Chapter 5.4/5
5.4/5 - Rainwater collection around fruit trees including use of rocks
Anab Siraj, University of Guelph, Canada
Suggested citation for this chapter.
Lanthier,C. (2022) Contour farming on hillsides to prevent erosion. In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org
Background
Fruit trees are an important biological resource for developing nations. They add vital micronutrients especially to pregnant women and children and they’re also important in commodity markets where they can make a profit (FAO, 2016). For example the bush mango tree is a highly demanded fruit tree in Cameroon Africa, locally and beyond, which generates income for local farmers (OUYA, 2103).
Unfortunately, many subsistence farmers live in the sub-tropics where there is limited rainfall to grow fruit trees. One of the main problems in the subtropics is that it can get very hot and dry and only receive about 200-750 mm of rain each year, resulting in failure of crops and trees (Rainwater Harvesting Handbook, n.d.). Because a lot of people cannot afford expensive irrigation systems in developing countries, the need for a technique to collect rainwater or moisture from air around fruit trees is needed. This article will explain low costs approaches to irrigate fruit trees.
Benefits
Water harvesting techniques can have enormous benefits especially in places where it can get really dry. Once they’re set up, not only do people use them again and again without any maintenance problems but also they’re very cheap and efficient.
In terms of dealing with desertification and degradation, water harvesting seems to be the perfect solution because the best feature about this technique is that it can be built on any slope, thus farmers can use large flat lands in the deserts (Zhang, Carmi & Berliner, 2013).
There was a study done in the Negev desert of Israel, where water harvesting methods were practiced on a large scale by the Nabataean people of Israel in the past (Fidelibus & Bainbridge, 1994). Crop production by these people was very impressive in a desert with an annual rainfall of 3-4 inches annually (Fidelibus & Bainbridge, 1994). Due to these results, microcatchment has been used as a means for supporting crops as well as to establish vegetation for parks and roadside rest areas (Fidelibus & Bainbridge, 1994).
There are a lot of other crops that have had successes with the microcatchment. A study was done in the semi arid regions of California where there is very low sporadic rainfall, the growth and seed production of jojoba trees were compared (Fidelibus & Bainbridge, 1994). Three jojoba trees were given three different treatments. The first one with no water harvesting catchments, the second with a clear-smoothed 20 metre square catchment, and another with no water but with a water repelling coat. The trees that received micro catchment produced more flowers and seeds compared to the untreated ones. This resulted in a much higher fruit yield (Fidelibus & Bainbridge, 1994).
Another experiment was done in the arid areas of Rajasthan, India, where jujube trees were planted. It was found that the growth and fruit production was improved significantly by microcatchment techniques (FAO, 2016).
Some of the other benefits are that the leaves and fruits provide food for the family as well as fodder for livestock. Perhaps one of the main benefits is that its wood is not only used for building purposes but it also provides fuel for cooking and heating (Ffolliott, Gottfried and Rietveld, 1995). That means that it can also be a way to generate income (as they can expand marketing opportunities) for poor households. Women don’t have to walk miles and miles just to collect wood. Trees also protect soil, which can be important for growing crops because the leaves can act like a fertilizer when they fall to the ground and add nitrogen to the soil, which is very important to the growth of crops (Rainwater Harvesting Handbook, n.d.). Some trees also offer many nutritional benefits for both women and children. For example, citrus, papaya, avocado and guava trees provide important micronutrients such as iron and vitamins C and A (FAO, 2013).
Description
Even during sporadic rainfall, if rain can be concentrated on a smaller area, reasonable yields will still be achieved (FAO, 2013). In the last few years significant focus has been on the use of micro catchments. This is a technique of harvesting rainwater in order to improve vegetation and prevent land degradation in low rainfall zones (< 250 mm), whereas the required amount is 300-400 mm to be able to grow trees (FAO, 2016). One of the practices is to create a short wall or pit around the tree. This will make sure that when it rains, the water will stay inside the pit instead of running off.
In very dry or desert like environments, the focus should be on atmospheric moisture. For example, in deserts there is morning dew that can be collected (FAO, 2016). There are also other indigenous practices in the desert that should be practiced when there is a shortage of rain. For example, in the Middle East, a very effective technique is used which is the use of porous rocks around fruit trees (FAO, 2016). The rocks are used to collect dew in the morning. The pores in the rocks will help to condense morning dew, from where it will drip down into the soil.
