Event ID: 2603110
Event Started: 5/21/2015 12:50:13 PM ET
Please stand by for realtime captions.
Welcome to today's conservation webinar. My name is Evan and I in the webinar coordinate for the West national technology support Center in Portland, Oregon. This webinar is being recorded and all participants joining the webinar are in listen only mode. You received the webinar audio to your speaker and there is no telephone Thailand. If you are having audio difficulties, please check the areas ways your volume can be adjusted. Please take a look at our webinar layout. We have a pod to let you download today's slides and we have the Q&A part -- pod.
To enlarge the webinar presentation used for errors to enter and exit the full screen view. There are a few messages in the Q&A pod that can assist you if you are having problems with the webinar interface. Today's webinar offers one hour credit and what our certified crop advisor and one our conservation planning credit. If you selected to earn CEUs when you enrolled in today's webinar, after the webinar his into Please return to your open browser window and complete step 2. You will take of brief posttest and enter your certification credentials and receive your participation certificate by email. We will submit your CEUs at the begin -- at the beginning of the month. Please submit your CEUs if you need to meet your local requirement. The on demand reporting of this webinar will be available tomorrow. Feel free to lecture colleagues know about this training opportunity. Additionally, today's webinar is on environmental benefits of organic culture. Please note the topic and date on your screen for the upcoming webinars.
Betsy Rakola is today's moderator. She is an organic policy advisor for the USDA marketing service and will be be introducing today's speaker Dr. Erin Silva. Betsy, the floor issuers to introduce Dr. Erin Silva Thank you for joining us on this first webinar series. Today's webinar is part of USDA's broader departmental guidance on organic. We are leading an effort to ensure that staff and everyone at USDA's programs and that we understand the scope and rigor of working on organics. We will work to achieve that is we explore the connection between organic and conservation practices. I want to ignore -- I want to acknowledge NRCS and Oregon Tilth.
You can register for all of the webinars that are upcoming at NRCS . I would like to introduce today's speaker Dr. Erin Silva .
Thank you Betsy and Evelyn.
I want to do more of an introduction. She is an assistant professor at the University of Wisconsin at Madison. She focuses on sustainable and organic cropping systems. She currently serves as cofacilitator of the Wisconsin organic advisory Council and is a member of the science advisory Board of the organic center. With that I will turn it over to Dr. Erin Silva this
The queue for the invitation. I am very glad to have the opportunity to speak on this topic. This semester, I had the opportunity with the team of scientists from across disciplines here at the University of Wisconsin to take of 3 Credit Court to look at systems and climate change. As with introduce, I will be talking about the environmental benefits of agriculture and climate change.
Just a brief outline of the presentation. First, I will be given an overview of climate change in agriculture this speak more specifically on the impact of organic agriculture on greenhouse gas emissions as well as sequestration and not just on-site emissions. And wrap up with potential improvements and mitigation strategies and their relation to two organic culture peer
A brief overview to put everyone on the same page. When we look at atmospheric CO2 levels and their impact on climate change, it is clear as we look at standard emissions of CO2 in the atmosphere, there has been a marked increase in these admissions from the mid-part of the 19th century up until today. And then if we look at how that has impact -- impacted the CO2 concentration in the atmosphere, we see that this follows the same curve. And grant to cut the X axes on these graphs are different, but our CO2 concentrations are following the same path as the CO2 emissions. Globally, this has resulted in changes in temperatures, rainfall patterns, and what this results in is not necessarily [ Indiscernible ] whether all the time. But extreme weather. Like droughts, floods and storms. And this puts our agriculture at greater risk. And increases the risk of resource and food insecurity.
This is some data from Wisconsin. From our Wisconsin initiative on climate change impact. This presentation is going to be a bit upper Midwest century. The same themes apply across the US as well as Wisconsin and the upper US. What we have experienced here in Wisconsin with respect to spring and fall freezes is that we see that the last spring these occurs 6 to 12 days earlier than typical and that the Palfrey's occurs 8 to 12 days later.
