Contrasting Concepts in Soil Test Interpretation: Sufficiency Levels of Available Nutrients Versus Basic Cation Saturation Ratios

2015 ◽  
pp. 39-54 ◽  
Author(s):  
E.O. McLean
Keyword(s):  
Soil Test ◽  
Test Interpretation ◽  
Available Nutrients ◽  
Basic Cation

Site specific soil‐test interpretation for snapbean

1990 ◽  
Vol 21 (17-18) ◽  
pp. 2181-2188 ◽  
Author(s):  
F. M. Rhoads ◽  
E. A. Hanlon
Keyword(s):  
Soil Test ◽  
Test Interpretation ◽  
Site Specific

scholarly journals The development and application of functions describing pasture yield responses to phosphorus, potassium and sulfur in Australia using meta-data analysis and derived soil-test calibration relationships

2019 ◽  
Vol 70 (12) ◽  
pp. 1065 ◽  
Author(s):  
Cameron J. P. Gourley ◽  
David M. Weaver ◽  
Richard J. Simpson ◽  
Sharon R. Aarons ◽  
Murray M. Hannah ◽  
...  
Keyword(s):  
Application Rate ◽  
Economic Benefits ◽  
National Database ◽  
Yield Response ◽  
Soil Test ◽  
Test Interpretation ◽  
Meta Data ◽  
Nutrient Use ◽  
Yield Responses ◽  
Pasture Yield

An improved ability to predict pasture dry matter (DM) yield response to applied phosphorus (P), potassium (K) and sulfur (S) is a crucial step in determining the production and economic benefits of fertiliser inputs and the environmental benefits associated with efficient nutrient use. The adoption and application of soil testing can make substantial improvements to nutrient use efficiency, but soil test interpretation needs to be based on the best available and most relevant experimental data. This paper reports on the development of improved national and regionally specific soil test–pasture yield response functions and critical soil test P, K and S values for near-maximum growth of improved pastures across Australia. A comprehensive dataset of pasture yield responses to fertiliser applications was collated from field experiments conducted in all improved pasture regions of Australia. The Better Fertiliser Decisions for Pastures (BFDP) database contains data from 3032 experiment sites, 21918 yield response measures and 5548 experiment site years. These data were converted to standard measurement units and compiled within a specifically designed relational database, where the data could be explored and interpreted. Key data included soil and site descriptions, pasture type, fertiliser type and rate, nutrient application rate, DM yield measures and soil test results (i.e. Olsen P, Colwell P, P buffering, Colwell K, Skene K, exchangeable K, CPC S, KCl S). These data were analysed, and quantitative non-linear mixed effects models based upon the Mitscherlich function were developed. Where appropriate, disparate datasets were integrated to derive the most appropriate response relationships for different soil texture and P buffering index classes, as well as interpretation at the regional, state, and national scale. Overall, the fitted models provided a good fit to the large body of data, using readily interpretable coefficients, but were at times limited by patchiness of meta-data and uneven representation of different soil types and regions. The models provided improved predictions of relative pasture yield response to soil nutrient status and can be scaled to absolute yield using a specified maximal yield by the user. Importantly, the response function exhibits diminishing returns, enabling marginal economic analysis and determination of optimum fertiliser application rate to a specific situation. These derived relationships form the basis of national standards for soil test interpretation and fertiliser recommendations for Australian pastures and grazing industries, and are incorporated within the major Australian fertiliser company decision support systems. However, the utility of the national database is limited without a contemporary web-based interface, like that developed for the Better Fertiliser Decisions for Cropping (BFDC) national database. An integrated approach between the BFDP and the BFDC would facilitate the interrogation of the database by advisors and farmers to generate yield response curves relevant to the region and/or pasture system of interest and provides the capacity to accommodate new data in the future.

