Maintaining Fertility with Variable YieldsFebruary 3, 2014 | Category: Agronomy |
January turned the page to the 2014 growing season, and with that comes crop planning. A vital part of the crop plan is managing the fertility plan. Approaches to fertility differ, but are primarily based on replenishing nutrients removed by the crop.
Sound fertilizer management begins with regular soil tests. These tests provide the basis to the fertility program. However, fertilizer management choices on the farm between the regular soil tests can greatly influence crop development and the results of
Creating a “nutrient balance sheet by field” provides a simplistic approach to managing nutrients. A nutrient balance sheet is essentially like your bank account. Record the quantity of nutrients applied to a given crop. Subtract the amount withdrawn from the field by the harvested crop from the nutrients applied. If the amount applied is more than the amount removed, the excess nutrient is available to the next crop. If the amount applied is less than the amount removed, then additional fertilizer needs to be applied to bring the nutrients back into balance. A more holistic approach to nutrient management takes into account factors such as soil texture, form of the nutrient applied and nutrient availability to the
Several areas of the province experienced higher than expected harvested yields in 2014. If these fields were fertilized at the rate of estimated crop removal, they may have withdrawn significant amounts of nutrients from the soil reserve. This is an important consideration when determining fertilizer application rates the following season. The reverse is also true – if lower than expected yields removed lower quantities of nutrients, these excess nutrients may be available for the following crop.
Fertilizer prices have also dropped significantly since last spring. This may allow some producers to build soil nutrient reserves where applications rates may not have met crop removal rates. Nutrients such as phosphorus and potassium may fall into this category. Remember, the most efficient placement of phosphorus for any crop is seed-placed, if the option exists.
Monitoring and maintaining the nutrient balance sheet provides a simplistic approach to managing nutrient application in the cropping plan. Adjusting fertilizer rates according to crop removal maintains fertility levels for optimum crop production. Maintenance of optimum fertility levels provides the foundation for maximum crop yield.
Shawn Winter, CCA-ON, Maizex Seeds Product Development Manager