Soil-sampling errors and advisory analyses

1955 ◽  
Vol 46 (1) ◽  
pp. 1-8 ◽  
Author(s):  
R. G. Hemingway
Keyword(s):  
Soil Type ◽  
Representative Sample ◽  
Soil Sampling ◽  
Sampling Errors ◽  
Soluble Phosphorus ◽  
The Common ◽  
Phosphorus And Potassium ◽  
Analytical Errors

1. Twenty-four sampling units from 50 fields of differing soil type and past manurial history have been examined separately for pH and 1% citric soluble phosphorus and potassium to determine the errors which can occur in obtaining a representative sample for analysis.2. Soils which had received lime and fertilizers within 3 years of the sampling date showed appreciably greater sampling errors than those which had not.3. The sampling errors were greater than the analytical errors and were such that the common practice of classifying soils into six fertility groups was not justified. Three major groups are more reasonable and practical for routine advisory purposes.

PHOSPHORUS AND POTASSIUM SUPPLY FOR ALFALFA IN SOILS SAMPLED AT DIFFERENT DEPTHS

1957 ◽  
Vol 37 (1) ◽  
pp. 63-72 ◽  
Author(s):  
R. L. Halstead ◽  
K. F. Nielsen ◽  
A. J. MacLean
Keyword(s):  
Total Phosphorus ◽  
Greenhouse Experiment ◽  
Water Soluble ◽  
Organic Form ◽  
Pronounced Difference ◽  
Soluble Phosphorus ◽  
Potassium Supply ◽  
Different Depths ◽  
Phosphorus And Potassium ◽  
Depth Water

Results of a greenhouse experiment, comprising soil samples taken at three depths from each of six locations in eastern Ontario, indicated that the phosphorus-supplying power of the surface was considerably greater than that of the corresponding subsurface samples of four of the soils. The relative amounts of total phosphorus in surface and subsurface samples varied with the soils, the most pronounced variation being an increase in a sandy soil with depth. The proportion of the total phosphorus found in organic form varied from 18 to 56 per cent in the surface and from 5 to 33 per cent in the subsurface samples. The amounts of acid-soluble phosphorus extracted from five of the soils increased with depth. The amounts of NaHCO3-soluble phosphorus were higher in the surface than in the subsurface samples of five of the soils. The values for acid-soluble phosphorus in five of the soils and for NaHC03-soluble phosphorus in three of the soils were not in agreement with greenhouse results.The data from the greenhouse experiment did not indicate a pronounced difference between the potassium-supplying powers of corresponding surface and subsurface samples. Exchangeable potassium did not vary appreciably between surface and subsurface samples of four of the soils but decreased in two of the soils with depth. Water-soluble potassium decreased with depth in most instances.

Importance of phosphorus and potassium in soil-specific nutrient management for wet-season rice in Cambodia

2019 ◽  
Vol 56 (2) ◽  
pp. 204-217
Author(s):  
Kea Kong ◽  
Sarith Hin ◽  
Vang Seng ◽  
Abdelbagi M. Ismail ◽  
Georgina Vergara ◽  
...  
Keyword(s):  
Soil Type ◽  
Field Experiments ◽  
Nutrient Management ◽  
Clay Content ◽  
Fertilizer Application ◽  
Exchange Capacity ◽  
Economic Feasibility ◽  
Specific Recommendation ◽  
Wet Season ◽  
Phosphorus And Potassium

AbstractRice is widely grown in rainfed lowlands during the wet season in the Mekong region. Limited nutrient availability is a common constraint on crop yield, and the optimal rate of fertilizer application depends on the soil type. The objective of our study was to evaluate rice productivity and the economic feasibility of various nutrient management regimes in Cambodia. We conducted field experiments on three soil types (Prey Khmer, Prateah Lang, and Toul Samroung, equivalent to Psamments, Plinthustalfs, and Endoaqualfs, respectively) in four provinces (Battambang, Kampong Thom, Pursat, and Siem Reap) during the 2016 and 2017 wet seasons to compare nine (2016) and seven (2017) N–P–K combinations. Grain yield ranged from 0.9 to 4.8 t ha−1 in 2016 and from 1.0 to 5.2 t ha−1 in 2017, depending on soil type and nutrient management. The Prey Khmer soil contained around 80% sand, and rice yield responded most weakly to nutrient management. The moderate fertilizer input in the current soil-specific recommendation was effective on this soil type. However, on more fertile soils with a higher clay content and a higher cation-exchange capacity (Toul Samroung and Prateah Lang), an additional 20 kg N ha−1 combined with adding 15 kg ha−1 of P2O5 or 20 kg ha−1 of K2O significantly increased yield and economic return. Although P and K use during Cambodia’s wet season is uncommon, our results demonstrate the importance of these nutrients in improving the country’s rice production.

