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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Assessment of Multielement Extractants for Prediction of Available Potassium in Thai Soils) ผู้เขียน:ดร.สุรเชษฎ์ อร่ามรักษ์, รองศาสตราจารย์, ดร.จงรักษ์ จันทร์เจริญสุข, รองศาสตราจารย์, นายชัยฤกษ์ สุวรรณรัตน์, ผู้ช่วยศาสตราจารย์, ดร.เอ็จ สโรบล, ศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractIn many countries, the efficiency of Mehlich 3 and ammonium bicarbonate – DTPA (ABDTPA) has long been elucidated as multielement extractants for simultaneous measurement of nutrient elements including potassium (K) in soils. However, information on their efficiencies for assessing the availability of K in Thai soils is still inadequate. This study was conducted to assess the efficiency of the two multielement extractants in predicting available K in some Thai soils. The relationships between the amounts of K extracted by Mehlich 3 and AB-DTPA with those extracted by NH4OAc, the conventional extraction method, widely used in soil testing laboratories in Thailand, and those taken up by corn was investigated. The results indicated that the amounts of K extracted by both Mehlich 3 and AB-DTPA were highly correlated to those extracted by NH4OAc (r = 0.969** and r = 0.894**, respectively) and those absorbed by corn (r = 0.930** and 0.902**, respectively). In addition, coefficient of determination (r2) for the relationship between amounts of K taken up by corn and extracted by the three extractants were 0.887 (NH4OAc), 0.866 (Mehlich 3), and 0.813 (AB-DTPA). Therefore, Mehlich 3 and AB-DTPA can be effectively used for determining K availability status in Thai soils. Nevertheless, Mehlich 3 was identified to be better measurement extractant than AB-DTPA. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Evaluation of Mehlich 3 and Ammonium Bicarbonate-DTPA Extractants for Prediction of Available Zinc in Calcareous Soils in Central Thailand) ผู้เขียน:นัทฐา ทักษ์รัตนศรัณย์, ดร.จงรักษ์ จันทร์เจริญสุข, รองศาสตราจารย์, ดร.สุเทพ ทองแพ, ผู้ช่วยศาสตราจารย์, ดร.เอ็จ สโรบล, ศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThis study was conducted in order to evaluate the efficiency of Mehlich 3 and ammonium bicarbonate-DTPA (AB-DTPA) extractants for predicting available zinc (Zn) in calcareous soils in the central part of Thailand. The relationships between the amounts of Zn extracted by Mehlich 3 and ABDTPA with those extracted by DTPA (the conventional extraction method widely used in soil testing laboratories in Thailand) and those taken up by corn were elucidated. The results showed that the amount of Zn extracted by both Mehlich 3 and AB-DTPA was significantly correlated with that extracted by DTPA (r = 0.951** and r = 0.950**, respectively) and that absorbed by corn (r = 0.954** and r = 0.925**, respectively). Moreover, the coefficient of determination (r2) for the relationship between amounts of Zn taken up by corn and extracted by the three extractants was 0.845 (DTPA), 0.855 (ABDTPA) and 0.910 (Mehlich 3). Accordingly, Mehlich 3 and AB-DTPA could be used effectively for estimating Zn availability in calcareous soils in central Thailand. However, Mehlich 3 was superior to AB-DTPA. |
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