The effects of alley cropping using Sesbania grandiflora on soil fertility and productivity of Hibiscus sabdariffa on BRIS soil in Kelantan

More than 90 % of soil structure of BRIS soil is sand and has very low physical and chemical characteristics and the soil is considered unsuitable for agricultural purposes. However, BRIS soil has the potential to be used by agricultural sectors by enriching it with suitable soil treatment. Although BRIS soil is a problematic soil, Hibiscus sabdariffa is suitable to be planted on this soil because it provides a well aerated and deep rooting zone. This study was carried out to determine the effects of alley cropping by using Sesbania grandiflora on soil fertility and productivity of Hibiscus sabdariffa on BRIS soil in Kelantan. This study was conducted at Kampung Mujur, Bachok, Kelantan. There were four treatment used, which include control, NPK fertilizer, green manure fertilizer and organic fertilizer. The growth performance analysis of Hibiscus sabdariffa was carried out to determine the effects on the height of stem, number of leaves, the diameter of stem, the number of branches and biomass production (fresh and dry weight) of Hibiscus sabdariffa plants. The organic matter was determined by using Loss – on- ignition. Nitrogen was determined using Kjeldahl method. Phosphorus was determined using UV spectrophotometer while Potassium, Magnesium and Calcium was determined using atomic absorption spectrophotometer. The result showed that the green manure fertilizer treatment gives the best performance of growth and development of Hibiscus sabdariffa. As for the results of soil analysis, it was found that there was a higher organic matter (14.03 %) with the use of the green manure fertilizer treatment, the total organic carbon (8.14 %), Mg content (0.47 %) and Ca content (0.67 %). Lastly, in terms of chemical composition, the N, P, K, content was higher in green manure fertilizer treatment with a total of 0.11 % for N, 44.67 % for P and 0.17 % for K respectively. Hence, from this study, the green manure fertilizer treatment is the best fertilizer used and this treatment is suitable in increasing the fertility of BRIS soil because it improves water holding capacity, reducing water loss and leaching in sandy soil. Thus, the integration with Sesbania grandiflora and green manure fertilizer treatment tends to increase Hibiscus sabdariffa production and maintain the plants’ growth. Moreover, these results indicates that the application of green manure and organic fertilizer can improve BRIS soil fertility and also increase the Hibiscus sabdariffa production.