Chapters 5.39

5.39 -Mesquite tree as a Stable for Smallholder farmers Challenged with Climate Change

Shannon Megarry, University of Guelph, Canada

Suggested citation for this chapter.

Megarry,S. (2022) Mesquite tree as a Stable for Smallholder farmers Challenged with Climate Change, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org

Background to Mesquite

The mesquite tree (Prosopis glandulosa), is an important part of many ecosystems and has potential to assist smallholder farmers. The name “mesquite” is the name for several plants in the genus Prosopis which contains over 40 species (Sharp, 2020). They are native to the United States and Mexico. They usually grow in northern Mexico and thrive into southern Kansas (Sharp, 2020). The mesquite tree thrives in dry conditions (Grant, 2018) and hence may be helpful for parts of the world which are becoming drier due to climate change including the subtropics. A unique trait about this tree is that it can harvest moisture from incredibly dry soil because of its deep thick root structure (Grant, 2018).

There are 5 different species of mesquite that are native to the Southwest (Taylor and Campbell, 2020). The Honey Mesquite (P. glandulosa) covers the most land area as it ranges from the Pacific Coast to the Gulf of Mexico (Taylor and Campebell, 2020). Another type of mesquite is the Velvet Mesquite tree (P. velutina) which is found in areas such as southern Arizona and New Mexico (Taylor and Campbell, 2020). The fourth type of mesquite is known as the Screwbean Mesquite (P. Pubescens) which covers many regions but mostly found in southeast California and the Colorado River (Taylor and Campbell, 2020). Another species called Tornillo (P. reptans) is more native to southern Texas and is referred to as the Dwarf Screwbean because of its small screw-like appearance (Taylor and Campbell, 2020). In some species of the mesquite, tree flowers will appear in the spring and summer that form a flat pod or bean that is 2 to 6 inches (51 to 152 mm) long (Wild Flower, 2009) .

Nutrients

Mesquite trees are legumes, in the same family as beans and peas (Taylor and Campbell, 2020). They form symbiotic relationships with rhizobia bacteria in the soil, to convert atmospheric nitrogen gas into usable nitrogen fertilizer. As nitrogen is a building block for amino acids/protein, the protein content of its seeds are high. According to Grant (2018), the seeds contain 35% protein and 25% fiber. Indeed, many indigenous communities use this tree as a part of their diets. Individuals that live in the Sonoran and Mojave Deserts rely on a diet that heavily consists of nutrients from this tree. In the spring, the flowers on this tree are picked and eaten before they fruit (Taylor and Campbell, 2020). Flour made from the pods are commonly used for baking. The seeds are ground, and water is added to make pastries such as cakes, pies, and pancakes (Taylor and,, 2020). The pods of this tree are also consumed in liquid form: the pods are boiled and water is added, and in some instances beer and wine is also produced (Taylor and Campbell, 2020). Local honey farmers can also benefit from this tree, as the flowers provide bees with nectar to produce honey (Clark, 2020). Furthermore, beans of the tree are very sweet and are ideal for diabetic individuals because they do not require insulin to metabolize (Grant, 2018). In the context of climate change, the mesquite tree has the potential to become a good source of nutrients in dry regions.

Growth and reproduction

The growth of a mesquite tree depends widely on its environment, including its temperature, rainfall and soil type. The mesquite tree under ideal conditions can grow to a height of 40 feet (12.1 meters) in about 20 years (Duffy, 2018). It is classified as a fast to medium growing tree and grows about 13 to 25 inches (0.33 to 0.63 meters) per year (Duffy, 2018). The largest mesquite trees grow because they have access to a reliable water source where its thick long roots can obtain moisture (Grant, 2020). The mesquite tree can be found near streams and rivers and does not do well where soils are overly soggy (Grant, 2018). The mesquite tree has 3 growth stages. The first stage is the seedling stage, from germination until the first leaf sprouts (Lyons and Rector, 2004). The second stage is the juvenile stage, once the first leaf is visible until the plant grows to maturity and produces woody xylem tissue (Lyons and Rector, 2004). After the juvenile stage comes the mature stage. These 3 stages are accelerated if the soil temperature is 80 to 90 degrees F (26 degrees to 32 degrees Celsius), while its growth is slower above 95 degrees (35 degrees Celsius) (Lyons and Rector, 2004). It takes about 3 years for the plants to reach full maturity and they are able to produce flowers and seeds. For example, the Honey Mesquite occurs in two growth forms. If the plant has a single stem or few stems, then this indicates that its growth was optimal and thrived during the juvenile stage (Lyons and Rector, 2004). If it is a multi stemmed plant, it demonstrates that the main stem has been removed or damaged during the juvenile stage (loss of apical dominance) (Lyons and Rector, 2004).

Human Uses

The uses of mesquite are numerous. Almost every part of the tree is used depending on the local culture. The tree itself has been used for fence posts, food, and furniture (Lyons and Rector, 2004). The wood of the tree is very strong and thick which makes it useful for making furniture and tools (Grant, 2018). Household items such as tables, stools and bed frames have recently been made out of the wood from this tree. In addition, the strong roots have been used for weaving baskets. (Taylor and Campbell, 2020).

The tree is used beyond beyond material items. Parts of this tree such as the pods, flowers, leaves and even the roots have reportedly been used to cure many diseases and for medical advancements. Healers in the indigenous communities have relied on the sap to help reduce pain and swelling associated with cuts (Taylor and Campbell, 2020). Because of the low glycemic index (25) of its seeds, many scientists are interested in mesquite food products to lower blood sugar and help treat diabetes (Taylor and Campbell, 2020). The sap of the mesquite tree also has many uses. Candies and gum have been created because of its sticky thick consistency. The texture of the sap was also used as almost a glue for baskets and other items to make them durable and tight (Taylor and Campbell, 2020). These trees also provide habitats to animals. Because of its quickly growing canopy, it provides shade and habitat to birds and animals; coyotes and other wildlife rely on the pods of the mesquite to survive during the winter months when food is scarce (Grant, 2018).

