Lagoons and ponds are required storage facilities for large cattle operations. Their purpose is to collect watershed from the livestock areas and hold it until it can be properly dispersed according to nutrient management plans.

In an effort to reduce nutrient losses from manure applied to cropland, a number of best management practices have been created. They were crafted using the best available information at the time and, ever since, researchers continue to analyze if they are the best or if they could be better. Three soil scientists were at the North American Manure Expo in Prairie du Sac, Wisconsin, recently to share what they’ve learned about nitrification inhibitors, timing of manure application and type of application to better explain their roles in preventing the loss of nitrogen and phosphorus.

The act of storing solid and liquid manure does alter the composition of manure from its raw state and could be consider a form of treatment on the manure. However, as dairy farms have altered the way they handle manure from simply storing it, soil scientists are looking into how those newer methods are affecting nitrogen and phosphorus in the end product. Speaking at the North American Manure Expo in Prairie du Sac, Wisconsin, last month, Chris Baxter, associate professor of soil & crop science, University of Wisconsin – Platteville, explained the three types of manure treatment systems that were considered include liquid/solid separation, anaerobic digestion and composting.

Most people understand that anaerobic digesters produce a biogas that can be used to create power (usually in the form of electricity). But few realize that farmers seldom install digesters primarily for this reason – if at all. More often than not, farmers install a digester to enhance their nutrient management plan, as well as control odors, destroy pathogens, kill weed seeds, etc. For these farmers the ability to produce power is a secondary benefit. The revenue from power sales simply helps pay for the digester system that gives these other benefits to their farming operation.

A California groundwater study focused on nitrate levels has placed the agriculture industry – and more specifically the dairy industry – in the spotlight. One of the key findings in the study points the finger directly at agriculture. Fertilizers and animal wastes applied to cropland are by far the largest regional sources of nitrate in groundwater, the study said.

The University of California Davis, under contract with the State Water Board, conducted an independent investigation of nitrate contamination of drinking water in the Tulare Lake Basin and the Salinas Valley. The report examines sources of nitrate contamination, impacts and costs, as well as outlining potential funding and policy options. Dairy farms of the Tulare Lake Basin and the manure nitrogen they produce are prominently mentioned in the report. Agriculture is listed as responsible for 96 percent of the nitrate accumulation with dairy being about one-third of that, so we need to not only pay attention to the ensuing discussion, but to be active participants. Denial is not an option.