Parsons On Citrus: Keep An Eye On Irrigation

The National Weather Service predicts the drought in the Southeast will continue to persist or intensify this spring. La Niña conditions will continue for the next few months, and rainfall in Florida is predicted to be below normal through next month. While irrigation can be withheld from citrus in the fall and winter, adequate water in the spring is necessary to maintain good yields. With the prediction of a dry spring, growers may need to review their management practices to make sure they are providing sufficient irrigation to their trees and the new developing crop.
Florida’s sandy soils are notorious for holding very little water. Hence, frequent irrigation, particularly in the hotter spring months of April and May, is necessary to maintain the soil near field capacity.

Plugged In

One thing that has made it easier to manage irrigation is improved technology in the area of soil moisture probes. Tensiometers are still a low-cost method to get a snapshot estimate of soil moisture status. But many growers do not take the time to maintain them properly. Newer technology has recently become available that allows growers to follow changes in soil water status over time. Water content at different depths can be monitored, so the grower can see developing trends in changing water content. Sensors also can indicate how deep water has moved in the soil profile.
 
Technology is now available that allows growers to access data on soil moisture via radio and Internet or cell phone. Growers can monitor soil water status in distant fields from their home office or any other location. Knowledge of irrigation status can enhance water utilization and save growers from making unnecessary trips to remote fields.
 
Growers also can set soil water status trigger points to start irrigation. These trigger points can be changed with the season. With less stress in the spring, better fruit set is assured. Greater soil water depletion in the fall and winter can save water and pumping costs while helping to concentrate juice solids.
 
We now have the capability of a fully automated irrigation system, where tree consumptive use determines the frequency and amount of irrigation applied. When the soil dries to a pre-set trigger point, the irrigation will automatically come on. Changes in irrigation frequency are based on tree uptake of water from the soil. Thus, irrigation frequency can automatically adjust to hot, cool, dry, or rainy conditions.

In The Field

We installed an automatic system in a grove of mature Hamlin/Carrizo trees on ridge Candler sand. It was interesting to see when the trees “called” for irrigation (i.e., dried the soil to a pre-set depletion level that triggered an irrigation cycle). Using green microsprinklers (roughly 15 gallons/hour) and half hour irrigation pulses at a 25% moisture depletion level, we found that trees commonly triggered an irrigation pulse two to three times per day in the spring. With this system, trees usually started irrigation pulses around noon, late afternoon, and early evening. When it rained, irrigation was delayed. In the winter when evapotranspiration was lower, trees commonly triggered an irrigation just once a day at 25% depletion. If the depletion level were set at 50% in the winter, irrigation usually occurred every other day. The depletion level trigger point can be adjusted based on grower preference, tree size, and soil type.
 
These automatic systems cannot replace grower judgment, but they can monitor soil water status, reduce over-irrigation and potential nutrient leaching loss, and start irrigation based on plant water use. Besides monitoring water status, most soil water sensors are eligible for cost share reimbursement in the Southwest Florida Water Management District under the Facilitating Agricultural Resource Management Systems program. This program makes it more affordable for growers to use soil water sensors.

Leave a Reply

Featured Stories

CitrusAg Land Value Goes Back To The Future
December 20, 2014
Good ground and longevity are the best positions moving forward. Read More
VegetablesSeminis Hosts Growers For Its 2014 Southeastern Field Day
December 19, 2014
Seed company showcases new varieties available now and in the pipeline. Read More
CitrusFeed The People With Food And Food For Thought [Opinion]
December 19, 2014
Educating the general public about agriculture is a daunting task that can be accomplished one bite at a time. Read More
CucurbitsNew Product Takes Aim At Nematodes
December 19, 2014
NIMITZ receives EPA and Florida registrations. Read More
Crop ProtectionSuccess Sans Methyl Bromide Could Prove Costly
December 19, 2014
Economic factors must be accounted for when seeking a suitable replacement. Read More
VegetablesEnza Zaden Cuts Ribbon For New Florida Vegetable Research Facility
December 18, 2014
Seed company shows off new digs and new varieties at its Myakka City field station. Read More
VegetablesRispens Seeds Highlights Their Latest Vegetable Varieties
December 18, 2014
For more information, contact: Rispens Seeds 1357 Dutch American Way, P.O. Box 310, Beecher, IL 60401 708-946-6560; 888-874-0241; fax: 708-946-6115 Read More
Protected Agriculture2014 Marks The 50th Anniversary Of The Double-Poly Greenhouse [sponsor content]
December 18, 2014
Double-poly greenhouses revolutionized the greenhouse industry back in the 1960s, opening the way for developments that still impact the industry 50 years later. Read More
CitrusSouthwest Florida Citrus Bus Tour Yields Learning Opportunity
December 18, 2014
Find out what Florida Grower editor Frank Giles saw and heard during Peace River Valley Citrus Growers Association's annual outing. Read More
Fruits6 Food Trends For 2015
December 17, 2014
University of Florida experts predict what will be cooking for the upcoming year. Read More

