War on the Range – Ranchers versus Mesquite



Southern Arizona ranchers have been battling mesquite trees for almost 100 years. The principal reason is that mesquite trees and shrubs suck up the water and thereby degrade the range making it less suitable for raising livestock. It also makes the grasslands less accommodating to wildlife.

Mesquite is a very hardy plant that produces an abundance of seed pods. The seeds and pods are collected and stored by rodents. Many animals, including livestock and deer, eat the seed pods, but the seeds themselves pass through undigested and are deposited with some fertilizer.

The problem as described to me by a southern Arizona rancher:

Southern Arizona is characterized by intermittent drought. This results in marked death loss of the perennial forage grasses, however, drought seldom causes death of whole mesquite plants. Mesquite have a long tap root enabling it to reach underground moisture and can tolerate drought. Grasses do not have that advantage. As the tree grows it demands more moisture. The result is each year, depending on the rainfall, less and less forage is produced as the tree shades the ground and quickly takes up the moisture. As the mesquite grow, noxious plants also become established with their deeper roots which make them drought resistant. These include burroweed and snakeweed. These also crowd out grass. As the ground is bare, when a heavy rain falls there is not grass and grass roots to hold the soil so erosion becomes an issue.

According to University of Arizona Technical Bulletin 74, published in 1938:

Certain range lands of the grassland type in southern Arizona are undergoing an invasion by the mesquite tree and noxious shrubs to the extent that the native stand of palatable forage is being materially reduced. The development of this problem has taken place at a pace gradual enough that its seriousness was not fully realized by stockmen until the cumulative effects of some forty years’ transition in the vegetation type of the affected areas became increasingly apparent.

The report goes on to discuss various methods of mesquite eradication including use of petroleum products, arsenic, acid sprays, and other chemical means. These methods proved ultimately ineffective. Petroleum did not kill the roots so the mesquite soon sprouted new growth. The chemicals remained on the stumps and were thus dangerous to livestock and wildlife. Burning individual trees was also ineffective. Only sodium arsenite solution would kill the roots, but it was difficult to prepare and handle.

The US Department of Agriculture weighed in with Circular 908 published in 1952:

One of the most serious and perplexing problems in southeastern Arizona is mesquite invasion of grasslands. Mesquite occurs there in varying degrees of abundance on 9 million acres of range land. The problem is likewise serious elsewhere in the Southwest. Mesquite is now firmly established on considerably more than 70 million acres of range in Texas, New Mexico, and Arizona. An estimated half of the area now occupied by mesquite has been invaded since the advent of domestic livestock. The increase of mesquite is viewed with ever-increasing alarm by range operators.

The principal reasons for concern are : (1) Mesquite, even under moderate grazing use, is still persistently increasing both by invading open grassland and by thickening of old stands. (2) Cutting mesquite, especially in bottom-land areas, usually results in an impenetrable thicket of sprout regrowth and new seedlings. In many of these “jungles,” grazing has had to be abandoned. (3) Livestock handling costs are increased, especially in dense upland mesquite thickets where it is difficult to gather livestock for market or to find screwworm-infested animals for treatment. (4) Increases in mesquite are usually accompanied by decreases in quantity and quality of perennial grass forage and corresponding reductions in livestock production. (5) Still more serious from a long-time viewpoint is the accelerated erosion generally found on uplands as well as bottom lands wherever mesquite has encroached.

The USDA further opines on the cause of the mesquite invasion:

The probability is that neither protection nor heavy grazing has much to do with the increase of shrubs here, but it is primarily the direct result of the prevention of fires.

I spoke with several ranchers who are battling mesquite in southern Arizona. For many years they have been using mechanical means to cut the trees and shrubs and digging out the roots. They try to remove at least 80% of the mesquite. Studies at the Santa Rita Experimental Range show that removing about 80% and leaving some mature trees makes the range more amenable to wildlife than thick mesquite stands or open range.

Before removal work can be done, the ranchers have to make surveys for endangered species such as the Pima Pineapple Cactus, which was listed in 1993 (and there is still no recovery plan). They also have to survey for cultural resources.

