The Principles of Improved Grazing

Dan Durham, NRCS District Conservationist

Last week local land managers had the opportunity to hear grazing expert Jim Gerrish speak about ways to improve their soil and financial bottom line through improved grazing management.  Mr. Gerrish has an extensive background in agricultural research as well as decades of hands-on experience with his own ranching endeavors.

The premise of his message was that a better understanding of fundamental ecosystem processes such as the water cycle, photosynthesis, and the nutrient cycle can increase production, lower costs and result in more economically and environmentally sustainable ranching operations.

Throughout the day Jim addressed many important concepts and practical applications. However, one of the most basic (yet often overlooked) ideas he discussed was the role of plant leaves as “solar panels”.

We all know that photosynthesis is the process that allows plants to take sunlight and, in the presence of water and carbon dioxide, use that solar energy to produce leaves, roots and fruit.  This process occurs primarily in plant leaves, so essentially each leaf acts like a small solar panel.

The more leaf area that a plant (or a square foot of pasture) has at any point in time, the more solar energy it can collect and use for growth.  Therefore, as land managers we need to always consider how much leaf area is on the landscape to maximize productivity.

If pastures are grazed too heavily there is very little leaf area remaining to capture sunlight.  Therefore, regrowth is going to be slow and overall forage production will be less than the potential for that site.  When grazing animals are carefully managed to leave more grass, we retain the plant’s photosynthetic capacity so it can regrow quickly and produce more biomass over the course of the growing season.

According to Jim, a difference of a couple inches of grass residue left after grazing can mean up to 60% greater forage production in the long run.  That equates to dollars in your pocket.  It turns out that leaving some grass behind also improves your soil, makes plants more drought tolerant, and means your livestock are only eating the most nutritious part of the plant.

Improved grazing management can be accomplished a number of ways, but much of the recent workshop focused on the use of temporary electric fencing to quickly rotate grazing animals through multiple pastures.

By allowing critters to use smaller paddocks for shorter periods of time they eat the best part of the plant and then move on, leaving plenty of solar panels behind and allowing for rapid regrowth.  Increased plant residue also reduces evaporation and puts carbon and nutrients back in the soil.  Some land managers think they do not have enough time to rotate their animals.  However, there is quite a bit of evidence to suggest the economic and natural resource returns make it well worth the additional labor.

Moreover, there are all kinds of gadgets on the market these days to make rotational grazing much easier including better; electric fencing, geared fence reels, solar fence chargers, step-in fence posts, automatic gate openers, and portable water systems.

Management intensive grazing techniques are most applicable to irrigated or sub-irrigated pastures where the plants are not limited on water and will therefore allow for multiple grazings during the growing season.  Typically these pastures are also closer to home so checking and moving livestock is pretty easy.

However, the idea of leaving some grass behind for increased regrowth, root development and soil health is also important on rangeland pastures.  In fact, there are already local ranchers that recognize the importance of grass residue and are using electric cross fencing to shorten their rotations on native pastures with great success.

Like many things in natural resource management, if you think it will work, you are probably right.  Likewise, if you think it will fail, you are also probably right.  Each generation of land managers has adopted new tools and techniques that they have found work for them and will improve their operation and land.

There is overwhelming evidence that finding ways to leave more grass on the landscape is a concept that this generation should give a lot of consideration.  In the words of Jim Gerrish, “There is no such thing as wasted grass!”.