AIT - UNESCO - IHE

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Water Engineering and Management at the Asian Institute of Technology with specialization in Agricultural Water Management for Enhanced Land and Water Productivity and degree of Master of Science at the UNESCO -IHE

Thesis (M.Sc.) - Asian Institute of Technology - Institute for Water Education Netherlands, 2013

This research was aimed to evaluate land, water , and economic productivity of some scenarios of rubber intercropping system in Banyuasin in order to improve its productivity and to provide recommendation for the optimization of rubber intercropping system productivity in Banyuasin. Simulation study was done using t he WaNuLCAS model to determine the maximum land, water, and economic productivity under three main scenario factors. The first factor was rubber plant spacing arrangement system, whi ch consisted of three case s, i.e. base case (single row, 3 x 7 m), single row (3 x 6m), and double row (2 x 6 x 14m) plant spacing arrangement system. The second factor was water management treatment, which consisted of four cases , i.e. without irrigation and drainage, irrigation in dry periods , drainage in wet periods, and irrigation and drainage in both dry and wet periods . The third factor was cropping system scenari o, which consisted of four cases , i.e. without intercrops, intercropped with upland rice -upland rice -upland rice, with upland rice -upland rice -maize, and with cowpea -maize cropping system. Calibration and validation show that the values of Pearson Correlation Coefficient (R) of rubber tree girth and yields of upland rice, maize, and cowpea wer e more than 0.95. R for latex yield calibration is 0.97, whereas for validation is 0.83. Goodness of Match ( GOM ) values for all parameters are between 0.95 and 1.09. Root Mean Square Error ( RMSE ) for the various parameters w as less than 5% compared to the observed values . Double row plant spacing arrangement system could improve rubber tree girth and biomass , but could not improve latex yield per hectare, SGVP, as well as land and water productivity. Drainage scenario could improve rubber tree girth , bioma ss, latex yield per hectare, SGVP, as well as land and water productivity. Intercropping system scenario could not improve rubber tree girth, biomass, latex yield per hectare, SGVP, as well as land, water and economic productivity. The best land and water productivity could be achieved by all scenarios with drainage system (more than 0.75 US$/m 2 /year and 0.5 US$/m 3 /year for land and water productivity respectively) . These values were 70% higher than base case scenario. Therefore, it is recommended to prep are drainage system under rubber plantation in Banyuasin.