Additionally, if we look at the upper Midwest precipitation trends from 1910 until 2012, what we see here is that there has been a marked increase in terms of the amount of annual precipitation in a given year. In fact, eight out of 10 of the wettest years for daily precipitation have occurred since 1978.
Additionally, we are seeing some seasonal changes in the patterns of precipitation. Seeing more snowfall in the winter, whether Springs, which particularly for organic farmers which have to use mechanical tillage and have to worry about the lack of seed treatment, that has been an issue to put organic farmers at risk. But we have also seen a decrease in precipitation as well as -- or a bit of a dryer stretch of precipitation dash -- What is causing these changes? When we look at greenhouse gas emissions, and the impact of these omissions in the atmosphere, we are looking beyond CO2. We also need to look at where those emissions are coming from. If we look at the breakdown of emissions by economic sector, we see that agriculture is in the minority as compared to those other sources of the mission. Allegedly, transportation, industry and commercial and residential use.
If we look at what these greenhouse gas emissions, what other sources? Many of these greenhouse gas emissions are contributed to carbon dioxide. 82%. 10% are derived from methane were as 5% are derived from my just on-site. We talk about greenhouse gas emissions, we are talking beyond carbon dioxide.
We look at emissions from various gases, many of these admissions come from the combustion of fossil fuels. With respect to the generation of electricity, transportation, industry as well as residential and commercial sources.
Will be go to nitrous oxide, we see where agriculture and management practices have a significant contribution to this particular greenhouse gas in our atmosphere. Agricultural soil management accounts for 74% of nitrous oxide emissions from the US. That is a significant contributor to nitrous oxide emissions. When a manager -- management and should dash contributes another 5% per
Agriculture has a significant impact to nitrous oxide emissions in the atmosphere.
We talk about methane emissions, here is where agriculture has a more significant role. Here we are talking about the methane that is committed by animals like Terry or beef cows. And the newer management contributes another 10%. Agriculture here not quite as significant as much as oxide. But it is a significant contributor to the overall greenhouse gas emissions in this category this
The other thing to know will be look at these different greenhouse gases is, there are different global warming potentials that are attributed to these areas greenhouse gases. If we use carbon dioxide as a baseline here, here we are using a baseline of the potential of 1. These other greenhouse gases that are rising and concentration in the atmosphere. We look at preindustrial levels versus the levels in the last few years. Methane and nitrous oxide, those two greenhouse gases where agriculture has a significant role have more significant global warming significance the carbon dioxide. We're saying here is that methane has 23 times the potential impact as carbon dioxide. And nitrous oxide has almost 300 times the global warming potential as carbon dioxide. Were as these different gases may not be emitted in the same quantity as carbon dioxide, the impact is quite marked with respect to global warming.
When we look at the carbon cycle, and how agriculture relates to the carbon cycle, one important thing to note is that carbon can not only be emitted through the atmosphere, it can be sequestered from the atmosphere through various mechanisms. As plants emit carbon dioxide to the atmosphere, this can capture carbon dioxide. There have been some studies that there are annual fluctuations within a certain year, depending on when -- is winter in the northern hemisphere . That entire carbon dioxide. What also may occur is that carbon dioxide can be sequestered into the soil as it interest the soil as organic matter. As we look at the overall pools of carbon dioxide, atmospheric carbon dioxide equals about 750 Gt where as the soil pool is about 1500 Gt. So quite a lot of carbon is locked up in the soil. The ocean is a significant pool of carbon dioxide as well. But what is important to note here is that there is an opportunity for carbon dioxide to be sequestered from the atmosphere into the soil.
It is a little bit of a different story here with nitrous oxide. Certainly, there are opportunities for atmospheric nitrogen to be fixed. We talk about nitrous oxide, it is a bit more of a one-way street. When nitrous oxide is emitted, unlike the carbon cycle where we are able to recapture some of that CO2, this is not the case with nitrous oxide. Here, in terms of management, looking at limiting those nitrous oxide emissions is key.
