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I wrote this article for ACORN’s summer 2015 newsletter and am now republishing it here.
At the end of March of this year (2015), we found a memo in our inbox from Ecocert (the organic certifying body that we are certified with). In this memo, we were told that we would no longer be able to use the biodegradable plastic mulch (made with non-GMO corn starch) that we had been using unless we removed it after use. We were surprised and concerned. It was definitely a little last-minute! We still had leftover rolls of it at the farm from last season and had made our order for this season back in December (when we do a lot of our inputs purchases). And the removal part….it’s pretty tough to completely remove something that biodegrades as it’s in use.
Bryan and I have been using biodegradable plastic mulch (which I will refer to from now on as biofilm to reduce typing) since the first year we started Broadfork Farm. As small farm operators, we have appreciated the reduction in our time spent weeding in particular. But there are other benefits to using plastic mulch, like warming the soil and retention of moisture in the soil. With our deep feelings of stewardship for the soil, we have also liked how we have been able to keep more of the soil covered during the season (with the biodegradable mulch in the beds, our pathways have been maintained in living mulch that we mow). Soil left bare tends to create its own “cover” of a dry, dead, erodible soil layer.
We knew that, as a manufactured product, biofilm wasn’t the perfect solution in our utopian organic vision. But it was a solution we preferred to regular plastic mulch (with the required pulling up at the end of the season and taking to the landfill) or frequent cultivation. There are of course other mulches like straw or leaf mulch but they didn’t fit in as well with our whole system (but rather have fit in with some crops in certain instances when we could access sufficient quantities without prohibited substances).
We had often talked about the fact that we didn’t think we could have made 100% of our household income from our farm from our first year without the use of biofilm. We even listed it as one of our 5 favourite market gardening tools! Especially in our first year while we converted hay fields to vegetable fields…while growing vegetables. The sod clumps that we’d overturned were too lumpy to be able to use a wheel hoe (or any other kind of hoe for that matter) for weeding.
So, after receiving the Ecocert memo, I contacted other people involved with the Organic Standards and asked, what’s up with this? It turned out, that our Canadian Organic Standards had never allowed the use of the biofilms (without removing from the field after use) that are currently available in the marketplace. But there was a lot of confusion around this, both by farmers and certifiers. I think the confusion stemmed from the language of the Standard (very Standard-y) and the uncertainty of exactly what substances each biofilm on the market contains.
This is what the Standards said:
Fully biodegradable films: permitted without removal if they do not contain substances prohibited by par. 1.4.1 of CAN/CGSB-32.310, Organic Production Systems — General Principles and Management Standards.
I think it was clear to everyone that the biofilms couldn’t contain GMOs or pesticides. And the ones organic farmers were using don’t contain these.
Many organic farmers had happily been using this input for years and so, when the memo came out right at the beginning of the growing season, it was a big shock. People involved with the Crops Permitted Substances List (PSL) working group of the Organic Standards Technical Committee, the Standards Interpretation Committee (SIC), and the Canada Organic Office (COO) at the CFIA all started trying to figure out an appropriate and fair solution.
So, why aren’t biofilms allowed? Well, all of the biofilms on the market currently contain a certain percentage of petroleum source materials (which are prohibited) that seem to be referred to as raw fossil-based ingredients (by manufacturers). The biofilm that we had been using, while having the lowest percentage of petroleum source materials of any other biofilm, is still around 20%. I didn’t like learning that. And I was disappointed it wasn’t clearly expressed by the companies that were manufacturing and selling these biofilms. I had thought the biofilm we were using was actually 100% non-gmo corn starch.
Then there is the issue of biodegradability. Most farmers who have used these biofilms know that the biodegradability varies (so the ‘fully biodegradable’ part of the above Standard was a tricky one). It varies from farm to farm, field to field, season to season. In particular, it varies based on the life in the soil, the soil temperatures, and the soil moisture. There has been a bit of research done on this but not enough. The primary ingredient in the biofilm we’ve used, the corn-starch material Mater-Bi, is shown to be compostable in ideal composting situations but that’s not the same as using it on top of the soil in highly variable field conditions.
As I was trying to learn as much as possible about this input, I realized that there are currently too many unanswered questions. Like what happens to all the bits (even the bits we can’t see with the naked eye) that don’t fully biodegrade? Are they contributing to those floating garbage islands in the ocean? Are they being taken up into the web of life through food chains (insects, birds, mammals) and their materials concentrated? And to what effect? Are the microorganisms in the soil changing…adjusting to a new food source….and if so, is this harmless or harmful on the balance of life in the soil? Are there residue buildup issues we should be concerned with (the labelling always says “No toxic residues’ but what is this claim based on? Over how many years and with how much biofilm use? Is this claim unlimited?)?
