Discuss the role of agroforestry and canal-bank/riverbank plantations in balancing ecological conservation with State forest revenue, with reference to Tamil Nadu's teak cultivation experience.

Agroforestry — raising trees on farm bunds, canal banks and riverbanks outside notified forests — allows States to earn timber revenue without felling natural forests. Tamil Nadu's Thanjavur canal-bank teak scheme, begun in 1955-56 in the Cauvery delta, is an early Indian model of this dual-purpose approach [1].

The Tamil Nadu teak experience

• Started in 1955-56 at the instance of the then Chief Conservator of Forests, teak was raised along the entire canal network of Thanjavur district, covering about 8,000 hectares, with similar belts on the Cauvery and Tambaraparani banks [1].
• The first auction of Thanjavur canal-bank teak was held at Saliamangalam in September 1976, offering over 2,500 poles, with sales planned every three to six months — converting a conservation measure into a recurring revenue stream [1].
• The model endures: in the Thanjavur–Tiruvarur–Nagapattinam belt, teak timber worth roughly ₹14 crore was auctioned in the Tiruchi and Thanjavur circles in 2020-21, alongside annual planting of about a lakh saplings [2].

Ecological gains

• Bank stabilisation: root networks check canal and riverbank erosion, curb encroachment and strengthen embankments against floods [2].
• Pressure relief on natural forests: Tamil Nadu's teak traditionally came from the Western Ghats; a cultivated non-Ghats source reduces extraction from ecologically fragile reserve forests [1].
• Carbon sink and green cover outside recorded forest area, aiding the one-third tree-cover goal of the National Forest Policy, 1988 [3].

Balancing tensions

• Long 30-year rotations demand patient financing and protection from theft [2].
• Monoculture teak yields lower biodiversity than mixed native plantations, so revenue plantations cannot substitute for natural forests.

Thus, canal-bank plantations show that conservation and revenue need not be rival objectives when trees are grown outside forests. Scaling this through the National Agroforestry Policy, 2014 — India's first such policy — with mixed species, farmer participation and simplified felling-transit rules can align State revenue with SDG 15 on life on land [4].