IMPROVING SOIL HEALTH WITH GRAZING MANAGEMENT
By Heather Smith Thomas
Soil – A Lively Substance
Plants and soil work together. Plants feed diverse soil biology that stimulates nutrient cycling and improves soil functions. Diverse plants lead to diverse soil organisms.
“Every plant has a unique chemical signature,” says Jeff Goodwin, state GLCI grazing land specialist in Temple. “These plant metabolites help balance soil carbon-to-nitrogen ratios in the soil that help plants. These biotic substances increase mycorrhizal fungi populations and feed other soil biology. Plants convert soil energy into chemical energy for the soil ecosystem.
“This fungus builds an association with plant roots that increases the plant’s ability to sequester water and nutrients throughout the soil profile. In return the fungus receives sugars from the plant. This coexistence is beneficial for both organisms,” says Goodwin.
When these fungi are present, it’s a clue that the plants and soil are healthy.
“This is a relationship that we like to see when we dig up a plant and look at the roots. A good soil management system is all about building carbon back into the soil, building a higher level of organic matter and getting more biological activity again in the soil,” he says.
Malcolm Beck, founder of Garden-Ville, an organic gardening and farming business, and a farmer near Selma, consults with farmers about soil health.
“Learning about holistic management has helped many farmers and ranchers regain productivity on their land, dividing it into smaller pastures to crowd the cattle together, rotating through the pastures. They graze competitively and eat on every plant and trample what’s left, creating litter that adds organic matter to the soil. They also leave a lot of manure,” explains Beck.
“I’ve learned to listen to old-timers. They rotated livestock with crops to keep the soil fertile and more productive for the next crops.” The most important thing is a proper population of bacteria and fungi. If there is soil litter (old grass) there will be certain fungi which are instrumental in restoring soil health. They feed on dead organic matter.
“This breakdown of organic matter, plus the bodies of the fungi when they die, adds more to the soil, along with the nutrients the fungi collected,”
“Many plants have a deeper root system than most grasses. This is why I like legumes in a pasture. They not only fix nitrogen, but they also increase the biological activity down deeper in the soil.”
It has been said that cattle producers are actually grass farmers, marketing grass through cattle. Managing a property for healthy soil provides ecological and economic benefits that include everything from increasing productivity to filling gaps in grazing systems.
Consider 5 principles to manage for soil health:
- Armor the soil. Bare ground is the No. 1 enemy to healthy soil. Keep it covered to minimize bare ground.
- Minimize soil disturbance by using reduced or no-till practices on cropland and using adaptive grazing strategies on grazing lands.
- Increase plant diversity of all crop types, warm and cool season grasses and forbs.
- Keep living roots in the ground all year.
- Integrate livestock grazing.
Many producers are implementing some of these principles. Focusing management on all 5 enables producers to use their property to its full ecologic potential and may help an operation to remain economically sustainable by minimizing costly inputs.
A USDA and Texas A&M AgriLife Extension cooperative project demonstrates these 5 soil-health-building principles and allows producers to compare innovative management strategies to traditional production methods.
This project is near Riesel on the USDA Agricultural Research Service (ARS) Riesel Watersheds. The partners are USDA Natural Resources Conservation Service (NRCS), Texas Grazing Lands Conservation Initiative (GLCI), the USDA ARS and Texas A&M AgriLife Extension Service.
Jeff Goodwin, state GLCI grazing land specialist in Temple, says the project is separated into 2 demonstration areas of 350 acres each that are managed separately. The "south ranch" uses conventional practices common to the region such as application of inorganic fertilizers to increase production, managing monoculture forages, continuously grazing the pasture, and feeding hay through the winter. The "north ranch" is being managed with soil-health-building practices such as planting multispecies cover crops, integrating no-till systems, no fertilizer, using adaptive grazing strategies such as pasture rotation and no supplemental hay for the livestock.
"We feel we can build soil health and consequently reduce the inputs (fuel, fertilizer, machinery, labor, etc.) while producing a comparable level of forage production. This enables us to get away from a high production model and go to a more low-input system focused on ecology and economics," says Goodwin.
In recent decades, Goodwin says, "We have focused on managing the above-ground production in our pastures, but have not paid enough attention to what's happening below ground. NRCS has focused heavily on the physical and chemical aspect of soils, the pH, soil structure, soil texture — all of which are very important. However, until the past few years, we haven't been focused on a critical component, which is the soil's biological activity," he says.
More armor, less disturbance
Soil armor is a new term to most producers. The soil needs to be covered to minimize bare ground. In most cases this is accomplished by forage or crop residue. Bare ground is detrimental to soil health because soil organic matter is lost and soil temperature may increase to a level that limits biological activity.
"In my opinion, the reason our soils are so degraded is because we've lost or severely reduced biological activity. We've lost the right combination of microbes that need to be there," says Goodwin.
Why are they gone? Because there's no longer enough organic matter.
