Hedgerow Control. This is Hoverfly 742, maintaining 2000.
Heading 180. Requesting land clearance.
Hoverfly 742 turn left.
Heading 090. Descend to 1000 until established on the ILS runway.
Coyote brush 32 approach. Cleared to land.
Hoverfly 742. Turning left. Heading 090.
Decsend to 1000 until established on the ILS runway. Coyote Brush 32 approach.
Cleared to land.
MUSIC
So you've probably figured out by now that I'm not your typical air traffic controller.
I don't direct airplanes in and out of airports
but you might think of me as
an organic air traffic controller or a biological air traffic controller.
What I mean is that as I managed the airspace above this organic farm since 2001
I've tried to encourage a diversity of beneficial organisms to come here to help us to control our pests.
And the three main components of our farm that help with this
are hedgerows on the farm edges
cover crops that we usually grow when our fields don't have cash crops
and insectary plants that we interplant with our vegetables and strawberries.
I like to think of the three components
as providing a buffet of food options
for beneficial organisms on our farm.
Over the next few minutes I'll give you a short tour of our 22 acres of high value land
and explain how a conservation biological control program here works to control pests
as we conduct and share
cutting-edge, commercial scale research on organic vegetable and strawberry production.
I'm fortunate to have great collaborators here with lots of practical farming experience
and a passion to think 'out of the box' and develop new and creative sustainable farming strategies
that apply to organic
and conventional systems.
To help you understand our farm let's fly up to get a bird's eye view.
The cool Pacific Ocean is about 15 miles that way as Salinas Valley opens to Monterey Bay.
Our organic farm is connected to about another 150 acres of conventional USDA research land.
A simple way to understand the layout of our organic farm is too divided into four main sections
that includes strawberries in one section each year
and vegetables and cover crops in the other sections.
For example, this section had broccoli this last summer
and was just planted to strawberries.
Our new strawberry planting also includes a novel cover crop in strategy in the furrows.
Okay, so let me now provided few details about these three critical biological control components
starting with my favorite place on the farm, the hedgerow.
In some ways it reminds me of the biologically diverse tropical forests and Papua New Guinea
where I grew up and which surrounded many of the agricultural fields there.
Our hedgerow's a fun place to explore that's filled with biodiversity
and is just a relaxing place to take a break when you need one.
I consider it a sacred place, because it reminds us of the balanced natural ecosystem
that once dominated this landscape and that has so much to teach us to help us to improve our agricultural systems.
The hedgerow is essentially the 'supporting backbone' of our biological control system.
What I mean by 'supporting backbone' is that the hedgerow is the most stable,
complex and permanent part of our farm.
And it's a refuge for beneficial organisms when we disturb our fields with intense tillage between crops.
The hedgerows are then the major source of beneficial insects to recolonize our new plantings.
I remember the fun and productive day that our hedgerow was planted in 2003
with the help of volunteers
and our local hedgerow guru, my friend Sam.
Since then our hedgerow has been low- maintenance
because it includes a diversity of drought tolerant, native, perennials
which were irrigated only during the first year.
Now a key benefit of the hedgerow and the adjacent berm with flowering annuals
is that the diversity of plants ensures that there's always something flowering
to provide beneficial insects like hover flies
with the pollen and the nectar that they need to reproduce and thrive.
For example the coyote brush plant where hoverfly 742 landed,
it flowers in the fall and winter when there are few other sources of food for adult hoverflies on our farm.
Now there are some challenges with hedgerows.
For example,
some people think that hedgerows increase the risk of food safety problems from rodents
and try to minimize this with fences and toxic baits along the borders with neighboring hedgerows.
But, I've not seen any compelling scientific evidence to support this concern about food safety.
In fact, recent research suggests that removing non-crop vegetation, like hedgerows,
may actually increase food safety pathogens.
Now one clear challenge with hedgerows is from leaf feeding birds
like the White Crowned Sparrows.
They like to overwinter in the hedgerows
and eat leaves of some crops right next to the hedgerow.
