Chapters 5.48

5.48 -Use of Peanuts (Groundnuts) for Smallholder Farmers to Combat the Effects of Climate Change

Isabel Fuentes,University of Guelph, Canada

Suggested citation for this chapter.

Fuentes,I. (2022)Use of Peanuts (Groundnuts) for Smallholder Farmers to Combat the Effects of Climate Change, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org

Introduction

Peanut (Arachis hypogaea), called groundnut in Africa, is a drought tolerant legume crop that can help smallholder farmers cope with drought associated with climate change. Peanuts are believed to have originated in South America, and domestication of the crop has been traced to Bolivia and Argentina (Akram et al., 2018; FAO, 2011). The peanut is the world’s third more important source of vegetable protein and the fourth most important source of edible vegetable oil, with 46% of production concentrated in Africa (Rao et al., 2015). The target countries for peanut crops are subtropical and tropical areas of Africa, Asia and South America due to the fact that a large percentage of peanut cultivation occurs in low-income countries with food deficits and few resources (Akram et al., 2018).

Growth and Cultivation of the Peanut

Peanut has multiple varieties including the Runner, Virginia, Spanish, and Valencia (APC, n.d.). These four varieties are the most commonly known, however there are additional varieties being released globally including in Africa (ICRISAT, n.d.). Peanut varieties continue to be improved and changed in order to adapt to environmental factors. In a survey conducted in Uganda, it was reported that more than 50% of the country’s peanut-producing area was occupied by improved and modified varieties that are resistant to factors such as drought (ICRISAT, n.d.). These varieties differ based on size, colour of skin, kernel to pod ratio, flavour, and stress resistance (APC, n.d.). Farmer organizations can obtain peanut varieties through ICRISAT as well as the USDA FSIS.

The optimal temperatures for peanut growth ranges between 25-30 degrees Celsius and due to their genetic variability, peanuts have the ability to adapt to tropical and semiarid climates (Dutra et al., 2018). Studies indicate that peanut pod growth at 34 degrees Celsius was restricted at these temperatures and the pods grown at these temperatures weighed 1.5 g, compared to pods grown at 26 degrees Celsius which weighed 2.7 g (Cox, 1979). Based on this, the temperature that peanuts should be grown at should not exceed 30 degrees Celsius during the growing season in order to ensure proper growth (Cox, 1979). The peanut plant is drought resistant and requires only 38.1-50.8 mm of water per week to grow; in total over the growing season, peanut crops require an average rainfall of >400 mm to produce a reasonable crop (GRDC, 2017). As a result, significant peanut farming takes place in areas with water shortages (Akram et al., 2018). An especially drought-tolerant peanut variety was introduced in Asia through farmer varietal selection and is now being grown on 25,000 ha of the 800,000 ha growing area in India (ICRISAT, n.d.).

Peanut roots associate with rhizobia bacteria that convert atmospheric nitrogen gas into nitrogen fertilizer which improves both itself and the soil around it (Akram et al., 2018). Accordingly, peanut is often intercropped with other crops (e.g. cereals, root crops) to maximize the yield of those crops. Intercropping is a system where multiple crops are grown at the same time in one area (Zhang, 2020). For example, the intercropping of maize and peanuts has been extensively used in semi-arid regions of China, with similar growing conditions to African climates (Zhang, 2020). The natural nitrogen fixation of peanuts contributes to the soil health for maize (Akram et al., 2018). Though peanut is not typically fertilized with nitrogen, phosphate and other macro and micronutrients, such as zinc, iron, manganese, copper, boron, and molybdenum, are necessary for peanut growth, with the molybdenum essential for rhizobia bacteria (Peanut Production Guide, n.d.). As a result, deficiencies molybdenum have been shown to reduce yields and/or the protein content of the seeds. The plant prefers to grow in light-coloured, light textured soils with good drainage and moderate amounts of organic matter with a pH range of 6.0-6.5 due to the fact that the peanut grows best in slightly acidic soils (Putnam et al., 1991).

Peanut plants have aerial flowers, and after pollination, the fertilized ovaries develop into stalk-like structures that contain embryos called pegs (Akram et al., 2018). The basal cells of the fertilized ovary elongate in the pegs and pro-embryo development causes these pegs to elongate, resulting in penetration of the soil layer, a process referred to as “pegging” (Akram et al., 2018). Countries with drought occurring often have an increased hardness of the top-soil layer, which can restrict pegging of peanut plants, however if the drought affected pegs are re-watered, pegging can resume (Akram et al., 2018). The ability of the peanut pegs to continue growth and pegging after being re-watered is an adaptive trait that maximizes the survival of the fertilized embryo, unlike crops such as maize or other grains where embryos are often lost without a chance for revival (Akram et al., 2018).

Benefits of peanut and adoption by smallholder farmers

Peanut contains numerous nutritional benefits that could aid in combatting food shortages and malnourishment in the developing world (Akram et al., 2018) including vitamins and minerals, healthy proteins, fatty acids and carbohydrates. Peanuts provide a rich source of micronutrients that benefit human health. One ounce of peanuts contains 25% of the recommended dietary allowance (RDA) of Niacin, 10% of RDA of Folate, 20% of RDA of Vitamin E, 26% of RDA of Manganese, 10% RDA of Zinc, 12% of RDA of Magnesium, and many more (Peanut Institute, 2019). Peanuts can be added to dishes including stews or eaten by themselves as a snack (AGMRC, 2018). Furthermore, peanut can additionally be made into oil to be used for cooking (AGMRC, 2018) which reduces cooking times and hence the need for fuelwood collected by women and children. Additionally, peanuts possess a rich source of medicinal compounds linked to improved health and a decreased risk of diseases (Akram et al., 2018). Another benefit of the peanut is the fact that it is a “zero-waste” plant, meaning that all parts of the plant including the roots and hulls can be utilized by farmers in part as a nitrogen biofertilizer for the soil (NPB, 2017).

