Soil Degradation Challange - Report Example

Introduction

Soil degradation is one of the major challenges the world is grappling with, as it threatens food systems and ecological healthy (Scherr., 2001; Zhu., 2020). The degradation is pronounced in sub-Saharan Africa (Zoebisch, & De Pauw.,2017, Ussiri, & Lal.,2019), depriving more than 35% (Montanarella et al., 2015) arable landmass of its ecological roles. Degradation in this region is aggravated by factors such as; unregulated deforestation (Chinzila., 2017), indiscriminate use of chemicals as fertilizers and pest control, and improper agricultural practices (Tindwa et al., 2019) among others. Vegetation clearances expose the soil to erosion factors, which accounts for more than 70 billion tons of agricultural soil loss (FAO., 2017).

In Kenya, soil erosion ranks as the primary mechanism of soil degradation, and its effect is exacerbated in arid and semi-arid regions. Soils in such areas are less developed, with inherently low clay content characterized by imbalanced salts responsible for particulate deflocculation. The additive effect of such factors results in poor and weak structured soil that is easily eroded if not protected. Susceptibility of such land to erosion is worsened by erratic rainfall experienced in drylands (Sidle et al., 2018), resulting in the development of gullies and landscape ravines. According to Henry (2018), drylands support the majority of the most impoverished communities, who depend on the natural endowment for their survival, such as; charcoal burning, firewood, and livestock. Their poor resource status hinders the effective implementation of soil degradation management strategies (Shiferaw.,2002). As the rate of desertification continues growing, many counties in Kenya are at the verge of losing their productive farmland (Nguru & Rono., 2013), A good example is, West Pokot region which was once a forested county is now among the leading soil degraded areas in Kenya.

Historically, the Pokot people were nomadic pastoralists who entirely depended on livestock as a source of their livelihood (Kasmai, Akpa & Olayemi., 2018). Constant movement in search of pasture and water ensured that soil degradation is in check as the land was left to recover for a specified period. The development of restrictive land policies that advocated against nomadism (Migot-Adholla & Little.,1980), coupled with exponential population growth, gradually forced Pokot people to adopt a sedentary lifestyle (Silvestri et al., 2012). Consequently, they were forced to adopt crop farming practices alongside livestock keeping (Orindi, Nyong & Herrero., 2007), which resulted in deforestation of their steep-sloped land for agriculture, fuel, and charcoal. This transition marked the start of alarming soil erosion that has scaled up to annual mudslides in the region (Huho& Kosonei., 2014, DRYLANDS.,2016). The prolonged impact of the constant erosion process has had implications at both farm and landscape levels.

At farm level impacts of soil erosion are magnified in the poor crop productivity hinged on soil fertility loss (Kagabo et al.,2013). With an average land slope of more than 10%, the loss of nutrients at the farm level is primarily by surface runoff. According to (Lal & Mishra.,2015), a land of more than 5% slope losses about 1.5 tha-1 of topsoil, more than 0.1 Kgha-1 nitrogen, 8.0 Kgha-1 phosphorus, and 5.0 Kgha-1 potassium. Water erosion also significantly contributes to the loss of soil organic carbon (Cantón et al., 2.14), which is a fundamental aspect of soil fertility. To curb soil erosion at the farm level, the farmers have adopted various soil and water conservation techniques, which include; stone bands, planting live fences around their farms, and terrace construction. The application of the techniques is subjective, with each farmer adopting one or a combination of methods depending on understanding.

Unlike live fences and stone banding, which have been practiced for a long time, land terracing is a new technology on the process of adoption as a farm level soil and water conservation strategy. Given the community skewed gender issues, implementation and maintenance of such structure have been slow and improperly done with less consideration of fundamental factors such as; type of soil characteristics, slope, and rainfall intensity. Thus, this study was conducted to evaluate in general how farmers utilize different soil and water conservation strategies at farm level with specific interest on terrace types, construction protocols, maintenance practices, and deemed benefits in the Chepareria sub-location of West Pokot County, Kenya.

Description of the study area

Data collection

A three methodology approach was used in the collection of data; (1) focus group discussion, (2) survey, and (3) observation and measurement.

• Focus group discussion

A group of 12 farmers and key informants (group leaders) from each sub-location (Parak, kapikitony, and Kaprowo) were engaged in the discussion of soil and water conservation techniques. The main focus of discussion was on farm level and landscape soil conservation measures, their benefits, future advancements, and challenges. Regarding terraces, an in-depth discussion was given to the designs, construction protocols, maintenance, and reinforcement.

• Survey

Open-ended purposive-exploratory questionnaires were administered to 40% of the farmers who had terraces constructed in their farms within the study area. Participants were systematically and randomly sampled as per their sub-locations.

• Observation and measurements

The surveys were followed up by Observation of the soil and water conservation measures installed at the farm level and their management practices. On the other hand, terrace characteristics such as vertical interval, dyke cross-sectional area, terrace length, siltation level, and farm slope were measured.

Vertical interval

Vertical interval, which refers to space between two subsequent terraces were directly measured using a tape measure. Measurements taken were from the center of one terrace dyke to the center of a subsequent terrace dyke.