Moving on to some data with respect to agriculture is impact on these areas greenhouse gases. As I mentioned, I will be a bit Wisconsin centric in this talk. And I will be talking about the Wisconsin integrated cropping systems a trial which was located in Arlington Wisconsin. This cropping system trial has been active for about 25 years now. And this represents six different cropping systems which are representative of the upper Midwest. In Wisconsin we have quite a diverse agricultural system that is integrated with livestock. As you can see, the plots are quite large. They are about three quarters of an ape or -- three quarters of an acre. We wanted most accurately represent the impact of these various cropping system approaches on yield trends as well as changes in the soil quality and soil health over the last 25 years and beyond.
Looking at the six cropping systems that are represented, the way that this cropping system was designed, it was divided into 2 different approaches. The first approach, the grain approach was looking at the side separated from livestock. Here we are looking at more of a commodity grain approach. With a variety of management practices and a range of complexities. We have a treatment which is continuous corn with typical tillage practices. We have a system that is a reduced till corn, soybean rotation. And the third system is a corn, soybean, winter wheat rotation with a clover cover crop which is managed organically. These are systems that are separated from livestock and maneuver inputs.
The second set of treatment is more indicative of our integrated livestock industry in the state. Here we have a corn phase with three years of alfalfa, manage conventionally. We also have a corn phase with a alfalfa seeding year that has been interceded with the [ Indiscernible ] that is managed organically followed by a rotational grazing system. Really a pasture-based system in which we do have heifers actively grazing on that field.
This is manage conventionally. Although it does have minimal input. A bit of synthetic nitrogen and minimal herbicide applications. Again, looking at a range of complexity in terms of rotational strategies, as well as the diversity of crops that are included. Again, with the blue box, we have those 2 organic treatments.
As we look at the data that it has emerged from 25 years of areas input, various yield data collected off of this trial, and various other data with respect to soil quality. The first thing I want to talk about is comparing the emissions of the system as it relates to a lifecycle inventory assessment. And we're talking about lifecycle inventory assessment, one of the challenging things when developing these assessments were deciding where are the boundaries? Are we looking at embedded omissions which are associated with the input to that systems which are marked the synthetic fertilizers and therefore the energy that has been needed for the synthesis of that fertilizer. We looking at the energy associated with seed production or when transportation? How far out are we expanding our boundaries to look at impact with respect to CO2 emissions and others greenhouse gas emissions? Or are we focusing primarily on the infield emissions? Those associated with the Agricole approaches -- practices .
I want to note, make fill that all of these treatments and all the data that I am presenting, they represent these treatments managed with test management practices as per the recommendations of the University of Wisconsin. Soil tests are done, best management practices with respect to applications and it is done as appropriate as we are recommending for farmers across Wisconsin.
Again, looking at the lifecycle impact assessment, what I want to present data on first is embedded emissions. Embedded emissions are those omissions that are community -- accumulated emissions embedded -- emitted over the entire production process. And looking at those omissions that can be attributed to diesel fuel use, fertilizer, pesticides inputs, grain drying, supplemental have received while they are on the pasture. In this data was derived from the GaBi databases.
What we see here, the embedded emissions from the different treatments from 1993 until 2008. We see those treatments that I outlined previously on the X axis. Treatment 3 being organic and treatment 5 being organic. These results are very much in line with other studies that have been done, not only in the US but also in Canada and in the EU. And what we find here is that in comparison with conventional systems, organic systems tend to excel with respect to their contributions from their embedded components because of the lack of use of synthetic fertilizers as well as the use of pesticides.
Looking at those green bars, particularly in the first 3 treatments which are the commodity grain treatments, you can see without the input of synthetic fertilizer, and without the input of pesticides, the overwrought embedded emissions are quite less than the continuous corn. A lot of the emissions associated with these various treatments are associated with synthetic fertilizer.
The organic treatment relies on that clover cover crop as well as of rotational phase of soybean. And it also included palletized treatment maneuver.
We saw more of emissions with respect to the forage treatment. And here we see a bit higher emissions with respect to the organic treatment. This is attributed to additional passes over the field with the tractors in order to perform cultivation. Where we aren't having a longer alfalfa phase, we have less synthetic fertilizer applied and overall, less pesticides applied, we see organic being on par with the conventional system.
