Improving Dairy Compost
Modification of Low Quality Dairy Manure Compost with Organic Amendments
Abstract:
Composts produced with dairy manure from that area tend to contain high levels of inorganic components (50 to 75%, mainly quartz sand and limestone fragments) and often fail to meet the pH and organic matter standards set by TX DOT and other users. Addition of high carbon amendments to finished composts is being employed as a means to adjust these parameters to meet the TxDOT standards. Four “low quality” compost products were amended with three high carbon by-products (peanut hulls, sawdust and wood chips) by physically mixing the amendments (10% and 30% v/v basis) with the composts.
TMECC have been adopted as the industry standards for compost testing but due to strict QA/QC requirements, analytical costs tend to be relatively high. Service laboratories that do not use TMECC or are not STA certified often offer “analytical packages” for lower costs. A comparison of compost test results provided by Soil Control Laboratory (an STA certified laboratory) and the Texas Cooperative Extension Soil, Water Forage Testing Laboratory (a service laboratory) showed that values for selected nutrients (total N, P, Ca, and Na), pH and soluble salts varied significantly between the two laboratories but there were no differences in organic matter levels.
Results:
The full report presents the methodology, data and analysis of this compost improvement study.