Progress 09/01/22 to 08/31/23
Outputs
Target Audience:Scientists working in the field of greenhouse gas emission from agriculture with emphasis in organic grain and forage production systems. Producers interested in reducing the carbon footprint. Private companies interested in commercializing carbon credits as climate commodities (new) Changes/Problems:As stated in the prior section, the powerful Visisense instrumentation requires and inmmense amount of labor to be deploeyd in the field. We obtained images that will be useful in our communication with producers, but failed to obtain "movies" showing changes in soil oxygen concentration across the soil profile That would have let us detect with more accuracy what needs to be changed to avoid the low oxygen boundaries that leave to nitrous oxide emissions. The system is more suitable for lab work than for field work. What opportunities for training and professional development has the project provided?Dr Montes and Dr. Kemanian, particularly the former, successfully deployed the Visisense instrument and learn to obtain high quality images of soil oxygen concentration that very clearly show the formation and destruction of anoxic soil conditions. How have the results been disseminated to communities of interest?Dr. Kemanian made two presentations in the context of the ASCENT project, funded by the Federal Aviation Administration. One of the goals of this project is to accurately estimate the carbon intensity of sustainable aviation fuel produced from agricultural feedstock. Knowlegede developed in this project is clearly of utility to address challenges in fields beyond organic agriculture. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
[Entering this section for the second time. Unfortunately, figures with oxygen concentration are not being accepted by the system.] The Visisense O2, pH and CO2 optical measurement system was successfully deployed in the field. The instrument was encased in a waterproof chamber that included the camera and the auxiliary light sources. The system was powered with two solar panels and voltage transformer that charged the laptop computer that controlled the system and recorded the images. The oxygen foil sensor produced high resolution images of oxygen concentration along the soil profile. Figures showing the oxygen concentration in the soil profile with saturated water conditions and very dry soil were succesfully obtained (but cannot be displayed here). A figure showing an earthworm track low-oxygen footprint coming across the profile was also obtained (an earthie, we guess?). Sensing foils for pH and CO2 did not work well, as their signal response is to dissolved CO2 and fluid water pH and the soil conditions never produced enough fluid water to be measured by the foil photoluminescence. The clay rocky soil in which the system was deployed presented challenges to deploy the system with sealed boundaries that prevented gas diffusion through the sides of the chamber while at the same time providing a very tight contact between the foil and the soil profile. Rocks needed to be removed which resulted in irregular patchy profile surface, that did not provide a continuous tight contact with the sensing foil attached to the flat surface of the waterproof chamber. Therefore, the visisense system did not reflected the oxygen gradient along the soil profile depth. The instrument seems to be more adequate for controlled conditions work than for field deployment.
Publications
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Progress 09/01/19 to 08/31/23
Outputs
Target Audience:Academic audience: Scientists focused on reducing greenhouse gas emissions with a focus on doing so in organic systems that rely on cover crops, manure, and tillage to manage nutrient supply. Producer / Farmer audience: organic community focused on refining nitrogen management and on balancing the tradeoff associated to nutrient management in organic systems. Changes/Problems:As stated before, dealing with Covid and establishing on farm trials was extremely challenging. The lack of response of the treatments also discouraged the implementation of some of these practices in the field. Our conclusion is that A) some trials need to move to an even more controlled setting to avoid the observed variation among blocks (more even soils or even lab conditions) and B) some trials need to be done entirely on producers fields to measure the observed variation in emissions in commercial conditions and when a given climate-smart practice is implemented. The last report also stated some challenges installing and operating the Visisens instrumentation. Wonderful instrument, but not that appropriate for the heterogenities of the field. It is more adequate for lab work. We expected that the visuals from this instrument would serve as a communication vehicle to interact with producers. The images are great, but the labor required to obain pictures that could be mounted in the form of a movie, are staggering. However, we think this technology will continue moving forward, and we plant to submit a manuscript including some of the college