freitas1966

Example dataset containing real data reported by Cate &amp; Nelson (1971) from Freitas et al. (1966).
Soil test potassium values (STK) and relative yield as percentage (RY).

datasets

A compilation of functions designed to assist users on the correlation analysis of crop yield and soil test values. Functions to estimate crop response patterns to soil nutrient availability and critical soil test values using various approaches such as: 1) the modified arcsine-log calibration curve (Correndo et al. (2017) <doi:10.1071/CP16444>); 2) the graphical Cate-Nelson quadrants analysis (Cate & Nelson (1965)), 3) the statistical Cate-Nelson quadrants analysis (Cate & Nelson (1971) <doi:10.2136/sssaj1971.03615995003500040048x>), 4) the linear-plateau regression (Anderson & Nelson (1975) <doi:10.2307/2529422>), 5) the quadratic-plateau regression (Bullock & Bullock (1994) <doi:10.2134/agronj1994.00021962008600010033x>), and 6) the Mitscherlich-type exponential regression (Melsted & Peck (1977) <doi:10.2134/asaspecpub29.c1>). The package development stemmed from ongoing work with the Fertilizer Recommendation Support Tool (FRST) and Feed the Future Innovation Lab for Collaborative Research on Sustainable Intensification (SIIL) projects.

Adrian A. Correndo

soiltestcorr

Soil Test Correlation and Calibration

Austin Pearce

Fernando Miguez

Deanna Osmond

Ignacio A. Ciampitti

freitas1966 function

this data frame has 24 rows and the following 2 columns:<dl>
<dt>RY</dt>
<dd>relative yield, %</dd><dt>STK</dt>
<dd>soil test potassium, ppm</dd>
</dl>

Format

Dataset 2 — freitas1966

this data frame has 24 rows and the following 2 columns:<dl>
<dt>RY</dt>
<dd>relative yield, %</dd>

<dt>STK</dt>
<dd>soil test potassium, ppm</dd>


</dl>

freitas1966: Dataset 2

Description

Usage

Arguments

Format