In terms of carbon sequestration in these systems, we look to the carbon cycle, carbon sequestration offers an opportunity to remove carbon from the atmosphere and have it tied up in the soil in the form of soil organic matter. There are different stabilities of those different carbon tools in the soil. Whether it be short-term or long-term, agricultural management represents an opportunity to promote carbon sequestration.
We look at agriculture and the global carbon budget, carbon dioxide mitigation via agriculture is an attractive option. Agricultural land can be managed as a carbon sink. And particularly, with various management strategy, we can start to reverse the historic losses of soil organic carbon that we have experienced as we have transitioned land from Prairies here in the upper Midwest to agricultural land. We have seen a loss of carbon over the last century.
It is an attractive mitigation option, in part because it is immediately implementable. We know a lot about the types of practices that promote carbon sequestration. Many of these practices are considered best practices. It is a cost effective practice as well. Several of these practices are good management practices broadly.
Here again, I am taking data from the WICST trial looking at soil organic trends. This data, what we see here, and we look at change in soil carbon over 20 years is that overall, we see a loss of carbon. Let me explain this table a bit. As we look at the uppermost part of this graph, this first set of six this first set of 6.. We see organic carbon at the zero to -15 organic sets.
Here we are representing soil organic carbon over the depth of 0-30 cm. The third line is representing up to a 60 cm depth and the bottommost line is representing carbon up to a 90 cm depth. What we are looking at, changes in soil carbon from some baseline soil samples that were taken when the WICST trial was implemented. This was back in the late 1980s. Up until when Dr. Sandford was analyzing the samples 20 years after the WICST trial began.
Again, down here on the X axis copy have the various treatments. Continuous corn, that strip till corn soybean rotation, the organic chlorine, so he called we rotation, the conventional alfalfa, organic alfalfa and the pasture.
What we see here in respect to the grain system, on the WICST trial, starting from a very rich and high organic matter organic soil, there is a loss of carbon in all system. Including the organic system. We do not see additional losses of carbon in the organic system as compared to the reduced tillage system. Here with the WICST data, we do not see a game. Similarly with the organic alfalfa versus the conventional alfalfa, both of these systems are showing a loss in carbon with in the upper soil doubts, we see that with the alfalfa phase, there are certain circumstances where there may be more of a neutral carbon impact, or even some the data point may show again At there is no overall distant -- difference person that we do see a game in carbon is with the pasture-based system. That system where we are looking at perennial grasses and legumes, little to no soil disturbance, here is where we are seeing gains in carbon and carbon sequestration. And certainly we look at organic agriculture particularly on livestock-based system, and the regulations that are set forth by the national organic program, pastor is a key element to organic management. We are looking at overall, with organic management and potential impact, certainly, the integration of pasture within the overall system it has the impact.
Even though it was not managed organically per se, this represents overwrought a similar trend that you might expect to see in an organic pasture.
I want to emphasize that this data set, we are starting from a carbon rich high organic matter soil to begin with. And the vegetation was historically dominated by tallgrass prairie and oak savanna communities. Historically, these oils are highly productive and were arty starting from a starting point of high organic carbon.
I do want to give some of the data that is represented of others soil types. And look at the comparison of conventional system first is organic systems. This next data set was taken by a publication from [ Indiscernible Name ] in 2007. It's looking at total soil combustible carbon averaged over 2001 and 2002 at the conclusion of a nine-year cropping system comparison. This was on the East Coast. Here, we are looking at data at various depths. What we do see in this case is that organic cropping system as compared with no tillage or with cover crop integrated do have a significantly higher total soil combustible carbon than those other systems. Another type, organic management versus conventional. And here we are seeing more significant increases overall in the organic system versus the conventional.
This is another set of data that was presented I [ Indiscernible Name ] in 2010 looking at carbon sequestration at the USDA farming system project in Maryland. Here we see some of those similar results. We are looking at a no till system versus a chiseled till system, both of those being conventionally managed and we are looking at carbon to a one meal -- 1 m soil that depth. And here we see more market benefits with respect to organic management with carbon sequestration.