An experiment carried out on the Canary Island of Lanzarote consisted of the use of porous volcanic rock to grow vegetation and trees; such rock is available abundantly on the island (Graf, Kuttler & Werner, 2008). This not only reduced evaporation losses but also supplied water to the roots by condensation, which increased fruit yields by 40. (Graf, Kuttler & Werner, 2008).
Another really good example come from China where there is a long history of growing melons in soil beds covered with a layer of gravel that is 100-150 mm thick; the dew on the gravel drips down to the soil through condensation. As a result of this practice, yield increased by as much as 28% (FAO, 2016).
Lastly, another simple method is specifically for hillsides. The idea is to create a stone or contour bund that will surround the fruit tree to collect rainwater. There are several designs a farmer can use based on the type of landscape and soil they have (Ibraimo, Munguambe, 2007). For example, contour bunds are effective for dry and flat lands whereas semi-circular bunds are useful for tree planting on degraded lands (Ibraimo, Munguambe, 2007).
Another indigenous practice is the use of filling unglazed porous clay pots with water and burying them beside fruit trees. The pots slowly leak water. The best feature about this technology is that the pots can be made locally with available materials and skills and are also less likely to be damaged by animals and insects (Bainbridge, 2001). A study in Pakistan showed that the survival rate of tree seedlings with the use of clay pots was 96.5% compared to 62% for hand watering (Bainbridge, 2001). However, there are some drawbacks which include the cost of the labour which is $40/ha and the energy required to fire and install them (United Nations Environment Program, 2003).
The availability of water for trees depends on how much water is collected in the soil that is not lost to evaporation and percolation (Zhang, Carmi & Berliner, 2013). Therefore, it is important to consider making a deeper pit compared to a shallow one to have effective results. The trees planted inside the deeper pits had much higher survival rate compared to the ones planted in the shallow ones in the study that was done in Negev, Israel, noted above (Zhang, Carmi & Berliner, 2013).
Critical Analysis
Although there are some appropriate techniques to accumulate rainwater when needed, there are some trade offs. They all require labour. Building a pit or a bund may be a bit challenging, as the tools to make the pit may not be available. In order to make a stone bund, a farmer will need stones but not everyone will be able to afford or physically transport these stones (FAO, 2016).
For the use of clay pots, one of the disadvantages is that the porosity of pots decrease with time, therefore they have to be replaced (United Nations Environment Program, 2003). It is also possible that the turbid water with a high silt and clay content may accumulate in the pores of the pots and thus clog them (United Nations Environment Program, 2003).
In addition, in order to collect the morning dew, there may not be porous rocks available to farmers in their area, which puts them at a disadvantage.
It is also essential that the benefits outweigh the costs when growing a specific tree. Individuals have to take care of the soil and tree needs, which can take a few years before the tree becomes productive, so the farmer has to be very patient (Noordwijk & Verbist, 2000).
Picture Based Lesson to Train Farmers
For the South Asian version (pictures only, text for you to insert), click this link for lesson 6.4:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.4_south_asian.pdf.
For the East/South Asian version (pictures only, text for you to insert), click this link for lesson 6.4:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.4e.s.a.pdf
For the Sub-Saharan Africa/Caribbean version (pictures only, text for you to insert), click this link for lesson 6.4:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.4subsaharan_africa_carribean.pdf
For the Latin-America version (pictures only, text for you to insert), click this link for lesson 6.4:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.4latin_america.pdf
For North Africa And Middle East version (pictures only, text for you to insert), click this link for lesson Chapter 5. 5.3:http://www.sakbooks.com/uploads/8/1/5/7/81574912/5.3n._africa_middleeast.pdf
Source: MN Raizada and LJ Smith (2016) A Picture Book of Best Practices for Subsistence Farmers: eBook, University of Guelph Sustainable Agriculture Kit (SAK) Project, June 2016, Guelph, Canada. Available online at: www.SAKBooks.com
Resources & practical tips to get started
Rood, Sicco, Steve Netto, and Debbie Waldecker. "Restoration." Restoration (n.d.): n. pag. Microcatchment Water Harvesting. Web. 6 Nov. 2016. Retrieved from: http://www.sci.sdsu.edu/SERG/techniques/microcatch.pdf This contains lots of information regarding what micro catchment is and how it can help contribute towards agriculture.
