# Introduction

#### Adrian Correndo & Austin Pearce

The `soiltestcorr` package is a collection of functions intended to contribute to reproducible correlation analysis between crop relative yield (RY) and soil test values (STV). The package development stemmed from ongoing work with the Fertilizer Recommendation Support Tool (FRST) and the Feed the Future Innovation Lab for Collaborative Research on Sustainable Intensification (SIIL) projects.

This tutorial will introduce and demonstrate the currently available functions.

## 1. Installation

You can install the latest CRAN version of `soiltestcorr` with:

    install.packages("soiltestcorr")

Alternatively, you can install the development version of `soiltestcorr` from GitHub with:

    # install.packages("devtools")
    devtools::install_github("adriancorrendo/soiltestcorr")

    library(soiltestcorr)

    #> Registered S3 methods overwritten by 'ggpp':
    #>   method                  from
    #>   heightDetails.titleGrob ggplot2
    #>   widthDetails.titleGrob  ggplot2

Suggested packages are

    library(ggplot2) # Plots
    library(dplyr) # Data wrangling
    library(tidyr) # Data wrangling
    library(purrr) # Mapping

## 2. Available models in `soiltestcorr`:

### 2.1. Modified Arcsine-Log Calibration Curve

### 2.2. Cate & Nelson (1965)

### 2.3. Cate & Nelson (1971)

### 2.4. Linear-plateau

### 2.5. Quadratic-plateau

### 2.6. Mitscherlich

## 3. Publication in `SoftwareX Journal`:

https://doi.org/10.1016/j.softx.2022.101275

## 4. Shinyapp:

https://ciampittilab.shinyapps.io/soiltestcorr/