How to Filter Nitrate Salts From Soil

The most common nitrate salt found in soil is ammonium nitrate, because it is used as a fertilizer. Nitrate is mobile in the soil, which means it does not adhere to soil particles well. Because nitrate is free in the soil it can easily be leached away. Ammonium nitrate, in particular is extremely water soluble. With over fertilization, damaging amounts of nitrate salts can accumulate in the soil. If your soil is shallow, and there is a concern about ground water contamination you may want to filter nitrate salts out of your soil. Ground water polluted with too much nitrogen can cause be dangerous to humans. Removing nitrate salts from the soil reduces certain chemical cycles. Filtering nitrate salts from the soil also changes the microorganism composition of the soil.

Things You'll Need

• 3-foot-square piece of cloth
• Bucket
• Large flat pan

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Instructions

1. • 1

     Lay the cloth flat on the ground and put your soil in the center of the cloth. If you have lots of soil to filter, do about a shovel full at a time. The cloth can be an old rag or several layers of cheese cloth. It should allow water to pass through it quickly but not a lot of soil particles.

   • 2

     Lift the cloth from the corners with one hand and hold it over the bucket. With your other hand pour water through the soil held in the cloth. The best thing to use would be a hose hooked up to a spigot. Keep the pressure low and make sure you get all of the soil thoroughly wet.

   • 3

     Squeeze the sides of the cloth around the soil after it has been rinsed with water several times.

   • 4

     Pour the water collected in the bucket into a large flat pan. Place the liquid in the sun. The material left behind contains nitrates filtered from your soil.