Smallholders, including women, can generate income from these trees by selling hair dye, various foods and household furniture. For local furniture the profit margin is reportedly 45%. Mesquite sells for $10 USD per board foot. Specialized tools are required however (Hernandez, 2016). Lip balm and moisturizer can be made from the sap of the pods when water or other local products are added (Hernandez, 2016).

Cost of planting a mesquite tree

The cost of a mesquite tree is also an important consideration for smallholder farmers to consider. The estimated labor cost to plant one mesquite tree is $6 to $12 USD per hour in the United States (Texas Natural Resources Server) though labour costs would be lower in developing nations, but access to digging equipment might be problematic. There are a few steps involved in planting a mesquite tree. Step one is to estimate the mesquite density (Texas Natural Server) It is recommended to block off a square area of 66 feet (it is recommend to have a large area but 66 feet not mandatory) (Texas Natural Resources Server) Step two is to estimate the cost per acre. The estimated cost per acre of a mesquite tree is around $25 to $30 in the United States (Texas Natural Resource Server). These trees are planted from seedlings and needs lots of light to grow. Smallholder farmers can harvest dry and mature pods as a source of seeds (Felker, 2005; Nakano, 2009), however assistance will be required initially to obtain seeds. This tree should also be protected against poachers cutting it down for the purpose of firewood, through awareness and protection interventions.

Challenges associated with mesquite

Although there are many positives of the mesquite tree, it is important to consider the challenges as well. This tree has been referred to as the “devil tree” because of its large roots that absorb all the water from its surroundings, causing weaker trees to die off (Clark, 2018) by preventing water access (Balushi et,al., 2017). Mesquite reduces the growth of nearby cultivated plants such as Acacia tortilis, by competing for air, water, and soil nutrients (Balushi et,al., 2017). Its roots can be incredibly invasive, so near houses they can penetrate through sewer systems; furthermore, its branches can break off and cause damage (Las Aventuras, 2010). The Honey Mesquite grows like a vicious weed and has very pointy thorns (Clark, 2018). According to Balushi et,al., (2017) its spikey stems can also be harmful and damaging to local livestock.

The mesquite tree has been documented to impact other regions of the world greatly. For example, the mesquite tree was introduced into India decades ago, but its negative environmental impact on local species is just now becoming clear. The mesquite plants are invading the only habitat for the endangered Indian wild ass (Equus heminous khur). Because of the large structure of the tree, it is pushing these animals out of their habitats (Vieira, 2005). This observation suggests that mesquite should be introduced into new habitats cautiously.

Conclusion

With the increase in global temperatures mesquite trees may survive while other plants die off, due to their aggressive ability to scavenge for deep sources of water. According to the NOAA Global Climate change summary (2019), “The combined land and ocean temperature has increased at rate of 0.07°C per decade since 1880; however, the average rate of increase since 1981 (0.18°C / 0.32°F) is more than twice as great” (Lindsey and Dahlamn, 2020). The increase of temperatures will lead to harm to animals, destruction of habitats, and loss of nutrient dense plants (Lindsey and Dahlamn, 2020). Due to the mesquite trees ability to adapt, its strong structure, nutrient dense pods, and low maintenance, it is an excellent crop for smallholder farmers that should be given more attention as a solution for the issues that climate change will bring about.

Additional Information

https://www.youtube.com/watch?v=0RShK_4h9Pg Video showing how to grow a mesquite tree

https://www.youtube.com/watch?v=tYZFbE6X7e8 Video of how long it takes to grow a Mesquite tree

https://link.springer.com/article/10.1186/1476-7961-2-8 Article about the allergens of Mesquite tree

https://www.sciencedirect.com/science/article/abs/pii/S0140196318305408 Article on Mesquite trees response to water decline

https://pvtimes.com/community/in-season-mesquite-one-of-the-deserts-most-plentiful-crops-89100/ Article on the benefits of Mesquite tree

https://www.wikihow.com/Plant-a-Mesquite-Tree Step by step on how to plant a mesquite tree

https://www.woodmagazine.com/materials-guide/lumber/wood-species-2/mesquite step by step of cost and how to create furniture out of mesquite wood

References

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2. Clark, C. (2013, January 02). All About Mesquite or Devil Trees - Dengarden - Home and Garden. Retrieved December 01, 2020, from https://dengarden.com/landscaping/mesquite-trees-mesquite-bushes-devil-trees-thorns-seedpods

3. Duffy, C (2018).How Long Does it Take to Grow a Mesquite Tree? Retrieved December 01, 2020, from https://www.hunker.com/13428741/how-long-does-it-take-to-grow-a-mesquite-tree

4. Felker, P. (2012). Pod Mesocarp Flour of North and South American Species of Leguminous Tree Prosopis (Mesquite): Composition and Food Applications. Food Reviews International 29: 49-66. https://www.tandfonline.com/doi/abs/10.1080/87559129.2012.692139

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8. Nakano, H. (2009). Plant Growth Inhibitors From Mesquite (Prosopis juliflora). In Desert Plants: Biology and Biotechnology (Ed: K.G. Ramawat), pages 341-352. doi:10.1007/978-3-642-02550-1_16

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14. Vieira, Í, Mendes, F., Gallão, M., & Brito, E. (2006, March 07). NMR study of galactomannans from the seeds of mesquite tree (Prosopis juliflora (Sw) DC). Retrieved December 01, 2020, from https://www.sciencedirect.com/science/article/abs/pii/S0308814606000458

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