The mechanical method means bulldozers to knock down the trees and dig up the roots. One rancher told me it costs $300-$400 per acre and can get only one acre per hour. This is an expensive and tedious operation.

More recently, ranchers have been experimenting with chemical warfare again. Dow Chemical has developed an herbicide that is specific for mesquite. It is deployed by helicopter spraying. This costs about $106 per acre and can cover 80 acres per hour. This is similar to crop dusting operations used on farms.

The ranchers say another main reason for mesquite removal is to reduce soil erosion and restore native grasses. Since chemical removal has begun, ranchers have noticed return of many native grass species.

After reading a version of this article published in the Arizona Daily Independent, another southern Arizona rancher send me these comments:

Mesquite proliferation can be a problem, but they multiply and then decrease quite apart from grazing. It’s fairly cyclic and occurs even where no grazing has occurred (there’s a very deep and large area surrounded by cliffs in Mexico–never grazed–where scientists measured mesquite increase. It increased at the same rate as in the grazed pastures elsewhere.

Mesquites do consume a lot of water and at greater than 20% cover they are problematic, however, at lower than 20% overall, they are a major feed item for both cattle and wildlife–the beans are highly nutritious and so are the leaves. Also, they make a rich, nitrogen-enhanced (they are nitrogen fixers) soil beneath the tree which grows and maintains good native perennials, just so long as the tree cover is not beyond 20-30% and sunlight reaches the area below the tree for some good part of the day. Shade is also good! The upshot is: these trees are natives and are highly adapted to this climate; they have significant value for both wildlife and cattle as forage and as shade for natives that prefer less direct sun like plains bristlegrass and viney mesquite (that’s a grass in spite of the name) and others.

Here we are not at war with mesquites; however there are areas where their density exceeds desirable. Right now the cost of control (just private land–forget trying to do anything on federally managed land) and the issues with flood plains or critical habitat for assorted species are overwhelming and make constructive control financially impractical.

The screw worm issue mentioned in that 1952 publication is past tense; screw worms were effectively controlled decades ago by the propagation and dissemination of sterile male screw worms by the federal govt. and ranchers. It used to be a huge problem in the summer–now not, We can only surmise that such control would be met by howls of opposition from those who would prefer not to eradicate pest insects.

Controlling mesquite makes the range more productive, saves water, and benefits wildlife.


For information on traditional use of mesquite trees see:

Mesquite trees provide food, fuel, medicine, and more


Book review – Chilton Vs. The Center For Biological Diversity

Chilton cover

Jim & Sue Chilton are friends of mine. They own and operate a cattle ranch south of Arivaca, Arizona. The ranch’s southern boundary is the U.S. – Mexican border. They have had trouble will illegal border-crossings, with the U.S. government, and with radical environmental groups.

Their story is told by J.P.S. Brown in his new book Chilton Vs. The Center For Biological Diversity: Truth Rides A Cowhorse

This book exposes the betrayal of trust of federal agencies and the skullduggery of a radical environmental group. I enjoyed reading this story. And remember, as Jim Chilton says, “Every day is Earth Day to a rancher.” This is because his economic well-being depends upon keeping the range productive and in good shape.

Amazon Synopsis: Truth Rides a Cowhorse is the story of a cowboy’s fight to defend his livestock against activist environmentalists who spend millions of dollars in a campaign to rid the world of the cow while it spends more millions on a campaign to save the whale. Which of these two great animals has done more for mankind?


“This is the true story of the legal battle and the VICTORY of the Chilton Ranch in Arizona. Jim and Sue Chilton took on the legal battle to fight against the environmentalists and prove that the Chilton Ranch is the best example of a well run organization that cares not only about it’s cattle, but the ranch and the Chilton name and in doing so they honor all three.”

“Amazing story by one of the great story tellers of our time. Not a unique situation involving manipulation of endangered species and grazing laws to feed the appetite of an ever inflated bureaucracy. Joe Brown is worth checking out. This is how the ‘west was won.’”

