Grazing Management For Healthy Watersheds Dr. M. Karl Wood Director Water Resources Research Institute New Mexico State University

What is a healthy watershed? Desired Functioning Condition? What are the Goals? Are the Goals Obtainable and Sustainable?

Watershed Goal? Resource Exploitation Sustainable Use Resource Protection

Exploitation Sustainable Protection Use Watershed Goal? The extremes result in attitudes of supremacy From: Thompson, P.B The Spirit of the Soil - Agriculture and Environmental Ethics. Routledge Publ. New York, New York

New Mexico Historical Perspective Wild Ungulates native to New Mexico Cous deer Mule deer Whitetail deer Pronghorn Desert bighorn Rocky Mountain bighorn Elk Bison Javelina

Domestic and Wild Ungulates Introduced in last 500 years Cattle Swine Sheep Horses Burros Goats Barbary sheep Oryx Ibex

Grazing Effects on Plants

Land Management Practice Plant and Rock Cover Plant Volume Animal Grazing, Trampling, and Burrowing Soil Surface Roughness Soil Surface Configuration Soil Moisture Evaporative Loss Soil Organic Matter Content Soil Particle Sizes Soil Structure Soil Bulk Density and Porosity Runoff and Infiltration

Grazing Effects on Plants 1. Grazing reduces plant cover and volume Little Great Stimulation Resistance Resistance Response 2. Plants species respond differently to grazing Antelope bitterbrush Black gramaBlue grama

Grazing Effects on Plants 2. Plants species respond differently to grazing continued… Moderate to No Grazing Bunchgrass Heavy Grazing Sodgrass Blue grama

Reduced Plant Cover and Plant Volume Effects the Watershed 1. Decreased interception and transpiration 3. Decreased water infiltration into soil surface 4. Increased runoff and erosion 2.Decreased organic matter additions to soil, which affect soil structure and porosity 5. Increased runoff and erosion lead to loss of sustainability after about 50% utilization of present year’s growth

Grazing Effects on Plants Continued… Grazing can retard or stop invasion of salt cedar Observed on: 1. Capitan Creek on the Pecos River 2. Middle Fork of the Gila River 3. Redstone Allotment of the Gila River

Trampling or Hoof Action Effects on Plants 1.Trampling reduces plant cover and volume. 2. Plant cover and volume reductions may: a. Decrease Interception and Transpiration b. Damage or kill the plants c. Stimulate plant growth

Trampling or Hoof Action Effects on Soils

Trampling Effects on Soils Soil Surface Runoff and Roughness Erosion Wet Soil Dry Soil Southwestern soils are usually dry! Increases Decreases Increases

Trampling Effects on Soil Runoff and Trails Erosion Up & Down Slopes Across Slopes Configuration Increases Decreases

Trampling Effects on Soil Bulk Density Porosity Water Holding Runoff and Capacity Erosion Bulk Density and Porosity Bulk Density increases are usually mitigated with cold-weather freeze-and-thaw conditions. Increases Decreases Increases

Trampling Effects on Soils When ungulates are removed from watersheds, pocket gopher populations often increase, even exponentially. Gopher mounds may add up to 5 tons/acre/yr of sediment into streams!

Trampling Effects on Soils Gopher tunnels often lead to piping and eventually a side gully! A benefit of trampling is control of pocket gophers!

Animal Wastes and Nutrient Cycling Soil Runoff and Erosion Wind

Animal Wastes and Water Pollution Fisheries in high fertility watersheds won’t benefit much from dung and urine additions but may suffer from over- enrichment. Only that dung deposited on bare ground connected to a runoff system is expected to be eroded from a watershed. Fisheries in watersheds of low fertility may benefit from accelerated erosion and elevated nutrient levels

Livestock and Wild Ungulate Management Strategies Fences It is easy to fence out livestock It is difficult to fence out wildlife Total number of ungulates may not change from fencing out livestock

Livestock and Wild Ungulate Management Strategies Fences and exclosures may be problematic because they: Lead to aesthetic considerations Are expensive Have annual maintenance hassles Create problems with animal movement Often result in unused forage

Livestock and Wild Ungulate Management Strategies Stocking Rates Extreme 100% Utilization - Rarely sustainable Heavy 75 “ - “ “ Moderate 50 “ - Usually sustainable Light 25 “ - “ “ Exclusion 0 “ - “ “

Livestock and Wild Ungulate Management Strategies

Livestock and Wild Ungulate Management Strategies Grazing systems

Grazing Systems – Example from Texas Rolling Plains Stocking Infiltration Sediment System Rate Rate Production cm/hr kg/ha Exclosure None Deferred-Rotation Moderate Continuous Moderate Short Duration Moderate Continuous Heavy Wood and Blackburn J Range Manage. 34: ; b 14 b 28 ab 40 ab 114 a 15.2 a 13.9 ab 11.4 bc 8.2 c 8.1 c

Grazing Systems – Example from Fort Stanton, New Mexico Stocking Infiltration Sediment System Rate Rate Production cm/hr kg/ha Exclosure None Continuous Moderate Short Duration Heavy after resting Short Duration Heavy after grazing Continuous Heavy Weltz and Wood JRM 39: ; J Soil & Water Cons. 41: b 307 a 221 a 565 a 334 a 7.4 a 4.9 b 3.9 c 2.3 d 2.6 d

Grazing Systems – Example near Fort Sumner, New Mexico Stocking Infiltration Sediment System Rate Rate Production cm/hr kg/ha Exclosure None Continuous Moderate Short Duration Heavy after resting Short Duration Heavy after grazing Weltz and Wood JRM 39: ; J Soil & Water Cons. 41: c 80 b 25 c 268 a 6.3 ab 5.5 b 7.0 a 3.8 c

Livestock and Wild Ungulate Management Strategies Range Improvements Plant Control BiologicalBurning HerbicidesMechanical

Livestock and Wild Ungulate Management Strategies Range Improvements Plant Enhancements SeedingFertilizingWaterspreading

Livestock and Wild Ungulate Management Strategies Monitoring Explore Evaluate Keep Records Measure Observe

Conclusions Four noteworthy points can be made regarding the question: Can we graze watersheds? 4 th If we don’t get our management act together, the public won’t let us graze watersheds because of high resource value and potential for damage from improper grazing! 1 st Yes, we can graze these areas! 2 nd We should be able to increase forage produced without damaging other uses! 3 rd We don’t know yet how to do this in all areas!

If on the other hand the prime objective is watersheds, we should restore the grass, which all the evidence indicates is a better watershed cover than either brush or woodland.” Aldo Leopold “If the prime objective is wood products, we may continue to overgraze, letting in the woodland and sacrificing watershed values. A Good Quote

God Bless America!