Chapter 5.2

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514px-Terraces.jpg

Source:https://en.wikipedia.org/wiki/Erosion_control

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

Introduction

In arid and semi-arid nations, those with <1000 mm of annual rainfall, subsistence farmers are faced with the difficulty of growing their crops while reliant on low and often inconsistent rainfall (Nyamangara and Nyamgumbo 2009). The Northern and Southern parts of Africa for example, are often plagued by these rainfall issues with erratic rainfall years correlating to low crop yields (Kijne et al., 2003). When rain does come, the water comes at high intensities, proves to be very erosive, and results in soil runoff (Biamah et al., 1993). A secondary issue is that water runoff detaches soil particles resulting in erosion and loss of soil fertility (Aina 1993). The effects of this issue can be seen when looking at the strong correlation between overall GDP growth in African nations and heavier rainfall seasons. (Biazin and Stroosnijder 2012). Adversely, long lasting droughts have been shown to have dire effects globally including crop yield, poor human nutrition, severe malnutrition and famines (Sivakumar 1992). This pattern shows the importance of water retention practices for subsistence farmers in low rainfall area. One such method which has shown to be effective, is tied ridging. Tied ridging has been shown to be successful in harvesting rainwater in low rainfall areas, reducing water runoff and creating higher water retention in crop fields (Biazin and Stroosnijder 2010).

Practice and Products Required

Tied ridging is the practice of creating small, divided furrows 2 to 3 m long in order to create small basins within which the water accumulates (Araya and Stroosnijder 2010). Tied ridging is similar to many subsistence farmers’ current tillage practices of creating long ridged furrows in a field, with the addition of repeated walls of soil in the furrows in order to create small soil basins. This method involves adding a disk to the back of an ox-drawn ridging plow, dropping the disk down for 2-3 m to leave small ridges of soil after which the disk is lifted for a few seconds (to establish the position of the mound of dirt or tie) and then dropped down again to create the next basin. A typical resulting basin should be around 15 cm wide and 15 cm deep (Biazin and Stroosnijder 2012). The recommended length of the furrows is between 2-3 m long (Bimah et. al., 1993). In order to prevent breakage of the ridges, it is best to create the ridges before the first rainfall (Biamah et al., 1993). Tied ridging is optimal for lands with less than a 7% slope gradient, after which the runoff benefits of the practice are negated (Lal 1995). This practice aims to prevent uneven distribution of rainfall, promote soil productivity and create higher water retention in crops (Araya and Stroosnijder 2010). Tied ridging’s similarities to current tillage practices allows for easier understanding of the practice and more seamless introduction to subsistence farmers.

Possible Benefits

Tied ridging has been shown to prevent runoff and improve water retention, resulting in higher crop yields. Empirical evidence shows improved water retention when this method is used in the drought season and more even distribution of water across the crop field (Araya and Stroosnijder 2010). As the soil is now contained within small ridges, it drastically reduces the amount of soil and water runoff (Donovan and Casey 1998). In a 1993 study in Kenya, tied ridging resulted in 13.7% seasonal runoff, significantly lower than the 38.0% and 42.7% runoffs observed in manure and conservation tillage practices respectively (Biamah et al., 1993). In a 1967 study in Burkina Faso, tied ridges were shown to result in 0.9% water runoff, a vast improvement over ploughed ridges with water runoff rates of 12.2% (Aina 1993). These studies lend strong support to the water harvesting powers of the tied ridging method.

secondary benefit of reducing water runoff is the retention of the nutrient-rich organic matter which maintains soil nutrients, thereby resulting in better soil fertility (Donovan and Caset 1998). This nutrient retention benefit, along with the water retention, has been shown to increase crop yields. Tied ridges can make dramatic improvements to farmers’ yields, especially in low rainfall seasons, which can create more consistent year-round profits (Biazin and Stroosnijder 2012). In the aforementioned study conducted in Kenya, researchers found the soil moisture content to be 1.8% to 2.1% higher in tied ridging plots versus minimum and conventional tillage practices up to a soil depth of 100 cm (Biamah et al., 1993). In that same study, tied ridging resulted in 513 kg/ha-1 in maize green yield versus less than half that, 221 kg/ha-1, using conventional tillage methods (Biamah et al., 1993).

