Letting the Soil "Speak"
Nitrogen is the chief nutrient added to cereal crops like corn that makes them grow faster and stronger. But adding too much nitrogen can be detrimental. Excess nitrogen can run off the field with rainwater or leach through the soil and contaminate groundwater.
Now, a fast, simple, and reliable test is on hand to help farmers determine how much organic nitrogen is available in the soil—and avoid overapplying nitrogen fertilizer.
ARS researchers in Raleigh, NC, calibrated the test with lab, greenhouse, and field studies. It works on the premise that soil isn’t an inert, dead plot of dirt but, rather, alive with insects, bacteria, fungi, and other organisms that help make nutrients available to plants.
Using this "Soil-Test Biological Activity" approach, farmers can better determine how much or how little nitrogen to apply for optimal crop yields, cutting production costs and risks to surface and groundwater supplies.