images. The image of the earthworm coming across the soil profile (described in the prior report) is rather astounding. What opportunities for training and professional development has the project provided?As stated before, Allison Koehle graduated with Master of Science degree in 2021; Farzaneh Tahriri was trained in the use of Cycles and also mentored on the importance of nitrous oxide emission in ag systems using data from this experiment. Rainey Rosemond, a new PhD student in Ecology and Elizabeth Rader, a new MS students in Meteorology, toured the field to learn about the factors affecting emissions of nitrous oxide emissions. How have the results been disseminated to communities of interest?As stated in prior reports, Allison Koehle made a presentation of data in the American Society of Agronomy annual meeting and presented a seminar in the department of Plant Science. There is substantial dissemination of results and usage of information through every user of the model Cycles, and that includes the work by a graduate student (Curt McConnell, already graduated) that used Cycles extensively. McConnell is currently a biogeochemist working in a private company dedicated to commercialization greehouse gas emissions reduction in agriculture. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The award allowed us to complete a large amount of work in the field and in the laboratory. Almost 7,000 gas samples were analyzed using Gas Chromatography for N2O, CO2 and CH4 concentration during the field measuring campaigns of 2021 and 2022. The measurements were used to estimate emissions from the treatments applied in this experiment. Supplementing the gas emission measurements, we obtained 6,000 soil temperature and 18,000 soil water content field measurements. In total 1,150 soil samples were analyzed for organic matter, nitrate, and ammonium. The results of the experiment were largely unexpected, and unlike prior experiments, there was substantial inter-block (replication) variability. That speaks well of the experimental desing, but since the variance increased with the mean of each block, detecting statistically significant differences is more challenging. There was no effect of the tillage treatments and the cover crop combination on N2O emissions, except for a minor effect of removing legume biomass before cover crop incorporation. This result is puzzling as we had observed on previous research differences in N2O emissions from cover crops. Emissions tended to be higher in legume cover crops like clover, and lower in gramineous cover crops like triticale. Furthermore, the smart tillage treatments were designed to enhance or inhibit the conditions for N2O production in the soil. Our hypothesis was that the effects of cover crop type and smart tillage were additive and therefore would have produced significant differences between treatment in N2O emissions, i.e., cover crop and smart-tillage combinations should have suppressed emissions. The results of the ANOVA for the cumulative N2O emissions of the experimental design with statistical model: N2O cumulative emissions = global mean + Year + Block + CoverCrop + Tillage + CoverCrop x Tillage + B x CC x T + Error, yielded the following results. Neither cover crop, tillage, or the interaction were statistically significant. The Year and Block effect were significant, with the year and block effect of comparable magnitude (Pr of > F of 0.001) Cumulative emissions were 15.8 and 6.1 kg/ha of N in years 2021 and 2022, respectively. Emissions from clover cover crops were on average about 20% higher than those from triticale, but these diffferences were not statistically significant (12.3 vs 9.8 kg/ha of N on average for both years). There was however substantial differences in emissions among blocks, highlighting the well know spatial variation of nitrous oxide emissions, but also obscuring treatment effects. Emissions in some blocks were staggeringly high (almost 50 kg of N as nitrous oxide in 2021; blocks 1 and 2), while others were very subdued (blocks 3 and 4). In plain terms, the most promising management practice to control emission is reducing the mass of legume incorporated after termination of the cover crop. In prior research, we stated that additions of aboveground biomass of legumes above 2 Mg/ha seems to trigger higher emissions. Therefore, we have soft evidence indicating that reducing emissions may depend on controlling the input of nitrogen via legumes. Surprisingly, mixing residues to dliute the mass of cover crops and manure in a larger soil volume had no significant effect on emissions. We are attempting other statistical analysis more suitable to the data structure (i.e. accounting for non-additivity of block effects) and that may change these primary conclusions. The magnitude of the emissions in some blocks are definitively among the highest that we have ever measured.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
McConnell, C.A., Rozum, R.K., Shi, Y. and Kemanian, A.R., 2023. Tradeoffs when interseeding cover crops into corn across the Chesapeake Bay watershed. Agricultural Systems, 209, p.103684.