Environment Best Suited to Tied Ridging

The method of tied ridging has been found to be most effective in coarse soils rather than dense clay soils, and areas with up to 1000 mm of annual rainfall (FAO, 2016). Tied ridging on clay soils has been shown to create water-logging and thus is better avoided (Aina 1993). Water-logging has also been shown in high rainfall areas and seasons, and therefore best used in areas characterized by low rainfall (Ogunwole 2004). In times of unseasonably high rainfall, a solution to avoid water-logging is to open up the ridges further creating larger surface areas within which the rainwater collects (Araya and Stroosnijder 2010).

Limits to Adoption and Proposed Solutions

Despite the empirical evidence supporting its efficacy, there are issues which require attention in order for subsistence farmers to adopt the practice (Dube et al.) There are important impediments in promoting the adoption of this practice, which lie in the economical and labour requirements of the practice, as well as the promotion both of insects and weeds.

With respect to the machinery needed, the practice is reliant upon equipment with assumed costs of around $300 CAD (Dube et al.). This presents resistance in adoption, especially for farmers who are without any of the equipment (Dube et al.).

Tied ridging also requires heavy labour upon inception of the practice, and requires upkeep throughout the season in order to ensure the ridges stay intact (Dube et al.). The high levels of labour required, often by men, have seen the method faced with resistance when introduced (Dube et al.). Another difficulty lies in the need for animal labour, which is not readily available to all subsistence farmers (Dube et al.).

A proposed solution to the above challenges is to create the practice as a communal operation, which is seen as a way of circumventing apprehensions surrounding labour requirements and associated costs (Dube et al.). Alternatively, a local entrepreneur may be able to rent the equipment on a fee basis. Another way to reduce the labour time is to lengthen the ridges up to 4 m long, as little to no difference has been found in terms of yield between basins of 2 and 4 m in length (Wiyoa, Kasomekerab, Feyena, 1999).

With the increase of still water comes the potential for the proliferation of insects in the soil. As a result of the pooling of water, which is especially prominent in more dense soils, insects may be attracted (Vesterager et al., 2007). This has been addressed by increasing the use of insecticides on the soil, as a preventative measure (Vesterager et al., 2007).

Another challenge that can be encountered is that of weeds. With the creation of extra water as well as bare soil between the rows of ridges, it creates conditions prone to more weeds (FAO 2016). A possible solution to this is to plant a cover crop over the bare land. As well as preventing the emergence of weeds, the core crops can also serve a variety of other uses such as animal feed and firewood or fuel sources (FAO 2016).

Picture Based Lesson to Train Farmers

Click on the image to access a higher resolution image as well as lessons adapted for different geographic regions.

For the South Asian version (pictures only, text for you to insert), click this link for lesson 6.2:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.2_south_asian.pdf

For the East/South Asian version (pictures only, text for you to insert), click this link for lesson 6.2:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.2e.s.a.pdf

For the Sub-Saharan Africa/Caribbean version (pictures only, text for you to insert), click this link for lesson 6.2:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.2subsaharan_africa_carribean.pdf

For the Latin-America version (pictures only, text for you to insert), click this link for lesson 6.2:http://www.sakbooks.com/uploads/8/1/5/7/81574912/6.2latin_america.pdf

For North Africa And Middle East version (pictures only, text for you to insert), click this link for lesson Chapter 5. 5.1:http://www.sakbooks.com/uploads/8/1/5/7/81574912/5.1n._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

Practical Resources and Links To Get Started

Indiamart primarily sells in India, with low end prices for ploughs starting around 14,000 INR ($277 CAD) http://www.indiamart.com.

