1. Population and Activities of Peatland Microorganisms on Oil Palm Plantation based on Soil Depth and Age of Plant ; Oktanis Emalinda. 2. The Effect of Organic Fertilizers on Growth and Yield of Water Spinach (Ipomoea reptans Poir) ; Selvia Dewi Pohan. 3. The Effect of Organic Fertilizer Types and Phosphate Fertilizer Doses on Growth and Yield of Chili (Capsicum Annum L.) var. Lotanbar ; …