"Carbon in organic matter is food for soil organisms. Soil organic matter is increased if we keep the soil covered and minimize soil disturbance. If we keep plowing, we keep releasing the carbon. This is a reason we now try to use reduced tillage methods in cropping systems to keep a cover on soil. In pastures, we try to stop haying them and start grazing them instead," he says.
This NRCS project is implementing no-till and adaptive grazing strategies to keep the soil armored. The differences of both management systems are being measured by soil testing for nitrogen, phosphorus and CO2 respiration, which gives an indication of biological activity.
Species diversity and live roots
For years, ranchers have been overseeding bermudagrass pastures with rye grasses or clovers, but generally use just 1 or 2 species. Increasing the diversity above ground allows for a more diverse underground community. Specific soil microbes require specific plant types. The more diverse the microbial population in the soil, the better the forage will respond due to increased biological activity.
"In this project we are planting diverse 12-species mixes that include grasses, forbs, and legumes at a cost of about $30 per acre," says Goodwin. "We find that they use less water than a monoculture overseeding and produce more (forage). Last year we produced 5,500 pounds of forage per acre on a 5-acre test plot. During the cool season we used it to graze 30 cow-calf pairs for about 25 days during that dormant stage. This extends the grazing season and helps fill that winter gap," he says.
The 5 legumes in the mix were another benefit, he says. "Legumes have the ability to fix atmospheric nitrogen due to their symbiotic relationship with rhizobium bacteria. Diverse cover crops are planted during the fall, including legumes. They facilitate carbon and nutrient cycling through a period the pasture is normally left dormant," says Goodwin.
"One of the reasons we picked that 5-acre pasture was because it was a degraded bermudagrass field that wasn't growing much forage at all. In 1 season, with no fertilizer, the process we implemented increased the coverage of bermudagrass in that field by about 35 percent — with no tractors or fuel, just with plants and cows. These are the kind of things that we are excited about," he says.
Diverse forage species provide an excellent opportunity for producers to be creative and keep a living root in the ground year round. Soils are most productive when the soil microbes have access to living plant material. A living root provides a food source for beneficial soil bacteria and ensures that symbiotic relationships between plant roots and mycorrhizal fungi continue to occur.
"We are keeping a living root in the ground by limiting dormant seasons. On cropland and pastures we are implementing multispecies cool or warm season cover crops opposite the intended cash crop to keep that living root in the ground," he says.
Adaptive grazing management
Adaptive grazing is a management strategy that helps the landowner use a major tool on the ranch (cattle) more effectively. The goal is to mimic natural grazing systems (in which wild grazers move in large herds) that will increase soil function.
"This type of system continually adapts to the ecological, climatic, animal, and human conditions," says Goodwin. Adaptive grazing includes several strategies — management-intensive grazing, rotational grazing and ultra-high stock density grazing (also known as mob grazing). These systems are based on how the plants need to be used and/or to meet a nutritional requirement for the grazing animal.
"Adaptive grazing uses the animal to improve manure distribution, reduce plant selectivity, increase plant diversity, and improve soil function.
"Our approach in this project is to focus on all grazing lands. It's not just a cropland or a pasture approach. We are also looking at rangeland. This boils down to proper grazing management, managing for residual stubble heights on key grazing species, and proper grazing distribution.
"The most important key to any grazing system is the amount of rest you give the plant, allowing it to fully grow back before it is grazed again," he says. If a person can move away from season-long grazing on a pasture, breaking it up into segments and using it rotationally, then plant health and productivity are always improved.
"We applied adaptive grazing strategies to the north ranch, which is stocked with 30 cow-calf pairs. The first thing we did was combine the 2 herds into a 1-herd, 14-pasture rotational grazing system," he says. This concentrates the cattle on a smaller area where they recycle urine and manure to naturally fertilize the soil. This also gives the other areas a rest and a chance to regrow.
"Not only did we immediately increase the amount of rest for each pasture, but we also increased the overall grazing distribution to uniformly graze the plants," says Goodwin. Instead of overgrazing their favorite plants and leaving some of the others, the cattle in this situation tend to eat all the plants, using more total forage biomass.
"The second thing we did was stock the north ranch according to how much it can produce. The south ranch was left at its traditional stocking rate. We have minimized the dependency on supplemental forage by balancing animal demand with forage production rather than the common practice of stocking the ranch at maximum carrying capacity. In that situation, when they are out of grass (during a drought, or winter) the rancher has to buy hay. We built in some flexibility by backing off numbers to a realistic stocking rate and implementing the rotational grazing system," Goodwin explains.
Kent Ferguson, state rangeland management specialist in Temple, says that using cattle to improve the pastures is the simplest and least expensive way to do it. "All it takes is periodically opening and shutting a few gates," he says. Anyone can create a rotational system on just a few acres or on 1,000 acres.
"More ranchers/farmers throughout the U.S. are becoming interested in using their livestock as a tool to improve soil health. We are optimistic that our project will show these benefits. We have it set up for 10 years, so we will be able to see how it works through dry spells and wet spells," says Ferguson.
