Agricultural Applications of Whey Permeate
At its most basic level, whey permeate is an agricultural co-product, and as such, has direct applications to the agriculture industry. Although frowned upon nowadays, land spreading on crop fields was once a common outlet for whey permeate as well as for other waste streams. Alternatively, whey permeate can be used as-is or dried to a powder for swine feed, with reduced use as animal feed for ruminants. While this process is certainly able to absorb a good portion of the waste stream and mitigate its environmental impacts, it does not valorize the product nor the cheese manufacturing industry. New applications still need to be developed to better utilize the forecasted production of whey permeate for the next century.
Many research articles cite the land spreading of whey and whey permeate as a common method of disposal. The results, which date back as far as 1923, are quite varied . While most of the research conducted has focused exclusively on the use of whey, this dearth of knowledge highlights the need of examining the effects of land spreading of whey permeate.
Whey permeate has several nutrients that facilitate plant growth. Some of them are present in relatively large amounts, such as phosphorus and potassium . Previous results have shown that when whey is applied to cropland the soil can act as a sink and the whey penetrates into the depths of the soil. Whey nutrients absorbed by the soil have been shown to persist for future crops . However, dosing of whey in excess of 4 acre-inches on cornfields has been shown to inhibit plant growth . Various spreading practices can be employed based on the type of soil, the type of crop being grown, the season, and the region . A more recent study has confirmed that whey may be beneficial, but the excess of nitrite and nitrate formation from the whey application could lead to leaching into drinking water and therefore result in health complications for humans and animals within an ecosystem .