Ironically, these same birds may actually help us though
because they can also eat weed foliage under the canopy of some of our cover crops.
Speaking of cover crops, let's now consider their role and biological control on our farm.
We grow lots of cover crops in rotation with our vegetables and strawberries and have seen huge benefits.
This bumper sticker is one that I designed a few years ago,
and it does a pretty good job of summarizing some of the benefits of cover crops
in terms of their ability to
reduce runoff, and improve soil quality
and boost crop yields with fewer fertilizer inputs.
But it doesn't say anything about cover crop benefits for biological control.
So here's another bumper sticker I just designed to help clarify this.
It's got a few common beneficial insects that I often see in our cover crops.
I've also seen other beneficial organisms like gopher snakes.
Now just like the cover crop provides the gopher snake with a good habitat to hunt for gophers
the cover crop also provides beneficial insects
with a source of insects to eat like aphid species that are usually different
from the aphids that on a cash crops.
Flowering weeds in our cover crops can also provide pollen and nectar for adult hoverflies
and parasitic wasps.
But the problem with many of these weeds is that they produce seeds quickly
and therefore can increase the hand weeding costs in our subsequent cash crops.
So we carefully manage our cover crops to suppress weed growth and flowering.
Although wild radish is one weed that we really don't mind in our cover crops
because it doesn't flower until late in the spring
when the cover crops are usually ready to be mowed down
and incorporated back into the soil.
Alright, now for the last part of our biological control buffet,
the insectary plants.
There many different types of insectary plants in our region
but I'll just briefly describe two ways that my research has improved the efficiency
of using one popular insectary plant...
sweet alyssum.
First, I'll describe it for transplanted lettuce and then also for direct seeded lettuce.
Alyssum flowers are a great source of pollen and nectar for adult hoverflies
and encourages them to move through lettuce fields.
In the process, the female hoverflies lay eggs on lettuce that has aphids.
And the larvae that hatch from these eggs eat the aphids, live !
When I started working with transplanted lettuce and 2004,
farmers here usually gave up about 5 to 10% of their field to grow alyssum in strips
or as randomly scattered plants through the field.
But I found that a far more land-efficient approach to get plenty of alyssum flowers into the field
was simply to insert alyssum transplants
between the regularly spaced lettuce without displacing any lettuce.
In other words, you don't need to give up space for alyssum.
We the call is 'additive intercropping'.
The last method I'll described as a simple, efficient, and novel way that I've been working on
to help farmers plant alyssum seeds
with the same precision seeder that they use to plant pelleted lettuce seed.
These seeders provide very uniform and regular spacing of the pelleted seed.
To achieve this, I teamed up with the local seed treatment company
that was able to pellet the alyssum seed to the same size as a pelleted lettuce seed.
This was a complicated process because the alyssum seed is much smaller than lettuce seed
and therefore the alyssum seed had to be coated and much more pelleting material than the lettuce seed.
But it's worked beautifully !
And it means that farmers here can now mix just a few teaspoons of pelleted sweet alyssum
into their pelleted lettuce seed,
and the alyssum will be scattered randomly through the field.
The lettuce thinning and weeding crews
are then trained to easily identify alyssum seedlings and leave these to flower for the hoverflies.
It's a great system !
That's our biological control buffet here at the USDA organic research farm
in the 'Salad Bowl of America', Salinas, California.
Our system isn't perfect but
we're pretty happy with it. We're always trying to fine tune it...make a little bit better... more efficient.
So I hope you'll stay tuned as we do that.
And I also hope that you can find ways that
you can support farmers that are using the types of techniques that I described here today.
You know what.... I got to get you back up there to hedgerow control tower because
Hoverfly 742 that landed on this
Coyote Brush plant right here
has already fueled up with pollen and nectar
and is ready to takeoff on another mission out there to look for aphids.
So I don't want to delay her.
I want to encourage her, and I want to keep her safe.
Hedgerow Control. This is Hoverfly 742. Requesting take off clearance.
Roger, Hoverfly 742. You are cleared for takeoff !
MUSIC (Fly me to the moon)