The Tribune, Chandigarh, India - Agriculture Tribune

Poplar, leading the tree charge

Surinder Singh Hara, one of the pioneers in poplar plantation in the region, shares his experiences over 20 years of agroforestry. Experimenting with options is his forte.

Agroforestry — growing of trees in fields with crops—has many variations in the world, each suited to the country’s need. The model that has evolved in Haryana, western UP, and Punjab is unique and the only example of its kind in the world.

It may be defined as growing of “commercial timber trees for wood industry in agricultural fields” with irrigation, manuring, plant management technology, etc., in a harvest cycle of 10-12 years. Crops growing underneath are of secondary consideration and form a small part of the gross income. Selective shade-loving or shade-tolerant crops are grown to complement timber production and cash flow.

Practice of this special kind was started 23 years ago with poplar trees in Jagadhri, Haryana, in 1979-1980. Then there was not a single acre under poplars and till 12 years ago (1990) there was no factory for poplar-based wood products. Today, thousands of farmers are growing poplars in North India and over 200 factories in the twin cities of Jagadhri and Yamunanagar alone produce poplar timber products worth over Rs 1,000 crore per year.

Agroforestry has not only benefited farmers, it has also created a wood industry, generated employment of various kinds, benefiting millions in related economic activities like transporters, wholesalers, retailers, etc. It has helped consumers with an affordable supply of wood and is import substitution for timber and timber products, which India imports worth thousands of crores of rupees a year.

Also, agroforestry is as good, if not better, than natural forests for environmental improvement, pollution control, etc, especially as it can be started around pollution-causing urban centres. It is a win-win situation for all.

How it started

The gap between the demand and supply of timber is well recognised. The shortage and high prices of timber encouraged fast-growing tree species like poplar and eucalyptus. A major matchstick manufacturer imported poplar clones for the North Indian climate and clones were multiplied in nurseries in 1978-79. In Haryana, only two farms, Hara Farm and Kalsia Farm, in the Jagadhri area started nursery and field plantations in 1980-81. Hara Farms experimented with different clones, irrigation schedules, doses of manure and fertilizers to determine the optimum quantities of nitrogen, phosphorus, potash, and micronutrients needed for faster growth. It was realised that potash and phosphorus are required in larger doses than nitrogen, zinc and copper. Nutrition deficiency should be observed and corrected as necessary.

After irrigation and plant nutrition, the third essential is sunshine, which cannot be increased like water and nutrition. The available sunshine has to be optimised by planting the right number of trees (density per acre), in the right direction (north to south) at appropriate distances between lines and plants. We had greater distance between lines and less between plants for sun to come through and also for convenience of growing other crops. Our experience shows that 200 sq. ft. of sunshine per tree is necessary for normal growth, which means a density of 200-220 trees/acre. Greater density produces greater tonnage but economic benefits are best at 200 trees per acre in a 10-year cycle.

Other essentials to increase yield and quality are pest and disease control. Insect attack and fungal disease can increase rampantly in mono cropping. Spraying at 80-100 ft height is impossible besides being prohibitively expensive. We have improved methodology for effective pest and disease control. Each year all trees are, as a precaution, treated with systemic insecticides (furadon was found to be good) and fungicides, all through the growing period.

To improve wood quality, pruning is essential for knot-free logs. All trees are suitably pruned for six years, till a tree height of 70 feet. Pruning is a specialised operation. It improves quality and quantity of useful timber per tree. We have realised that general pruning of branches from below is not ideal as the tree loses food-producing leaf mass. Only the branches competing with the leader should be pruned, as the horizontal branches only produce food. Such branches may be pruned in the later years when they stop getting sun. Keeping this in mind, usually pruning is not required in the first two years as sun reaches almost the whole tree; only a clear leader has to be maintained during this period.

Genetic superiority

Importance of genetically superior plants can never be overemphasised, in fact it is the basis of successful agroforestry. On Hara Farms, we select constantly the best trees for propagation. It has been found that cuttings from all branches of a tree do not have the same vigour. Branches growing at 30-40 degrees have better potential than the ones growing horizontally. We take cuttings only from such branches for planting a nursery. Cuttings from a nursery are replanted again in a nursery the next year as it is found that two-year plants have better growth.

