Crop diversification and intercropping in tea lands

Abstract

67 clearing will solve the problem of removal of prunings from the tea field. On a long term-basis, fuelwood plantation could bring a supplementary income to estates from the sale of timber to pulp mills. Sloping Agricultural Land Technology (SALT) This technology was originated in the Philippines, and the acronym SALT was first used by the Mindanao Baptist Rural Life Center (MBRLC) in late 1980s, who tested this concept in the Mindanao Islands in the Philippines for farming in sloping lands. Basically, SALT is a method of growing crops in 5 to 7 m bands between contour rows of nitrogen-fixing trees. The nitrogen-fixing trees are thickly planted in double rows, called "hedgerows". When hedges are 1.5 to 2.0 m tall, they are cut down to about 0.5 to 1.0 m, and the cuttings or tops are placed in alleys to serve as a mulch and organic matter (Watson, 1990). Th$ primary objective of SALT is ti achieve sustainability in upland agriculture, through conservation and recycling of natural resources. It is a biological system that improves soil fertility, and protects the soil from degradation. Investigations on the feasibility of using SALT in tea lands, initiated in 1992, have shown that it could be used as an alternative measure for soil conservation and fertility management in tea plantations (Ekanayake, 1994 b). The technology, adopted in the Philippines, was modified to suit the conditions prevailing in tea plantations in Sri Lanka The spacing between hedgerows was changed to 7-8 m, so that at least 5-6 rows of tea could be planted in between them. The hedgerows are lopped at regular intervals. The loppings can provide surface mulch, which not only conserves soil moisture, improves soil fertility but also smother weeds. Therefore, SALT is a sustainable soil management technique which helps to enhance productivity. However, this technique is not widely adopted in tea plantations due to limitations such as loss of land area for hedgerows, difficulty in establishment of hedgerows at the initial stages, competition of hedgerow species with tea, lack of suitable species that suit all elevations etc (Ekanayake, 1999). Intercropping The term intercropping refers to cultivation of a mixture of crops planted in a defined pattern of spatial arrangement (Bavappa & Jacob 1982). The intercropping of two or more on the same land has a number of advantages such as better land utilization, higher productivity, enhanced net returns, favourable cost-benefit ratio, reduced risk of dependence on a single crop and the generation of additional employment opportunities. Tea is a light and humid loving but shade tolerant tree species (Kulasegaram, 1980). The light utilization efficiency of a monocropped tea plantation is very low due to its low light saturation point (Yu Shanqing, et al 2001). The growth of tea is negatively affected by strong light, high temperature and low humidity. Therefore, the tea is usually grown under shading of trees and there is a high potential of supplementing the necessary shade by interplanring with other economical tree species. During the last few decades, most tea producing countries such as India, China, Soviet Union and Sri Lanka have been focusing on the study of ecophysiological conditions on tea for multicropping (Yu Shanqing, et al 2001). In Sri Lanka tea small holders in the mid country had been traditionally cultivating pepper, coffee and cloves in an adhoc manner for a long time. With spice crops gaining economic importance during the last two decades, there was greater attention for planned mix cropping not only among smallholdings but also among larger plantations (Ekanayake 1994.a). Prior to 1990, intercropping with tea was confined to export agriculture crops such as pepper, coffee and cloves. During the last decade, intercropping with tea has been extended to other plantations crops such as rubber and coconut. Intercropping with other plantation crops Investigations undertaken on intercropping with other plantation crops during the last two decades have shown very promising results. Particularly, tea/rubber and tea/coconut are being successfully intercropped in the low country and some parts of the mid country. In the case of tea and rubber, a special subsidy scheme is in operation, where a grower can get 75 % of the tea subsidy and 75 % of the rubber subsidy. In the case of tea and coconut intercropping, grower can get the subsidy for the % tea component and inputs such as coconut seedlings and fertilizer from the Coconut Development Authority. The details of guidelines on tea/rubber and tea/coconut are given below. Tea and Rubber Intercropping During the early 1980s, investigations on tea and rubber intercropping were initiated by the Institute, in collaboration with the Rubber Research Institute.