Indigenous farming practices in Arunachal Pradesh improve soil, water, and farm sustainability

In the hills, survival depends on understanding the land. When rainfall is intense and slopes are steep, soil and water can be lost as quickly as they arrive. Modern solutions often try to fix these problems from the outside. But in Arunachal Pradesh, many communities have long managed them from within.

A recent study shows that traditional farming practices developed over generations are not just cultural habits. They are practical systems that conserve soil, manage water, and sustain agriculture in some of the most challenging landscapes.

Water and soil are extremely important for sustaining agriculture but are facing increasing threats in hilly areas such as Arunachal Pradesh, where high annual rainfall (1380-5000 mm) and mountainous topography lead to high runoff, while human activities such as deforestation, burning of forests and grasslands, urban growth, mining, stone quarrying, and unsustainable agricultural practices have led to soil erosion. 

The study titled ‘Traditional soil and water conservation by tribal farmers in Arunachal Pradesh: A case study on erosion control’ published in the Indian Journal of Traditional Knowledge, authored by Suryavanshi, A., et al., finds that the region has a number of traditional farming practices that have been followed by the Garo tribes for generations that maintain the richness of the soil, prevent erosion and save water. 

The study assessed the relevance and effectiveness of these indigenous practices in enhancing productivity and natural resource management and for developing region-specific policies to  support and benefit farmers in Arunachal Pradesh.

The study used surveys, field observations, group discussions, and key informant interviews to explore the role of various management practices in soil and water conservation (SWC) and agricultural production adopted by tribal farmers across three elevation zones: low (172-718 m), medium (719-1094 m), and high (1095-1886 m).

Conservation practices implemented by farmers

Farmers used a range of methods such as wetland rice cultivation (Esirik), contour farming, mulching, agroforestry, vegetative barriers, bamboo channel irrigation systems (Kombo), mixed crops, water-harvesting structures, and traditional soil conservation methods.

Esiarik (Wetland rice cultivation) 

Paddy cultivation covers approximately 0.13 million hectares and yields around 0.23 million tons of paddy, with an average productivity of 1814.8 kg/ha in Arunachal Pradesh.

Wetland rice cultivation, locally referred to as 'Esiarik', is most commonly practised in the Leparada district, followed by the Tirap and lower Subansiri districts of the state. The rice variety grown by this method is referred to as Mipun. The method involves terraced cultivation on hillsides in areas where soil has a good water-retaining capacity and shapes steep, sloped land into flat, step-like terraces to cultivate crops. Terraces are constructed with shoulder bunds (Pabey) to retain water and maintain a water depth of 8-12 cm in the region. The height and horizontal spacing of terrace bunds are similar in all elevation zones. 

This method helps regulate water levels, reduces wastage of water, improves irrigation efficiency, and maintains a uniform depth of water in the fields while limiting runoff and soil erosion. Wetland rice fields act as carbon sinks, absorbing CO₂ from the atmosphere and storing it in soil, thus helping to mitigate climate change by reducing greenhouse gas emissions.

Contour farming 

Contour farming is done on sloping land and involves growing crops perpendicular to the slope, which helps reduce slope length, absorbs the force of heavy rainfall, prevents soil erosion and reduces runoff. As high as 68 percent of the farmers in the region use contour farming on slopes to conserve water and soil. 

Farmers in the region grow maize, yam, tapioca, ginger, turmeric, colocasia, and sweet potato using contour farming and have found that this has led to a 10-15% increase in crop yield and a 50% decrease in soil erosion. 

Mixed cropping.

In Arunachal Pradesh, mixed crops are cultivated in Jhum regions. Jhum cultivation is a traditional land-use system in which a patch of the forest is utilised for agricultural cultivation for a few years and then cultivation is shifted to a new site for the next cycle. This method is widely practised in North East India and is best suited for the climate and topography of the region. However, in recent years, an increase in population is forcing farmers to reduce the time span for Jhum cultivation, leading to a reduction in soil fertility. Mixed cropping provides an answer to this. 

While the major crop in the region is rice (Bali-upland rice), cereals, legumes, oilseeds, fruits, cash crops, and spices are also grown by the farmers in the region by using mixed cropping on Jhum land. 

Mixed cropping aids in crop growth by making maximum use of nutrients from the soil by providing different nutrients at different depths, ensuring nutritional security for the farmers. It helps improve soil quality, maximises resources, helps in recycling nutrients and biomass, protects crops and helps mitigate drought impacts.

Mulching 

Mulching involves the practice of covering the soil surface around plants with organic protective material such as wood, straw, leaves, or plastic sheeting. The material acts as a "blanket" to conserve soil moisture, prevent erosion in times of heavy rainfall, suppress weeds, regulate soil temperature, and improve soil fertility. 

Mulching is practised by 75% of the farmers in the area. Farmers mainly use dry leaves of the Toko tree common in the region as mulch for plants like bananas, mandarin, papaya, and pineapple. In addition, rice crop residue is spread across fields during the winter months of December and January for mulching, which reduces irrigation requirements by 30%. 