Alibaba is a global online marketplace from China primarily selling products in bulk orders. Ploughs are available for as little as $18 contingent upon the ordering of 100 items. This may present an opportunity for community or governmental intervention in order to help facilitate this purchase within a community https://www.alibaba.com.

The University of Nebraska has published a guide for smallholder farmers to determine whether or not the tied ridging practice will work well with their field conditions, entitled ‘A Decision Guide for Tie-ridging in the Semi-Arid Areas of Ethiopia’ https://www.google.ca/#q=‘A+Decision+Guide+for+Tied-ridging+in+the+Semi-Arid+Areas+of+Ethiopia'.

It also might be helpful to provide farmers with visual resources,pictures of the field with tied ridges (https://energypedia.info/images/thumb/b/bd/TieRidge.png/275px-TieRidge.png).

References

1. Aina, P. (1993). Soil tillage in Africa: Needs and challenges. Rome: Food and Agriculture Organization of the United Nations.

2. Araya, A., & Stroosnijder, L. (2010). Effects of tied ridges and mulch on barley (Hordeum vulgare) rainwater use efficiency and production in Northern Ethiopia. Agricultural Water Management, 97(6), 841-847. doi:10.1016/j.agwat.2010.01.012

3. Biamah, E., Gichuki, F., & Kaumbutho, P. (1993). Tillage methods and soil and water conservation in eastern Africa. Soil and Tillage Research, 27(1-4), 105-123. doi:10.1016/0167-1987(93)90064-v

4. Biazin, B., & Stroosnijder, L. (2012). To tie or not to tie ridges for water conservation in Rift Valley drylands of Ethiopia. Soil and Tillage Research, 124, 83-94. doi:10.1016/j.still.2012.05.006

5. Donovan, G., Casey, F. (1998). Soil Fertility Management in Sub-Saharan Africa. Washington, D.C.: World Bank

6. Dube, D., Nagambie, I., Nehanda, G., Senzanje, A., 4.1 Tied Ridging -- Domboshawa, Zimbabwe. (n.d.). Retrieved October 10, 2016

7.FAO (2016) Conservation agriculture. Food and Agricultural Organization of the United Nations, Rome. Retrieved November 20, 2016 from -http://www.fao.org/ag/ca/AfricaTrainingManual/html

8. Kijne, J. W., Barker, R., & Molden, D. J. (2003). Water productivity in agriculture: Limits and opportunities for improvement. Oxon, UK ; Cambridge, MA: CABI.

9. Lal, R. (1995). Tillage systems in the tropics: Management options and sustainability implications. Rome: Food and Agriculture Organization of the United Nations.

10. Nyamangara, J., Nyamgumbo, I. (2009). Interactive effects of selected nutrient resources and tied-ridging on plant growth performance in a semi-arid smallholder farming environment in central Zimbabwe. Nutr Cycle Agroecosyst, 88:103-109. doi: 10.1007/10705-009-9282-7

11. Ogunwole, J. O. (2004). Effects of Fertilizer and Time of Ridge-Tie on Yield and Fibre Quality of Late Sown Cotton in the Dry Savanna Zone of Nigeria. Journal of Sustainable Agriculture, 24(3), 97-107. doi:10.1300/j064v24n03_07

12. Sivakumar, M. V. (1992). Empirical Analysis of Dry Spells for Agricultural Applications in West Africa. Journal of Climate, 5(5), 532-539. doi:10.1175/1520-0442(1992)0052.0.co

13. Vesterager, J. M., Nielsen, N. E., & Høgh-Jensen, H. (2007). Effects of cropping history and phosphorus source on yield and nitrogen fixation in sole and intercropped cowpea–maize systems. Nutrient Cycling in Agroecosystems, 80(1), 61-73. doi:10.1007/s10705-007-9121-7

14. Wiyo, K. Kasomekera, Z., & Feyen, J. (2000). Effect of tied-ridging on soil water status of a maize status of a maize crop under Malawi conditions. Agricultural Water Management, 45(2), 101-125. dos: 10.1016/s0378-3774(99)00103-1