The book is available from Amazon in both print and electronic versions.

Cattle grazing may restore grasslands and reverse desertification

In a series of lectures, Dr. Allan Savory, a biologist and former Zimbabwean farmer claims that mis-managed cattle grazing, such as has occurred in Africa, has turned grassland into desert, but properly managed cattle grazing can reverse the process, reclaim the desert, and turn it once again into productive grassland.

Savory was a member of the Rhodesian Parliament and had to go into exile after opposing the policies of Ian Smith. In 1992, Savory founded the Savory Institute in Boulder, CO, and the Africa Centre for Holistic Management in Victoria Falls, Zimbabwe. You can watch videos of his 2009 lectures here and a February, 2013, lecture here (22 minutes).

Savory’s basic thesis on grazing is this:

“In the past, large wild herds of herbivores such as caribou and buffalo migrated over the land to find food and avoid predators. These herds grazed, defecated, stomped and salivated as they moved across the grasslands, building soil and deepening plant roots. Once these herds had migrated onward they would not return to an area until it had recovered.”

“Unfortunately, over time, the wild herds disappeared and were replaced by small numbers of domestic, sedentary livestock. Without the timely stomping and excrement of large numbers of animals, the cycle of biological decay in these grasslands was interrupted and the once-rich soils turned into dry, exposed desert land.”

Savory’s solution is to concentrate grazing in small areas and move the cattle frequently. I have seen this method practiced in the Cape Province of South Africa when I was doing geologic exploration there many years ago. There, the land is very flat as shown in my photo. There are miles and miles of miles, as one South African colleague put it.

The Savory setup is to establish a central water source, then encircle it with six to eight, relatively small, wedge-shaped pastures enclosed with barbed wire. Cattle are grazed in one or two of the wedges and moved frequently. This short-term, intense grazing does help restore the grasslands in this area.

Would this method be beneficially applicable to cattle grazing in Arizona? To find out, I consulted a friend who is a cattle rancher in Southern Arizona, an expert on desert grasses, and familiar with the Savory system. The answer is “no” at least in Southern Arizona, because:

The Savory Method is highly intensive, requires enormous expense in mini-pasture fencing and constant moving of livestock. Desertification is certainly a concern in Africa. But here it is of less concern because of our intensively monitored and managed systems (developed largely on the Santa Rita Research Ranch in the Green Valley area by U of A agricultural experts). We manage according to agreement with the Forest Service and State Land Department based on this locally-derived science. Desertification is simply not happening in this area.

The pattern here is larger pastures with rest-rotation systems geared to our bimodal rainfall regime with the primary growth in the summer. Entire summer rest is provided (in fact, about 20 months) every other year on most of our summer pastures. Our herds are generally in one large pasture for a season and then are moved to pastures with forage that has had a significant regrowth period. This process seems to produce the best plant community including wildlife habitat and promotes sustainable or steadily above-sustainable production of herbage with the widest variety.

Our rugged, distant, forest pastures don’t lend themselves to mini-pastures: we’d have to drill many more wells or put in more miles of expensive pipelines. We would also have the problem of maintaining many fences cut by folks moving illegally north. The Savory system may well get good results in flatter, privately owned, access-controlled land, but that is quite different from Southern Arizona ranchland.

We see, therefore, that there is not a universal solution, but great benefit when methods of better practice are designed for local conditions. And in each case examined here, cattle grazing can benefit the environment.

While this result may be surprising to some and contrary to the precepts of radical environmental groups, it is just common sense that cattle growers have an economic interest in keeping the range healthy and productive.

See also:

Buenos Aires National Game Refuge This post gives a history of ranching in the Altar Valley.

Ranching and agriculture in Arizona, The Arizona Experience

Ranching and agriculture in Arizona, The Arizona Experience

This month, as part of the celebration of Arizona’s centennial, the Arizona Experience website showcases ranching and agriculture, industries that added $10.3 billion to the Arizona economy in 2010.

