These past two years UF/IFAS Columbia County Extension has participated in an on-farm trial comparing fertilizer types and application methods on field corn. Field corn is commonly grown in the Suwannee Valley region and has a high nitrogen requirement. The Suwannee Valley region is home to the Santa Fe and Suwannee rivers along with their associated springs which serve as major tourist attractions. There is concern increased nitrogen, especially in the form of nitrate, in spring water can lead to increased algal growth. Recent research has also pointed to water quantity playing a major role in the growth of algae in our springs. Spring flow can be reduced due to human consumption or by extended periods of dry weather conditions when there is a decrease in groundwater recharge; this leads to more stagnant water conditions and increased algal growth. This on-farm trial aims to compare fertilizer types and application methods to increase nitrogen use efficiency in field corn. We have also worked with the grower to adopt soil moisture sensor technology to manage his irrigation.
Banding or sidedressing fertilizer refers to the application of fertilizer in a straight line, generally between rows of young plants. This application method is more efficient than broadcasting fertilizer which involves uniformly spreading fertilizer throughout the entire field. When growers sidedress fertilizer they may be able to apply up to 30% less fertilizer compared to broadcasting. There is cost share available (75% up to $50,000) on sidedressing equipment through the Suwannee River Water Management District.
The use of control release fertilizer is believed to increase nitrogen use efficiency. Control release fertilizer is coated in a polymer which releases nutrients at a slower rate dependent on soil temperature. One major advantage of control release fertilizer is that it only needs to be applied once, before or after planting because the polymer allows for nutrients to be slowly released over an entire crop season. In contrast, field corn fertilized with conventional fertilizer is usually applied multiple times after planting due to the mobile nature of nutrients, such as nitrogen, in the soil and the potential for nutrient leaching or runoff. The use of control release fertilizer reduces the number of times a grower needs to apply fertilizer saving them time and money on fuel. Control release fertilizer is beneficial for growers who do not have the ability to fertigate using a pivot. Once corn reaches a certain height, growers who do not have access to pivots or choose not to fertigate do not have the ability apply more fertilizer to their crop. Control release fertilizer can help growers under these management regimes avoid nitrogen deficiency later in the season. One downfall of control release fertilizer is the higher price compared to conventional fertilizer. There has been discussion in the region on the potential for cost share options for control release fertilizer in the future. However, currently there is no cost share available for control release fertilizer. This year research trials were conducted in the Suwannee Valley region on the use of control release fertilizer on field corn, watermelon, and carrots.
Last year there was an approximately 20 bu per acre increase in the yield of corn sidedressed with control release fertilizer compared to corn broadcasted with conventional fertilizer. This year funded by a grant through the Stetson Sustainable Farming Fund the project will collect yield information between the two nutrient management treatments and track the movement of nitrate in the soil at 0-6, 6-12, 12-24, and 24-36 inches. Last season we worked with Charles Barrett of UF/IFAS NFREC Suwannee Valley and provided the grower a free demo soil moisture sensor. This year the grower used cost share through the Suwannee River Water Management district to get his own soil moisture sensor. The grower credits soil moisture sensors for saving him money and water.
See video below for more information on the first year of the on-farm trial at Ronald Norris Farm:
“This product was developed with support from the Sustainable Farming Fund at Stetson University and as established through a U.S. District Court, Middle District of Florida, Jacksonville Division, Consent Decree in the case of Environment America, Inc., d/b/a Environment Florida and Sierra Club v. Pilgrim’s Pride Corporation, Case No: 3:17-cv-272- 32JRK. Any opinions, findings, conclusions or recommendations expressed within do not necessarily reflect the views of either the U.S. District Court, Middle District of Florida, Jacksonville Division, the Institute for Water and Environmental Resilience, or Stetson University.”
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