Indexed on: 22 Sep '20Published on: 22 Sep '20Published in: Environmental Science and Pollution Research
Variable charge soils have low agricultural productivity associated with low pH, low cation exchange capacity (CEC), and low pH buffering capacity (pHBC). As a result of rapid acidification rates, these soils are prone to infertility resulting from Al phytotoxicity and deficiency of P, Ca, Mg, and K, and thus require amendments that can ameliorate soil acidity and enhance soil CEC and pHBC. A 30-day pot experiment was carried out using a clay Ultisol and a sandy Ultisol amended with straw decayed products (SDPs) of peanut, pea, canola, and rice. The results showed that applying SDPs increased the soil CEC, organic matter content, and exchangeable base cations in the two Ultisols. The ameliorative effects of the SDPs were superior for the sandy Ultisol than for the clay Ultisol. The addition of SDPs significantly increased soil pH and pHBC of the two Ultisols, and simultaneously decreased soil exchangeable Al. Among them, the greatest effect was found in the treatment with pea straw decayed products (PeaSD). The soil pHs of clay Ultisol and sandy Ultisol treated with PeaSD were respectively 5.70 and 7.37 and were 1.26 and 2.63 pH units higher than those of control. Also, applying SDPs increased maize seedling biomass in both soils and the most significant effect was found in the treatment with PeaSD, which were 0.97 (clay Ultisol) and 2.5 (sandy Ultisol) times higher than in the respective controls. The results of this study demonstrated that carefully selected straws for SDP production can effectively improve soil chemical properties, enhanced soil pHBC, and thus promote agricultural sustainability.