This post was originally published on the Soil Health Nexus blog. It has be adapted and re-published here.
Is there a correlation between soil health (or soil productivity) and manure? A report recently released from the Soil Health Nexus team looked to answer this question by analyzing soil health related variables and manure land application details.
The study was conducted by Teng Lim, Donna Brandt, Allen Haipeng Wang, Saranya Norkaew, and Randy Miles of the University of Missouri, using data collected under the Missouri Cover Crop Cost-Share Program and experimental field plots.
Overall, they found no significant difference between the fields with and without manure application for most of the variables collected, with the exception for phosphorus. The lack of correlation is thought to be due to the small portion of state-wide samples associated with manure land application, and high sample variability.
When the team narrowed the data to the county level, manure application showed to increase active carbon contents for two of the top three counties where manure application data was collected. The manure application also significantly increased organic carbon, phosphorus, potentially mineralizable nitrogen, and water stable aggregate values for another county.
To better investigate these findings and determine if this pattern would hold for plots with consistent tillage, and repeated crop and fertilizer treatments, data was also collected from experimental field plots. Results from the field plots demonstrate that manure application clearly resulted in higher soil organic carbon, active carbon, phosphorus, and water stable aggregates, and lower bulk density.
These findings confirm that the benefits of manure application to soil health, and manure’s impact on phosphorus levels. These findings regarding manure use and important soil health indicators are important considering the measurable economic and environmental impacts of nutrient and manure management, especially for increasing the carbon content in the crop fields, manure land application can be one of the recommended practices.
Last year the Soil Health Nexus team produced eight new extension publications synthesizing and interpreting the latest science on linkages between manure management, soil health, and water quality. More information and access to all the publications can be found on the Soil Health Nexus website.