Dara: Biocontrols can aid soil health, productivity
ATLANTIC CITY, N.J. — At the outset of his presentation Dr. Surendra Dara, an expert in bio-controls from the University of California-Santa Barbara, asked farmers gathered at the Vegetable Growers Association of New Jersey annual convention a question: “Do you think biologicals work?”
A few hands went up.
“OK, two, three, that’s a good response, compared to what I typically see, it’s good to see that you believe in these biologicals,” he said on Feb. 5 in a conference room at Harrah’s Hotel and Casino.
Dara, an expert with strawberries, vegetables and Integrated Pest Management, discussed ways farmers in New Jersey can apply biocontrols to improve soil health and productivity on their growing fields.
Dara said he has been doing bio micro-control experiments for more than 35 years and he offered some practical suggestions for farmers.
“I have noticed a huge difference from my Ph.D. days until now. It was a hard sell previously. But now, there is a lot of interest and there are all kinds of new technologies even though this stuff has been around for a long time.”
Now, he said farmers have a number of biocontrol agents, bio-pesticides and soil amendments that can be put into action on farm fields.
“A number of micro-organisms can be used as bio-stimulants, soil amendments or to improve soil structure,” Dara said. “Each one has a specific mode of action to attack these pests. If you look at bio-fungicides they mostly attack their target species, whether it’s an arthropod or a fungus or bacteria. If we look at bio-pesticides and they have multiple modes of action, depending on the target, you can target mites or ticks or other insects: you can have bacteria, nematodes, fungi and so on, yet each one has its own mode of action.”
Bio-stimulants that build the immune systems of certain plants can be used prior to an expected infestation, he said.
“We also have microbes that improve the water and nutrient absorption in soil and we also have soil amendments that contribute to crop health,” Dara said.
He likened soil composition to what’s going on in the human body, arguing we have more microbes inside and on our bodies than the actual number of cells in our bodies.
“There are trillions of microbes and so many good ones and bad ones,” he noted, “so there is a very dynamic system that’s going on under the surface of the soil.”
What most farmers want is a balance of beneficial microbes in the soil, he said.
With the rise of intensified farming in places like California and Arizona, “for obvious reasons the object was to increase crop productivity yet to control pests and new insecticides and herbicides were creating imbalances,” Dara said. “In places where you have a lot of these natural populations going down you have more of these harmful pests and diseases procreating because they don’t have any natural enemies [left] in the [soil] system.”
“Over the past 10 to 15 years there has been increasing demand for natural options and producing crops sustainably, but there has been confusion over what is natural and organic and what is not,” Dara said. “As we know, not all natural products are safe: you accept nicotine from tobacco as that is natural, and with marijuana it is natural, yet in some states now, we can take it,” he said, and just because something is organic does not mean it is pesticide free.
In general, there has been a positive trend toward using natural materials and biologicals and microbes, “but at the same time we need to understand, to maintain the productivity of any cropping system we need the guidance of a book and that is not within the scope of this presentation.”
Dara noted many studies have been conducted in the last two decades showing the effectiveness of bio-stimulants and preserving the healthy microbes already in the soil.
“We need to take advantage of those studies and the knowledge that’s out there to improve production, but at the same time we need to make sure the companies that produce this stuff have good quality products,” he said. “Everybody should understand how these micro-organisms work and how we use them effectively.”
Any number of commercially available microbes can be used for building and enhancing the soil microbiomes, so that soils in less productive fields can be enhanced with better water holding capacity, better ability to fight pests and diseases and to increase nutrient absorption through the soil.
“Depending on the cost and concentration of the microbes, you can use them on crops in one or more ways. In strawberry and other crops in California, [one type of] fungus is an important tool to destroy pathogens, control weeds and sometimes even nematodes.”
The important thing is combining and rotating with different strategies and different materials, he said.
“The idea with integrated pest services management is to produce the resistance and integrate multiple control options,” he said. “We want to combine sometimes and sometimes we want to rotate these treatments.”
In closing, Dara stressed that biologicals do work. “Whether they’re insects, predatory arthropods or microbes, they will work,” he said. “We just need to know how to use them in different systems, so it’s important for all of us to work together to collect more data and increase our overall knowledge and increase their use so we can put them to better and better use in agriculture.”