Nitrogen Content in Soil
The following article is written by Virginia Pannill, a summer intern in the Culpeper Extension office. Virginia is a Senior at Ferum College majoring in Animal Science and is the youngest daughter of Joan Pannill and the late Clay Pannill of Rapidan.
One of the key substances required to produce large yields of corn is nitrogen, therefore it is vital that farmers know how much nitrogen they have in their soil. To figure out a soils nitrogen content, a soil sample can be taken from the field and tested. When nitrogen is applied to the soil the plant absorbs it as nitrate and uses it to grow. There are numerous stages that take place during the growth of a single corn plant which all require nitrate, however the V8 and VT stages require the most nitrate. The corn takes up half of its nitrate content during this 30-day period, which makes nitrate management the key goal in corn production.
The first step to figuring out how many pounds of nitrate are in the soil per acre is to take a soil sample, which can be done by an extension agent from a county extension office. After the soil sample is taken, the extension agent can run a Pennsylvania Soil Nitric Test in the office. Once the data from the test is delivered to the producer, they can decide what they need to do to get the yield that they are working towards. However, it is important to keep in mind that once the corn reaches a certain stage in development it is difficult to apply the nitrogen to the field due to the corns height.
If the producer needs to apply nitrogen to their soil, it is most practical to apply small amounts of nitrogen in the beginning and larger amounts towards the middle of the growing season. If large amounts of nitrogen are applied in the beginning of the season it will be lost because the plant does not need to absorb it until further in development. The corn plant needs the most amount of nitrate once it reaches knee high length so that it can then grow to shoulder length and develop into its tassel stage within a two-week time period.
By completing soil tests and receiving reliable information the producer is better able to understand how much nitrogen to apply to their soil. Applying the appropriate amount of nitrogen to the soil saves both money and time and is better for the environment.