WATER and WATER QUALITY
| Introduction | IPM | Monitoring | Treating and Recycling | Managing Pesticide Wastes | Air, Water, Media | Management Plan |Introduction to Water Quality Management The use of fertilizers and pesticides is a very important aspect of the commercial production of high quality greenhouse crops. In the Unites States alone, agricultural applicators have increased the use of nitrogen fertilizers from 2 million tons in 1955 to more than 12 million tons in 1990. Pesticide use has more than tripled since 1964, with approximately 1.5 billion pounds per year now being applied. These significant increases indicate the many benefits derived from the use of fertilizers and pesticides. However, these chemicals also pose a potential threat to our fragile environment.
Runoff from rain or irrigation can concentrate fertilizers and pesticides at collection points where they may enter surface and groundwater reserves. The continued, largely unregulated, use of such chemicals could potentially contaminate lakes, streams, ponds, wells and groundwater.
Injurious effects such as fish kills, reproductive failures in birds and acute illnesses in humans and animals have been correlated with contaminated water. However, the exact source(s) of these damaging chemicals is not always apparent. Because we have a poor understanding of the results of long-term exposure to chemicals, the exact identification of hazards is difficult.
At present, half of the population of the United States relies on underground sources for drinking water. Rural residents are even more dependent on these natural water resources. More than 90 percent of rural water is now being retrieved from groundwater sources. But of all the groundwater withdrawn each year, only a small amount is used strictly as drinking water.
Most groundwater (82 percent) is used for agricultural irrigation. The availability of large volumes of high quality irrigation water is an important factor in the production of greenhouse crops. It is extremely important to protect and conserve this natural resource. A significant quantity of this irrigation water will reenter the water cycle to replenish groundwater supplies. Therefore, fertilizers and pesticides must be used wisely.
The following guide has been compiled to provide growers both with recommendations for optimum growth and with production alternitives to help reduce the use of fertilizers and pesticides. A balanced approach which combines traditional cultural practices with a concern for the environment will be an important key to protecting our natural water resources and the future growth of the Texas greenhouse industry.
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