Distribution of Exchangeable Calcium,Magnesium and Potassium as Affected by Fertilizer Application to Red Soil
Distribution of Exchangeable Calcium, Magnesium and Potassium as Affected by Fertilizer Application to Red Soil出 版 物:《Pedosphere》 (土壤圈(英文版))
年 卷 期:1995年第5卷第4期
页 面:343-348页
核心收录:
学科分类:09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学]
主 题:distribution of exchangeable Ca ̄(2+) Mg ̄(2+) and k ̄+ fertilization leaching red soil
摘 要:A leaching experiment was carried out with repacked soil columns in laboratory to stndy the leachingprocess of a red soil derived from sandstone as affected by warions fertilization practices. The treatments wereCK (as a control), CaCO_3, CaSO_4, MgCO_3, Ca(H_2PO_4)_2, Urea, KCl, Mnltiple (a mixture of the above-mentioned fertilizers), and KNO_3. The fertilizers were added to the bare surface of the soil columns, andthen the columns were leached with 120 mL deionized water daily through peristaltic pumps over a periodof 92 days. At the end of leaching process, soils were sampled from different depths of the soil profiles, i.e.,0-5 cm, 5-10 cm, 10-20 cm, 20-40 cm, and 40-60 cm. The results showed when applying Ca, Mg, andK to the bare surface of the soil columns, exchangeable Ca ̄(2+), Mg ̄(2+), and K ̄+ in the upper layer of thesoil profile increased correspondingly, with an extent depending mainly on the application rates of Ca, Mg,and K and showing a downward trend. CaCO_3, CaSO_4, MgCO_3, and Ca(H_2PO_4)_2 treatments had scarcelyany effect on movement of exchangeable K ̄+, while CaCO_3, and CaSO_4 treatments significantly promotedthe downward movement of exchangeable Mg ̄(2+) although these two treatments had no obvious effect onleaching losses of Mg. The fact that under Urea treatment, exchangeable Ca ̄(2+) and Mg ̄(2+) were higheras compared to CK treatment showed urea could prevent leaching of exchangeable Ca ̄(2+) and Mg ̄(2+). Theobvious downward movement of exchangeable Ca ̄ (2+) and Mg ̄(2+) was noticed in KCl treatment. In Multipletreatment, the downward movement of exchangeable Ca ̄(2+) and Mg ̄(2+) was evident, while that of K ̄+ was lessevident. Application of KNO_3 strongly promoted the downward movement of exchangeable Ca ̄(2+) and Mg ̄(2+)in the soil profile.