The approach that is recommended here by Allan Savoury is quite different from the approach that is outlined by John Liu (see previous post). Here Allan has concluded that Managed Intensive Rotational Grazing (MIRG) is actually very good for regenerating the ecology of an area.
Managed Intensive Rotational Grazing (MIRG)
The thinking behind MIRG is that if you let animals graze on open pasture they will selectively eat on areas where the finer and more tasty grasses are and leave the areas where the not so tasty grasses are. The pasture is then grazed unevenly and so also is the spread of manure, which is not the ideal. They can also have the tendency of returning to the areas where the more tasty grasses are before they’ve had a chance to fully recover. So MIRG is about creating small fenced in areas where the animals are kept for shorter periods and then moved onto another area that is ready for grazing. They are constantly being rotated around and don’t come back to an area until it has had time to heal and regenerate sufficiently. Sometimes, after the larger animals have grazed in an area, other smaller animals such as chickens are brought in that feed off larvae and help to remove parasites found in the manure. They also help to spread the manure as they scratch through it.
Joel Salatin of Polyface Farm refers to himself as a ‘grass farmer’. He is one of the most well known farmers who uses the MIRG system. Salatin’s farm produces chicken, beef, turkey, eggs, rabbits, and pigs (as well as tomatoes, sweet corn, and berries) on 100 acres of pasture. He often talks about never violating the “law of the second bite” meaning that the animals aren’t allowed to take a second bite of grass before the blade has a chance to fully recover.Grass follows an S-shaped growth curve. Immediately after it’s grazed, it takes some time to recover, then it goes through a blaze of fresh growth. After a while, its growth tapers off and it begins to put its energy into making seeds. The “law of the second bite” states that you can’t let the grass be grazed again before it has fully recovered from the first grazing.
If animals are allowed to continually graze on large areas, they’ll stick to the most desirous species and the tender new shoots, which are the most tasty, hence violating that law and causing the grasses to weaken. This causes bald spots and weedy, brushy species to emerge. Over time, and close cropping, the grass land will deteriorate so much that it can turn into a desert. Undergrazing however can be problematic as well, leading to “woody, senescent grasses.” Salatin gets it right by “grazing the optimal number of cattle at the optimal moment to exploit the “blaze of growth”, improving the quality of land and creating a lot of grass.