicente, M., Calvo-Seas, E., Álvarez, S., and Cerdà, A. (2020). Effectiveness of Cover Crops to Reduce Loss of Soil Organic Matter in a Rainfed Vineyard. Land, 9(7), 230. doi: 10.3390/land9070230.

Luo, J., Zhou, X., Rubinato, M., Li, G., Tian, Y., and Zhou, J. (2020). Impact of Multiple Vegetation Covers on Surface Runoff and Sediment Yield in the Small Basin of Nverzhai, Hunan Province, China. Forests, 11(3), 329. doi: 10.3390/f11030329.

Medeiros, H. R., Martello, F., Almeida, E. A. B., Mengual, X., Harper, K. A., Grandinete, Y. C., … Ribeiro, M. C. (2019). Landscape structure shapes the diversity of beneficial insects in coffee producing landscapes. Biological Conservation, 238, 108193. doi: 10.1016/j.biocon.2019.07.038

Mendonça, E. de S., Lima, P. C. de, Guimarães, G. P., Moura, W. de M., Andrade, F. V.,. (2017). Biological Nitrogen Fixation by Legumes and N Uptake by Coffee Plants. Revista Brasileira de Ciência Do Solo, 41(0). doi: 10.1590/18069657rbcs20160178.

Mertens, M., Höss, S., Neumann, G., Afzal, J., and Reichenbecher, W. (2018). Glyphosate, a chelating agent—Relevant for ecological risk assessment? Environmental Science and Pollution Research, 25(6), 5298–5317. doi: 10.1007/s11356-017-1080-1.

Midega, C. A. O., Wasonga, C. J., Hooper, A. M., Pickett, J. A., and  Khan, Z. R. (2017). Drought-tolerant Desmodium species effectively suppress parasitic striga weed and improve cereal grain yields in western Kenya. Crop Protection, 98, 94–101. doi: 10.1016/j.cropro.2017.03.018.

Migwi, .G.G., E.S. Ariga, and R.W. Michieka. (2017). A survey on weed diversity in coffee estates with prolonged use of glyphosate in Kiambu County, Kenya. International Journal of Scientific Research and Innovative Technology, 4(2).

Motta, E. V. S., and Moran, N. A. (2020). Impact of Glyphosate on the Honey Bee Gut Microbiota: Effects of Intensity, Duration, and Timing of Exposure. MSystems, 5(4), e00268-20. doi: 10.1128/mSystems.00268-20.

Motta, E. V. S., Raymann, K., and Moran, N. A. (2018). Glyphosate perturbs the gut microbiota of honey bees. Proceedings of the National Academy of Sciences, 115(41), 10305–10310. doi: 10.1073/pnas.1803880115.

Ndiritu J. M., Muthama J. N., and Kinama J. M. (2021). Optimization of ecosystems services for sustainable coffee production under changing climate. East African Journal of Science, Technology and Innovation, 2, 2(sepcial Issues), 21.

Quiroga, S., Suárez, C., Diego Solís, J., and Martinez-Juarez, P. (2020). Framing vulnerability and coffee farmers’ behaviour in the context of climate change adaptation in Nicaragua. World Development, 126, 104733. doi: 10.1016/j.worlddev.2019.104733.

Rahn, E., Läderach, P., Baca, M., Cressy, C., Schroth, G., Malin, D. … Shriver, J. (2014). Climate change adaptation, mitigation and livelihood benefits in coffee production: Where are the synergies? Mitigation and Adaptation Strategies for Global Change, 19(8), 1119–1137. doi: 10.1007/s11027-013-9467-x.

Rose, T. J., and Kearney, L. J. (2019). Biomass Production and Potential Fixed Nitrogen Inputs from Leguminous Cover Crops in Subtropical Avocado Plantations. Agronomy, 9(2), 70. doi: 10.3390/agronomy9020070.

Shackelford, G. E., Kelsey, R., and Dicks, L. V. (2019). Effects of cover crops on multiple ecosystem services: Ten meta-analyses of data from arable farmland in California and the Mediterranean. Land Use Policy, 88, 104204. doi: 10.1016/j.landusepol.2019.104204.

