A biodegradable mulch film made from livestock manure could let farmers cut fertiliser, recycle manure and avoid plastic residues in the soil, according to research led by Yong Hou at China Agricultural University and published in the journal Engineering Agriculture.

The manure-based slurry film (MSF) is meant to replace the polyethylene film widely used to hold moisture and warm the soil, which leaves residues that build up in fields. In field trials with silage maize, the new film maintained yields when fertiliser was cut by 30 percent, and raised yields significantly compared with plastic mulch when fertiliser was cut by 15 percent.

Unlike plastic, which only covers the soil, the film slowly releases organic matter, nitrogen and phosphorus that feed soil microbes. The researchers found more of the microbial groups involved in converting nitrogen and releasing potassium, stronger early root growth and better phosphorus and potassium supply later in the season.

The technology also gives livestock farms an outlet for manure, linking animal and crop production. The researchers acknowledge a drawback: making the film currently takes a lot of energy and water, so its overall environmental footprint is still higher than plastic mulch in some respects. Future work will focus on simpler, less energy-hungry manufacturing.

Photo: Florian Gerlach (Nawaro) / Wikimedia Commons (CC BY-SA 3.0)

Source: Farms.com