Search Result of "soil analysis"

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ผลงานตีพิมพ์ในวารสารวิชาการ

Predicting Phosphorus Buffer Coefficients of Some Representative Soils for Maize Production in Lao PDR by Three Soil Analysis Methods

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ผลงานตีพิมพ์ในวารสารวิชาการ

Soil analysis in crime scene by X-ray diffraction for biomedical engineering

ผู้แต่ง:ImgDr.PICHED ANURAGUDOM, Assistant Professor,

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Equations for Calculating N-Fertilizer Rates for Khaw Dauk Mali-105 Rice from Soil Analysis)

ผู้เขียน:ImgA. Suwanarit, ImgS. Buranakarn, ImgS. Kreetapirom, ImgP. Kangkae, ImgJ. Phumphet, ImgP. Phiatanen, ImgS. Somboonpong, ImgS. Ratanasupa, ImgP. Romyen, ImgS. Wattanapayapkul, ImgK. Naklang, ImgS. Rotjanakusol, ImgP. Charoendham, ImgW. Palaklang, ImgS. Satawathananon, ImgW. Inthalang

สื่อสิ่งพิมพ์:pdf

Abstract

Comparisons were made to assess the reliability of 10 chemical methods for evaluating the availability of N in soils to Khaw Dauk Mali-105 rice and for calculating rates of N-fertilizer for rice. The methods studied were: (1) measuring soil organic matter by Walkley and Black’s method, (2) measuring total soil N by Kjeldahl’s method, (3) extracting soil N with acidified K2Cr2O7 solution, (4) extracting soil N with basified KMnO4 solution, (5) extracting soil N with acidified KMnO4 solution, (6) extracting soil N with solution of CaCl2 and K2SO4, (7) extracting soil nitrate according to Keeney and Nelson (1982) and then measuring the extracted nitrate by Kjeldahl distillation, (8) extracting mineral N in soils with 2N KCl followed by distillation of NH3 with MgO and Devarda alloy, (9) measuring NH4-N production from incubation of soils under waterlogged conditions for 7 days, and (10) measuring NH4-N production from incubation of soils under waterlogged conditions for 14 days. The study was made with field-plot experiments at 18 sites inside and outside the Khaw Dauk Mali-105 producing areas. Only the indices from the methods (9) and (10) gave significant relationships (at 95% confidence level) with the relative paddy yields, with Method (10) showing slight superiority over the method (9). None of the chemical methods gave significant relationships among the index and the relative dry matter and amount of N in plants. The equations for calculating rates of N fertilizer required for desired paddy yields were: (a) log (100 - y) = 2 - 0.0226b - 0.0374x for method (9) and (b) log (100-y) = 2 - 0.00533b - 0.0584x for method (10); where y is the desired grain yield (as % of maximum yield), b availability index value for soil N (in ppm N), and x rate of fertilizer N required (as kg N/rai, 6.25 rais = 1 ha). Both of the two equations gave highly significant correlation between the actual paddy yields and the predicted paddy yields. However, method (10) was more recommended than method (9) for it was more reliable than method (9) in prediction of the yield.

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 033, Issue 2, Apr 99 - Jun 99, Page 224 - 233 |  PDF |  Page 

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