
University of Rhode Island
Episode 6 | 13m 51sVideo has Closed Captions
Interview with Rebecca Brown, Ph.D., about crops and agriculture at URI.
We visit Rebecca Brown, Ph.D., at the University of Rhode Island to discuss the methods of regenerating soil, the benefits it provides for the future of food production as farmers deal with climate change, and how it plays an important role in reducing greenhouse gases.
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Adaptive Capacity is a local public television program presented by Rhode Island PBS

University of Rhode Island
Episode 6 | 13m 51sVideo has Closed Captions
We visit Rebecca Brown, Ph.D., at the University of Rhode Island to discuss the methods of regenerating soil, the benefits it provides for the future of food production as farmers deal with climate change, and how it plays an important role in reducing greenhouse gases.
Problems with Closed Captions? Closed Captioning Feedback
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Learn Moreabout PBS online sponsorship(uplifting music ends) - [Alex] I'm down at the University of Rhode Island.
I am with Dr. Brown.
And what is the name of this facility that you're working with?
- So this facility is part of the Gardener Crops Research Farm, which is managed by the Department of Plant Sciences and Entomology and the College of the Environment and Life Sciences.
- Okay, now I see, well you have a beautiful looking garden, just over here beyond us.
And this is a high tunnel.
What type of research are you actually doing?
- So, most of my research focuses on vegetable production, particularly vegetable production techniques that are useful for commercial growers growing for local market which describes most of our vegetable producers here in Southern New England.
Most of them are growing for direct retail, through farmer's markets, through CSAs, sale to chefs.
Or to local grocery store chains.
- So not necessarily large grocery stores, more of the small farm to table type of producers and the smaller farms.
I know there's always been an issue with getting farm land in Rhode Island.
- Yes.
- And so a lot of people are working on, you know, anywhere from one to two acres to, if they're lucky, maybe 16 acres.
- Right, we work with farmers all the way up from the people with just one acre or less than an acre, up to farms like Confreda's that are farming close to 400 acres and are selling to the grocery stores as much as, you know, directly from their own farm stand.
- Yeah, in terms of research, when it comes to the hotter temperatures that are coming out, I know regeneration of the soil is now really big.
They're saying no-till for a number of years now.
What types of things can we talk about when it comes to regenerating the soil and why is that so important?
- So soil regeneration is largely a result of a realization that the microbial life and also the micro and even the megafauna in the soil are a very important part of keeping a soil healthy.
- Yes.
- And so part of soil regeneration is maintaining and building soil organic matter.
And no-till is important to that because tillage adds oxygen to the soil and it breaks the pieces up smaller.
And when you combine small pieces and oxygen with organic matter, that organic matter breaks down very quickly.
- Okay.
- Another piece of regenerative agriculture though is trying to keep soils covered with green growing plants as much as possible, because a number of our important soil microbes need living roots in order to persist.
- Yeah.
- So it's going beyond even the cover cropping that's been a part of organic agriculture for a long time.
Adding the idea of doing things like planting green, which is planting no-till into a cover crop that is still green and growing and then killing that cover crop rather than killing the cover crop first, and then planting.
A lot of this is not really being used much here in Rhode Island because it's intended much more for larger scale production, much more for commodity crop production, and less so for vegetable.
But we are certainly encouraging our farmers to take care of their soils.
We are doing a lot of work with different approaches that depend a lot on the size of a farm.
So for very small farms, often they don't have either the space or the equipment to manage cover crops effectively.
- Okay.
- And so they are going to rely on compost as their main source of additional organic matter.
And if they are doing no-till, which a lot of them are, or minimal till they're going to be relying on tarping, which is a practice of covering the soil and even crop residue with opaque materials, usually plastic, and that allows the organic matter to heat up and break down, and it also kills any plants because it's cutting all the light off.
- [Alex] Okay, now the compost also keeps the moisture in the soil?
- [Dr. Brown] It depends on how the compost is used.
- Okay.
- So any sort of organic matter in a soil acts as a sponge.
Okay, so the more organic matter you have, whether it's from compost or a cover crop, or from, say, dairy manure, you know, so a lot of your dairy farmers are relying on spreading their manure as their organic input.
It's gonna act as a sponge and it's gonna help hold water, which is very important both in a drought year like this, but also with a heavy rainfall situation.
