Search Result of "Spatial Variability"

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ผลงานตีพิมพ์ในวารสารวิชาการ

Nitrogen and water uptake on sloping lands of Thailand

ผู้แต่ง:ImgSiriwong, S., ImgDr.Thanuchai Kongkaew, Assistant Professor, ImgCadisch, G., ImgHilger, T.,

วารสาร:

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การประชุมวิชาการ

Nitrogen and water uptake on sloping lands of Thailand

ผู้แต่ง:ImgSiriwong, S., ImgDr.Thanuchai Kongkaew, Assistant Professor, ImgCadisch, G., ImgHilger, T.,

การประชุมวิชาการ:

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:การกระจายของปริมาณเกลือในชุดดินกำแพงแสน

ผู้เขียน:Imgดร.สุนทรี ยิ่งชัชวาลย์, ศาสตราจารย์

สื่อสิ่งพิมพ์:pdf

Abstract

Most soil properties show spatial relationships. This is useful for interpolation. Employing the geostatistical technique, analysis of semi-vriograms will establish the spatial relationships, while ordinary kriging ia the algorithm for interpolation. The area of study was a rectangular plot of 120 ha around a reservoir in the experimental field of Kasetsart University at Kamphaeng Saen. The soil was Kamphaeng Saen. The soil was Kamphaeng Saen soil series (Typic Haplustalfs). Sampling pints were the intersection of 100x100 m2 grid for a total of 127 points. Soil sampling included the top layer of 0-5 cm and the lower layer of 25-30 cm at two periods: during April and November of 1989. Soil properties under study were electrical conductivity of soil saturation extract (ECe), practical sodium adsorption ratio (SARp) and pH soil:water solution of 1:1 Semi-variograms of the three properties were spherical functions, with sills about equal the ordinary variance. The ranges were around 300 m for ECe and SARp, and 500 m for pH. Interpolation was by punctual kriging at the 10x10 m2 scale, giving a total of 12,831 points. Estimated and actual data were displayed in maps of isopleth. The results showed that there were only 3 locations that ECe was higher than 4 dS/m, indication saline soil condition. These were the southern rim of the reservoir, middle and the top right-hand corner of the plot. Since most of the soluble salts were predominantly calcium and magnesium, sodium hazard was limited in only two locations. The areas in the southern rim of the reservoir and in the top right-hand corner contained few patches with SaRp > 13 mol0.5/m1.5, indicating a saline-sodic soil. The pH of the area was mainly in the range of 6 – 8. With kriging, the distribution patterns of salt can be demonstrated with much more details.

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 030, Issue 3, Jul 96 - Sep 96, Page 341 - 350 |  PDF |  Page 

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Correlation and Spatial Variability of Soil Properties Affecting to Sugarcane Yield in Kamphaeng-Saen Soil)

ผู้เขียน:Imgนายอรรถศิษฐ์ วงศ์มณีโรจน์, ผู้ช่วยศาสตราจารย์, Imgชวลิต ฮงประยูร*

สื่อสิ่งพิมพ์:pdf

Abstract

The effects of some soil properties on yield, yield components and qualities of millable cane were analyzed using classical stepwise regression methodologies. The aim of the study was to determine the soil variability, which was effected yields and qualities of the millable cane. By this, 140 grid sample units of 20 ? 20 square meters were allocated in the sugarcane field on Kamphaeng-Sean soil series. In each grid unit, there was 15 rows of 1.33 meters apart. Duck manure and 16-20-0 chemical fertilizer were used as a basal fertilizer. Soil chemical analysis was determined by standard analytical methods. Yield and sugarcane quality such as CCS and fiber percentage was collected in each individual grid. Stepwise regression analysis show significant affects from total soil nitrogen and exchangeable potassium to sugarcane yield and CCS respectively. Semivariogram of yield (millable cane), number of cane and cane weight give a guideline for precision agriculture or site-specific nutrient management approach.

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 038, Issue 6, Jul 04 - Dec 04, Page 109 - 112 |  PDF |  Page 

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Variability in Soil Properties Along an Udalf Toposequence in the Humid Forest Zone of Nigeria)

ผู้เขียน:ImgEffiom Oku, ImgAyuk Essoka, ImgEunice Thomas

สื่อสิ่งพิมพ์:pdf

Abstract

Uniform soil management without any knowledge of the variability of soil properties could result in some parts of an agricultural field receiving insufficient inputs, while other parts receive an excess. Profile soil samples were collected and analyzed for some physico-chemical properties along an Udalf toposequence and their variability assessed. Soil pH was consistently least variable along the toposequence and at all depths. Highly variable properties on the upper slope (crest) included Ca, Mg, Na, K, and P; on the middle slope (hill slope) they were K, organic C, N, silt and clay; and on the foot slope (valley floor) they were Mg, organic C, available P, EA, silt and clay. Moderately variable properties were: C. electrical conductivity (EC), effective cation exchange capacity (ECEC), bulk density, clay, gravimetric moisture, volume wetness and degree of saturation on the upper slope; Mg, Na, EC, and ECEC, base saturation, sand, bulk density, gravimetric moisture and volume wetness on the middle slope; and on the foot slope Ca, N, EC, ECEC, base saturation, bulk density, gravimetric moisture, volume wetness and degree of saturation were moderately variable. The use of bulk samples randomly collected to determine soil properties should be minimized. Large soil sample sizes are needed for soil property studies along the toposequence, as most properties varied from highly to moderately variable. Uniform soil management along the toposequence should be avoided.

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 044, Issue 4, Jul 10 - Aug 10, Page 564 - 573 |  PDF |  Page 

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Researcher

ดร. ธนูชัย กองแก้ว, ผู้ช่วยศาสตราจารย์

ที่ทำงาน:ภาควิชาปฐพีวิทยา คณะเกษตร บางเขน

สาขาที่สนใจ:ความอุดมสมบูรณ์ของดิน, Soil Fertility, Soil Conservation

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