Manures Effectivity to Enhanced the Availability of Phosphorus, Crops Growth and Yield of Rice and Corn in Acid Upland Soil - Sulaiman, Yoyo; Balai Penelitian Tanah, Kebun Percobaan Tamanbogo, Jl. Raya Sukadana, Purbolinggo 34192, Lampung Timur (UNIVERSITY OF LAMPUNG, 2008)