Keep an eye on cattle needs
"In our project we are fecal testing the cattle and assessing their body condition every month," says Goodwin. "Each month we can look at the numbers from their fecal analysis, and this tells us their dietary crude protein intake, the digestible organic matter, etc., so we can track the forage quality of their diet along with their body condition score for that month. This gives us a better idea about when or if we might need to start supplementing protein," he says.
Some ranchers start supplementing beef cow herds with protein in October or November just because they always have. "But if you do this type of fecal testing — which costs about $30 per sample — it can tell you if your cows are getting 8 percent, 9 percent or whatever the protein percentage might be, in what they are grazing. If it's anything above the 8 percent requirement for maintenance for a dry cow, then you don't need to feed protein. You would just be throwing your money away. So this is a good economic tool for ranchers to use.
"We do this testing at the Grazing Animal Nutrition lab, through Texas A&M, here in Temple," Goodwin says.
A healthier economic picture
"We are managing the north ranch with conservation practices focused on improving soil health," Goodwin says. "On the south ranch we are doing everything traditionally — feeding hay, applying fertilizer and continuously grazing. We are analyzing the economics of both systems. We want to know if this system with fewer cows and fewer inputs is more profitable than trying to maximize production with all the necessary inputs the increased forage production demands.
"It is exciting to work with landowners and be able to show them on a piece of paper how they can limit their inputs, match their cattle numbers with their forage production, and make more profit," Goodwin says.
"We are utilizing adaptive grazing strategies that balance forage production with the animal demand, instead of filling those forage deficiencies with high-cost hay. When we produce hay, we put on fertilizer after each cutting to get an adequate crop. The plants use the fertilizer and then the hay is cut and removed from the field. The same process is repeated the next year. This constantly mines the soil of nutrients.
"By contrast, when you graze the forage, you are recycling about 90 percent of those nutrients back into the ground," says Goodwin.
The agriculture industry for the past 30 years has been focused on increasing production by increasing inputs. Ranchers have been led to believe that the only way to make a profit was to keep increasing production (bigger cattle, higher weaning weights, using more fertilizer on pastures and hay meadows for higher yields, using monocultures rather than diverse forage species).
"In doing those practices, we are actually making less money. Most of the time, when you increase production you have also increased your inputs. When you increase the inputs you decrease your profit.
"This thinking was based on cheap fertilizer, cheap fuel, cheap feed and basically cheap everything. Fertilizer used to be inexpensive and now it's more than $1,000 per ton. Diesel is $4 a gallon. It often doesn't pencil out to use these inputs. We are trying to figure out some ecologically viable and economically feasible alternatives," says Goodwin.
"I am not saying that inorganic fertilizer does not have a place, because there are fields that need an establishment rate — a shot of fertilizer to get started. However once the system gets rolling, the rancher can decide whether to keep the high-input model or look for less expensive alternatives to keep it going. Management techniques and vegetative alternatives in place of inorganic fertilizer can help sustain pastures at a level that is profitable," he says.
"Implementing these soil health practices has the potential to reduce expensive inputs to bare minimum, and ensure the profitability of a farm or ranch," says Ferguson. "The beautiful thing about this process is that it can work on any acreage. You just have to use the right scale and proper stocking rate to fit the land, in concert with the forage production — using fertilizer from the animals to improve the soil health and fertility," he says.
The selling price for a producer's cattle is important, but so is the cost to get those cattle produced and to the market. "I think our project has the ability to show this. It's something local, and our ranchers here can see how it works," says Ferguson.
The things we can learn about reducing input costs can help us stay in business during tough times. "The average producer cannot spend that kind of money to grow grass to sell cows," Ferguson says. It makes more sense to let the cattle help improve the soils to grow more grass.
"The key is managing our livestock and using the herds in high enough density on pastures to where we can recycle those nutrients. This grazing strategy, with the application of other soil-improving practices, enables us to have forage growing year-round," he says.
"When you go to other places around the country and see these kinds of demonstrations, you might think it won't work in your own area or on your own place. This project is on a typical blackland farm, nothing special, and people here can relate to what we are doing," says Ferguson.
"Some farmers in the Northeast and Midwest have been practicing these methods for a long time, managing for soil health. They are producing outstanding corn yields — just as high as their neighbors — but with zero fertilizer," he says.
The same thing is being done with mob grazing, building soil health with cattle. "What we want to try to do here in Texas is model our efforts after what some of these other states are doing, and start grazing more of our croplands," says Goodwin. "In Texas, unless the farmer is growing small grains — wheat or oats — for grazing purposes, it's rare that we ever allow a hoof on a cropland field. There are miles of cropland fields, with no cattle or fences. We are missing an opportunity to use cattle and get the full use from our resources," he says.
Before farmers had inorganic fertilizer it was standard practice to rotate cattle with crops, so the cattle could add nutrients back to the soil. "When a person just had 40 acres and a mule, we were much more in tune with keeping soil productive than we are today with our 40-foot plows. Farms got larger, and farming technology got away from the basics of plant and soil health. As an industry we need to explore all alternatives, but at the end of the day if we're managing our grazing lands for soil health, we will be closer to balancing economic viability with ecologic sustainability."