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Progress 09/01/21 to 08/31/22
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Dr. Kemanian presented a webinar that included these results in a Cornell webinar series. Cornell Working Lands and Greenhouse Gases Webinar, 8 March 2022. Title: Organic Nitrogen Management for Greenhouse Gas Reduction in Agroecosystems: Between a Gentle Seesaw and a Catapult What do you plan to do during the next reporting period to accomplish the goals?Install Visisense instrumentation in the field to monitor the soil oxygen profile in a soil plane rather than just using the Apogee sensors.
Impacts
What was accomplished under these goals?
The field measurement campaign of 2022 was completed timely, thus complementing 2021 and fulfilling our experimental field goals. The year 2022 was substantially drier than 2021. In practice, it mean that sampling of dry soil required a substantial physical effort to keep work on schedule. We obtained about 3,500 gas samples in the field that were measured for carbon dioxide, methane, and nitrous oxide concentration using a gas chromatograph; 9,000 measurement of soil water content and temperature; 600 measurements of soil mineral nitrogen; and measurements of oxygen concentration in the soil, although these measurements were spottier and not very informative as the soil did not saturate during the time we had the sensors in the field. Nitrous oxide emissions were lower than in 2021, by a factor of a third or a half, and treatment effects were largely absent. Average emission were approximaely 6 kg/ha of N, still a relatively large number, but lower than the emission in the prior year (up to 15 kg/ha). Tillage effects were, surprisingly, very weak (not statistically significant). Cover crop biomass removal seems to be the only treatment that shows a consistent reduction in emission. Some of the environmental variables measured in 2022-2023 are shown in the figure below. Cleary, oxygen concentration was responsive to precipitation events and to increasing temperature. It takes several days for the oxygen concentration to recover after precipitation events, but it does not drop sharply. The sharp decrease in concentration in January is hard to interprete as it relates to freezing soil event. It is likely that subsoil oxygen consumption coupled to an ice-sealed topsoil explain this result. Figure 1. Temperature, precipitation, soil moisture and oxygen concentration in the top soil (10 cm) and the bottom of the plow layer (20 cm).
Publications
- Type:
Journal Articles
Status:
Submitted
Year Published:
2022
Citation:
Kemanian, A.R., Shi, Y., White, C.M., Montes, F., St�ckle, C.O., Huggins, D.R., Cangiano, M.L., Stefani-Fa�, G. and Nydegger Rozum, R.K., 2022. The cycles agroecosystem model: Fundamentals, testing, and applications. Testing, and Applications.
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Progress 09/01/20 to 08/31/21
Outputs
Target Audience:That primary target was academic and included both experts interested in developing methods to measure greenhouse gases, which are critical for climate commodities verification, and experts interested in the control of nitrous oxide. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A graduate student, Allison Koehle, will graduate in May of 2022 (graduated). Koehle become an expert on the science of N2O emissions in ag systems, and expert field and lab operator that can proficiently manage field experiments and sophisticated equipment, and an agile data analyst that use both parametric and non-parametric statistics for data analysis. How have the results been disseminated to communities of interest?Allison Koehle presented a poster with the operation of the semi-automatic chamber in Salt Lake City, at the annual ASA-CSA-SSSA meeting. The poster session was well attended. Private companies also expressed some interest in our work. What do you plan to do during the next reporting period to accomplish the goals?The experimental work will be repeated to collect two years of data, with no variation on the treatments. However, addition oxygen sensors will be added to each plot. We plant to submit a paper on methods (semi-automatic chamber) in 2022, and a paper with the results of the experiment by the end of 2023. Data on soil oxygen concentration remains to be analyzed.
Impacts
What was accomplished under these goals?
