Importance of Quality Water in Farming
Irrigated agriculture represents 20 percent of the total cultivated land and contributes to 40 percent of the total food produced worldwide. On the average, irrigated agriculture is at least twice as productive as rainfed agriculture to allow more intense production and more diverse crops. This proves how critical water is in agriculture and food security worldwide.
Agriculture production is the largest water-consuming sector industry. It is highly dependent on water and is prone to water shortage as a result of various factors such as growing population, urbanization, and global warming, which have led to increased requirement for water. In recent years, agricultural regions around the world have been affected not only by water shortage, but quality water shortage, as well.
Quality of water is a critical aspect of agriculture production. And there are many factors which determine water quality. Alkalinity, pH, and soluble salts are among them. Poor quality water can bring about slow growth, poor aesthetic quality of the crop, and in some cases, death of the plants. For instance, high soluble salts can injure roots and may interfere with water and nutrient absorption in crops. Salts in water can accumulate in leaves which may result to burnt edges.
pH and Alkalinity
Alkalinity and pH are two vital factors in determining the suitability of water for irrigating plants. pH is a measure of the concentration of hydrogen ions in water and other liquids while alkalinity is a measure of the water’s ability to neutralize acidity. Irrigation water tests should always include both pH and alkalinity because a pH test by itself is not an indication of alkalinity of water. High alkalinity, not pH, exerts the most significant effects on growing medium fertility and plant nutrition.
Soluble Salts
Calcium and Magnesium are essential elements for plant growth and determines the hardness of water.
Sodium and chloride can be directly toxic to plants and may raise the soluble salts level of the growing medium or inhibit water uptake by plants resulting to reduced growth and increased susceptibility to diseases. Depending on crop sensitivity, sodium and chloride should always be monitored to check for applicable tolerance levels.
Potassium and phosphate present in irrigation water at high levels indicate the presence of pollution from fertilizers or other contaminants.
Sulfate levels must be maintained to a level needed for good plant growth.
Ammonium and nitrate indicate possible contamination of the water source from the use of fertilizers, and must, therefore, be corrected to prevent further contamination.
Micronutrients and Trace Minerals
Micronutrients like copper, zinc, manganese, iron, and boron are important micronutrients, but can occur in excessive or deficient quantities in water; and must therefore be tested, monitored and corrected as necessary. Using the appropriate water filtration system does the job.
Water Filtration System
Water used in irrigating agricultural crops should be tested to ensure it passes quality standards for plant growth and to minimize the risk of discharging pollutants to surface or ground water.
While not all suspended solids may not be harmful to crops, they may clog pipes, valves, nozzles, and emitters in an irrigation system. These include sand, soil, leaves, organic matter, algae, and weeds. And while ground water is usually clean, it is highly recommended to test the quality of water as well as the type and density of suspended solids present, flow rate necessary to supply the irrigation system, and most importantly the level of filtration needed to determine the type of filtration system to be used. Screen or disk filters work for bigger solids and may work as first level filtration, but micro contaminants may require more industrial filtration systems. Likewise, the size of filters should be able to handle heavy flow rate.
Regular maintenance of the irrigation system is a must to check for leaks, clogs, and cracks that may be an entry point for contaminations. It also includes regular cleaning and replacement of filters to ensure efficient water filtration at all times.