Best Practices for Land Selection and Preparation in Tasar Plantations

Tasar silk – also called “the gold of forests” – depends heavily on the health of its host food plants like Terminalia arjuna (Arjun) and Terminalia tomentosa (Asan). And the health of these plants starts long before a single seed is sown. It starts with choosing the right piece of land and preparing it properly. A poorly selected or unprepared site can lead to stunted plant growth, low foliage yield, and ultimately, poor silkworm rearing outcomes. In this post, we break down the best practices for land selection and preparation in tasar plantations – from terrain evaluation and soil testing to deep plowing and green manuring.

Why land selection matters in tasar plantations 🔗

Tasar silkworms (Antheraea mylitta) are reared outdoors on food plants that grow as tall trees in natural and managed settings. Unlike mulberry sericulture, which can be practiced in compact garden plots, tasar cultivation requires relatively open land with conditions suited to perennial tree growth. The Central Silk Board notes that eight primary food plants for tropical tasar silkworms are recognized, including Asan, Arjun, Sal, Sidha, and Jarul, and these species thrive best at low altitudes between sea level and 600 metres. If the land doesn’t meet the basic requirements for growing these trees, the entire rearing operation suffers – higher larval mortality, lower foliage, and reduced cocoon output.

Key criteria for selecting the right land 🔗

Terrain and topography 🔗

The ideal land for a tasar plantation is flat or gently sloping. Flat terrain ensures uniform water distribution and prevents runoff that could wash away topsoil and young seedlings. A slight slope (up to about 5-10%) is acceptable and can actually aid natural drainage, preventing waterlogging around the root zone. However, steeply sloping terrain should be avoided – it increases the risk of soil erosion and makes field management difficult. The Food and Agriculture Organization (FAO) emphasises that terrain assessment, including measuring erosion indices like soil texture, structure, and erodibility rate, is critical before any plantation activity begins.

Soil type and fertility 🔗

Tasar food plants grow on a range of soil types, but they respond best to well-drained, moderately fertile soils. Lateritic soils – which are common in tasar-growing regions of Jharkhand, Chhattisgarh, Odisha, and parts of Madhya Pradesh – are red, heavy, and well-drained but typically poor in nitrogen, phosphorus, potash, lime, and other plant nutrients. These soils, however, respond well to manuring and good cultivation practices. Saline, alkaline, or waterlogged soils are not suitable for tasar food plants and should be avoided during site selection.

Freedom from grazing and competing agricultural activities 🔗

The selected land should be free from grazing by cattle and goats and not actively used for competing agricultural crops. Grazing animals can damage young saplings, trample nursery beds, and compact the soil. If the land has been used for paddy or other seasonal crops, remnants of previous agricultural activities – including altered soil chemistry from fertilizers or pesticides – could affect the growth of tasar food plants. Before repurposing such land, a thorough evaluation of its history and current condition is essential.

Accessibility and water availability 🔗

While tasar food plants are largely rain-fed, access to a water source during the initial years of establishment is beneficial, especially for nursery irrigation and transplanting. The land should also be reasonably accessible for field operations such as weeding, pruning, and silkworm rearing activities.

Soil testing: the non-negotiable first step 🔗

Before any physical preparation of the land begins, soil testing is essential. Soil testing reveals the chemical, physical, and biological properties of the soil – information you need to decide what corrections are necessary. According to the Indian Council of Agricultural Research (ICAR), soil testing helps maximise crop yield and maintain soil health through the 4R approach: right source of fertilizer, at the right rate, at the right time, and in the right place.

Key parameters to test include pH level, macro-nutrients (nitrogen, phosphorus, potassium), secondary nutrients (calcium, magnesium), micro-nutrients (zinc, copper, iron), organic carbon content, and electrical conductivity. In India, farmers can use portable soil testing kits available through Krishi Vigyan Kendras (KVKs) and state agricultural departments, or they can send samples to accredited labs for more detailed analysis.

If the soil is found to be too acidic, liming may be required. If it is alkaline, gypsum application can help. Nutrient deficiencies detected through soil tests guide the application of organic and inorganic amendments during the land preparation stage itself.

Step-by-step land preparation for tasar plantations 🔗

Step 1: Clearing unwanted vegetation 🔗

The first practical step is to clear the selected land of all unwanted vegetation – shrubs, bushes, weeds, stumps, and debris. This can be done manually using hoes, axes, and cutlasses, or mechanically with equipment like brush cutters and bulldozers for larger areas. The goal is to eliminate competition for light, water, and nutrients and to prepare a clean surface for subsequent operations. According to the FAO, removal of indigenous vegetative ground cover is a standard first step in land preparation for plantations, as existing vegetation creates excessive competition for essential resources like nutrients, moisture, and solar radiation.

Care should be taken not to disturb the topsoil excessively during clearing. Manual clearing is generally safer for soil structure than heavy mechanized clearing, especially on sloping land where topsoil is thinner.

Step 2: Deep plowing 🔗

Deep plowing is a critical operation in tasar land preparation. Unlike ordinary plowing, which typically works the soil to about 15-20 cm, deep plowing reaches a depth of 50 cm or more. The purpose is to break up compacted sub-soil layers (hardpans), improve water infiltration, enhance root penetration, and modify the soil’s long-term water retention capacity.

