ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ระดับวิกฤตและความสามารถในการให้ธาตุทองแดงของชุดดิน ตาคลี เลย และโคราช สำหรับการผลิตข้าวโพด

ผู้เขียน:Chiranee Vanichkul, ดร.อำนาจ สุวรรณฤทธิ์, ศาสตราจารย์เกียรติคุณ, Preeda Parkpian

สื่อสิ่งพิมพ์:pdf

Abstract

Pot experiments were conducted to examine critical levels and supplying powers of Cu in Takhli, Loei and Khorat soil series, as well as reliabilities of two methods of soil analysis, i.e., extraction with 0.1 NHCI and extraction with DTPA. Samples of the three soils were applied with different rates of CuCl2 and then repeatedly cropped with corn in small pots until a difference in corn dry matter was found between Treatments receiving different rates of Cu. Soil samples were taken before each cropping for analyses of available Cu by the two analytical methods mentioned above. Results showed that the three soils were not deficient in Cu. However, copper status of Takhli and Khorat soils were close to the critical levels. It was estimated that annual corn cropping could be practiced for at least 5, 37 and 2 years on Takhli, Loei, and Khorat soils, respectively before response of corn to Cu application could be obtained. Narrowest ranges of extracted Cu that covered critical levels for Takhli, Loei and Khorat soils were 0.40 - 0.45, 1.05 - 1.30 and 0.25 - 0.35 ppm, respectively when extracted with 0.1 N HC1 and were 3.0 - 3.3, 2.4 - 2.7 and 0.8 - 0.9 ppm, respectively when extracted with DTPA. Considering the three soils as one group, the narrowest ranges were 0.35 - 1.05 and 0.9 - 3.0 ppm for extractions with 0.1 NHCI and with DTPA, respectively. Narrowest ranges of Cu concentrations in corn plants were 5.6 - 6.8, 4.7 - 4.7 and 3.5 - 3.7 ppm for Takhli, Loei, and Khorat soils, respectively. Considering the three soils as one group, the narrowest range of Cu in plants was 3.7 - 5.6 ppm. It was concluded that extraction with 0.1 NHCI gave more reliable prediction than extraction with DTPA. However, differences in critical levels found for each soil suggested that Cu concentration in plants would provide more reliable prediction than amounts of Cu extracted from soils by the two methods.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 027, Issue 1, Jan 93 - Mar 93, Page 44 - 55 |  PDF |  Page

ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Zinc Critical Levels and Supplying Powers of Takhli, Loei, and Khorat Soil Series for Corn Production)

ผู้เขียน:ดร.อำนาจ สุวรรณฤทธิ์, ศาสตราจารย์เกียรติคุณ, Chiranee Vanichkul, Preeda Parkpian

สื่อสิ่งพิมพ์:pdf

Abstract

Pot experiments were conducted to examine critical levels and supplying powers of Zn in Takhli, Loei and Khorat soil series, as well as reliabilities of two methods of soil analysis, namely, extraction with 0.1 NHCl and extraction with DTPA (pH 7.3). Results showed that Takhli soil was so severely deficient in Zn that Zn visual deficiency symptoms were observed whereas Loei soil was Zn-deficient but not so severely that visual deficiency symptoms could be observed. Khorat soil series was estimated to be able to support corn production for at least 37 years before it needed Zn application for maximum growth. Narrowest ranges of extracted Zn that covered critical levels for Takhli, Loei and Khorat soil series were 2.5-4.8, 9.6-13.9 and 6.9-16.0 ppm, respectively when extracted with 0.1 NHCl and were 1.2-2.0, 8.6-12.6 and 3.4-12.4 ppm, respectively when extracted with DTPA. Considering the three soils as one group, the narrowest ranges were 4.8-9.6 and 2.0-8.6 ppm for extractions with 0.1 NHCl and with DTPA, respectively. Narrowest ranges of Zn concentrations in corn plants were 18-32, 50-57 and 52-107 ppm for Takhli, Loei, and Khorat soil series, respectively. Considering the three soils as one group, the narrowest range of Zn in plants was 32-52 ppm. It was concluded that extraction with 0.1 NHCl gave slightly more reliable prediction than extraction with DTPA. However, differences in critical levels found for the individual soils suggested that Zn concentration in plants would provide more reliable prediction than amounts of Zn extracted from soils by the two methods. Takhli and Loei soil series needed 6.3 and 43.8 kg Zn/ha to produce maximum growth of corn plants. However, 62.5 kg Zn/ha applied to the three soils was not toxic to corn.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 026, Issue 4, Oct 92 - Dec 92, Page 432 - 440 |  PDF |  Page