Clonal propagation of trees is imperative in agroforestry. Reproduction from seed of any tree species cannot give a uniform tree stand. Agroforestry trees must have a uniform height. At Hara Farms thousands of trees growing in each plot have a uniform stand (+ or – 2 ft). We have reached yields of 20 tons/acre/year and are now aiming at 25 tons.

Intercropping

We grow food and spice crops under the poplar trees, which improves the economy of agroforestry. While in winter, when the sun can shine through the trees, almost any crop can be grown, during summer months we have felt that only haldi can be grown viably as it is a shade-tolerant plant. Most other trials failed. Of haldi, Rajapuri variety was found ideal in our area.

Modern plant breeding technology—genetic modification, tissue culture and genome technology—as available in the past 5-10 years has now brought possibilities in timber production unheard of earlier. The creation and propagation of genetically superior stock is highly technical and requires expensive infrastructure, beyond the capacity of an agroforester. But the benefits are far greater.

Nursery quality tells on future growth
G. S. Shamet

To grow as much wood as possible and to grow it quickly is an urgent need to check forest depletion. Poplars, especially the exotic clones of P. deltoids, can prove to be a saviour as they are fast growing and can be harvested in 8-10 years. Their wood is soft, white and of uniform texture and well suited to various industries.

For ideal growth, technique has to be paid attention. Here we tare a look at certain aspects of growing poplars:

Nursery

Raising quality nursery stock is an important operation for the success of any plantation programme. Production of healthy plants free from disease and pests deserves special attention these days. The factors which influence quality stock production in poplars are: the type of reproductive material, setting period, density, condition of soil, moisture, nutrient supply, pest control and weeding, etc. In other words, the raised stock should have the advantage of all favourable growth conditions in the nursery so that the benefit gets carried over to the plantation site.

For successful production, the nursery area should be flat, fertile and rich in organic matter. The soil should preferably be sandy loam with a pH of around 6.5 -7.0. The area should be weed/brush free, receiving adequate sunshine and preferably in the north-west aspect. Ridges, river/streamsides, windy, shady and frosty locations should be avoided.

The cuttings are planted in the month of January-March, depending upon the species. These are made from vigorous and disease-free one-year-old ETPs (entire transplant) in the nursery/stool nursery beds and planted in sunken beds at 60 x 45 cm spacing. Cuttings 20-22 cm long and 1-2cm thick are planted in such a way that the upper 2-3 cm portion with one bud remains above the ground and the rest is inserted/firmed up in the hole. After planting, the nursery bed is immediately irrigated.

Planting

The best time for planting the Populus species is January to mid-February in low/mid hills and February-March in high hills. One-year-old ETPs with straight stems are planted in pits of 45 cubic cm (prepared one month in advance), further holed to 30-45 cm with an auger/crow bar in such a way that the stem remains at the centre and collar goes well below the soil.

Since poplar is a fast growing species it requires nourishment and protection for its proper growth and development. A basal dose of 2 kg well-rotten FYM + 10 g BHC 10% dust (or 200g neem cake) + 10-15 g superphosphate should be mixed with soil before filling the pit. Similarly, the first dose of 50 g urea should be applied in the first week of July (depending upon rainfall) and the second 75g -100g during the second or third week of August in the first year. The fertiliser should never be applied near the stem and in dry soils. Hoeing and weeding twice in the basin before and after monsoon should also be done.

The spacing adopted is 3m for boundary line, 3-4 x 15-20 m for mid row and 3 x 4 m or more, depending upon block planting/nature of crops (vegetables and grasses) grown.

Which tree to go for
Avtar Singh

Agroforestry is one of the best farming systems that can be used for diversification. It is a land-use system in which woody perennials (trees, shrubs, palms, bamboo, etc.) are used on the same land-management unit as agricultural crops and/or animals, in same form of spatial arrangement or temporal sequence.

