California Farmers Find Ways To Lower Input Costs
It hasn’t quite reached the point where the industry is micro-managing an individual cotton plant for optimal production, but producers, pest control advisors (PCAs) and researchers are seemingly headed in that direction. The underlying challenge, of course, is making sure any management tool, no matter how sophisticated, makes sense from an economic standpoint.
Brock Taylor of Brock Taylor Consulting in Clovis, Calif., works with variable rate technology in cotton production in an attempt to reduce inputs and increase yields in an economical format.
“The main thing is to identify management zones and see where we can use various technologies to either reduce inputs and/or increase yields,” he says.
Finding The Right Strategy
In ongoing trials with Ted Sheely of AZCAL Farms near Stratford, Calif., Taylor has looked at various approaches to see if production blocks can be better managed to reduce variations in production and improve overall performance. Sheely owns and operates AZCAL which is a 10,000-acre diversified farming operation on the west side of the southern San Joaquin Valley. It is an ideal setting to implement a large-scale variable rate experiment.
Various management components in the variable rate trials have included:
• Electromagnetic salinity
“Some of these soils have a significant amount of variability within one field,” Taylor says. “We were trying to see if we could smooth out some of that variability, better allocate our inputs and improve the overall performance of the field.”
Initial yield monitoring in 2002 showed that there was significant variability within the field just in terms of yield – from a low of about 2.5 bales per acre in some spots and up to 4.5 bales per acre in others. Subsequent salinity mapping indicated that excess salts in some parts of the field were likely to blame for much of that variability.
“Thirty percent of California cotton is impacted by saline-sodic conditions,” Taylor says. “That holds true for most of the AZCAL cotton acreage as well. There appeared to be a significant impact on yields due to excess salinity, poor water infiltration and poor soil moisture availability.”
Value Of Variable Rate
To address those challenges, a variable rate irrigation trial was initiated. To help push salts farther down into the soil profile, the saline-sodic areas of the field were sprinkler irrigated two to five times in lieu of the first furrow irrigation.
“The goal was to push the salts down and increase crop growth as measured by Nodes Above White Bloom (NAWB) to nine,” he says. “We also felt that by sprinkling those areas we could avoid creating the anaerobic, saturated conditions that slow down the growth of the cotton.”
A detailed cost analysis was prepared to determine the cost effectiveness of implementing such a strategy. Additional input costs for the sprinkler irrigation included labor for sprinkler setup, but water costs were essentially the same since there was very little if any extra water applied. One 24-hour furrow irrigation was replaced with two 12-hour sprinkler sets.
“Basically, by changing our irrigation management just a little on that block, we were able to increase yield by half a bale to the acre in the lower yielding zones,” Taylor says. “We came out with an additional revenue of $7,782 on 78 acres by addressing the salinity problems in those areas.”
Taylor is also using variable rate technology to make decisions about gypsum, seeding rates, nitrogen, Pix and defoliants. All are based on soil samples that are taken in representative areas of the field. Higher seeding rates and lower nitrogen rates are applied in high salt areas while lower rates of Pix and defoliants are applied in the high salt areas.
“We’ve demonstrated a 25-30 percent savings in materials with this technology,” he says. “It’s been very effective at cutting inputs while simultaneously increasing yields.”
Impressive Results Achieved
The initial trials have moved far beyond the original scope of the project because the results were so impressive. The average yield is proof enough the management approach is working. Plant growth in the higher saline portions of the field have been brought up closer to the performance of the cotton in the better soils.
“Last year, we used this approach on 4,000 acres,” Taylor says. “We had fields that averaged over four bales – both Pima and Acala.”
Even though it may sound complex, not to mention expensive, Taylor says the innovative program is well worth the investment.
“We’re spending less than a dollar an acre to do the soil sampling, and we’re developing several variable rate maps from that data,” he says. “Then we use those maps to drive our variable rate decisions.”
Sheely is also impressed with the overall results.
“It’s important that we get the most we can out of every input,” he says. “Water, in particular, is a very critical resource and one that will only become more valuable over time. Matching the inputs to the variation in the soil has enabled us to greatly enhance our efficiency and maximize our yields.”
In Search Of Efficiency
Increased efficiencies will no doubt be critical to California’s agricultural future. In 2007, water became so sought after on the west side of the San Joaquin Valley that some producers paid up to $700 an acre-foot for it.
Although recent winter storms are providing some much needed relief, shortages and high water costs are still projected for the upcoming season. Variable rate technology and precision management approaches will likely be the only way producers will truly remain economically viable over the long term.
Brenda Carol is the Contributing
Editor for Cotton Farming magazine. Contact her in Murphys, Calif.,
or (209) 728-9226.