Studies on the Characteristics of Humic Acid and its Utilizations. (Ⅲ) Utilizations of Humic Acid (Nitrohumates)

土炭흄酸의 性狀및 應用에 關한 硏究 흄酸(니트로흄酸鹽)의 應用 (第3報)

The adaptabilities of various nitrohumates (-K, -Na and $-NH_4$ salt) as a soil conditioner and a raw material for soluble phosphatic fertilizer were studied. 1. Nitrohumates (especially $-NH_4$ salt) protect the soil from fissures and control the phosphoric acid adsorptive functions of soils considerably. 2. Most effective nitrohumic acids as a soil conditioner were prepared with 15% $HNO_3$ solution composed of five times of original humic acids (by weight) at $80^{\circ}C$ for 2 hrs under continuous stirring. 3. When 50% (by weight) of $NH_4$-nitrohumate were added to apatites in water and boiled for 2 hrs, maximum 26% of $P_2O_5$(apatite contains 37% of $P_2O_5$) were changed into water soluble forms.