Simple Soil Tests for On-Site Evaluation of Soil Health in Orchards

Esther O Thomsen,Jennifer R Reeve,Diane G Alston,Robert Newhall,Grant Cardon,Catherine M Culumber

doi:10.3390/su11216009

Abstract

Standard commercial soil tests typically quantify nitrogen, phosphorus, potassium, pH, and salinity. These factors alone are not sufficient to predict the long-term effects of management on soil health. The goal of this study was to assess the effectiveness and use of simple physical, biological, and chemical soil health indicator tests that can be completed on-site. Analyses were conducted on soil samples collected from three experimental peach orchards located on the Utah State Horticultural Research Farm in Kaysville, Utah. All simple tests were correlated to comparable lab analyses using Pearson’s correlation. The highest positive correlations were found between Solvita® respiration, and microbial biomass (R = 0.88), followed by our modified slake test and microbial biomass (R = 0.83). Both Berlese funnel and pit count methods of estimating soil macro-organism diversity were fairly predictive of soil health. Overall, simple commercially available chemical tests were weak indicators of soil nutrient concentrations compared to laboratory tests. Modified slake tests, Solvita® respiration and soil organism biodiversity counts may be efficient and cost-effective tools for monitoring soil health on-site.

Highlights

Soil health or quality is typically defined as the ability of soil to function while maintaining or improving water and air quality, and supporting biota [1,2]
Twelve simple tests for measuring soil physical, biological and chemical properties were correlated to comparable laboratory analyses for their ability to distinguish between soils of known soil health characteristics
The slake test included in the Natural Resources and Conservation Services (NRCS) test kit was selected as a simple measure of aggregate stability and two additional slake tests were developed as further simplifications

Summary

Introduction

Soil health or quality is typically defined as the ability of soil to function while maintaining or improving water and air quality, and supporting biota [1,2] (pp. 3–21; pp. 23–35). Soil health or quality is typically defined as the ability of soil to function while maintaining or improving water and air quality, and supporting biota [1,2] Maintaining soil health is essential for agricultural sustainability and the long-term viability of all land-based natural systems [3]. Maintaining soil health can prevent loss in system productivity while improving long-term financial outcomes for farmers. Little progress has been made in increasing grower involvement in soil testing and soil health maintenance [6,7]. Soil health tests are not always convenient, affordable, reliable, or feasible for interested individuals [8] as well as an ongoing lack of education [7]

Objectives

Methods

Results

Conclusion