Another trial that was based in the US, these are some slides that were shared by [ Indiscernible Name ]. Kathleen and Cindy are both highly involved with the Iowa State University Neely-Kinyon LTAR site. This is more similar to what we have in Arlington, Wisconsin. These are larger scale plots and they have 44 plots with four rotations and those rotation includes five different crops.
Here, looking at soil organic carbon after 12 years of management, they did similarly fine higher carbon in the organic system. They did find an increase in organic carbon, again in line with those of the two experiments that I outlined for you. As well as increases in total nitrogen, and several other soil quality indicators. One thing that I do want to note here, as an important difference between the WICST trial and the data that we have what [ Indiscernible Name ] has set up. The green rotation also includes a two-year alfalfa phase. Were asked the WICST trial, it has a very distinct delineation between the commodity grain and the livestock system. In this trial, based out of Iowa State, there is more of an integration. Some of the differences with respect to the results seen at Iowa State versus what we have here at the WICST trial, they are related to that two-year alfalfa phase. A strong impact of that perennial phase on soil carbon and building soil organic carbon in the soil. The importance of trying to integrate a perennial phase or pay phase into the rotation to maximize the benefit.
And finally to wrap up the data set with respect to organic agriculture, I want to wrap up with a swift study that was based out of a group of scientists from FiBL the this group has conducted a meta-analysis of 74 studies. They took 74 different studies that compared organic farming practices with conventional practices as they related to carbon. As a result, they found that organic farming practices lead to increased soil organic stocks in the upper 20 cm of soil over a period of 14 years. The two calculations that they were able to derive going to be studies and categorizing them with various factors is that about 3.5 mg of carbon per hectare higher in organic the non-organic systems. And one of the criticisms that some of these analyses are subject to, with respect to looking at the passive organic system is often the reliance of conventional resources in organic management. So for instance, in organic farmer in the US can use compost, they can use the newer, they can use some inputs that have been derived from a conventional agriculture setting. Similarly, if the EU, in organic farmer can [ Indiscernible ]
They try to separate out the reliance on conventionally derived inputs. They have also took a set of farms that were more closed with respect to the [ Indiscernible ] of those inputs. Looking at bars for the maneuver was produced on farm and where the forage for the animals were produced on farm as well. And here with a zero net input organic system, there was a significant and positive relationship of about 2 mg of carbon per hectare.
They also estimated that soil carbon sequestration by switching to organic agriculture could offset 3% of the current total greenhouse gas emissions for Europe and 2.3% for the United States or 25% of the current agricultural emissions. Quite a significant impact.
I want to move on to nitrous oxide. As mentioned, just oxide is a greenhouse gas that does have -- it is significantly impacted by cultural management. It is important contributor of infield greenhouse gas emissions. Those that occur when crops are actively growing in the field. It is admitted to nitrogen is added to the soil through fertilizers. Both the newer base and synthetic analyzers. And is emitted during the breakdown of nitrogen from those are -- from those fertilizer sources. It is a very potent greenhouse gas depending on the estimates, it's about 300 times more potent than carbon dioxide.
We look at the impact of cropping systems on nitrous oxide emissions, this is beyond organic. This is broadly looking at the impact of cropping systems alleges oxide emissions. This is a review article by [ Indiscernible Name ] in 2013. This sum it up quite well when they say, although it is well-established the soils are the dominating source for atmospheric nitrous oxide, we are still struggling to fully understand the complexity of the underlying microbial reduction and consumption processes and the links to biotic and abiotic factors.
