Conservation Reference Materials
There are many species of grasses in Arizona introduced, either intentionally or accidentally, from other continents. Some are considered invasive species (species that will invade into native plant communities and may reduce or replace the native vegetation by competition for nutrients and water). Some of these species have been declared noxious weeds by the State of Arizona and there are efforts to control or exterminate them. Some of the more prominent ones are discussed here.
Currently there is much interest in “watershed restoration” in Arizona. Water is and will continue to be a major resource concern because Arizona is an arid state. It is generally agreed that Arizona’s watersheds are not in the best condition. Lack of effective vegetation cover results in excessive soil erosion which not only reduces productivity of the land, but also results in sediment deposits in streams and affects water quality. Lack of vegetation cover to slow runoff results in increased flooding downstream and may reduce ground water recharge. A number of treatments are used to try to restore hydrologic function on these watersheds, one of them being rock check dams. This article is intended to explain what rock check dams are, how they affect the watershed, and what are some of the considerations in their use.
Some say that proper stocking rate is the most important consideration in good range management. But what is “proper” stocking rate? There is not a simple answer because what is “proper” depends on how we measure it. For example, to many range professionals, proper stocking would be that which will maintain or improve the range condition. For most ranchers, it might mean the stocking rate that would return the greatest income. For some wildlife interests, it would be that stocking rate which minimizes conflict with wildlife values. And for some radical anti-grazing interests it means no livestock at all.
The hydrologic cycle is precipitation, evaporation, interception, infiltration, percolation, transpiration, runoff. All water in Arizona comes from precipitation on the watersheds (except that in the Colorado River). It is the source of all stream flow, springs, and ground water (some of the latter accumulated over many thousands of years). The main focus of watershed management is to capture and safely release water from precipitation. Capture means to store the water in the soil where it falls to the extent possible. Safe release means to let the excess moisture flow into streams or percolate into ground water slowly so that it does not cause excessive flooding and erosion and has time to percolate into the ground water.
While producers in Arizona may currently use efficient practices in growing crops or grazing livestock, certain practices aimed at improving soil health may actually make their production even more efficient and profitable by reducing costs of irrigation, fertilizer and pesticide use, tillage, etc. on farmlands, and by increasing animal production and reducing feeding costs onrangelands. According to Natural Resources Conservation Service (NRCS) Soil Heath Expert Jay Fuhrer, there are five principles of soil health. Our own AACD Technical Consultant, Dr. Lamar Smith, has analyzed and synthesized them for us here.
All Arizona residents are aware that water is a very precious commodity in the state. Water in Arizona comes from three main sources and is applied to three main uses. "Increasing Irrigation Efficiency" is a high-level look at irrigation practices and efficiency as it is applied to agriculture. Learn about the three main methods of agricultural irrigation in Arizona and their efficency rates. Readers will learn how these different metods are applied to different types of crops and how it works with the soil, thus increasing efficency.
It’s fire season in Arizona, and many of us are all too aware of the effects fire has on the land, private property, and human and animal life. But have you ever stopped to ask WHY fires in Arizona burn as often or as seemingly out of control in the summer as they do? Or how, when controlled, fire could actually be a good thing? “Arizona Fires” is a high-level, scientifically based white paper that looks at and gives readers an understanding of how vegetation and soils across the state are, and have been historically, impacted by fire. (And you don’t need a degree in rangeland or forestry to understand it; this writer can attest to that!) The big question, “what can be done?”, brings home the point of the paper. But don’t worry, we’re not left hanging, an opinion to a solution is offered.