Soil Testing: A Vital Tool In Commercial Agriculture

Kayla Domier

CONTENTS

• About me• Background

• Education

• Work experience

• Current employer

• My family

• Topic selection

• Why a learning module?

• Module

• Value of a learning module

• Summary

• Quiz question examples

• Questions?

MY BACKGROUND

• Originally from North Dakota, however spent middle/high school age in Wisconsin, then returned to North Dakota

• My father has worked for farmers since I was little Spent a majority of summer breaks in tractors/combines

• Agriculture wasn’t my dream desire, as I wanted to be a Teacher

EDUCATION

• B.S. in Biology from Mayville State University, 2008Minors in Earth Science and Chemistry

• Internships at both, on campus research labs and a commercial soil testing laboratory

• Started Agronomy program in Fall of 2013

WORK EXPERIENCE

• Research Laboratory, Mayville State University, 2007 to 2008 Research on Common Bean genetic markers related to disease

resistance, phenotypic and genotypic.

• Agvise Laboratories, Internship 2008 Commercial soil, water, plant tissue, manure, and fertilizer testing

laboratory.

CURRENT EMPLOYER

• Agvise Laboratories Agvise Laboratories is a commercial soil testing laboratory, where

services also include testing of fertilizer, water, manure, plant tissue, and other miscellaneous agricultural products (beet lime, etc.)

Employed as a Chemist

MY FAMILY

• 2 Children: Trinity (2) and Jaxson (1)

TOPIC SELECTION

• - Personal interest Initial internship opportunity in soil testing laboratory Internship converted to full time position

• Questions about soil testingWhy?How does this work?Who thought of this?

TOPIC SELECTION

• Not 1st choice Initially was interested in temperature effects on phosphorus testing

o This turned into an “at work” project, for the company

Still had a curiosity of soil testing

o History

o How and why tests are performed

WHY A LEARNING MODULE?

• Purpose: provide and present materials in an organized manner• Helpful in many ways Interactive training tool for new employees Informative, educational accessory to customers if requested

o Customers curious about what happens in a soil labo A way to introduce these customers to the background and basics of soil

testing before getting a tour of the soil testing lab

MODULE

• Multiple topics surrounding soil testing

History Importance Methods Data Analysis

o Interpretationso Fertilizer recommendations

• Goal: to provide information that will lead to complete understanding of the topics covered in the module

• Importance of soil testing

• History and development of region specific soil testing methods.

Introduction

• Importance of soil testing

Determine nutrient supplying potential

Record keeping

Monitor nutrient availability trends

Soil Testing

• Advancement of soil testingCritical periods of development

1845-1906: Expression of soluble nutrients in soil in terms of “active’ or “dormant”. 1906-1925: Emphasis on chemical data in relation to crop production. 1925-1952: Development of universally applicable soil test methods.

Adaptation of chemical tests to specific soil conditions 1952-2000: Consistency in data from different soil testing laboratories. 2000-current: Focus on soil health tests

History

• Soil types

• Crops

• Methodology

• Interpretations

• Fertilizer recommendations

• Economic potential

Critical factors

• Soil Types

Vary based on how soil was formed

Described based on o Texture

o Drainage

o Organic matter content

Factors

• Crops

Not all the soil tests apply equally to every soil and cropping situation.o pH, Lime Requirement (L.R.), Phosphorus (P), Potassium (K), Calcium

(Ca), Magnesium (Mg), Manganese (Mn), Zinc (Zn) tests are routinely recommended for all commercial field and vegetable crops as well as lawns and gardens

o Soluble Salts (S.S.) test is recommended where large quantities of fertilizers have been applied, particularly for potted plants, greenhouse beds, lawns or ornamental plantings or beds. Not generally applicable to field soils except in problem-solving situations

Factors

• InterpretationsTerms used other than sufficient,

deficient, and excessiveo Very lowo Lowo Mediumo Higho Very High

Comparing critical limit to results

Factors

• Fertilizer Recommendations

Fertilizer uptake efficiency based on soil test results

Recommendations supplied based on soil test-crop response correlation

o Based on studies conducted on specific soils and crops, crop selection and field history

