Research is being conducted by Ohio State University on this subject during the 1998 growing season. A number of growers around the state have agreed to submit water samples three times during the season. The combined results should provide some insight into how water quality parameters vary throughout the year. Ground water characteristics tend to be fairly stable unless the well becomes contaminated. Testing every three years should be frequent enough, unless you begin to detect problems.
Surface water includes rivers, ponds, lakes, streams or creeks.
These sources generally are more subject to water quality fluctuations than ground water. Temperature, wind, precipitation, biological activity, and runoff from upstream are just a few factors that impact surface water. An annual water test is advisable, although in truth, water quality characteristics may be subject to seasonal, daily, or even hourly changes. Your specific goals can guide your sample timing. For example, to get a sample that represents the prevailing alkalinity, pH, and nutrient contents, sample under normal rainfall and irrigation conditions, not during droughts or floods.