With both the sustainability of farm businesses and care of the soil in mind, the Organic Technical Committee brought forward a revision to the 2015 Canadian Organic Standards. This is that these biofilms with the prohibited substance of petroleum products (all that are currently on the market, remember) will no longer be allowed unless removed from the field….but that, in order for farmers to figure out new systems without the use of these products…or, fingers-crossed, time for the manufacturers to figure out a way to change their products to be compliant….organic farmers will still be allowed to use the biofilms as they have been (i.e. tilling back into the soil) until 2017. And, for this 2015 season, since the newly-revised 2015 Organic Standards won’t come out until the fall, the Canadian General Standards Board has sent out a bulletin saying that this new Standard will be in effect for this season as well (you can read that bulletin here).
As organic farmers, we are committed to being stewards of the soil. While we need all the help we can get with improved products and efficient techniques in order to provide ourselves a livelihood, as small-scale organic farmers, we realize that we are only the caretakers of this land for the tiny time period of our lifetime. This land needs us to consider our impact on the generations that follow ours. So, we are always researching, learning, and questioning what we thought we knew.
Bryan and I have decided that, beyond using up our leftover biofilm from last year (we cancelled the order we had made back in December after the memo came out), we wouldn’t use any more biofilm (unless the manufacturers make some serious improvements in the future). But how will we replace it’s benefits in our operation?
At this point, we’re thinking about increasing our annual use of landscape fabric (which can be rolled up at the end of each season and re-used for many years). This reduces our opportunities for living mulch in our pathways which we’ve really liked having…though there are always plenty of beds that don’t get any mulch at all (like beds of salad mix, carrots, salad turnips, radishes) that will still have the living mulch pathways.
We’ve also been experimenting with rolling/crimping rye and flail mowing rye and then planting fall brassicas (like cauliflower, broccoli, kohlrabi) into it.
Since biofilms haven’t been allowed on U.S. organic farms (but many farmers there have wanted to), there has been some thought and a little research coming from there on this topic. Here are a few resources you may find interesting for further reading:
HuaWei Product Page
During the growing and harvest seasons, vegetable producers often begin their day before sunrise and finish as the last light is seeping into the horizon. These long days are normal but varied. Challenges such as pests, disease, climate change, and weather make each day and each growing season unique and unpredictable.
Vegetable farmers control some of the variables they face—like weeds and the temperature and moisture levels of their soil—by using a product that comes with pros and cons: plastic mulch.
Shuresh Ghimire, assistant extension educator for vegetable crops in the College of Agriculture, Health and Natural Resources (CAHNR), is working with producers in the state to find alternatives to plastic mulch without eliminating the benefits it brings.
"Farmers are among the first to feel the effects of climate change. A successful crop, especially outdoors, is heavily based on climate variables like temperature and precipitation. Farmers need a solution, but we know we can do better than traditional plastic mulch," says Ghimire.
He is leading efforts to introduce more biodegradable plastic mulch for Connecticut's vegetable producers.
"The goal is to address these challenges and increase food production closer to home," says Ghimire. "This provides greater food security and lessens our dependence on traditional agricultural regions like California that are facing their own climate-related challenges."
Why is mulch necessary? Mulch reduces the need for herbicides, conserves soil moisture, moderates soil temperature, and can increase both crop yield and quality. This helps keep more profits in the growers' pockets when margins are tight.
However, there are negatives that come with plastic mulch. Most plastic mulch products are non-recyclable. Ongoing research highlights the negative environmental impacts of plastic mulch. It is also costly and labor-intensive for producers to remove at the end of the growing season.
These drawbacks have a big impact at the state and national levels. Connecticut has over 5,500 farms, including about 1,000 that produce vegetables on more than 9,000 acres. There are about 4.4 million acres used for vegetable production in the United States, roughly the size of Connecticut and Rhode Island combined. Plastic mulch becomes an unwieldy annual problem at this scale when it goes to a landfill at the end of each growing season.
Credit: University of Connecticut
Biodegradable plastic mulch was introduced as a solution in the 1990s. Today, it's an environmentally friendly and sustainable alternative to regular plastic mulch.
Biodegradable plastic mulch is plowed into the ground at the end of the growing season. This eliminates the recycling, environmental, and labor issues of traditional plastic mulch. The biodegradable mulch is applied at the same rate as the traditional plastic mulch, although slightly more loosely. At the end of the season, producers simply till the crops and biodegradable mulch into the soil, then plant their cover crop.