Where as the carbon sequestration we have a clearer picture as to what our best management practices to promote carbon sequestration, it's a lot less clear with best management practices in nitrous oxide emissions. There are some things that are emerging
When we look at nitrous oxide fluxes, this harkens back to that potency on nitrous oxide as compared to carbon dioxide. Unfortunately the gains could be offset by not just oxide emissions. Similar to the statement that I just read, the data with respect to agricultural management practices and the subsequent impact on nitrous oxide fluxes are a lot less certain. There have been circumstances and looking at conventional management that no till is either greater or equal to conventional tillage situations. With a strong affective soil type. Looking at study that have more specifically looked at images of nitrous oxide in organic systems, the literature has shown results that organic systems are equal or less. The data is variable. And that represents the complexity of the system and the fact that this is a very much driven by microbial activity which can be impacted by the microbial populations in the soil as well as environmental conditions such as moisture, temperature etc. It's very difficult to make broad generalizations with respect to management and soil type and nitrous oxide or
There are some main drivers of nitrous oxide emissions. Again applications of nitrogen fertilizers both organic and synthetic. The moisture and temperature of soils which will affect microbes in nitrification and tea nitrification processes. Poor training clay texture soils generally have higher denitrification and nitrous oxide losses. And soil compaction as well. In part because of the same phenomenon that nitrous oxide emissions tend to be in part enhanced by anaerobic conditions.
When we look at the impact of fertilizer applications, there is an intergovernmental panel on climate change that write regular reports with respect to the status of atmospheric greenhouse gases and emissions from different countries across the globe. They also have various calculations and equations that allow for the calculations of impact of various management strategies on greenhouse gas emissions. As part of their calculations with respect to greenhouse gas emissions as a relates to agriculture, they have a default for nitrous oxide emissions as 1% of the annual of fertilizer application. With this default the data has shown that here in the Midwest copy emissions can rain -- range quite broadly from .2% to 6.3%. The number may not be reflective on emissions in a given year pick
Looking at what we know about fertilizer and fertility and nitrogen in the soil, we could potentially minimize the impact of fertilizer application by trying to improve the synchrony between of nitrogen supply and demand. To minimize nitrous oxide emissions, we want to apply as close to the crops most active uptake. Whether or not that is due to trying to use soil tests to do more precision application, looking at position application methods through banding, or different precision delivery techniques, that is a key aspect to reducing nitrous oxide emissions. Also potentially improving the nitrogen use efficiency of the system.
Not necessarily issues that are unique to the organic community, just overall highlighting some of the challenges of nitrous oxide and management of the emissions of that gas.
Talking again about our WICST data, and data capture of of our trial in Wisconsin, there was a recent study published late last year by [ Indiscernible Name ] looking at the seasonal nitrous oxide and methane fluxes from grain and forage base production systems. And they use WICST as the data for this study.
They compared nitrous oxide and carbon methane fluxes over the 2010 at 2011 for all six of the cropping systems at WICST. These were actual field-based measurements. These are actually measuring nitrous oxide fluxes in the field.
What they found after measuring the seasonal fluxes of nitrous oxide emissions through various capture techniques in the field, without the organic grain and the minimal tillage corn, soy is being system had lower areas raised nitrous oxide emissions and continuous corn. Looking at the emissions catalytic over a given area versus on the yield basis. What were the primary differences? Both systems received lower rates of nitrogen across the full crop rotation. As compared to the continuous corn system which is quite demanding in respect to the nitrogen inlet crop.
In addition, the addition of the cereal grain which demands less nitrogen in corn for overall greater crop diversity led to benefits with respect to system impacts in nitrous oxide. Again, that is not necessarily -- but as with pasture and the impact of organic on sequestration and program regulations with respect to the pasture, there are some similar things here with national program regulations requiring the first rotation and particularly requiring the use of cover crops, particularly looking at soil building cover crops. Here, in part because of the practices that organic farmers need to use, we are seeing some benefits with respect to the organic systems.
The recommendations from this study were shifting from a high input continuous corn systems to more diversified systems with log rotations. Not necessarily inherent to the organic system that it is something that organic farmers, by having to follow the organic regulations are commonly using across the landscape. Diversified systems with log rotations. Shifting from longer rotations with a less frequent nitrogen application and increased rotational pastors system. They had benefits for reducing nitrogen fluxes. These are often integrated in organic management by default from the national organic program regulations.
The fact that we are seeing trends of diversity leading to less nitrogen oxide emissions they have been documented by other studies. [ Indiscernible Name ] in 2008 showed reductions in emissions in more diverse cropping systems. [ Indiscernible Name ] showed that inclusion of a soybean year and a corn-based cropping system reduced nitrous oxide emissions. Something that is inherent to the organic systems as per the national regulations.
