Marginal soil is infertile soil caused by various factors, one of which is the excessive accumulation of heavy metals. FOBIO microorganism-based biopesticide formula containing phosphate solubilizing bacteria is expected to be used to reduce excess heavy metals in the soil. Brasica rapa L. is a variety resistant to Pb heavy metal stress and absorbs more heavy metals into root tissue than leaf tissue with the help of microorganisms. This study aimed to determine the combination of Brassica rapa L. and FOBIO biopesticide in absorbing Pb in the soil, determine the growth of Brassica rapa L. at each Pb concentration, and determine the population of phosphate-solubilizing bacteria in the soil at each level of Pb stress after remediation. This study used variations in the concentration of heavy metals, particularly Pb. Parameters observed included plant growth, Pb concentration in the soil before and after remediation, and the population of phosphate-solubilizing bacteria. The results showed that combining FOBIO biopesticides and Brassica rapa L. could reduce Pb concentration in the soil. The growth of Brassica rapa L. plants was significantly different after treatment. The findings confirmed that increasing, the concentration of Pb led to a decrease in the population of phosphate-solubilizing bacteria.

The obstacles faced in increasing and stabilizing the production of pakcoy Brassica rapa L. one of them is due to pest attacks. The main pests that attack pakcoy plants are Plutella xylostella L., C. pavonana, earthworms (Agrotis ipsilon), and grayworm (Spodoptera litura). The use of pesticides can provide the only form of crop protection available Developing countries from some pesticides that have been banned from use in the European Union (EU), as they have recognized the harmful properties of such pesticides. Vegetable pesticides are effective against various destructive pests and diseases. Broadly speaking, vegetable pesticide raw materials are easy to obtain, cheap, easily accessible, quickly decompose, and have little toxicity to receiving agents. Simplisia vegetable pesticide product is a pesticide product based on soursop leaves, lemongrass, and papaya leaves. All three ingredients contain chemical compounds or extractive substances. This study used vegetable pesticide simplicia products with several concentrations to suppress the attack of pakcoy leaf-destroying pests. The research took place in the experimental garden was carried out for 4 weeks from the seeding period to harvest. Research is carried out by experimental methods. The results of this study show that vegetable pesticide simplicia is able to suppress the attack of pakcoy leaf pests with a very significant concentration found in the P2 treatment, which is 40grams per liter of water