In California’s San Joaquin Valley where grape vines are pushing their crop into spring, growers and others are gathering at educational tailgate meetings to talk about stretching their irrigation efforts to make the last drop count, new labor regulations which take effect this year, and nitrogen management.
The tailgate meeting held at Mission Bell Winery in Madera included some specific pointers on conserving vineyard soil moisture from Lindsay Jordan, University of California viticulture farm advisor for Madera, Merced, and Mariposa counties.
Her advice holds particular importance as the region enters an expected fourth year of drought conditions.
It is very important that growers understand the site they are farming and what they are losing from evaporation and leaching, Jordan said, adding it’s not simple. Some leaching can be beneficial as it moves salts away from the root zone.
A ground cover can provide some water loss through evapotranspiration, she says, but it helps preserve soil aggregates and can improve infiltration. If it is mowed and residue left in the vineyard, it results in mulch which helps conserve water.
Jordan says preserving soil aggregates improves water holding capacity, adding that “tillage is the mortal enemy of aggregates.” It may be wise to look at “chemical alternatives to tillage for weed control.”
Growers should avoid “compaction and crusting” which impair infiltration of water, she explains. Salt levels appear to rise with increased use of groundwater.
Jordan and others recommend soil and water testing “to arrive at benchmarks of where you stand. Well water conditions might be changing.”
Since water is lost through evapotranspiration through the canopy’s leaves, Jordan says irrigating too much too soon can mean losing additional water as the canopy size increases.
“A big canopy will lose more water throughout the season,” the viticulture advisor said.
Keith Backman with Dellavalle Laboratory Inc. said that intentional leaching is best done during the winter time when the soil is moist.
“That’s the way to get the water deep,” he said, adding that since the plant is not in leaf there is not the evapotranspiration loss that would otherwise result.
Backman says a standard nutrient management program should include: a well water analysis for nitrogen and salt content; a tissue analysis in the spring; a summer analysis and post-harvest analysis; and a post-harvest soil analysis for salts in the root zone and residual nutrients.
Aside from water losses that occur when water goes below the plant’s roots, there is also the concern about nitrates which can leach into the groundwater.
Nitrogen management plans
Two representatives of water quality coalitions talked about the need for growers to complete nitrogen management plans to comply with directives from the Central Valley Regional Water Quality Control Board.
“I know there are a lot questions. Nobody wants to do it, but we have to get it done,” said Clint Phelps with the East San Joaquin Water Quality Coalition.
He handed out a worksheet for completing a form that estimates nitrogen use and explained that the completed form should remain at the farm site.
Phelps, and Cristel Tufenkjian with the Kings River Water Quality Coalition, said summary information from the form may in time be reviewed by the coalition upon request.
There are differing deadlines, but starting in 2015 some of the plans for high vulnerability areas must be certified by various means, including self-certification and certification by a nitrogen management plant specialist.
Educational tailgate meetings were also held in Pixley and Ceres.
New ag labor laws
At all three meetings, growers were told of new agricultural labor laws that include the addition of mandatory paid sick leave for all workers, effective July 1.
The Healthy Workplaces, Healthy Families Act of 2014 requires employers to provide one hour of paid sick time for every 30 hours worked. Employers can cap the available sick leave at three days a year.
Patrick Moody with the law firm of Barsamian and Moody said accrued sick leave carries over to the following year but can be capped at a maximum accrual of 48 hours. The employer may also limit use of accrued paid sick leave to 24 hours per year.
Moody noted it is a violation of the Fair Employment and Housing Act for an employer to discriminate against an undocumented person issued a driver’s license.
Beginning Jan. 1, many employers - particularly farmers – should pay attention to new rules regarding contracted labor. A new state law also holds businesses accountable for wage and hour violations committed by a labor contractor or staffing agency.
Gene Glendenning, Fresno manager with the Cal-OSHA Consultation Area Office, said growers can be held liable if a farm labor contractor “does not live up to requirements.”
He says supplying the equipment used by a contractor’s work crew can increase liability.
“If you do that your protection from any contract just blew up,” Glendenning said.
Also new this year is more increased requirements for farm labor contractors and employees to complete training in the prevention of sexual harassment.
Also being looked at are proposed changes in regulations governing heat illnesses. These can be viewed online.
Sylvia Reyna, agriculture industry specialist with TheZenith, said these proposals include requiring shade when the temperature exceeds 80 degrees Fahrenheit and requiring that the employer supervise the employee during preventative cool-down rest periods to determine if symptoms are abating or getting worse.
Also proposed is a pre-shift meeting to cover the company’s high heat procedures, to encourage employees to drink plenty of water, and remind them of their right for a cool-down rest period when necessary.
Employers would be prevented from sending an employee home that is exhibiting signs or symptoms of heat illness without first offering onsite first aid or providing emergency medical services.