This is some data from the USDA farming systems project in Maryland looking at nitrous oxide emissions. Here we are looking at some conventional systems, no till edges until, organic three-year and here we see more of that challenge with the very ability that we see from nitrous oxide emissions from year-to-year. Where there are not clear trends. We do see a trend overall in curative emissions were organic is producing less cumulative emissions than conventional systems. But there is a weak statistical significance there. This is somewhat based on that challenge of trying to make broad estimates of nitrous oxide emissions because of the strong environmental. Should is absurd.
I will not talk much about methane. Time is getting short other than to mention that methane is driven by ruminant domestic livestock. Manure management can play a key overall. Studies have not show significant differences in methane emitted versus -- from organic versus conventional systems . We just do not see that same sort of differentiation that we see in some of the other greenhouse gases.
I want to talk briefly as we wrap up about lifecycle impact assessment. And some caveats that we need to be aware of. Lifecycle impact assessment is getting to the what does it mean step of the lifecycle analysis? This is where we are looking at global warming impact. We are looking here are some key aspects where we are interoperating the calculations derived from these assessments were we need to think about where of the system boundaries? As well as what is the functional unit? Are we comparing the introduction of those embedded emissions? Are we looking at expanding the boundaries to go to where those inputs are derived? And looking at the functional unit. Is what we are hearing about emissions on a per acre basis or per hectare basis? Or what we are concerned about the emissions concerned about the yield basis? This can skew our interpretation of the results.
The concern of boundaries. We including the production of the newer? And those that may be based on a conventional farm? Are we looking at the seed production aspect? That is not necessarily doing -- using organic management. And how do we account for those inputs that may be incorporated into conventional the newer reduction or seed production into the overall impact of the organic management system? I do not have a clear answer. Of wanted to share that as a caveat in something we need to consider.
Of want to show, as a brief example of this with the carbon footprint of a grass-based versus confinement dairy system. This is depending on what aspect of the system we are considering. We may see different results and make different conclusions. This is just a partial table that was pulled from this publication of [ Indiscernible Name ]. What I want to highlight here is that if we simply look at the impact of pastors, we see that -- and we looked at the impact of pasture sequestration, we see where there is a market benefit and terms of the grass benefit and grass-based sequestration.
If we look at other stages upper the production process, we see that there are other aspects where that grass-based system fall short with respect to enteric fermentation or respect to fertilizer input in that system. It is highlighting that when we are doing these assessments, it's important to consider probably the components that may feed into these assessments.
Finally, as we wrap up, I wanted to talk about strategies to reduce impact. First looking at carbon sequestration. Some themes that we know with respect to control management, reducing the frequency and intensity of soil tillage. This is something that is being addressed widely by research programs across the country including my own. Looking at cover crop base for distilled techniques for organic to reduce organics reliance on tillage for weed management. Including more pay crops into annual rotation.
The production of high residue yield crops and reduced follow periods. To improve pasture management, conservation set-asides and restoration of degraded land and the use of manure as a fertility input. As we look at organic here, there are some highlighted areas that are already being incorporated into many organic farms as per the national organic program regulations. Cover crop base no till, use of cover crops, pasture management and the use of the newer as a fertility input. Not inherent to the organic system that are practices that organic farmers are commonly using per the national organic standards. But with respect to nitrous oxide emissions, the use of soil testing to determine fertilizer requirements. Better timing and placement of fertilizer, use of nitrification and controlled release utilizer, and integration -- integrating diversity into the crop rotation. As we look at organic, particularly with the integration of diversity, organic farmers are commonly using within their farming strategies or
With that, there are some future webinars that we wanted to highlight. I would be happy to take any questions.
Thank you. We do have a number of questions and I want to acknowledge that we are coming up on 2 PM here. If you are able to stick around for a few more minutes, we will do that so that we can facilitate a few of the questions that were getting in. The Mac the first question that I received here is Regarding manure application. The newer application is not exclusive to organic farming. Are there any comparisons you are aware of from [ Indiscernible ] or when we are looking at the organic farming [ Indiscernible ] are we looking at the result of applying the newer compost?