The more water the soil can hold, the less water runs off.
- Yes.
- Okay.
Compost spread on the surface can act as a mulch and keep the moisture from evaporating from the soil surface.
And it really depends on what you're trying to do.
Whether it's a practice you want to use.
- [Alex] Now, when we talk about cover crop, because a lot of people don't know what that means.
- Sure.
- So if there's a field that's been planted, harvested, and you're not ready to plant again, you will put something in that field to keep the soil healthy.
- Yes.
So the term cover crop originates almost 100 years ago when they were primarily concerned about erosion.
And so the idea was that you kept your soil covered so that it couldn't erode.
We now know that it's more than just that.
Right, that organic matter's important and that living roots are important.
So a cover crop can play many, many different roles.
Cover crops prevent erosion, they can soak up excess nutrients that are in the soil and preserve them for the next cropping season.
This is very important because organic matter breakdown and nutrient release do not perfectly match plant uptake.
So at the end of a growing season, in the fall, you are likely to have leftover nutrients.
Cover crops can of course add organic matter because they produce biomass.
Legumes can fix nitrogen from the atmosphere, and provide it to the subsequent crop.
Some cover crops are very deep-rooted, they can break up compaction, and help with drainage.
And cover crops can also suppress weeds, and they can provide pollinator benefits.
If you're dealing with tarping or with walk behind equipment you may need a cover crop that produces less biomass, but can be handled without tillage or with small scale.
- And then eventually that cover crop is used again for planting?
- Yes, so that field would be used again, and so the cover crop has to be terminated in some way.
And there are different ways, depending on the crop, depending on your operation, your equipment, your goals.
But in some way, that cover crop is killed.
And either you no-till plant into the stubble of that killed crop or you plant into the living crop and then kill the crop, or you till the crop under.
In vegetable production because we have very few herbicide resistant crops and we generally don't use the ones we have, we can't really use the planting green method, where you plant into a living cover crop and then you kill that cover crop, that relies on herbicides.
We tend to rely a lot more on tillage except on those small scale farms that are using tarping.
- In terms of the future, I mean, we have a great high tunnel here.
The produce that you're growing is very healthy looking - Thank you.
- As, as well as the produce outside.
As the temperatures become warmer, do you think we are gonna be looking at more growing in greenhouse facilities and possibly hydroponic facilities?
- I don't think that's necessarily a factor of increasing overall high temperatures because they're already using a lot of the same technology further to the south.
Where I think that temperature change is going to affect high tunnel use is actually in the fall, because our falls have been getting warmer.
Even faster than our summers.
And that allows us to grow much more in the way of vegetables in that September, October, November period.
But one of the things that we still have is, you know, it can be warm for weeks, and then all of a sudden we'll get a cold front from Canada, the temperature will drop, it'll stay cold for a day or two, and then it'll warm right up.
In a high tunnel you're protected from that.
- Yeah.
- Outside you're not.
So in that respect I think high tunnels are definitely gonna be beneficial.
Hydroponics though is much more about being able to provide a consistent product year round.
- Yes.
- And so I think more what's driving the growing interest in hydroponics is a combination of the increased cost of producing in places like California and shipping to the east coast.
And the increased demand for locally grown.
But people have become used to having a consistent product from a consistent supplier all year.
The solution here in New England to that is to go indoors and grow hydroponically.
- Yeah, because it extends the growing season.
I mean, what time of the year now in a high tunnel like this can you actually start putting plugs in to grow?
- Well, so it depends on what you're growing.
- Yeah.
- Okay.
So most market farmers who are doing high tunnels will grow salad greens in their tunnels and other things like beets, and onions, and carrots, crops that can take the cold from October through into early April.
And then sometime in April they will plant their tomatoes in the tunnels.
Some growers are actually planting their tomatoes in between rows of things like beets, or carrots, or even lettuce.
- Yep.
- They harvest those out in May.
The tomatoes stay in and get bigger, they're growing tomatoes all the way through, usually by the time you get to October people are losing interest in tomatoes.
And so they're pulling the tomatoes out.
- I want to thank you very much for spending time with us today and talking about vegetable production.
- Sure.
- I think it's important that people know what's going on.
- Well, thank you for coming to URI.
- Thank you.
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Adaptive Capacity is a local public television program presented by Rhode Island PBS