The Farming and Ranching page provides an overview of the State’s agriculture. This page deals briefly with the water issue and notes that “Crops are thirsty. Agriculture consumes approximately 70% of the state’s water.” The page also notes something that I was unaware of: “dairy is Arizona’s leading agricultural product,” it outsells cotton.

“Yuma is the winter lettuce capital of the world, supplying an estimated 95% of the nation’s head lettuce, leaf lettuce, and romaine lettuce along with a cornucopia of seasonal veggies. In fact, Arizona ranks second in the U.S. in head lettuce, leaf lettuce, romaine lettuce, cauliflower and broccoli production. Apple growers over the last 5 or 6 years average close to 20 million pounds per year. After rapid growth in the in 1980s, Arizona’s annual pecan harvest is worth $52 million. Total revenues from the agriculture industry are second only to mining.”

Cattle ranching came to Arizona over 300 years ago. Spanish conquistadors grazed cattle in the Huachuca Mountains and the Santa Cruz River valley as early as 1690. Discovery of gold and copper brought people and railroads to Arizona and that resulted in a cattle boom. By the 1890s, about 1.5 million head of cattle roamed Arizona. But that boom soon faded due to overgrazing. Since then, however, cattle growers have learned to be good stewards of the land, because their livelihoods depend on it. Currently, about 870,000 head of cattle are raised on 3,800 Arizona ranches. In 2010, Arizona ranchers produced enough beef to feed 4.6 million Americans. That year, the state’s 391.2 million pounds of beef made a total economic impact of $3.2 billion.

Today, “Many ranchers practice Coordinated Resource Management (CRM), a conservation practice that adjusts grazing and cattle movement to optimize renewal of grasslands, soil, and wildlife habitat. Many cattle graze on U.S. rangelands, about 85 percent of which are unsuitable for crops. Most ranchers work to prevent overgrazing of these areas, as over-grazed land no longer offers food. Ranchers may plant trees for windbreaks, improve plant density and work to decrease invasive plant species, manage overgrowth to prevent fire, or plant cover crops to decrease erosion.”

The cotton page, Cotton Today, notes that “About 900 cotton farms produce an average total of 600,000 bales (but yields vary every year) and supplied approximately $362 million in cash to the state economy in 2011. That’s enough cotton for at least one pair of jeans for every person in the United States.” “Arizona is the birth place for Pima Cotton, a long-fiber variety (known as long staple cotton) named for the Pima Indians who helped cultivate it.” That page also addresses water use and use of insecticides. “Cotton is one of the most heavily sprayed crops, but too much pesticide can pollute fields and water sources. The industry is always on its toes in an attempt to stay one step ahead of pests like the boll weevil and the pink worm. One breakthrough came when some cotton seeds were genetically modified to include Bt, a natural insecticide. This cotton actually kills boll weevils trying to feed on it, so farmers spray less.” Another weapon is in a warehouse near Sky Harbor airport in Phoenix which grows about 22 million pink bollworm moths per day. “But there is something special about these moths. A few minutes in a radiation chamber has taken away their ability to reproduce. Of course, the moths don’t know that. When they are released on area cotton farms, they mate with naturally born adults. However, no babies are produced by these moths. The next generation of moths remains at a manageable size, ensuring the next generation of cotton.”

Another resource on the main Arizona Experience page is the Teachers Center. “Teachers can open a lesson plan for 4-12 grade students about local commodities approved by the Arizona Department of Education. Handy guides to seasonal produce and an interactive farmers’ market locator are resources for the classroom.” The Teachers Center also leads to a lesson plan contest where teachers are invited to build and share lesson plans. There are $25,000 in prizes.


The Arizona Experience is sponsored in part by the Arizona Geological Survey.

Buenos Aires National Game Refuge where Endangered Species and Illegal Immigration Collide

The 118,000-acre Buenos Aires Game Refuge in Southern Arizona’s Altar Valley was created in 1985 “to establish and manage populations of the masked bobwhite quail” under the Endangered Species Act (ESA). The Altar Valley is also a major route for illegal immigration and drug smuggling.

