Alleviating soil acidity through plant organic compounds

A laboratory experiment was conducted to evaluate the effects of water solu ble plant extracts on soil acidity. The plant materials were: black oat, oi l seed radish, white and blue lupin, gray and dwarf mucuna, Crotalaria spec tabilis and C. breviflora, millet, pigeon pea, star grass, mato grosso gras s, coffee leaves, sugar cane leaves, rice straw, and wheat straw. Plant ext racts were added on soil surface in a PVC soil column at a rate of 1.0 ml m in(-). Both soil and drainage water were analyzed for pH, Ca, Al, and K. Pl ant extracts applied on the soil surface increased soil pH, exchangeable Ca -ex and K-ex and decreased Al-ex. Oil seed radish, black oat, and blue lupi n were the best and millet the worst materials to alleviate soil acidity. O il seed radish markedly increased Al in the drainage water. Chemical change s were associated with the concentrations of basic cations in the plant ext ract: the higher the concentration the greater the effects in alleviating s oil acidity.