For tasar food plants – which are deep-rooted perennial trees – this is especially important. Compacted soil restricts root development, limits access to sub-soil moisture and nutrients, and can cause waterlogging during heavy rains. Deep plowing, ideally carried out during the dry season (before the monsoon), loosens the soil profile and creates conditions favourable for robust tree establishment. It also helps turn over and bury weed seeds, reducing early-season weed pressure after planting.

Step 3: Bunding 🔗

Bunding refers to the construction of small earthen embankments or ridges around the plantation area or along the contour lines of sloping land. Bunds serve several purposes: they check soil erosion by reducing the velocity of surface water runoff, they help retain rainwater in the field (improving soil moisture), and they define field boundaries for systematic plantation management.

In tasar-growing regions, where rainfall can be heavy and erratic during the monsoon season, bunding is particularly important. Contour bunding on sloping land prevents the washing away of fertile topsoil and newly applied amendments. For flat land, peripheral bunding helps retain water within the planting zone, reducing irrigation needs during the critical establishment phase.

Step 4: Soil correction and amendment 🔗

Based on soil test results, specific corrections are applied at this stage. Common soil amendments for tasar plantation land include:

Lime application – for acidic soils (pH below 5.5), agricultural lime is added to raise the pH to a level that supports nutrient availability and microbial activity. Gypsum application – for sodic or alkaline soils, gypsum helps reduce sodium levels and improve soil structure. FYM and compost – farmyard manure (FYM) and compost are mixed into the soil to increase organic matter content, improve soil structure, and provide a slow-release source of nutrients. The Central Silk Board recommends filling planting pits with a mixture of soil, 10-20 kg of FYM/compost, along with bone meal, wood ash, and karanj cake per pit during transplanting.

Step 5: Green manuring 🔗

Green manuring is one of the most effective and sustainable ways to boost soil fertility before establishing a tasar plantation. It involves growing fast-growing crops – typically legumes – and then plowing them back into the soil while still green. As these plants decompose, they release nitrogen, phosphorus, and other nutrients into the soil, improving both its chemical and biological health.

Leguminous green manure crops like Sesbania, Crotalaria (sunhemp), and Vigna (cowpea) are particularly useful because their roots harbour nitrogen-fixing bacteria (Rhizobium). According to research published in Food and Energy Security, incorporating leguminous green manure into soil significantly increases organic matter and available nitrogen, and can boost subsequent crop yields by 12-29%. Green manuring also improves soil structure, enhances water-holding capacity, and promotes beneficial microbial populations – all of which are critical for the long-term health of a tasar food plant plantation.

The green manure crop is typically sown at the beginning of the monsoon season and plowed into the soil 6-8 weeks later, well before it sets seed. This gives the organic matter time to decompose before transplanting tasar food plant seedlings.

Pit preparation for transplanting 🔗

Once the land is cleared, plowed, bunded, and amended, the final preparation step before actual planting is pit digging. For tasar food plants, pits are typically dug at specified spacings depending on the plantation type. Economic (close-spaced) plantations of Terminalia arjuna, for example, use spacings as close as 1.2 m × 1.2 m, while broader spacings (6 m × 6 m or more) are used for natural or semi-natural plantations where trees are allowed to grow to full canopy size.

Standard pit dimensions are around 30 cm × 30 cm × 30 cm, though deeper pits (45 cm) may be used in compacted or lateritic soils. Each pit is filled with a mix of topsoil, FYM or compost, bone meal, and wood ash before transplanting. This enriched pit environment gives the young seedling immediate access to nutrients during its critical early growth phase. Transplanting is best done during June and July, coinciding with the onset of monsoon rains.

Common mistakes to avoid 🔗

Skipping soil testing is probably the most common and costly mistake. Without knowing what the soil lacks, you are essentially guessing at amendments – and incorrect application of lime, fertilizers, or manures can do more harm than good. Another frequent error is choosing waterlogged or flood-prone land, which can kill tasar food plant seedlings in their first season. Over-reliance on heavy machinery for land clearing on sloping terrain can strip away valuable topsoil, undoing the benefits of subsequent amendments. Finally, neglecting bunding on sloping land often leads to severe erosion during monsoon rains, washing away both soil and the nutrients added during preparation.

The long-term payoff of good land preparation 🔗

Well-prepared land establishes the foundation for a productive tasar plantation for decades. Terminalia arjuna plantations raised from 2-3 year saplings in properly prepared, closely spaced plots can become suitable for rearing within three years and yield over 17 metric tonnes of foliage per hectare. That’s a significant amount of feed for tasar silkworms – and it all traces back to the work done before the first sapling was ever planted.

Investing time and effort in proper site selection, thorough soil analysis, and systematic land preparation is not a luxury – it is the most fundamental step in building a successful and sustainable tasar silk enterprise.

What do you think? If you had to set up a tasar plantation in your region, what land characteristics would you prioritise first – soil quality, terrain, or water availability? And how would you balance the cost of thorough soil preparation against the long-term returns from a healthy plantation?

References

1. https://silks.csb.gov.in/lalitpur/food-plant-production-technology-of-tropical-tasar/
2. https://www.fao.org/4/ad083e/AD083e02.htm
3. https://hbmahesh.weebly.com/uploads/3/4/2/2/3422804/non_mulberry_food_plant_cultivation..pdf
4. https://www.icar.org.in/en/node/5512
5. https://earth5r.org/the-science-behind-sustainable-soil-how-soil-testing-is-transforming-organic-farming/
6. https://en.wikipedia.org/wiki/Deep_plowing
7. https://onlinelibrary.wiley.com/doi/full/10.1002/fes3.571