Thousands of people cross the border there every year. One source says that somewhere between 600,000 and 800,000 people per year had crossed the border, but local ranchers say the numbers are much lower than that now. The U.S. Fish & Wildlife Service (FWS) which runs the Refuge has issued a travel advisory warning people about the area:

“As a result of illegal immigrants crossing our borders, other unlawful acts do occur within the Refuge. Some of the illegal immigrants are armed, dangerous, and determined to complete the trip at any cost. Most often these are smugglers and drug runners. They may drive a stolen vehicle or they may hire human ‘mules’ to carry their contraband in homemade backpacks.”

“These illegal routes are lined with empty water jugs and other trash. Illegal immigrants frequently stop to camp, collect wood and start fires. These fires sometimes escape and cause damage to wildlife habitat. Trash left at these sites is not only unsightly, it is unsanitary and attracts a variety of scavengers. Nearby water sources are often so fouled by pollution that wildlife can no longer use them. Some overnight rest stops are so heavily used that the damage is extensive. During the rainy seasons, trails and vehicle routes become avenues for floodwaters, further increasing the resource damage.”

One area rancher said, “There are quite a few government agencies with various responsibilities to protect us from the onslaught of illegal activity that exists on or near our border.  That activity creates dangers to us personally and that is our greatest concern. That activity also harms our environment and undermines many of the environmentally protective measures that we ranchers have committed to and are undertaking.   I hope all the agencies can work closely together so that they can succeed in their mission.”

The fact that there still is illegal immigration means that the federal government is not adequately enforcing the ESA to protect the environment nor enforcing border security to protect people in and near the Refuge.

A short history of the area complied from FWS and local ranchers:

The Altar Valley was first homesteaded by Pedro Aguirre, Jr. in 1864 as the “Buenos Ayres Ranch.” He had been running a stagecoach and freight line between Tucson and mines near Arivaca, Arizona and Altar, Sonora, Mexico. Aguirre drilled wells, built earthen dams, and created Aguirre Lake. This ensured a water supply for cattle in the Altar Valley.

As railroads opened new markets, cattle numbers in southeastern Arizona exploded. But an extreme drought from 1885-1892 killed at least 50% of each herd. The remaining cattle stripped the land bare. This occurred before establishment of modern ranching practice. When the rains returned, no grasses were left to absorb the water. The rain eroded the land, creating the washes and gullies we see today. The earthquake of 1887 may have contributed to the erosion by either raising the land or lowering the water table.

Between 1909 and 1985, Buenos Aires Ranch changed ownership several times. It became one of the most prominent and successful livestock operations in Arizona. From 1926 to 1959, the Gill family raised prize-winning racing quarter horses. During the 1970’s and 80’s, the Victorio Land and Cattle Company specialized in purebred Brangus cattle, which are well suited to hot, dry climates. The ranch sold bulls and bull semen nationally and internationally with some bulls selling in the hundreds of thousands of dollars.

In 1985, the U.S. Fish and Wildlife Service purchased the Buenos Aires Ranch, and it became a National Wildlife Refuge. FWS brought in pronghorn antelope and masked bobwhite quails (which promptly became food for coyotes and hawks). FWS abandoned wells and waterlines because they were “unnatural.” With the lack of water, much of the wildlife left. (More recently, FWS re-established some of the stock ponds.) The Altar Valley is the northern fringe of the bobwhite’s range. At the time of Refuge creation, a study of the bobwhite was going on at Las Delicias ranch. That study indicated that the bottom of the valley was too extreme for the quail.

A more detailed history is presented in the book Ranching, Endangered Species, and Urbanization in the Southwest, by Dr. Nathan Sayre (2002) University of Arizona Press. (The book is available in local libraries).

Sayre recounts the history of cattle ranching in the Altar Valley by examining both the economics and ecology of ranching. The Altar Valley was a lush grassland, but one without perennial water sources. In a parallel story, Sayre examines the failed effort of the federal government to establish the Masked Bobwhite quail in the region, first by working with the ranchers, and then by buying out the ranches and establishing the Buenos Aires National Wildlife Refuge. When the Buenos Aires National Wildlife Refuge was created, cattle were removed and so were most of the developed water sources.