Vegetative barriers

Roots of vegetative barriers such as grasses, shrubs, trees, and cover crops bind the soil and prevent erosion, control sediment, and stabilise slopes on sloped lands. They are commonly used by communities throughout Leparada district. 

Fodder trees like Schima wallichii (Chilaunay), Ficus nemoralis Wall (Dudhilo), Melia azedarach L. (Bakaino), Ficus roxburghii Wall (Nebara), Artocarpus lakoocha (Badahar), Ficus nemoralis (Khaneu), Engelhardtia spicata (Mahua), and F. clavata (Khaneulutey) are used as barriers by the farmers. Crops such as F. macrophylla (Flemingia), Tephrosia purpurea (Sharapunkha), and C. ochroleuca G. Don. (Crotalaria) are used to control erosion and providing shade. Natural grasses such as Thysanolaena maxima (Amlisho) and Pennisetum agrostis (Napier) are also used as vegetative barriers.

Water harvesting structures 

Arunachal Pradesh receives as high as 2500 mm of rainfall heavy rainfall from June to September that leads to intense runoff. Communities in the region thus construct a range of water-harvesting structures, such as farm ponds, dugout ponds, lined ponds and Jalkunds, to store water. Jalkunds are small water harvesting structures, situated on hilltops or in the middle of slopes, whereas farm ponds are located in the lower areas of farms. Land at higher elevations is irrigated by pumping water from these ponds, while the land below is irrigated through gravitational flow. Water harvesting ponds are used by as high as 69% of farmers in the area for irrigation. 

Jalkunds are mainly found in Basar, Pagi, Gori, and Lipunamchi villages within the Leparada district and are used to irrigate maize, soybean, mustard, cabbage, chilli, peas, tomatoes, and potatoes. 

Traditional bamboo channel irrigation system 

Bamboo is abundant and is commonly used for transporting water from springs in the mountains to irrigate paddy fields during dry spells in the region. Hamilton's bamboo (Dendrocalamus hamiltonii), locally called ‘Eni’, available in various sizes, is used as a water conveyance channel referred to as ‘Kombo’ by the local tribes. Bamboo channels are built locally by the villagers and have a length of 10-15 m, a diameter of 10-12 cm, and a flow rate of approximately 0.2 L/s (without rain), sufficient for one field. The length of the channel varies from 5 to 10 km. The channels can last upto one year or more. About 50% of the farmers in the region use the bamboo channel irrigation system to irrigate their fields.

'Paper', the traditional soil conservation system 

Paper, a traditional soil conservation technique in Arunachal Pradesh, involves the strategic placement of bamboo or wood logs in Jhum fields across the slopes. This creates barriers to the runoff originating on steep slopes and prevents soil erosion, retains soil moisture, promotes healthy plant growth, and enhances soil fertility. The wooden logs typically measure 3-4 m in length and 8-12 cm in diameter, with horizontal spacing between them ranging from 4-6 m. 

This practice is increasing as farmers find it cost-effective, environmentally friendly, and well suited to local terrain and resources. Almost 60% of the farmers use Paper in their Jhum fields. The Paper technique can help retain approximately 160 tons of soil per hectare per year. 

Traditional Agroforestry for soil conservation 

Agroforestry is a sustainable land-use system that integrates trees and shrubs with crops and/or livestock on the same land to improve biodiversity, enhance soil health, and increase farmer income.

In the Sago circle, one of the administrative units of the Leparada district, agro-silviculture is practised by retaining trees such as Hollock and Mulberry within Jhum fields and planting them along the periphery. 

Similarly, in the Tirbin circle, Broom grass is cultivated along the margins of terraced crops, which prevents soil erosion. A variety of fruit trees like orange, pineapple, and banana, are planted alongside forest trees such as Gurjan, Siris, Blume, Needlewood and Wattle. These trees provide fuel, timber, and fodder and enhance the soil through nitrogen fixation. 

At times, grasses and bamboo are grown along side tree groves. Common bamboo species such as Hamilton's bamboo, Munro and Cane break Bamboo and common grasses such as Bermuda grass, Guinea grass, Cogon grass or kunai grass, Broom grass etc  provide ground cover to protect against soil erosion. Bamboo species, Bermuda grass, and Guinea grass are preferred by farmers in the region for soil conservation and erosion control.

What can be done at the level of policy and practice

• Conserve and integrate indigenous knowledge through documenting traditional conservation practices to ensure that they are not lost and can be scaled through watershed management programmes.

• Involve local representatives and village councils in decision-making to build ownership and ensure that interventions are context-specific rather than one-size-fits-all.

• Agricultural Extension workers can act as bridges and help farmers adapt indigenous methods with modern soil science.

• Use technology to map erosion-prone zones and use local knowledge to direct resources where they are needed the most.

• State-level watershed management policies should mandate the inclusion of indigenous practices, not just as “heritage” but also as active, proven strategies for resilience.

The paper argues that this will help in passing this valuable knowledge to future generations, help build ecological sustainability and help build resilience in high-rainfall areas.