Factors

• Economic Potential

Soil testing can save moneyo Being assured of nutrient supply

o Prevents over-application

o Saves money on avoiding un-needed fertilizer

Factors

Includes:

• Soil sampling

• Soil preparation

• Soil fertility nutrient testing

• N, P, K, OM, pH, and lime requirements

• Soil health assessment tests

Soil testing

• Soil sampling

Appropriate and correct sampling techniques are important for testing

Types of samplingo Zone

o Composite

o Grid

Use correct sampling tools

Soil testing

• Sample Preparation

Tested as received (moist state)

OR samples are dried and ground to a fine powder

o Homogenizing samples

o Composite representation

o Drying causes microbial activity to cease

Soil testing

• Soil analysis

Method selectiono Correlations between extractable

nutrients and yield

Methodso N, P, K, OM, pH, and lime

requirements

Soil testing

• Soil analysisNitrate-Nitrogen

o Helpful for pre-plant N, and pre-sidedresso Water or Salt Solution for extractiono Cadmium reductiono Intensity of color measured using

spectrophotometero Quantified into a value

Reflects nutrient concentration in soil extract

Soil testing

• Soil analysisPhosphorus

o Many methods available Based on pH of soils

o Olsen’s widely used Sodium bicarbonate solution, pH 8.5 Measured colorimetrically using a

spectrophotometer Intensity of color correlates to nutrient

content in soil solution

Soil testing

• Organic Matter

Loss on ignition Test sequence

o Dried - 105°C, 2 hours

o Weighed

o Furnace - 360°C, 2 hours

o Weighed

Calculated from difference between initial oven dry weight and ignition weight.

Soil testing

• pH Most common and important chemical test

Indicator of general chemical condition of soils

1:1 ration water/dilute salt solution to soil

Hydrogen ion concentration is measured at equilibrium using a calibrated pH meter

Soil testing

• Lime requirement

Buffer pH method

Sikora buffer (pH 7.7)

Change in pH of Sikora buffer indicates acidity of sample that has to be neutralized

o Higher acidity = higher lime quantity to be added to soil to raise the pH of soil to optimum soil production

Soil testing

• Soil health assessment

Focuses on assessing how well soil performs and functionsTests

o Haney tests

o Cornell soil health

Provides indicator of current soil healthProvides an opportunity to aid in improving soil health, as well as

maintaining.

Soil testing

• Biological – Microbial activity, soil OM, mineralizable N, organic nitrogen and carbon

• Physical – Aggregate stability, water holding capacity and penetrability

• Chemical – Nutrient availability (chemical fertility test)

Soil testing

• Data acquisition• Soil test result variability:

Technician Instrumentation Methodology

• Quality assurance/quality control in a soil lab: Control limits Accuracy Precision

Data analysis

• Previous crop data/recommendations based on results Build up and maintenance

Sufficiency

Fertilizer recommendations

VALUE OF A LEARNING MODULE

• Potentially presented in colleges as supplemental material on a soil testing topic

• Tool for commercial agriculture consultants

• New staff training tool in a soil testing laboratory

• Suitable tool for diverse learning situations

SUMMARY

Soil testing is an essential tool for agricultural production. Thismodule introduces the reader to the history of soil testing,importance of soil testing, methods currently in soil testing, as wellas the data analysis associated with soil testing to produce fertilizerrecommendations. The goal of this module is to develop a soundunderstanding of these topics that are essential components of soiltesting process.

EXAMPLE QUIZ QUESTIONS

1. This method is performed using 1:1 soil to water, that is mixed, and allowed to equilibrate for 10 minutes before measurements are taken. a. Organic Matter b. Nitrate c. Phosphorus d. pH

1. This method is performed using 1:1 soil to water, that is mixed, and allowed to equilibrate for 10 minutes before measurements are taken. a. Organic Matter b. Nitrate c. Phosphorus d. pH

1. Name the buffer solution that is commonly used for lime requirement determinations in Mid-west? a. Sikora b. Adams & Evans c. DTPA d. Barium Chloride-TEA

1. What is one possible solution to be used if the soil probe is sticky when collecting soil samples? a. Windex b. Baby Oil c. WD-40 d. Armorall

QUESTIONS?