An innovative approach for visualization of subsurface soil properties

2004 ◽  
Vol 84 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Z. Hu ◽  
B. Bass ◽  
C. W. Chan ◽  
G. H. Huang
Keyword(s):  
Soil Type ◽  
Concentration Distribution ◽  
Soil Layer ◽  
Soil Classification ◽  
Soil Sampling ◽  
Contaminated Site ◽  
Distribution Data ◽  
Contaminant Concentration ◽  
Type Distribution ◽  
Site Characteristics

Subsurface characterization is an important requirement in the decision-making process of selecting a remediation technique for petroleum-contaminated sites. The soil type distribution is one of the most important site characteristics, because it affects selection of the site remediation technique. The visualization of soil type distribution and also the contaminant concentration distribution in the subsurface can help the decision-maker understand the site and select the proper remediation technique. In this paper, we describe the software Soil-Visual (1.0, 1.1), which is used for visualizing the soil sampling data, the soil type distribution, and contaminant concentration distribution of a contaminated site. This software has two functions: (1) to determine the soil particle size distribution and contaminant concentration distribution of the entire site from limited soil sampling data; and (2) to visualize the multi-dimensional soil type distribution and contaminant concentration distribution data of each soil layer on a two-dimensional map. The red-green-blue (RGB) color illustration method has been used in this software to convert the multi-dimensional soil sampling data into a bitmap. Key words: RGB bitmap, soil classification, visualization

Using Historical Management to Reduce Soil Sampling Errors

2007 ◽  
pp. 49-64 ◽  
Author(s):  
Jiyul Chang ◽  
Jonathan Kleinjan ◽  
C Gregg Carlson ◽  
N Kitchen ◽  
David Clay
Keyword(s):  
Soil Sampling ◽  
Sampling Errors ◽  
Historical Management

scholarly journals Concentration gradients and their significance in Laminaria saccharina (L.) Lamour.

1954 ◽  
Vol 33 (1) ◽  
pp. 49-60 ◽  
Author(s):  
W. A. P. Black
Keyword(s):  
Chemical Composition ◽  
Seasonal Variations ◽  
Representative Sample ◽  
Concentration Gradients ◽  
Laminaria Saccharina ◽  
Stage Of Development ◽  
Profound Influence ◽  
Unpublished Work ◽  
Littoral Zones ◽  
The Common

In previous publications the author (Black, 1948a-c, 1949, 1950a) has reported the seasonal variations in chemical composition that occur in certain of the common Phaeophyceae. In the sublittoral and littoral zones it has been found that a correlation exists between the chemical composition and the depth of immersion of the plant (Black, 1950&, and unpublished work). Differences in composition, particularly during the summer months, also occur in the same species taken at the same time and depth but from different habitats (Black, loc. cit.), and there is also evidence that in the laminarians the stage of development of the plant has a profound influence on the composition. In all the above-mentioned analyses the entire plants have been separated into stipe and frond, dried under controlled conditions, milled, and a well-mixed representative sample of each taken for analysis.

Changes occurring during a year in the soluble phosphorus and potassium in soil under crops in rotation experiments at Rothamsted, Woburn and Saxmundham

1966 ◽  
Vol 66 (3) ◽  
pp. 399-412 ◽  
Author(s):  
I. P. Garbouchev
Keyword(s):  
Anion Exchange ◽  
Seasonal Changes ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Soil Samples ◽  
Npk Fertilizers ◽  
Arable Crops ◽  
Soluble Phosphorus ◽  
Phosphorus And Potassium ◽  
Exchangeable P

From May 1963 to April 1964 seasonal changes in soluble nutrients were followed in soil samples taken monthly from plots having none, PK, and NPK fertilizers in experiments at Rothamsted and Woburn. Phosphorus, potassium and magnesium concentrations in equilibrium extracts of the soils made with 0.0lM-CaCl2 solution were determined. Exchangeable P was determined with an anion exchange resin. Samples were taken under five arable crops growing in rotation, and under permanent grass on the two soils.

Reducing Soil Sampling Errors

2015 ◽  
pp. 131-136
Author(s):  
D.E. Clay ◽  
C.G. Carlson ◽  
Cheryl Reese
Keyword(s):  
Soil Sampling ◽  
Sampling Errors
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