Potentials of Multiple Cropping Systems in Young Rubber Plantations

Abstract

The long gestation period of rubber, Hevea brasiliensis, has often served as a disincentive for investors in the business of rubber farming. Multiple cropping of rubber inter-rows prior to canopy closure is being suggested as a way of enhancing an early return on investment. A two-year study was conducted at the Rubber Research Institute of Nigeria (RRIN), Iyanomo from 1988 to 1999, to evaluate the agronomic significance and economic potentials of utilizing resources in the vast inter-rows of young rubber plantations. The experiment involved intercropping of one, two, three and four crops selected from cowpea, soybean, melon, maize and cassava with young rubber. The most robust girth of rubber samplings was observed in the rubber + soybean + melon and rubber + melon + maize systems, with 2.25 cm and 3.66 cm, respectively, in the 1998 and 1999 seasons. Young rubber in the rubber + cow-pea system had the highest height increment rate of 9.91cm/month. The area harvest equivalent ratio (AHER) showed a comparative advantage of multiple cropping over sole cropping. Rubber + melon had the highest AHER of 2.41 while rubber + soybean had the least value of 1.20 among the intercrops. The highest net benefit of 102,782 with a marginal-net-benefit of 49,803 and 117,587 with a marginal-net-benefit of 79,974 in 1998 and 1999 were observed in the rubber + melon + cassava and rubber + soybean + cassava cropping systems, respectively. All of the cropping systems had marginal rates of return in excess of the minimum 100 percent, except the sole rubber and rubber + melon cropping systems during the 1998 season.