This is the biggest return on investment when switching to this innovative mulch, since it requires far less labor and eliminates removal costs. Composting and biodegradability tests ensure the biodegradable mulch used in vegetable production meets required environmental parameters. It must be 90% biodegraded into carbon and water within two years of plowing into the soil. The remaining 10% is microbial biomass, bacteria and fungi that help decompose organic matter into the soil.
Ghimire is currently conducting research trials on biodegradable plastic mulch in Connecticut and with national collaborators. This work has shown that biodegradable mulch and other forms of environmentally friendly mulching help with vegetable production because they modify the microclimate. This helps with crop growth and addresses climate change issues.
Ghimire is also conducting field trials to evaluate different aspects of biodegradable mulch use. One trial will evaluate the effect of biodegradable mulch on different crops, including tomatoes, since there is concern that their skin will adhere to the biodegradable mulch. His team is also studying long-term soil health after using biodegradable mulch.
After first being introduced to biodegradable mulch five years ago, Steve Bengtson has expanded his farm's use of the product. Bengtson owns Cold Spring Brook Farm in Berlin, where he grows a variety of vegetable crops.
"Cleanup at the end of the year with traditional plastic mulch involves mowing all the crops down, loosening the edges of the plastic, and pulling it up. A lot of the time the plastic is wet and there are weeds all over the place, making it hard to remove. Using biodegradable mulch, you just remove the irrigation drip line and harrow it in. I recommend people try it on their farm with different crops. That's how we did it," Bengtson says.
Connecticut crops grown with biodegradable mulch include sweet corn, eggplant, pepper, summer squash, broccoli, Brussels sprouts, and greens. Research on melons and other crops that sit on the mulch may follow if the results from Ghimire's tomato studies show promise. Organic vegetable production currently cannot use biodegradable mulch, although research is ongoing to determine acceptability in that setting.
"Biodegradable plastic mulch enhances vegetable crop quality, saves time for agricultural producers, and reduces labor costs," says Ghimire. "It's one of many climate-smart innovations helping agricultural producers adapt and increase resilience while ensuring a safe and abundant food supply locally, regionally, and globally."
Citation: Biodegradable plastic mulch: A climate-smart agricultural practice (2022, September 22) retrieved 29 April 2024 from https://phys.org/news/2022-09-biodegradable-plastic-mulch-climate-smart-agricultural.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
I wrote this article for ACORN’s summer 2015 newsletter and am now republishing it here.
At the end of March of this year (2015), we found a memo in our inbox from Ecocert (the organic certifying body that we are certified with). In this memo, we were told that we would no longer be able to use the biodegradable plastic mulchbiodegradable plastic mulch (made with non-GMO corn starch) that we had been using unless we removed it after use. We were surprised and concerned. It was definitely a little last-minute! We still had leftover rolls of it at the farm from last season and had made our order for this season back in December (when we do a lot of our inputs purchases). And the removal part….it’s pretty tough to completely remove something that biodegrades as it’s in use.
Bryan and I have been using biodegradable plastic mulch (which I will refer to from now on as biofilm to reduce typing) since the first year we started Broadfork Farm. As small farm operators, we have appreciated the reduction in our time spent weeding in particular. But there are other benefits to using plastic mulch, like warming the soil and retention of moisture in the soil. With our deep feelings of stewardship for the soil, we have also liked how we have been able to keep more of the soil covered during the season (with the biodegradable mulch in the beds, our pathways have been maintained in living mulch that we mow). Soil left bare tends to create its own “cover” of a dry, dead, erodible soil layer.
We knew that, as a manufactured product, biofilm wasn’t the perfect solution in our utopian organic vision. But it was a solution we preferred to regular plastic mulch (with the required pulling up at the end of the season and taking to the landfill) or frequent cultivation. There are of course other mulches like straw or leaf mulch but they didn’t fit in as well with our whole system (but rather have fit in with some crops in certain instances when we could access sufficient quantities without prohibited substances).
We had often talked about the fact that we didn’t think we could have made 100% of our household income from our farm from our first year without the use of biofilm. We even listed it as one of our 5 favourite market gardening tools! Especially in our first year while we converted hay fields to vegetable fields…while growing vegetables. The sod clumps that we’d overturned were too lumpy to be able to use a wheel hoe (or any other kind of hoe for that matter) for weeding.
So, after receiving the Ecocert memo, I contacted other people involved with the Organic Standards and asked, what’s up with this? It turned out, that our Canadian Organic Standards had never allowed the use of the biofilms (without removing from the field after use) that are currently available in the marketplace. But there was a lot of confusion around this, both by farmers and certifiers. I think the confusion stemmed from the language of the Standard (very Standard-y) and the uncertainty of exactly what substances each biofilm on the market contains.
