MANASOTA & PEACE RIVER BBDs Meeting Notebook 10-21-09.docx

B263
Evaluation of Different On-Farm Blueberry Systems To Improve
Irrigation Efficiency
Project Type Basin Initiatives
AOR(s)
Water Supply, Water Quality
Basin(s) Alafia River, Hillsborough River, Coastal Rivers, Withlacoochee River, Peace River
Cooperator(s)
University of Florida
Project Manager COHEN, RON
Task Manager(s)
Status Ongoing
Description
This project will compare different irrigation management techniques under real production conditions to determine the
most efficient way to irrigate blueberry plants. Due to current market conditions and plant diseases, many Central
Florida agricultural producers have converted their production acres to blueberries, which is a high valued cash crop.
Some of the newer blueberry growers have relatively little experience with blueberry irrigation and some of the existing
producers might not be familiar with better ways to manage different irrigation systems. Researchers will create a
demonstration plot in a grower's field. This plot will consist of different soils and irrigation methods to determine which
is best for specific growing conditions. The projects results will be presented to the growers during a field day for them
to learn and visualize the project's results.
Benefits
Information from this project could be used to conserve water. There are about 735 Mgals permitted for annual
blueberry irrigation. The amount of water saved will be a function of the number of acres planted and their water use,
which will change annually based on market and climatic conditions. If we assume a 5% savings from this project, it
would conserve about 37 Mgals per year. Information from this project will provide the District's FARMS additional
tools to help promote conservation.
Costs
This three year project will cost a total of $69,900. Funding for this project is prorated between five Basin Boards
(Peace River - 37%, Withlacoochee River - 22%, Alafia - 13%, Coastal 12% and Hillsborough River 8%) based on the
number of permits for blueberry production in their watershed. In FY2009, FY2010, and FY2011, the Basin Boards will
budget each year: Peace River - $9,080, Withlacoochee River - $5,497, Alafia - $3,406, Coastal - $3,105 and
Hillsborough River $2,211.
Additional Information
This project was origionally proposed in FY2008. At that time it was decided to wait until project B226 (Determine
Total Water Budget & Irrig. Req.for Mature Southern Highbush Blueberries) progressed so that information from that
project could be incorporated in this project. Blueberries require an acid soil or a soil that is amended to reach a
certain acidity level. To reach the proper acidity level, many blueberry growers use pine bark that is 1) incorporated
into the upper soil layer, or 2) placed as a layer on top of the soil. There is relatively little knowledge of the water
holding capacity or water movement through these two pine bark amended soil systems. Evaluating the soil water
characteristics of these two types of blueberry pine bark amended soils is important for efficient and responsible water
management. Several new soil moisture-measuring devices have become available in the past five years. These
probes are better than tensiometers because they require less maintenance and can show changes in soil water
status over time. By telling growers if water has moved below the main root zone, these probes can be beneficial in
improving irrigation management. A few of these probes have been evaluated under citrus trees in sandy ridge soils,
but have not been tried in pine bark amended ridge soils. Most growers irrigate in a way that they think will meet the
water needs of the crop. Blueberries are fairly shallow rooted, and it is not known what irrigation duration is needed
with the drip, microsprinkler, or overhead systems to wet the root zone in pine bark amended soil. Soil probes would
be beneficial in seeing how far water moves in these soils. Hence, they could potentially help reduce over irrigation
and deep percolation loss. Probes would be installed at different depths under the drip, microsprinkler, and overhead
systems in the field. Changes in soil water content from the different irrigation systems would be monitored. We would
determine how long it takes for irrigation water to reach different depths in the two soil systems. Water holding
capacity and bulk density of the two soil systems would be determined in the lab or field. Depth of soil wetting would
be determined periodically at different times of the year. The most efficient irrigation system would be determined.
Changes in soil water content at different depths (as roots take up water) would be shown to the grower to help him in
his irrigation scheduling decisions. Knowledge of when deep percolation loss might occur could help reduce over
irrigation.
020 - Peace River Basin 131