The Manure Surplus: Digging Into The Numbers

It may be one of the most important negative by-products of intensive animal agriculture, but it needs to be taken seriously: manure. Waste from animals can be an important way to fertilize land for plants to grow – though proponents of “veganic” farming argue that’s not necessary – and indeed, there are ways of having animal manure be used in a farming cycle without harming them. However, with factory farming, the number of animals generating manure is higher than what the land can sustain. According to a previous article covered in our library, “the manure produced by CAFOs comprises 65% of all manure from U.S. animal operations, to the tune of about 300 million tons per year, which is more than double the amount generated by this country’s entire human population.”

This study, from the Humane Party’s Economic Transition Team, was conducted to try “to understand the daily generation of animal manure due to animal agriculture and its implications.”  Using publicly available data, the researchers looked at recommended rates of manure application to farmlands, as well as the total farm land in each state, to try to assess whether the manure generated in each state is insufficient, sufficient, or excessive. Each state’s total land and farming-allocated land are taken into account to evaluate whether the amount of manure generated per state is insufficient, sufficient, or excessive to meet the fertilization needs of each state.

Needless to say, the results are bad, if not surprising: the amount of manure that exceeds the fertilization needs of crop and grazing land “by alarming rates,” and every single state exceeds the recommended amount of manure “that can be safely applied to their farmlands with manure locally generated.” What do they mean by “alarming”? Alaska, for example, is the state that least exceeds the amount, but it still generates 10 times more manure than “can be safely applied.” Looking at the actual numbers, it certainly gives pause:

The amount of manure generated in the entire U.S. is 8.74 billion pounds per day, a grand total of 3.19 trillion pounds per year. The entire farming industry generates enough manure in five days to cover the entire continental U.S. land territory with the annual recommended amount for farm land. The entire animal farming system generates enough manure annually to cover the entire extension of the continental U.S. 72 times with the recommended annual amount.

For advocates, the study shows conclusively that manure is a huge problem, and a major by-product animal agriculture that cannot be ignored. The effects of manure, whether economic, environmental, or health related, are “potentially devastating,” and the researchers note that further research needs to be done to not only understand these effects, but also to “understand the uses and measures undertaken to handle the excess manure.” However, even though the report is focused on manure, the researchers note that it is a symptom of the bigger problem: animal farming itself. For advocates, the study provides information that could be useful in general farmed animal advocacy, and getting to that root problem.