A phosphorus soil test interpretation for corn grown on acid soils varying in crystalline clay content

1984 ◽  
Vol 15 (12) ◽  
pp. 1481-1491 ◽  
Author(s):  
F R. Cox ◽  
I. D. G. Lins
Keyword(s):  
Acid Soils ◽  
Clay Content ◽  
Soil Test ◽  
Test Interpretation

scholarly journals EXTRACTION OF POTASSIUM AND SODIUM FROM ACID AND CALCAREOUS SOILS WITH THE KELOWNA MULTIPLE ELEMENT EXTRACTANT

1989 ◽  
Vol 69 (2) ◽  
pp. 235-242 ◽  
Author(s):  
W. VAN LIEROP ◽  
N. A. GOUGH
Keyword(s):  
Calcareous Soils ◽  
Water Extract ◽  
Complexing Agents ◽  
Soil Test ◽  
Test Interpretation ◽  
Ph Values ◽  
Correlation Techniques ◽  
Regression Slopes ◽  
Soil Groups

The objective of this study was to evaluate the Kelowna multiple element extractant and some EDTA and DTPA modifications for simultaneous determination of potassium and sodium in acid and calcareous soils. To that end, the relationships between K and Na concentrations extracted with 1 N NH4OAc and the Kelowna multiple element extractant (0.25 N HOAc + 0.015 N NH4F) were assessed. However, relationships between K and Na concentrations removed by the modified Kelowna multiple element extractants containing either EDTA or DTPA (KEDTA & KDTPA with NH4F; and AAEDTA & AADTPA without NH4F) were evaluated by comparing values against those obtained with the Kelowna extractant. Addition of these complexing agents was of interest because of their potential in enabling simultaneous extraction of available Zn. The procedures were evaluated by contrasting K and Na concentrations extracted from 100 Canadian soils — half which had pH values between 4.1 and 6.9 (H2O) and a second group with values between 7 and 9.6 — by means of graphing, regression and correlation techniques. Potassium and sodium concentrations removed by the Kelowna extractant ranged from 25 to 510 μg and from 10 to 1420 μg mL−1 soil, respectively. The Kelowna and its EDTA and DTPA modifications extracted K and Na as effectively from acid as calcareous soils. This conclusion was supported by the similar regression slopes obtained when relating concentrations of K and Na removed from these soil groups by the multiple element extractants against those removed by 1 N NH4OAc (r-values ≥ 0.97**). However, the new multiple element extractants removed an average of about 20% less K than 1 N NH4OAc from these soils, though similar Na levels. The lower K levels removed from the Kelowna extractant, or by one of its modifications, may require that soil test interpretation norms be adjusted to compensate for the lower values when using one of these to determine K-availability. A significant correlation was found between extracted Na levels and 1:2 vol/vol water-extract conductivities (r ≥ 0.83**) suggesting that "higher" Na levels may be soluble instead of exchangeable. Some Na test interpretations are discussed in the text. Key words: EDTA, DTPA

Fertilizer response for hybrid and open-pollinated canola and economic optimal nutrient levels

2010 ◽  
Vol 90 (3) ◽  
pp. 305-310 ◽  
Author(s):  
E G Smith ◽  
B M Upadhyay ◽  
M L Favret ◽  
R E Karamanos
Keyword(s):  
Yield Response ◽  
Available Phosphorus ◽  
Soil Test ◽  
Fertilizer Response ◽  
Brassica Napus L ◽  
Yield Data ◽  
Available N ◽  
Available Nutrients ◽  
Fertilizer Recommendations ◽  
N Fertility

Hybrid (HY) canola (Brassica napus L.) produces a higher seed yield than open-pollinated (OP) canola. While it is expected higher-yielding HY canola may require higher total available nutrients, especially nitrogen (N), the evidence is not conclusive. This study used canola yield data from several site-years and fertility experiments to determine whether HY and OP canola types require different rates of total available N (TAN) and total available phosphorus (TAP). The yield response of the two canola genotypes to TAP was the same, but for TAN the yield response was greater for HY canola. The quadratic yield response results were confirmed using three plateau equations. Optimal TAN for HY canola was higher than for OP canola. Soil test laboratories and producers growing HY canola need to modify N fertility for HY canola, compared with OP canola for which most of the current N fertilizer recommendations were developed. Key words: Economics, fertilizer, yield response, canola, hybrid, open-pollinated

Use of a fertility index in soil test interpretation

1973 ◽  
Vol 4 (2) ◽  
pp. 137-146 ◽  
Author(s):  
J.T. Cope
Keyword(s):  
Soil Test ◽  
Test Interpretation ◽  
Fertility Index

Integrating the mehlich‐3 extractant into existing soil test interpretation schemes

1996 ◽  
Vol 27 (5-8) ◽  
pp. 1237-1249 ◽  
Author(s):  
D. J. Eckert ◽  
M. E. Watson
Keyword(s):  
Soil Test ◽  
Test Interpretation
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