Manure’s Impact on Soil pH

Most manure sources can be an incredible addition to row crop farming operations. If it is handled, and applied, in an environmentally conscious manner it will provide long lasting results for multiple growing seasons. When utilizing manure is an option, there are several factors that should be taken into consideration. The species from where it came from, feed, storage, bedding type, and application methods.

The type of manure, from which species it comes from, will have drastically different manure analysis results. To use one example, below is a table from A&L Great Lakes Laboratories depicting the differences between species with both solid and liquid forms of manure and their inorganic to organic comparisons.

Ammonium content, an inorganic form of nitrogen, will acidify the soil as it undergoes nitrification converting to nitrate. On the other hand, there are several manure sources that will increase the soil pH. This is credited to the amount of carbonates and bicarbonates are in the manure.

The type of feed and bedding can have a large impact on the alkalinity of the manure. Some manure from poultry sources, that include calcium carbonate in the feed and eggshells, can increase soil pH for the next several years after application. Bedding can also be a high source of liming material. The sand, in sand bedded dairies, can be sourced from high alkaline parent materials.

It is important to analyze the manure and know the source and type of manure before application. The ammonium content and calcium carbonate equivalent (CCE) of the manure can be determined by lab analysis. Some soil types, topography and soil nutrient levels may impair the use of manure as a fertilizer source.