Selection of trees for agroforestry is of critical importance from the viewpoint of promoting tree cultivation on farmer’s field. The selection may be based on certain criteria like growth and production rate, nitrogen fixing ability, tree architecture, response to management practices, compatibility with crops/pastures and their marketability. Selection is also governed by climatic, edaphic, cultural and farming systems compatibility of the species. In agroforestry trees should be either leafless during the agricultural season or have light crowns and tall boles with sparse branches, preferably at an angle. They should supply the farmer his needs of small timber, fuel and fodder.

In Punjab poplar, eucalyptus, dek, subabul, kikar, etc., are considered best tree species for agroforestry .

Poplar

This is considered to be the best agroforestry species for intercropping, having high rate of growth, short rotation, good economic returns and has less effect on intercrops. But proper management of intercropping is necessary. Farmers plant this species on their cropland and within 6-7 years harvest and market it to the industry. During the Kharif season soybean, maize and grain legume can be grown while during the Rabi season wheat, potato, peas, etc., can grow successfully.

The wood of poplar is used in papermaking, plywood, matchsticks, packing cases, sport goods, light construction and furniture. Poplar is winter deciduous and adds tremendous amount of leaf litter to the soil. The Punjab Agricultural University has released seven clones of poplar for growing in Punjab. These are PL-l, PL-2, PL-4, PL-5 (for the central plain region), PL-6, PL-7 (for semi-arid region) and PL-3 (both for central plain and semi-arid region).

Eucalyptus

Eucalyptus is another tree to be grown with crops. Fast growth, straightness, self-pruning and wide utility of wood are some of the main features of eucalyptus. At present the wood is being used for furniture, doors, windows, crates, packing cases, fuel, pulpwood and even as a source of rayon. The tree is used a windbreak, especially for the protection of fruit crops. There is a potential scope for eucalyptus as a timber tree to attain profitable status in the years to come. Eucalyptus can be grown as a boundary plantation as well as block plantation. But preference should be given to boundary plantation. It may have an adverse effect on the adjoining field crops. To minimize the effect, keep the rows of trees in the north-south direction. The distance between the trees should be 3 meters or more and prefer fodder crops rather than grain crops along the tree line.

Dek

Dek, or dhrek, is an indigenous species commonly distributed throughout the country. It is a fast growing and deciduous tree. It tolerates heavy lopping. The leaves are lopped for fodder. It is most suitable for growing on the boundaries of a field. The spacing should be 3 meters. It can grow on a variety of soils, including saline and alkaline. The wood is widely accepted in the market for furniture, doors, windows, packing cases, etc.

Subabul

This is a miracle tree as it provides fodder, fuel, pulpwood and timber. The forage is highly palatable, digestible and rich in protein. The leaves of subabul contain 25.6 per cent of crude protein. Its fodder is of great importance during the lean period when there is acute shortage of green fodder. Because of the presence of high protein and vitamin A in its leaves, deep root system, erect growing and ability to improve soil fertility, this tree has attained importance.

Subabul alleys produce about 31.4 and 17.79 q/acre/annum fodder and dry fuel, respectively. In between subabul alleys (rows) wheat, barley and sarson crops can be grown. In the Kandi area bajra-oats rotation in between subabul lines (3-4m x l-1.5m apart) is beneficial.

Kikar

This tree is a good source of fodder, fuel, timber and tannin. The wood is used for making furniture, doors, windows, etc. The pods and leaves contain digestible protein. Its bark is a rich source of tannin. Kikar is grown in semi-arid and Kandi regions. It can withstand extreme temperatures but it is frost tender when young.

Besides these tree species, by growing tahli, neem shehtoot and sagwan, farmers can make good profits. It is very clear that there should be no effect of the World Trade Organisation on agroforestry because all developed countries have banned the cutting of their forests. At present, wood is coming from the developing countries, which are cutting their forests at a very large scale and there will be shortage of wood in the next few years. Therefore, the future of agroforestry seems to be secure.