Doug Peterson, a northern Missouri Grassland Conservationist for the National Resources Conservation Service (NRCS), has traveled across the region over the past several months speaking to various groups and organizations about high density grazing, more commonly referred to as ‘mob grazing.’ He spoke Jan. 21 in Bolivar, Mo., at an event sponsored by Kit Pharo, of Pharo Cattle Company, Cheyenne Wells, Colo., and Pharo’s Missouri division operator, Weston Walker.
The main goal behind high density, or mob grazing, is to build and improve the soil. Doug Peterson, who has personally studied the advantages of mob grazing, said, “The soil is the basis of everything (in agriculture).” He went on to say that the soil in the grazing fields is the most important thing to take care of.
The first point Peterson makes is that the stock density (or amount of live weight of cattle per acre) is a powerful tool that should be used for the benefit of the farmer. A difference between MIG and mob grazing is the stock density. In a mob grazing system, you may have from 50,000 to 250,000 pounds of stock density. MIG density is usually only up to 50,000 pounds. This is the key difference between the two – and the key for the success of the “mob” of cattle all in one place at one time.
In the traditional MIG system, you’d see cattle scattered sporadically across a larger field or paddock, where in the mob grazing system, cattle are very close together and grazing in a small area. They are let into a field and only allowed to graze a portion of it (with a front temporary fence keeping them from the rest of the field). Then after 12 or 24 hours the front fence is lifted, and they migrate further into the field into an area similar in size to the first portion they grazed. This is continued every 12-24 hours until the field has been completely utilized, which Peterson said, is less than 60 percent eaten. Peterson cautions, “The main problem is over-grazing. It’s important that 40 percent or more of the forage is left.”
A big focus of this process is in protecting and regenerating the soil. Peterson said, “We can take tall grass and graze it hard to actually cause root die off and also trample part of the grass into the surface of the soil and get the effect (of reducing competition for greater legume growth) on the entire field or even an entire farm.” The ‘effect’ that Peterson is talking of is organic matter being broken down into the soil (that becomes like mulch), along with long rest periods, allowing for legume growth. Legumes are an incredible resource to attain nitrogen from the air, rather than just the soil. The long rest periods also allow the roots to grow deeper into the soil, tapping into essential nutrients that aren’t even touched with the short roots most of our plants currently have.
This process also increases the organic matter of the soil, which helps grow the soil micro-organisms, which also contribute greatly to the health of the soil.
This process can even take out the need for chemical fertilizers, which do a lot of damage to the micro-organisms in the soil. It also saves money on inputs each year, allowing for a greater profit. Overall, this system changes the use of your time from all of the things done to make the soil and forage more productive, to moving cattle more frequently and letting the soil and forage create their own productivity naturally.
