Linda Benedict, Rutherford, Allen | 11/22/2011 9:35:29 PM
D. Allen Rutherford
Louisiana’s rivers and streams (66,294 miles), natural lakes and human-made reservoirs (1,078,031 acres), fresh and tidal wetlands (5,550,951 acres), and estuaries (4,899,840 acres, where freshwater mixes with saltwater), combined with Louisiana’s territorial waters cover over a third of the state’s land area.
Water quality describes the chemical, physical and biological properties of water. It embodies many complex characteristics including temperature, dissolved oxygen and other gases (e.g., carbon dioxide, nitrogen, hydrogen sulfide), sediment levels, salinity, acidity, nutrients (nitrogen and phosphorus), as well as bacteria and other organisms that live in water. These characteristics are each dependent on local conditions such as geology, the terrain and topography, local drainage patterns, weather, and, of course, human influences. Interactions among the complex characteristics of water and the complexity of local conditions and influences determine the limits of how water can be safely used or simply enjoyed. For most of us, we just want to know if our water is safe for drinking or swimming and suitable for our plants and animals.
Louisiana’s topography is a diverse patchwork of both upland and bottomland forests, pastures, prairies and savannahs, marshes, swamps, and coastal waters. This naturally decorated landscape is interlaced with thousands of miles of rivers, streams, lakes, reservoirs, wetlands and estuaries. Including Louisiana’s territorial waters, our water resources cover over one-third of the Rutherford state’s area. Home to some of the world’s most diverse flora and fauna, this breadth of natural resource diversity is reflective of our state’s abundance of water resources. It’s no wonder our state is known as a sportsman’s paradise.
The importance of uncontaminated groundwater (water stored beneath the surface) for agriculture, forestry, human consumption and the environmental health of our ecosystems cannot be underestimated. Pesticides, herbicides, fertilizers, sediments and other chemicals often run off terrestrial areas into the nearby water bodies, where they can adversely affect aquatic life, the quality of drinking water, and, ultimately, limit our quality of life. Over the last century and a half, all aquatic ecosystems have been impacted as human population and cultural activities have increased across Louisiana’s landscape.
The LSU AgCenter’s mission is to provide research-based information to improve the quality of life and economic well-being for Louisiana residents. To fulfill this mission, AgCenter scientists study economically important crops (forestry, sugarcane, rice, soybeans, cotton, etc.), livestock and aquacultural spe cies (poultry, horses, beef, farm-raised fishes, etc.), and other natural resources (wildlife, freshwater marine fisheries, recreational hunting and fishing, etc.). The goal is to improve and enhance both their quantities and qualities. The value of plant agriculture ($6.4 billion), animal agriculture ($2.6 billion) and natural resources ($2.6 billion) is significant and critical to the economy of our state. Each of these valuable commodities is intimately dependent on an abundant and clean supply of water.
The AgCenter also has a stated focus on the health and safety of our biological environment, which requires examining the effects on water quality of all agricultural-related activities with the goal of maximizing production while minimizing damage. It is our duty to help conserve, protect, restore and maintain the state’s water resources.
The articles in this issue give an excellent look at the diversity of ongoing research and extension efforts by AgCenter scientists. Several research studies examine water quality issues and best management practices and strategies associated with specific commodities (rice, Saichuk and Gauthier, page 35; sugarcane, Viator et al., page 18; forestry, Bryant-Mason and Xu, page 9; aquaculture, Romaire et al., page 32).
Other studies identify and pose solutions to runoff associated with land-based activities. These include the effects of runoff from agricultural activities on water quality in adjacent water bodies (agricultural watersheds, Selim et al., page 22; erosion control to prevent sediment inputs, Weindorf et al., page 24; impacts of animal waste, Wang and Gaston, page 16; fertilizer runoff on levees, Beasley et al., page 14).
Several studies examine novel solutions to treating water to improve its quality (ornamental plants and storm-water runoff, Chen and Bracy, page 20; rice hulls as a biological filter, Davis et al., page 28) and water-use efficiency (efficient irrigation, Sheffield and Girouard, page 30).
Additionally, two research articles examine ecosystems with large-scale water quality issues unique to Louisiana (Atchafalaya Basin, Kaller and Kelso, page 12; Gulf of Mexico, hypoxic dead zone, Xu et al., page 8). Retired state climatologist Jay Grymes gives us an update on climate conditions and the recent drought (page 26).
Finally, we are given a synopsis of ongoing extension efforts that help public understanding of AgCenter past and present water quality research (LeBlanc et al., page 33). This extension-related article includes a clear explanation of newly proposed numeric nutrient criteria for water bodies, a demonstration project quantifying the ability of submerged aquatic vegetation to reduce nutrient levels, an update of the BMP manual in addition to an educational program designed for horse owners and producers, and an overview of a partnership program with Shell Oil Company that is designed to educate public school teachers on an array of water quality issues and concerns.
We hope this issue of Louisiana Agriculture magazine gives you a good overview of how AgCenter scientists are focused on addressing the important water-related issues of our time. We are continually faced with many complex and ongoing challenges to our natural resources, but we are committed to the task. We believe that well-designed research and tireless extension can make a substantial difference.
D. Allen Rutherford, Professor and Director, School of Renewable Natural Resources, and Interim Head, Department of Biological & Agricultural Engineering, LSU AgCenter, Baton Rouge, La.
(This article was published in the fall 2011 issue of Louisiana Agriculture magazine.)