There are greater contributions than just the newer. And certainly many of these practices with respect to good management in terms of carbon sequestration and nitrous oxide emissions are practices that conventional farmers are implementing as well. The difference I would like to stress is that these are integrated into the management as outlined by the regulations. There is more oversight and more certainty that organic farmers are using these practices. Certainly, the impact of the management strategy tend to be amplified as more of these different strategies are applied. With the organic system, you're looking at assistance-based approach, it's hard to separate out the impact of one management strategy versus the other. It definitely, but in the systems trials that I have observed, it is beyond manure. It has to do with the integration of cover crops in that system and overall increased while mass including particularly, the lowbrow biomass from where the perennial crop phase. The beneficial impact of men -- of CEU 20 [ Indiscernible ]
Speaking of the requirements of the USDA organic regulations, the regulations also require the conservation file diversity and on farm resources. Has your research or any of the research that you have reviewed looked at carbon storage by land plants like those in indiscernible areas?
Not that I am aware of. That is a good question. It's not to say that it is not out there. I have not run across it in any of my literature review. We have not done that here at the University of Wisconsin. That is an interesting aspect to consider.
Another question relates to tillage. Regarding the location of soil tillage is site-specific tillage was used more specifically, with that the way that we will be able to preserve the use of tillage as a tool while still sequestering carbon?
I do think that strategies to better target when and where tillage is implemented and trying to reduce tillage in the overall rotation is beneficial. There may be some studies out of the EU that look at differences in tillage intensity. They have done more with respect to looking at reducing tillage intensity in organic systems. But I cannot recall off of the top of my head the degree of change.
A couple of questions relating to yield and the analysis of soil organic carbon. Generally speaking, the questions are about whether a lower yield system might require more land area to produce the same yield and the same with that complicate any of the advantages that we are seeing with carbon sequestration?
That's exactly the point I was trying to get to. It's extremely important to look at what our functional unit is and how that relates to both policy and assessment of these various systems. With organic systems, particularly with our commodity brain systems, the yield gap between organic and conventional is surprisingly -- maybe not surprisingly, it is narrow. We look at doing those calculations on a land-based or a yield base calculation, it does not have as great of an impact. With respect to the data that I showed, because the yield gap is quite narrow, it would not impact those results markedly. I do see more of a difference there will be are looking at greenhouse gas emissions and livestock systems. I do believe there We see quite a difference with respect to yield of milk or respect to animals, eggs or be yield. There were seeing a widespread which is not inherently in the organic system. It is something that we do need to strongly consider with respect to looking at these results and deciding what sort of policy a best management practices to put into place.
Another comment. An interesting thing some kind of a model using bile-based fuels for equipment and fertilizer. The commentor was wondering if you have seen any modeling on that.
I have not. That's another great point. That is related to the other point that I brought up at the end of how far do we extend these boundaries? Looking at them further placing into these various models instead of fossil fuel -- or diesel fuel looking at something that may be biodiesel-based. But looking at the ripple effects of that that may be quite interesting.
Let's take one more question. We have a question wondering what your thoughts are on the impact of organic fertilizer on pastures. Which are more effective?
That's an interesting point. As part of a different aspect of our research project. Were doing an extensive effort with respect to understanding organic fertility practices with relationships to pasture productivity and quality on organic farms. It is definitely not -- particularly in those perennial system, it is a bit less clear with respect to the efficacy of organic fertilizers versus synthetic fertilizers and the further impact with respect to be areas greenhouse gases and carbon sequestration. There is less studies that do look at long-term studies of organic pastures systems. Even our pastor system here has very low inputs but it is not necessarily organically managed. It is an area where data is lacking.
With that, I think we will rapid up. A want to say thank you to Dr. Erin Silva for joining us today in sharing your insight. And thank you for Evelyn Johnson for hosting.
If you interested in joining us a future webinars, we have those up on the screen the date and time of those webinars. If you want to register the website address is there as well. And if you're interested in other resources on USA organic programs, take a look at our website.
With that copy will wish you a good afternoon.
[ Event Concluded ]