"5.Water Harvesting Techniques." 5. Water Harvesting Techniques. FAO, n.d. Web. 18 Nov. 2016. Retrieved from: http://www.fao.org/docrep/U3160E/u3160e0a.htm#TopOfPage This source contains easy information on “how to” make bunds around fruit trees that farmers can easily read and follow.
Sourcebook of Alternative Technologies for Freshwater Augmentation in Africa. N.p., 2003. Web. 30 Nov. 2016:
References
1. FAO (201x) Water Harvesting Techniques." 5. Water Harvesting Techniques. FAO, n.d. Web. 18 Nov. 2016. Retrieved from: http://www.fao.org/docrep/U3160E/u3160e07.htm
2. FAO.org." Basic Knowledge | FAO | Food and Agriculture Organization of the United Nations. N.p., n.d. Web. 20 Nov. 2016. Retrieved from: http://www.fao.org/sustainable-forest-management/toolbox/modules/use-of-treated-water-in-forestry-and-agroforestry/basic-knowledge/en/
3. Finding, Preliminary. Trees, Forests and Land Use in Drylands (n.d.): n. pag. Trees, Forests and Land Use in Drylands. Web. 20 Nov. 2016. Retreived from: http://www.fao.org/3/a-i5905e.pdf
2. Water and Soil Requirements." 2. Water and Soil Requirements. N.p., n.d. Web. 20 Nov. 2016. Retrieved from: http://www.fao.org/docrep/u3160e/u3160e04.htm
4. N, Hatibu. , H, Mahoo. , (1999). Rainwater Harvesting Technologies for Agricultural Production. A case for Dodoma, Tanzania. Retrieved from: http://www.sswm.info/sites/default/files/reference_attachments/HATIBU%20%26%20MAHOO%201999%20Rainwater%20Harvesting%20Technologies%20for%20Agricultural%20Production.pdf
5. R, Awodoyin. , J, Ugochukwu. , R, balogun. , Indigenous Fruit Trees of Tropical Africa: Status, Opportunity for Development and Biodiversity Management. , (2014, Nov 28). Retrived from: http://file.scirp.org/pdf/AS_2015010821152771.pdf
6. Waelti, Corinne, and Dorothee Spuhler. "Bunds." Bunds , SSWM. N.p., n.d. Web. 18 Nov. 2016. Retrieved from: http://www.sswm.info/content/bunds
7. An Introduction to Rainwater Harvesting." An Introduction to Rainwater Harvesting. N.p., n.d. Web. 18 Nov. 2016. Retrieved from: http://www.gdrc.org/uem/water/rainwater/introduction.html
8. Fidelibus, Matthew W., and David A. Bainbridge. "Restoration in the Colorado Desert:." Restoration in the Colorado Desert:. N.p., July 1994. Web. 18 Nov. 2016. Retrieved from: http://www.sci.sdsu.edu/SERG/techniques/microcatch.html
9.Sourcebook of Alternative Technologies for Freshwater Augumentation in Africa." Sourcebook of Alternative Technologies for Freshwater Augumentation in Africa. N.p., n.d. Web. 29 Nov. 2016: Retrieved from: http://journals1.scholarsportal.info.subzero.lib.uoguelph.ca/pdf/01401963/v30i0002/143_dffsd.xml
10. Bainbridge, David A. "University of Guelph Library." New Log In - Off-campus Log In - University of Guelph Library. N.p., 9 Aug. 2000. Web. 28 Nov. 2016: Retrieved from:http://journals1.scholarsportal.info.subzero.lib.uoguelph.ca/details/01401963/v95icomplete/22_eorhomatrotd.xml11. Ouya, Daisy. "Indigenous African Fruit Trees." N.p., 7 Aug. 2013. Web. 28 Nov. 2016: Retrieved from: http://blog.worldagroforestry.org/index.php/2013/08/07/the-little-understood-indigenous-african-fruit-trees/
12. Ibraimo, N., and P. Munguambe. Rainwater Harvesting Technologies for Small Scale Rainfed Agriculture in Arid and Semi-arid Areas (n.d.): n. pag. Feb. 2007. Web. 30 Nov. 2016: Retrieved from: http://www.sswm.info/sites/default/files/reference_attachments/IBRAIMO%20&%20MUNGUAMBE%202007%20Rainwater%20Harvesting%20Technologies%20for%20Small%20Scale%20Rainfed%20Agriculture%20in%20Arid%20and%20Semi-arid%20Areas.pdf