Some Inceptisols representing the Singla catchment area in Karimgaungedistrict of Assam, India, were studied for lime requirement as influenced by the nature of soilacidity. The electrostatically bonded (EB)-H^+ and E...Some Inceptisols representing the Singla catchment area in Karimgaungedistrict of Assam, India, were studied for lime requirement as influenced by the nature of soilacidity. The electrostatically bonded (EB)-H^+ and EB-Al^(3+) acidities constituted 33 and 67percent of exchangeable acidity while EB-H^+, EB-Al^(3+), exchangeable and pH-dependent aciditiescomprised 6, 14, 20 and 80 percent of total potential acidity. The pH-dependent acidity made a majorcontribution towards the total potential acidity (67%～84%). Grand mean of lime requirementdetermined by the laboratory incubation method and estimated by the methods of New Woodruff,Woodruff and Peech as expressed in MgCaCO_3 ha^(-1) was in the order: Woodruff (15.6) > New Woodruff(14.9) > Peech (5.1) > incubation (5.0). Correlations analysis among different forms of acidity andlime requirement methods with selected soil properties showed that pH in three media, namely water,1 mol L^(-1) KC1 and 0.01 mol L^(-1) CaCl_2, had a significant negative correlation with differentforms of acidity and lime requirement methods. Exchangeable Fe and Al showed significant positivecorrelations with EB-Al^(3+) acidity, exchangeable acidity, pH-dependent acidity and total potentialacidity, and also lime requirement methods. Extractable Al showed positive correlations withdifferent forms of acidity except EB-H^+ and EB-Al^(3+) acidities. The lime requirement by differentmethods depended upon the extractable aluminium. Significant positive correlations existed betweenlime requirements and different forms of acidity of the soils except EB-H^+ acidity and incubationmethod. The nature of soil acidity was mostly pH-dependent. Statistically, the Woodruff method didslightly better than the New Woodruff, incubation and Peech methods at estimating lime requirementand hence the Woodruff procedure may be recommended for routine soil testing because of its speedand simplicity.展开更多
文摘Some Inceptisols representing the Singla catchment area in Karimgaungedistrict of Assam, India, were studied for lime requirement as influenced by the nature of soilacidity. The electrostatically bonded (EB)-H^+ and EB-Al^(3+) acidities constituted 33 and 67percent of exchangeable acidity while EB-H^+, EB-Al^(3+), exchangeable and pH-dependent aciditiescomprised 6, 14, 20 and 80 percent of total potential acidity. The pH-dependent acidity made a majorcontribution towards the total potential acidity (67%～84%). Grand mean of lime requirementdetermined by the laboratory incubation method and estimated by the methods of New Woodruff,Woodruff and Peech as expressed in MgCaCO_3 ha^(-1) was in the order: Woodruff (15.6) > New Woodruff(14.9) > Peech (5.1) > incubation (5.0). Correlations analysis among different forms of acidity andlime requirement methods with selected soil properties showed that pH in three media, namely water,1 mol L^(-1) KC1 and 0.01 mol L^(-1) CaCl_2, had a significant negative correlation with differentforms of acidity and lime requirement methods. Exchangeable Fe and Al showed significant positivecorrelations with EB-Al^(3+) acidity, exchangeable acidity, pH-dependent acidity and total potentialacidity, and also lime requirement methods. Extractable Al showed positive correlations withdifferent forms of acidity except EB-H^+ and EB-Al^(3+) acidities. The lime requirement by differentmethods depended upon the extractable aluminium. Significant positive correlations existed betweenlime requirements and different forms of acidity of the soils except EB-H^+ acidity and incubationmethod. The nature of soil acidity was mostly pH-dependent. Statistically, the Woodruff method didslightly better than the New Woodruff, incubation and Peech methods at estimating lime requirementand hence the Woodruff procedure may be recommended for routine soil testing because of its speedand simplicity.
