By JAMES TABABA
Many agricultural areas in the Philippines are situated on slopes or steep terrain, which can pose challenges for farming. Sloping agricultural areas in the Philippines are particularly vulnerable to soil erosion and nutrient depletion, which can lead to reduced crop yields and lower soil fertility.
Soil erosion is a problem in sloping land because the slope of the land increases the speed and volume of water runoff during heavy rainfall, making it easier for the water to carry away soil particles. This erosion process can lead to the loss of fertile topsoil—which is essential for growing crops—and can result in reduced crop yields and even crop failure.
Despite the challenges posed by sloping agricultural areas, many farmers in the Philippines continue to plant crops on steep terrain, often relying on traditional farming practices and local knowledge to adapt to the unique characteristics of the land. In some regions, farming on sloping land is a longstanding tradition that is deeply rooted in local culture. Farmers may be hesitant to abandon this practice, even if it poses challenges. Moreover, flat land may be scarce or already in use for other purposes, such as urban development. As a result, farmers may have no choice but to plant on sloping land if they want to grow crops.
To mitigate the impact of soil erosion on agriculture in sloping land, farmers can use various conservation practices such as terracing, contour farming, mulching, conservation tillage, and the use of cover crops to help reduce erosion and promote soil conservation. Here are some of them:
Terracing is a local traditional practice on farms with sloping lands. It can be observed in certain areas of Banaue, Batad, and Mayoyao in Ifugao, as well as some parts of the Cordillera Mountains. Terracing is an effective method for preventing soil erosion because it reduces the speed and force of water runoff, which is a major cause of soil erosion.
Terracing is a farming technique that involves cutting into the slope of the land to create leveled areas at intervals. The soil excavated from the cuts is utilized to construct retaining walls, which not only prevent soil erosion and water runoff but also enhance the overall stability of the slope. Occasionally, stones are also incorporated into the construction of these walls to reinforce their structural integrity.
After the completion of terracing, farmers can utilize the leveled surfaces for crop cultivation. The terraces help retain water and soil nutrients. Additionally, the flat areas allow farmers to use machinery for planting, and harvesting.
Contour farming is a practice that involves planting crops perpendicular to the slope of sloping land. The purpose of contour farming is to reduce soil erosion and increase water retention by creating furrows that run horizontally along the slope. The furrows created through contour farming play a crucial role in regulating the velocity of water, enabling it to penetrate the soil more efficiently. Also, it minimizes the probability of surface runoff and enhances the soil’s capacity to retain moisture.
To carry out contour farming, identify the contour lines of the land, which are the points of uniform elevation connected by imaginary lines. Next, plant the crops perpendicular to these contour lines, thereby creating furrows that run along the slope of the land to minimize water runoff. To optimize the effectiveness of these furrows in reducing soil erosion, hedgerow crops can be planted in line with the furrows. Hedgerow crops are a variety of plants that are grown alongside or within hedges. Hedges are rows of bushes and trees that farmers usually use to define field boundaries. Hedgerow crops can consist of different types of plants, such as fruit trees, bushes, and flowers.
Cover cropping is a practice in agriculture where a secondary crop, known as a cover crop, is grown in between cycles of primary crops. The purpose of this practice is to protect and improve soil health by preventing soil erosion, retaining soil moisture, and increasing soil organic matter.
During the periods between main crops, the soil is left bare and vulnerable to the elements, especially heavy rainfall. Without any protection, raindrops can hit the soil surface with force, leading to soil erosion, especially in sloping lands. This can result in the loss of fertile topsoil, which reduces soil productivity and nutrient availability for crops.
By planting cover crops, a protective layer is created over the soil which shields the soil from the impact of rainfall. This minimizes soil erosion and keeps the soil in place. Additionally, the cover crop’s roots help to maintain soil moisture levels by absorbing water and preventing it from evaporating from the soil surface. Cover crops also increase soil organic matter through the deposition of plant residues, which improves soil structure, nutrient cycling, and water-holding capacity.
Mulching is a farming practice that involves covering the soil with a layer of organic or inorganic materials, such as leaves, straw, grass, wood chips, gravel, or plastic to improve soil health, conserve moisture, and prevent soil erosion.
Mulch reduces the impact of rainfall by acting as a protective that slows down the flow of water and prevents it from dislodging soil particles. Furthermore, organic mulches can break down and decompose, enriching the soil with additional organic matter, nutrients, and microorganisms. This improves soil structure, making it more resistant to erosion. Also, mulch helps in retaining moisture in the soil, reducing the need for irrigation and preventing the soil from becoming too dry and prone to erosion
Conservative tillage practices in sloping land typically involve minimal disturbance of the soil surface. It involves leaving crop residues on the soil surface and reducing the number of times the soil is disturbed. By leaving the crop residues on the soil surface, the soil is protected from erosion by reducing the force of rainfall and preventing wind from directly contacting the soil surface. By reducing soil erosion, conservative tillage practices help to maintain soil fertility, prevent nutrient loss, and promote crop growth.
Farming practices to reduce soil erosion are important for farmers to know because they can help prevent the loss of fertile topsoil, maintain soil health, and increase crop yields. Soil erosion can lead to reduced soil fertility, which can make it difficult for farmers to grow crops and sustain their livelihoods. By adopting conservation practices such as terracing, contour farming, cover cropping, mulching, and conservation tillage, farmers can reduce erosion and promote soil conservation, which can lead to more productive and sustainable agriculture. Additionally, these practices can also help mitigate the impact of extreme weather events, such as heavy rainfall or drought, which can further affect crop yields and soil health.