As planned, we measured nitrous oxide emissions and carbon dioxide emission from 40 plots growing cor in an organic experiment at Rock Spring PA. The main treatments were the preceding cover crop (triticale, red clover, or a mixture that include grasses and legumes), and the arrangement of manure and residue as incorporated in the soil. The treatments shought to reduce the concentration of animal manure and cover crops residues at the bottom of the plow layer by either separating animal manure from cover crops or by diluting the material through the plow layer, techniques lumped under the name smart tillage. A total of 2,880 flux determinations were completed through the growing season (40 plots x 4 gas samples = 160 samples x 18 days). When accumulated through the growing season, N2O emission for the system was high with highest emissions recorded in the legume cover crop treatments. Based on one year of data, emission with business-as-usual management was high (> 10 kg ha-1 of N2O-N during the growing season), confirming prior findings. Smart tillage techniques and removing aboveground legume biomass before corn planting did not decrease N2O emissions, indicating the potential for future research using deeper incorporation of residues. When the cover crop was tritical emissions were the lowest (11.4 vs 6.5 kg/ha of N2O-N) but grain yields decreased by 15% from 11 to 9.1 Mg/ha when comparing clover vs triticale. That also provides an estimate of the economic cost of reducing emissions in this system. High N2O emissions were strongly related to the CO2 emissions and lending credence to the hypothesis that high O2 consumption by microbial respiration is enabling high N2O emission by creating hypoxic but not anoxic conditions in the soil. A method to measure N2O emissions and other gas fluxes from the soil was greately improved through the development of an automated gas sampler. That allowed managing a large number of plots in tight time windows. The Visisens new optode sensor was set up for instalation in the field in the next year.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Saha, D., Kaye, J.P., Bhowmik, A., Bruns, M.A., Wallace, J.M. and Kemanian, A.R., 2021. Organic fertility inputs synergistically increase denitrification?derived nitrous oxide emissions in agroecosystems. Ecological Applications, 31(7), p.e02403.
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Progress 09/01/19 to 08/31/20
Outputs
Target Audience:The target audience remains the same and includes researchers, extension educators and through on-farm work stakeholders, i.e. producers, that can implement the practices investigated in this research. Changes/Problems:Testing new soil oxygen sensor that is more expensive but likely more stable under wet conditions. It is on loan from VisiSens, the same company that produces and sells the carbon dioxide and oxygen recording deviced. (We already purchased the imaging equipment.) What opportunities for training and professional development has the project provided?Allison Koehle, a Master of Science student, starting working on the project and is currently testing the oxygen sensors in the lab and setting up the model Cycles. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?Except for the delay caused by Covid, we have all elements to conduct the experiment in place and we will follow the protocol described in the proposal strictly. The only added piece is testing of the oxygen sensors in the lab and the modeling with Cycles, both well underway.
Impacts
What was accomplished under these goals?
We are in the first year of the experiment and we have accomplished the following: Objectives 1, 2 and 3: (i) The plot layout was carefully defined for the cover crop and tillage treatments; (ii) manure was purchased, mixed and applied at cover crop termination or as assigned to each treatment. The implementation of the treatments was postponed due to concerns about Covid-19. Objective 4) Equipment for measuring oxygen concentration has been purchased and is being test in the lab. We are testing fast reponse / less accurate and slower response / more accurate models from Apogee. We are also testing a more expesive but smaller sensor from VisiSens. In addition, we developed an automatic sampler for the static chamber used to measure nitrous oxide, carbon dioxide, and methane accumulation in the static chambers. The reason is that the field layout requires subtantial walking between plots. Time is a limitation, but also is the traffic on the plots. The new system, developed by Dr. Felipe Montes, is already operational in the lab. It uses electronically controlled valves and springs to "sample" a well mixed gas volume from chambers every 20 minutes. The system requires portable, rechargeable batteries. This innovative method will make sampling efficient and more standard. It is also safe: if a sample fails the chamber can be openned and the process completed by hand. We will publish a protocol with the method to make it available to other researchers. Restrictions due to Covid remain in place. We are planning to start our sampling campaign in Spring 2021, essentially resetting the clock one year. To compensate this delay, we started modeling the systems of interest with Cycles. A newly recruited student will complete simulations before the sampling starts.
Publications
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