This is what the Standards said:
Fully biodegradable films: permitted without removal if they do not contain substances prohibited by par. 1.4.1 of CAN/CGSB-32.310, Organic Production Systems — General Principles and Management Standards.
I think it was clear to everyone that the biofilms couldn’t contain GMOs or pesticides. And the ones organic farmers were using don’t contain these.
Many organic farmers had happily been using this input for years and so, when the memo came out right at the beginning of the growing season, it was a big shock. People involved with the Crops Permitted Substances List (PSL) working group of the Organic Standards Technical Committee, the Standards Interpretation Committee (SIC), and the Canada Organic Office (COO) at the CFIA all started trying to figure out an appropriate and fair solution.
So, why aren’t biofilms allowed? Well, all of the biofilms on the market currently contain a certain percentage of petroleum source materials (which are prohibited) that seem to be referred to as raw fossil-based ingredients (by manufacturers). The biofilm that we had been using, while having the lowest percentage of petroleum source materials of any other biofilm, is still around 20%. I didn’t like learning that. And I was disappointed it wasn’t clearly expressed by the companies that were manufacturing and selling these biofilms. I had thought the biofilm we were using was actually 100% non-gmo corn starch.
Then there is the issue of biodegradability. Most farmers who have used these biofilms know that the biodegradability varies (so the ‘fully biodegradable’ part of the above Standard was a tricky one). It varies from farm to farm, field to field, season to season. In particular, it varies based on the life in the soil, the soil temperatures, and the soil moisture. There has been a bit of research done on this but not enough. The primary ingredient in the biofilm we’ve used, the corn-starch material Mater-Bi, is shown to be compostable in ideal composting situations but that’s not the same as using it on top of the soil in highly variable field conditions.
As I was trying to learn as much as possible about this input, I realized that there are currently too many unanswered questions. Like what happens to all the bits (even the bits we can’t see with the naked eye) that don’t fully biodegrade? Are they contributing to those floating garbage islands in the ocean? Are they being taken up into the web of life through food chains (insects, birds, mammals) and their materials concentrated? And to what effect? Are the microorganisms in the soil changing…adjusting to a new food source….and if so, is this harmless or harmful on the balance of life in the soil? Are there residue buildup issues we should be concerned with (the labelling always says “No toxic residues’ but what is this claim based on? Over how many years and with how much biofilm use? Is this claim unlimited?)?
With both the sustainability of farm businesses and care of the soil in mind, the Organic Technical Committee brought forward a revision to the 2015 Canadian Organic Standards. This is that these biofilms with the prohibited substance of petroleum products (all that are currently on the market, remember) will no longer be allowed unless removed from the field….but that, in order for farmers to figure out new systems without the use of these products…or, fingers-crossed, time for the manufacturers to figure out a way to change their products to be compliant….organic farmers will still be allowed to use the biofilms as they have been (i.e. tilling back into the soil) until 2017. And, for this 2015 season, since the newly-revised 2015 Organic Standards won’t come out until the fall, the Canadian General Standards Board has sent out a bulletin saying that this new Standard will be in effect for this season as well (you can read that bulletin here).
As organic farmers, we are committed to being stewards of the soil. While we need all the help we can get with improved products and efficient techniques in order to provide ourselves a livelihood, as small-scale organic farmers, we realize that we are only the caretakers of this land for the tiny time period of our lifetime. This land needs us to consider our impact on the generations that follow ours. So, we are always researching, learning, and questioning what we thought we knew.
Bryan and I have decided that, beyond using up our leftover biofilm from last year (we cancelled the order we had made back in December after the memo came out), we wouldn’t use any more biofilm (unless the manufacturers make some serious improvements in the future). But how will we replace it’s benefits in our operation?
At this point, we’re thinking about increasing our annual use of landscape fabric (which can be rolled up at the end of each season and re-used for many years). This reduces our opportunities for living mulch in our pathways which we’ve really liked having…though there are always plenty of beds that don’t get any mulch at all (like beds of salad mix, carrots, salad turnips, radishes) that will still have the living mulch pathways.
We’ve also been experimenting with rolling/crimping rye and flail mowing rye and then planting fall brassicas (like cauliflower, broccoli, kohlrabi) into it.
Since biofilms haven’t been allowed on U.S. organic farms (but many farmers there have wanted to), there has been some thought and a little research coming from there on this topic. Here are a few resources you may find interesting for further reading:
During the growing and harvest seasons, vegetable producers often begin their day before sunrise and finish as the last light is seeping into the horizon. These long days are normal but varied. Challenges such as pests, disease, climate change, and weather make each day and each growing season unique and unpredictable.