Sayre starts by exploring the history of the masked bobwhite quail, a subspecies of the northern bobwhite, from its discovery in 1880s, its disappearance around 1900, to its return to the Altar Valley in the 1970s. During this period, the masked bobwhite acquired great symbolic value among ornithologists and wildlife managers as a victim of cattle grazing. Sayre concluded that the effort to reestablish the bobwhite was doomed to failure because the Altar Valley is at the very northern extreme of the quail’s habitat. They die in freezing weather which occurs frequently in mid-winter on the Refuge.

Subsequent chapters recount the development of ranches from the 1880s to the 1970s and the constant battle to provide water and forage while suffering droughts and floods. These chapters deal with the “cattle boom” in the 19th century, its ecological consequences, and how successive owners dealt with these conditions.

Sayre notes that more than 25,000 captive-bred birds have been released on the Refuge at a cost of $68 million, but few if any survive. “Despite the removal of livestock, Refuge biologists have not succeeded in establishing a self-sustaining population of masked bobwhites.” “An ambitious program of prescribed burning, intended to simulate the natural fire regime of the desert grasslands, has not resulted in any change in the vegetation on the Buenos Aires.”

The flyleaf of the book notes that “The creation of the Buenos Aires National Wildlife Refuge has been a symbolic victory for environmentalists, but it comes at the cost of implicitly legitimizing the ongoing fragmentation and suburbanization of Arizona’s…rangeland. Sayre reveals how the polarized politics of the rangeland conflict have bound the Fish and Wildlife Service to a narrow, ineffectual management strategy on the Buenos Aires, with greater attention paid to increasing tourism from bird watchers than to the complex challenge of restoring the masked bobwhite and its habitat.” (The Buenos Aires is now under a new director who is working on another updated plan.)

The Refuge has been a favored route for illegal immigration. It has also been the site of various accidental or intentional unplanned range fires set by the border crossers either for the purpose of being located and rescued or perhaps as decoys to draw resources away from routes being used for narcotics transportation.

But humans are not the only invaders. Because of earlier government soil conservation practices, the area of the Refuge was converted in large part to a plantation of exotic grass species. It started around 1900. According to a UofA News story, “Combined overgrazing and drought resulted in ecological disaster in the 1890s… A concerned federal government intervened at the turn of the century. Pioneering researchers lacked modern technology and time to experiment with re-establishing native grasses after their initial attempts to restore these grasses failed. Their worldwide search for the best ‘miracle’ grass to reduce soil erosion and provide livestock nutritive forage ended in the 1930s in South Africa, where they found Lehmann lovegrass. It established readily from seed, was easy to handle, and thrived on less than 10 inches annual rainfall. Lehmann lovegrass was widely seeded across southeastern Arizona from the 1940s through the 1970s.”

According to a local expert on desert grasses, Lehmann lovegrass “was the grass of choice for the highway department that seeded it alongside the roads to prevent erosion. The prolific production of very fine seed with the extra water afforded by runoff from highways contributed as much as anything to the spread of the grass. Additionally, the seed was readily picked up by vehicle tires and transported everywhere. Lehmann lovegrass greens up earlier in spring and stays green longer in the fall than many native perennials, so it provides good forage at those times; it is not the grass of first choice during the prime summer rainy season–native perennials are first choice– but fills its own important niche at other times. Lehmann tends to occupy the lower areas between hills and is slow to move up hills, especially the common limey, rocky slopes.” Lehmann lovegrass initially displaced native species and decreased the biodiversity of the Refuge, “but it seems to be hindered from displacing native grasses where those are well established.” Area ranchers report that native species are returning in some areas.

The Fish & Wildlife Service has failed in its original goal to establish a viable, permanent population of masked bobwhite quail in the Altar Valley. It seems that the major result of this experiment has been to turn productive land into non-productive land.