Better BMP Implementation

Better BMP Implementation

Improving irrigation management can reduce production costs, save water, and reduce the risk of nutrient leaching. Proper irrigation scheduling requires a target irrigation volume, a measure of soil moisture, and a knowledge of how much water the root zone can hold. A method to account for rainfall contribution to volume, soil texture, organic matter content, compaction, rooting depth, hard pan layers, and antecedent soil moisture all are factors in water movement in the soil. One of the problems with making good irrigation management decisions is that water movement in the root zone is difficult to visualize. A dye test can provide a simple and practical method to visualize water movement in the soil by showing the depth and width of irrigation water movement in the soil.

Irrigation Demonstration

The UF/IFAS BMP Implementation Team planned a demonstration to show the effects of over-irrigation on the fate of nitrogen for the Florida Sod BMP Kick-off Event it held at Strickland Sod in New Smyrna Beach. The plan was to put a water-soluble dye (that mimics the movement of water-soluble forms of nitrogen) in a sod field the day prior to the event, water it in, and then dig pits in the sod on the day of the event to show dye distribution in the soil. However, nature did not fully cooperate. Two days before the event, a storm system moved through the area and dumped several inches of rain, saturating the soil. We went ahead with the demonstration, and sprayed a water-soluble dye in two separate areas. A traveling gun was used to apply ½ inch on one of the areas and the other was over-irrigated with 3 inches.

Unexpected Results

Usually, the plot that is over-irrigated will show that the dye has moved down through and beyond the rooting zone. The results of this demonstration were quite interesting in that the usual effect was not observed, but another important lesson was learned. The dye penetrated in both plots to the same depth, about 4 inches. Two factors contributed to this occurrence:

1. The soil was very wet before the demonstration was started, and most of the soil pore spaces were already full of water below the 4-inch depth to which the dye penetrated. When the irrigation water hit the saturated zone, it was not able to penetrate any further and moved laterally towards the drainage ditch.

2. The production field is crowned for drainage purposes (as opposed to being level). Wet field conditions result in excess irrigation or rainfall running off the field.

Important Implications

This demonstration illustrated that when you have crowned fields and soil moisture near field capacity, much of the applied fertilizer can leave the farm via sheet flow regardless of irrigation depth. Although this demonstration was done on a sod farm, producers of other commodities can apply this lesson when making management decisions about fertilization and irrigation under wet soil conditions.

The take-home lessons for growers from this demonstration are as follows:

  • Consider land leveling.
  • Do not fertilize when you have wet soil conditions.
  • Do not fertilize when you expect heavy rainfall.

Additional information on conducting dye tests can be found in the IFAS EDIS Extension document at http://edis.ifas.ufl.edu/HS222. Growers interested in learning more about using dye tests to visualize irrigation can contact their local county Extension office or the UF/IFAS BMP Implementation Team.

Leave a Reply

Featured Stories

All Vegetables Stories >All Fruits Stories >All Nuts Stories >All Citrus Stories >

The Latest

OrganicResearchers Breeding Organic Tomato Varieties Receive $…
October 1, 2014
Purdue University accepts funding to lead multi-institution research to breed organic varieties that will resist foliar diseases. Read More
Vegetables14 Quality Cabbage Varieties [Slideshow]
October 1, 2014
Browse the slideshow below for information on cabbage varieties from the nation’s leading seed breeders and distributors. Read More
FruitsOrganic And Local Food Economies Receive More Than $52 …
October 1, 2014
Most of the grants were authorized through the 2014 Farm Bill. Read More
Insect ControlMore Than 600,000 Acres Removed From Golden Nematode Re…
October 1, 2014
The potato acreage was taken off the Animal and Plant Health Inspection Service’s list; under 6,000 acres in New York are still considered to be infested. Read More
Crop ProtectionTool Helps Track Insects On The Move At Night
October 1, 2014
Signals collected by the National Weather Service’s Doppler radar network may serve as an early warning system to track corn earworm, a major pest in sweet corn. Read More
NutsNew Walnut Budding, Grafting, and Planting Video Releas…
October 1, 2014
Lake County nurseryman Alex Suchan, who has been grafting trees for two-thirds of a century, is the star. Read More
GenNext GrowersGrowers Need To Be Mindful When Dealing With The Media
October 1, 2014
When being interviewed for a story, preparation is the foundation to help you successfully get your point across. Read More
Citrus Achievement AwardSharing Is Caring When It Comes To Curing Citrus Greeni…
October 1, 2014
Mike Sparks, 2014 Citrus Achievement Award winner, says being open with peers about what's working and not working is crucial in managing HLB. Read More
Florida Ag ExpoKnow How To Knock Back Nematodes
October 1, 2014
The 2014 Florida Ag Expo will provide critical tips in soilborne pest management. Read More
CEU SeriesCEU Series: Vow To Vanquish Weeds Among Vegetables
October 1, 2014
Herbicidal neglect can and will kill your crops. Read More
Insect & Disease UpdateUF Names Interim Director For Citrus Research And Educa…
September 30, 2014
Michael Rogers has been a central figure in Florida’s battle to survive greening. Read More
BerriesPractice Persistence When Battling Botrytis In Blueberr…
September 30, 2014
Cognizance of resistance is key to managing formidable fungus. Read More
CitrusFarming Is Quite The Scary Prospect For Some [Opinion]
September 30, 2014
Florida Grower managing editor Paul Rusnak says economic realities might frighten off future leaders from noble professions. Read More
FruitsNew Suppress Herbicide Gets Green Light From EPA
September 30, 2014
Approval gives organic growers new weed management tool. Read More
BerriesNew Fill-By-Weight Clamshell Filler For Blueberries
September 30, 2014
Lakewood Process Machinery's equipment offers a simplified user interface, minimized drop heights, a new dribble-gate system designed for an increased level of accuracy. Read More
Stone FruitLarge Cherry Crop Expected In Washington
September 30, 2014
Approximately 23.5 million boxes of cherries were sold during season. Read More
LaborWestern Growers President Speaks Out About Passage Of C…
September 29, 2014
California Governor Jerry Brown recently vetoed a Senate Bill 25 and approved Assembly Bill 1897. Read More
BerriesDrought Could Impact Spring California Strawberry Crop
September 29, 2014
Ventura County expects reduction of acres planted as surface water availability takes a hit. Read More