Vegetable farmers control some of the variables they face—like weeds and the temperature and moisture levels of their soil—by using a product that comes with pros and cons: plastic mulch.
Shuresh Ghimire, assistant extension educator for vegetable crops in the College of Agriculture, Health and Natural Resources (CAHNR), is working with producers in the state to find alternatives to plastic mulch without eliminating the benefits it brings.
"Farmers are among the first to feel the effects of climate change. A successful crop, especially outdoors, is heavily based on climate variables like temperature and precipitation. Farmers need a solution, but we know we can do better than traditional plastic mulch," says Ghimire.
He is leading efforts to introduce more biodegradable plastic mulch for Connecticut's vegetable producers.
"The goal is to address these challenges and increase food production closer to home," says Ghimire. "This provides greater food security and lessens our dependence on traditional agricultural regions like California that are facing their own climate-related challenges."
Why is mulch necessary? Mulch reduces the need for herbicides, conserves soil moisture, moderates soil temperature, and can increase both crop yield and quality. This helps keep more profits in the growers' pockets when margins are tight.
However, there are negatives that come with plastic mulch. Most plastic mulch products are non-recyclable. Ongoing research highlights the negative environmental impacts of plastic mulch. It is also costly and labor-intensive for producers to remove at the end of the growing season.
These drawbacks have a big impact at the state and national levels. Connecticut has over 5,500 farms, including about 1,000 that produce vegetables on more than 9,000 acres. There are about 4.4 million acres used for vegetable production in the United States, roughly the size of Connecticut and Rhode Island combined. Plastic mulch becomes an unwieldy annual problem at this scale when it goes to a landfill at the end of each growing season.
Credit: University of Connecticut
Biodegradable plastic mulch was introduced as a solution in the 1990s. Today, it's an environmentally friendly and sustainable alternative to regular plastic mulch.
Biodegradable plastic mulch is plowed into the ground at the end of the growing season. This eliminates the recycling, environmental, and labor issues of traditional plastic mulch. The biodegradable mulch is applied at the same rate as the traditional plastic mulch, although slightly more loosely. At the end of the season, producers simply till the crops and biodegradable mulch into the soil, then plant their cover crop.
This is the biggest return on investment when switching to this innovative mulch, since it requires far less labor and eliminates removal costs. Composting and biodegradability tests ensure the biodegradable mulch used in vegetable production meets required environmental parameters. It must be 90% biodegraded into carbon and water within two years of plowing into the soil. The remaining 10% is microbial biomass, bacteria and fungi that help decompose organic matter into the soil.
Ghimire is currently conducting research trials on biodegradable plastic mulch in Connecticut and with national collaborators. This work has shown that biodegradable mulch and other forms of environmentally friendly mulching help with vegetable production because they modify the microclimate. This helps with crop growth and addresses climate change issues.
Ghimire is also conducting field trials to evaluate different aspects of biodegradable mulch use. One trial will evaluate the effect of biodegradable mulch on different crops, including tomatoes, since there is concern that their skin will adhere to the biodegradable mulch. His team is also studying long-term soil health after using biodegradable mulch.
After first being introduced to biodegradable mulch five years ago, Steve Bengtson has expanded his farm's use of the product. Bengtson owns Cold Spring Brook Farm in Berlin, where he grows a variety of vegetable crops.
"Cleanup at the end of the year with traditional plastic mulch involves mowing all the crops down, loosening the edges of the plastic, and pulling it up. A lot of the time the plastic is wet and there are weeds all over the place, making it hard to remove. Using biodegradable mulch, you just remove the irrigation drip line and harrow it in. I recommend people try it on their farm with different crops. That's how we did it," Bengtson says.
Connecticut crops grown with biodegradable mulch include sweet corn, eggplant, pepper, summer squash, broccoli, Brussels sprouts, and greens. Research on melons and other crops that sit on the mulch may follow if the results from Ghimire's tomato studies show promise. Organic vegetable production currently cannot use biodegradable mulch, although research is ongoing to determine acceptability in that setting.
"Biodegradable plastic mulch enhances vegetable crop quality, saves time for agricultural producers, and reduces labor costs," says Ghimire. "It's one of many climate-smart innovations helping agricultural producers adapt and increase resilience while ensuring a safe and abundant food supply locally, regionally, and globally."
Citation: Biodegradable plastic mulch: A climate-smart agricultural practice (2022, September 22) retrieved 29 April 2024 from https://phys.org/news/2022-09-biodegradable-plastic-mulch-climate-smart-agricultural.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.