Soil Acidification in the Inland Pacific Northwest
Soil pH Video Series
Nitrification
Using a portable pH meter
Lime Application with Joao Antonangelo–No-Till Farmer
Published Fact Sheets
Soil pH and Implications for Management: An Introduction
Abstract: Decreasing soil pH, also called soil acidification, is a growing concern in eastern Washington and northern Idaho. Researchers and farmers have measured soil pH values below 5.0 throughout the Palouse region. Decreasing soil pH has serious implications for the cropping systems of the Palouse. This introduction is the first in a series of fact sheets on soil acidification and introduces the fundamentals of soil pH and acidification. Other fact sheets in the series will cover more specific information on topics such as the influence of pH on pathogens and microbes, herbicide activity, crop nutrition, liming, and variety selection.
Recommended Crop Species and Wheat Varieties for Acidic Soil
Introduction: As discussed in the Implications for Management – An Introduction, not all crop species—nor all varieties within species—respond the same to acidic soil (Figure 1). Of the crops commonly grown in eastern Washington and northern Idaho, legumes are the most sensitive to soil acidity, while wheat and barley are less sensitive, followed by triticale and grass hay/seed crops, which can tolerate more acidic soil (Table 1). Canola and buckwheat also fare better on acidic soils than legumes and some wheat varieties, although canola is relatively sensitive to manganese (Mn) toxicity, which can be a problem on some acidic soils.
How Soil pH Affects the Activity and Persistence of Herbicides
Abstract: Decreasing soil pH, also called soil acidification, is a growing concern in eastern Washington and northern Idaho. Researchers and farmers have measured soil pH values below 5.0 throughout the Palouse region, in particular. Decreasing soil pH has serious implications for the cropping systems of the Palouse.
Using a pH Meter for In-Field Soil pH Sampling
Abstract: Soil pH continues to decline across much of the Palouse and the Pacific Northwest, primarily as a result of the application of nitrogen for the production of wheat and other crops. A handheld sampling meter can be utilized for the infield checking of the soil pH with good results. Within a few minutes of arriving at a field location, it is possible to collect a soil sample, test the soil, and record the pH values.
Agricultural Lime and Liming
Part 1. Introduction: This section contributes to the discussion on the increasing incidence and severity of acid soils in the IPNW and emphasizes: i) soil sampling and monitoring concepts to consider when managing acid soil conditions; ii) the role of soil testing; and iii) characterization of liming materials used to elevate pH of acid soil.
Part 2. Laboratory Testing to Determine Lime Requirements: This publication has been archived. An updated publication Determining Lime Requirement Estimates for the inland Northwest: A guide to the updated Lime Requirement Calculator takes its place to define soil buffer capacity and explains why laboratory testing is needed to determine lime requirements for addressing acidic soils. It provides updated guidance on which buffer tests are most suitable to soils in our region and a companion Lime Requirement Calculator is provided to help calculate lime requirements and conversions from each of these laboratory tests.
Part 3. Agricultural Lime and Liming, Part 3: Aglime Product Selection & Comparison Calculator User Guide: The publication describes the attributes used to characterize liming material and how characteristics contribute to lime effectiveness and lime score. There is an example case study in the publication and an online tool is under development to help perform calculations to compare up to three liming materials for their relative effectiveness, costs, and economic efficiency.
Soil Acidity Impacts Beneficial Soil Microorganisms (FS247E)
Abstract: Beneficial soil microorganisms are also absolutely critical to soil fertility and plant nutrition, but soil acidification in the Pacific Northwest threatens their effectiveness. This publication outlines the response of beneficial soil microbial populations to acidification and how understanding this response may provide valuable in enacting sustainable approaches to soil acidification problems.