Another benefit of peanut crops to smallholder farmers is the health benefits to livestock that can be attained through feeding peanut by-products to animals. Peanut hay is widely used to feed cows, and it is rich in nutrient content and is comparable to grass hays (Hill, 2002). Peanut skins can also be included in cattle feed and with the right quantities of around 10% of the cattle diet, the skins can provide energy and protein to the cows (Hill, 2002). Peanut hulls can be used as roughage in beef diets and are often lower in price than other products, making it a beneficial economic decision for smallholder farmers (Hill, 2002).

Not only does this plant require an extremely low amount of water for growth, and offer an inexpensive feed option for livestock, peanuts have the smallest carbon footprint of any nut, making it a great sustainable crop that can directly combat climate change (NPB, 2017).

The potential adoption of a crop for a smallholder farmer is influenced by a number of factors. In a study on smallholder farmers in the Bawku West District of Upper Ghana, expected benefits of the crop, along with land size constraints, were the most significant factors that influenced whether farmers would adopt a new crop (Akundugu et al., 2012). A major benefit of peanut is the fact that it serves multiple food purposes (eaten on their own or added to other foods) and because it can also be processed into oil, a valuable commodity for local economies (Yuan et al., 2020). With a seed oil content of 50% by weight, leading to a yield of 3,000 pounds of seeds per acre, peanuts can produce 120-150 gallons of oil per acre under proper growing conditions (AGMRC, 2018). Peanut oil has become a valuable export: in 2005 three-quarters of U.S. crude peanut oil imports were supplied by India, valued at $58 million USD (Boriss, 2006).

Aside from the above products, peanut offers a number of additional post-harvest value-addition properties. Rather than selling raw seed, peanut can be roasted and salted and sold as a snack, processed into peanut butter, ground into flour, made into peanut-based beverages, and many more uses. These products all create potential opportunities for smallholder women farmers. Peanuts are considered to be a women’s crop, as women are involved at all stages of production, from selecting the crop variety all the way to processing and food production (FAO, 1998). In order to aid women in peanut production, resources such as tools and equipment, knowledge and access to markets, and land extension should be provided to female farmers (FAO, 1998). Additionally, women should be involved in all stages of development of technology and should be given technical skills training in order to improve the harvest (FAO, 1998). Examples of equipment for peanut processing include peanut shellers, aspirators to separate shells from in-shell material, and drying. Shellers range in price from $1,010-$2,800 USD, and peanut butter and roasting machines range from $150-2,300 USD according to Alibaba.com. The equipment is designed to maximize effectiveness and processing speed and will consequently maximize profits. As of June 2020, the value of raw peanut crops was $2050 USD per metric ton (Commodity Prices, 2020). With the proper equipment and women being provided with adequate resources, peanut crops can provide prosperity to smallholder farmers.

Critical Analysis

Some of the barriers to peanut growth include drought and iron unavailability in soil, both of which can interfere with the nitrogen fixation abilities of the peanut plant (Akram et al., 2018). Another possible challenge is that the seeds must be dried to a 10% moisture content before storage (NPB, 2017) which can be difficult for smallholder farmers, particularly in high-humidity environments. When peanuts are harvested, the moisture content ranges from 35-50%, (Grant, 2018). To dry the nuts naturally, plants can be stored in sheds, or indoors for one to two weeks under warm, low humidity conditions (Grant, 2018). An issue that can arise in peanut crops is a fungal disease caused by Aspergillus flavus. This fungus can cause aflatoxin in peanut crops, which is an extremely hazardous mycotoxin that can be detrimental to the development of children and can potentially lead to hepatitis, deterioration of the immune system, and even liver cancer (ICRISAT, n.d.). Due to this threat to human health, countries have established strict standards in order to ensure the quality of the peanuts they are receiving, and as a result, farmers in developing countries have lost opportunities to export peanut crops (ICRISAT, n.d.). To combat this, researchers have developed an aflatoxin testing kit that is inexpensive and can be used to detect aflatoxin in crops (ICRISAT, n.d.). These kits are currently being used in Kenya, Malawi, Mali and Mozambique to try and ease their way back into industrialized markets and get past the regulations (ICRISAT, n.d.). Smallholder farmers can purchase the inexpensive aflatoxin detecting kits in order to ensure the safety of their crops, and to provide themselves with better economic opportunities with safe selling of their products.

Helpful Links on Growing and Harvesting Peanut Crops

How Groundnut Oil is Made - https://www.youtube.com/watch?v=2GwQtQT3yAA

Making groundnut oil and snacks - https://www.youtube.com/watch?v=_GaRyYZYY-g

How to make peanut flour - https://www.youtube.com/watch?v=wZ7LOPGLrZs

All Natural Home-Made Peanut Butter - https://www.youtube.com/watch?v=7khA9O4PXKA

How to Harvest and Cure Peanuts - https://www.youtube.com/watch?v=U6KI4ucBM-I

Peanuts Grown in a Container from Planting to Harvest https://www.youtube.com/watch?v=sEfil-ZeX8A

Harvesting and Processing Peanuts in Northern Indiana - https://www.youtube.com/watch?v=8mSOYoY2FMA

Uganda Groundnut Crops - https://www.youtube.com/watch?v=L5TmRsTDs0U

How to Grow Peanuts - https://www.youtube.com/watch?v=YDTkS_y0H6k

Peanut Growing - https://www.youtube.com/watch?v=XlOOrij2uM4

References

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