Terrace Volume

According to designs of terraces used by farmers, their volume was calculated by the formula;

Height of cross-section × width of cross-section × length of the channel. The same method was used to calculate the amount of silt accumulation in the dyke.

Result and Discussion

The study found that gender is a critical factor in the adoption and maintenance of soil and water conservation measures at the farm level. Traditionally the Pokot men are mandated to look after livestock and protect the community against external aggression while women are responsible for farming activities. With a sedentary lifestyle, such norms and culture are still in practice. Women are involved in demanding homestead activities; hence less focus is given to soil degradation dynamics in their farm. Few realize the importance of conserving farmland soil, and They opt for more uncomplicated techniques such as stone banding and live fence planting. Those who practiced other soil and water conservation techniques such as terracing had been motivated by the no-governmental organizations working in the region.

Figure 1. Farm-level Soil and water conservation technologies adopted by farmers in Kapikitony, Parak, and Kapporwo before the FRN project.

FRN coordinated terrace construction

Farmer-Research network project has spearheaded soil and water conservation strategies, and one of the significant techniques advocated by the project is terracing of sloped farmlands. Terrace construction under the project was started in 2017. For the three years; 2017, 2018, and 2019, farmers attached to the project saw their farms terraced. The study found that 22.7%, 59.1%, and 4.9% of homesteads received terrace construction in the three years. The construction protocol was pegged on only two factors; the slope of the land and severity of gullies resulting in two main types of terraces; Fanya juu and Fanya Chini. Dimensions were set uniform for the three sub-locations that is; 1meter depth, and 0.6meter width.

Terrace volume per sub-location

Terrace volume indicates the amount of water and soil that can be held from surface runoff; this is an essential aspect of terrace construction in relation to the rainfall. Parak in which the highest point of Chepareria has an average of 103.8±21.45m3while 105.89±33.126 m3, and 129.6±15.966 Kapikitony and Kapporwo respectively. Other factors such as average slope and vertical interval are indicated in table 1

Table 1. Terrace average length, slope and vertical interval for the three Chepareria sub-locations

sub-location

Average terrace length

Average vertical interval

Average slope

Kapporwo

216.04±26.61

22.18±4.15

15.83±5.85

Parak

173.00±35.75

23.26±10.14

20.50±12.57

Kapikitony

176.48±55.21

20.24±7.21

10.00±4.47

Terrace benefits

Farmers who had their farms terraced in the past two to three years ranked terrace as the best farm level soil and water conservation practice. They have for experience accrued benefits pegged on improved soil fertility and water availability in their farms. Table 2 indicates some of the benefits realized by farmers.

Figure 2. Terrace benefits experienced by farmers in the three Sub-locations; Parak, Kapprowo, and Kapikitony.

Terrace challenges

Terrace channel siltation is a major challenge experienced by farmers in all the three sub-locations. It was found that 76±4%, 73±5%, and 72±8% of the terrace volume have been silted in Parak, Kapprowo, and Kapikitony, respectively. Farmers with filled terrace dykes estimate that it took less than 12-24 months. Some terraces which were constructed just before the heavy rains of 2019 filled in the same season, indicating the severity of soil erosion experienced in the area. Given that women are responsible for most of the farm activities in Pokot, 20% of the farmers find unsupported terrace construction difficulty because of its high energy demand and time consumption.

Terrace reinforcement

Reinforcement of terrace mounts is vital in regulating siltation and increasing their lifespan. It also reduces the cost and resources channeled to terrace maintenance. The study found that only 31.8% of farmers with terraces have them reinforced. Locally available shrubs, including; Aloe vera (Aloe spp) and cactus (Cactaceae spp), are commonly used reinforcement materials used by the farmers. Despite the low number of farmers who practice terrace reinforcement, all other farmers are willing to engage in future terrace reinforcement, acquiring the right information on the process and crops effective in support. However, farmers also have the criteria they wish the reinforcement materials to meet in terms of benefits. They discern for grass, trees, or crops that possess multiple benefits and can withstand the local climatic conditions. Table 3 indicates some of the reinforcement materials suggested by farmers.

Table 2. Some of terrace reinforcement materials suggested by farmers

Grass

Trees

Sweet potatoes

Vegetables

Shrubs

Dolichos

Kapporwo

50.00%

50.00%

66.70%

0.00%

0.00%

0.00%

Parak

70.00%

20.00%

80.00%

10.00%

10.00%

10.00%

Kapikitony

80.00%

60.00%

60.00%

0.00%

20.00%

0.00%

Alongside terrace reinforcement, farmers also plan to initiate a recommendation program that will see their neighbors and farmers from other parts, especially those on upland areas, terrace their farms. They claim the strategy will reduce the amount of water from higher sloped regions that flow in their farms, resulting in soil erosion and destruction of soil and water conservation structures.

Conclusion

Soil erosion is the principal land degradation process experienced in West Pokot aggravated by land characteristics (high slope), soil characteristics (young and fragile), and anthropogenic characteristics (livestock overstocking, improper cultivation, deforestation, and gender-related culture that hinder effective response to soil degradation among others). Advent of community farm level soil and water management practices is a promising tool that can be effectively be utilized to shift the fight against food insecurity which has threatened the wellbeing of the community for decades. Terrace construction has been embraced by farmers and technologies around it should be enhanced to ensure its efficiency.