Unless you know the problems in your garden soil, you are only guessing when you apply fertilizer. Most plants grow best in a soil that is neither too acid nor too alkaline. Using test strips are an easy way to test the garden yourself for pH and nitrogen.

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Soil Testing Using Test Strips

The next test you could do at home is with test strips. These are things that you can order from catalogs, or you might be able to find them at your local aquarium store. These pH test strips have a sensitivity range from 4 to 9.

The other thing that I like to test at home in nitrate nitrogen. The reason is because nitrogen changes in the soil constantly. So, your soil sample will tell you your starting point. But later on in the year, you may want to check it for yourself and see if your plants still have enough.

Both of these are very easy to use. I like to make a one-to-one soil/water mixture. You can use any jar or cup. Make sure it’s clean. Take that same soil sample you gathered, and you’ll need to mix it to make sure you’re getting a representative sample.

Take a little cup and sample it the same way you would measure flour. Don’t pack it, but keep it loose. Put one cup of soil and water together. It can be drinking water or distilled water. If it’s drinking water, just make sure it’s low in nitrate. After adding one cup of water, put the lid on and shake it.

Mix the soil and water together, and then let it set and let the soil settle out, because you need a liquid that’s clear. If it’s too brown, the test strip colors won’t show up very well. You can also stick a piece of filter paper, or paper towel, or coffee filter in the cup. Let the filter soak up or filter out some of the liquid. Just put it in the middle of the cup, and leave a depression, and then collect the clear water in the middle of the filter.

We’re going to use this sample that is clear, to show you how the test strips work. The pH test strip has one pad. You just dip it in the water and it starts to turn color. The nitrate test strip is the same way. You dip it, pull it out, and in 30 seconds it starts to turn color. Then you use the color charts on the bottles to compare the test strip.

This one is coming out to be about a 7 pH, which is just right. You want your pH to be about 6.5 to 7. On the nitrate test strip, we’re going to wait a little bit longer – and then it’s going to turn pink. If it’s 0 it’s white. If it turns pink – in the 5 range, it’s a little bit light. 10 to 20 is ideal, and then 50 would be too much fertilizer if it was a soil. If it was a compost, 50 would be about right, and it would be a good compost.

This feature story prepared with Rhonda Janke, Kansas State University Research and Extension, Sustainable Cropping Systems. For more information, visit your local county extension office or visit our website at KansasGreenYards.org.

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