Shao, Z., Zheng, C., Postma, J. A., Lu, W., Gao, Q., Gao, Y., and Zhang, J. (2021). Nitrogen acquisition, fixation and transfer in maize/alfalfa intercrops are increased through root contact and morphological responses to interspecies competition. Journal of Integrative Agriculture, 20(8), 2240–2254. doi: 10.1016/S2095-3119(20)63330-5.

Shannon, C.E. (1948) A mathematical theory of communication. The Bell System Technical Journal, 27, 379–423.) Check “The Mathematical Theory of Communication.

https://doi.org/10.1002/j.1538-7305.1948.tb01338.x

’t Mannetje, L. (2000). Measuring biomass of grassland vegetation. In L.’t Mannetje and R. M. Jones (Eds.), Field and laboratory methods for grassland and animal production research (pp. 151–177). Wallingford: CABI. doi: 10.1079/9780851993515.0151.

Tadesse, G. (2018). Impact of Climate Change on Smallholder Dairy Production and Coping Mechanism in Sub-Saharan Africa—Review. Agricultural Research and Technology: Open Access Journal, 16(4). doi: 10.19080/ARTOAJ.2018.16.556000.

Tolera, A., and Sundstøl, F. (2000). Supplementation of graded levels of Desmodium intortum hay to sheep feeding on maize stover harvested at three stages of maturity. Animal Feed Science and Technology, 87(3–4), 215–229. doi: 10.1016/S0377-8401(00)00205-4.

Vázquez, D. E., Ilina, N., Pagano, E. A., Zavala, J. A., and Farina, W. M. (2018a). Glyphosate affects the larval development of honey bees depending on the susceptibility of colonies. PLOS ONE, 13(10), e0205074. doi: 10.1371/journal.pone.0205074

Velmourougane, K., and Bhat, R. (2017). Sustainability Challenges in the Coffee Plantation Sector. In R. Bhat (Ed.), Sustainability Challenges in the Agrofood Sector (pp. 616–642). Chichester, UK: John Wiley and  Sons, Ltd. doi: 10.1002/9781119072737.ch26.

Vukicevich, E., Lowery, T., Bowen, P., Úrbez-Torres, J. R., and Hart, M. (2016). Cover crops to increase soil microbial diversity and mitigate decline in perennial agriculture. A review. Agronomy for Sustainable Development, 36(3), 48. doi: 10.1007/s13593-016-0385-7.

Wagner, S., Jassogne, L., Price, E., Jones, M., and Preziosi, R. (2021). Impact of Climate Change on the Production of Coffea arabica at Mt. Kilimanjaro, Tanzania. Agriculture, 11(1), 53. doi: 10.3390/agriculture11010053.

Williams, C.M., Eun, J.S., MacAdam, J.W., Young, A.J., Fellner, V. and Min, B.R. (2015). Effects of forage legumes containing condensed tannins on methane and ammonia production in continuous cultures of mixed ruminal microorganisms. Animal Feed Science Technology – Elsevier Science, 166, 364–372.

Yanza, Y. R., Fitri, A., Suwignyo, B., Elfahmi, Hidayatik, N., Kumalasari, N. R. … Jayanegara, A. (2021). The Utilisation of Tannin Extract as a Dietary Additive in Ruminant Nutrition: A Meta-Analysis. Animals, 11(11), 3317. doi: 10.3390/ani11113317.

Zaller, J. G., Heigl, F., Ruess, L., and Grabmaier, A. (2015). Glyphosate herbicide affects belowground interactions between earthworms and symbiotic mycorrhizal fungi in a model ecosystem. Scientific Reports, 4(1), 5634. doi: 10.1038/srep05634.

Zhao, Q., Xiong, W., Xing, Y., Sun, Y., Lin, X., and Dong, Y. (2018). Long-Term Coffee Monoculture Alters Soil Chemical Properties and Microbial Communities. Scientific Reports, 8(1), 6116. doi: 10.1038/s41598-018-24537-2.