The Latest

CitrusAg Land Value Goes Back To The Future
December 20, 2014
Good ground and longevity are the best positions moving forward. Read More
VegetablesSeminis Hosts Growers For Its 2014 Southeastern Field D…
December 19, 2014
Seed company showcases new varieties available now and in the pipeline. Read More
CitrusFeed The People With Food And Food For Thought [Opinion…
December 19, 2014
Educating the general public about agriculture is a daunting task that can be accomplished one bite at a time. Read More
CucurbitsNew Product Takes Aim At Nematodes
December 19, 2014
NIMITZ receives EPA and Florida registrations. Read More
Crop ProtectionSuccess Sans Methyl Bromide Could Prove Costly
December 19, 2014
Economic factors must be accounted for when seeking a suitable replacement. Read More
VegetablesEnza Zaden Cuts Ribbon For New Florida Vegetable Resear…
December 18, 2014
Seed company shows off new digs and new varieties at its Myakka City field station. Read More
VegetablesRispens Seeds Highlights Their Latest Vegetable Varieti…
December 18, 2014
For more information, contact: Rispens Seeds 1357 Dutch American Way, P.O. Box 310, Beecher, IL 60401 708-946-6560; 888-874-0241; fax: 708-946-6115 Read More
Protected Agriculture2014 Marks The 50th Anniversary Of The Double-Poly Gree…
December 18, 2014
Double-poly greenhouses revolutionized the greenhouse industry back in the 1960s, opening the way for developments that still impact the industry 50 years later. Read More
CitrusSouthwest Florida Citrus Bus Tour Yields Learning Oppor…
December 18, 2014
Find out what Florida Grower editor Frank Giles saw and heard during Peace River Valley Citrus Growers Association's annual outing. Read More
Fruits6 Food Trends For 2015
December 17, 2014
University of Florida experts predict what will be cooking for the upcoming year. Read More
VegetablesReed’s Seeds Showcases Their Latest Vegetable Var…
December 17, 2014
For more information, contact: Reed’s Seeds 3334 NYS 215 Cortland, NY 13045 607-753-9095; fax: 607-753-9511 rsjackie@twcny.rr.com Read More
CitrusStudy: Florida Citrus Valued At More Than $10 Billion
December 17, 2014
Industry continues to have large impact on the state’s economy. Read More
Apples & PearsNovember Cold May Hurt Washington Orchards
December 17, 2014
But it’s too early to tell if well-below-normal temperatures will increase tree mortality. Read More
NutsAlmond Growers Lose Trees In Storm
December 17, 2014
Last week’s welcome rains in California knocked down trees, especially older ones. Read More
NutsAlmond Conference Draws Record Attendance
December 17, 2014
Nearly 3,000 industry professionals attend 42nd annual event in Sacramento, CA. Read More
Insect & Disease UpdateManage HLB From The Bottom Up
December 17, 2014
Finding the right balance between the roots and shoots is critical to disease mitigation. Read More
VegetablesVariety Trials 2014: Seedway
December 17, 2014
As part of American Vegetable Grower’s (AVG) 2014 variety trial coverage, we visited Seedway’s seed trial at Spiral Path Organic Farm in Loysville, Read More
OrganicUSDA Proposes Expansion Of Organic Assessment Exemption
December 17, 2014
Action would increase the entities exempt from paying assessments for promotion programs on products certified as “organic” or “100% organic.” Read More