The role of Leguminosae plants for soil fertility in oil palm plantations

Abstract

The greatest and most lucrative plantation product in Indonesia is palm oil. The availability of nutrients in the soil affects how oil palm plants grow and develop. To overcome the low availability of nutrients in the soil to meet the needs of plants, fertilization operations are required. The concept of a green economy necessitates that the palm oil industry limits its usage of chemical fertilizers as well as chemical pest and disease management. Oil palm plants require a variety of fertilizers that are rich in macronutrients (N, P, and K), secondary nutrients (Ca and Mg), and micronutrients (B, Zn, and Cu). The potential use of biodiversity as a soil fertility agent, such as Leguminosae plants, must be researched. The purpose of this study is to define the function of Leguminosae plants in oil palm farms’ soil fertility. Several scientific papers that were pertinent to the research issue were studied for literature as part of the data collection process. Oil palm plantations in Indonesia have implemented the planting of legume cover crops (LCC). Planting LCC suppresses weed growth, protects the soil from direct sunlight and raindrops, reduces surface runoff, maintains soil moisture, and increases soil fertility. Neustanthus phaseoloides var. javanicus, Calopogonium caeruleum, C. mucunoides, Mucuna bracteata, M. pruriens var. utilis, and Centrosema pubescens are a few Leguminosae plants that can be used as cover crops. In addition to these species, planting Parkia timoriana, P. speciosa, and Archidendron pauciflorum trees can help improve soil fertility. Oil palm plantations with legumes have a higher clay texture, an average pH of 6.0, and high levels of N-total, P, K, and C-organic, whereas non-legume oil palm plantations have a sandy texture and high dust, an average pH of 5.3, and very low levels of N-total, P, K, and C-organic. Legumes, in addition to being a cover crop, can also be used as animal feed and to increase nutrient levels in plants. Planting LCC in oil palm plantations can affect the nutrient content of forages that grow under oil palm trees because the root nodules of LCC contain rhizobium bacteria that function to fix nitrogen from the air and are converted by the nitrogenase enzyme into ammonium and nitrate as a source of N for the LCC. The concept of integrated plantations can be applied to oil palm plantations by using LCC, which has hampered the growth of oil palm plants as animal feed, and P. timoriana, P. speciosa, and A. pauciflorum trees as economically valuable food plants.