Effects of Adding Clinoptilolite Zeolite on Dairy Manure Composting Mix on the Compost Stability and Maturity

The purpose of this project was to demonstrate the effects of adding natural clinoptilolite zeolites to a dairy manure compost mix at the moment of initiating the composting process on characteristics of the final compost and nitrogen (N) retention. On-farm composting of manure is one Best Management Practice (BMP) available to dairy producers. Composting reduces the volume of composted wastes by 20 to 60% and weight by 30 to 60%, which allows the final product to be significantly more affordable to transport than raw wastes. When done properly, composting can convert a considerable fraction of the N present in the raw manure into a more stable form, which is released slowly over a period of years and thereby not partially lost to the environment (Rynk et al., 1992; Magdoff and Van Es, 2009). During the manure handling and composting process, between 50 and 70% of the N can be lost as ammonia (NH3) if additional techniques are not used to increase nitrogen retention. Most of the time, manures from dairies and other livestock operations don’t have the proper carbon to nitrogen ratio (C:N) to be composted efficiently without added carbon. A balanced mix for composting should be between C:N of 30:1 to 40:1 (Rynk et al., 1992; Fabian et al., 1993). Since manures are richer in nitrogen (C:N ratios below 15:1), and bedding doesn’t add enough carbon during most of the year, a great proportion of the available N is lost as NH3 due to the lack of carbon to balance the composting process, resulting in a lower grade compost that can generate local and regional pollution due to NH3 emissions. In many arid zones there are not enough sources of carbon to balance the nitrogen present in the manure. Due to this lack of adequate carbonaceous material, additional methods to reduce the loss of N as NH3 during the composting process are needed. Several amendments have been evaluated in the past to achieve this reduction in N loss (Ndegwa et al., 2008). Zeolites are minerals defined as crystalline, hydrated aluminosilicates of alkali and alkaline earth cations having an infinite, open, three-dimensional structure. Clinoptilolite zeolite is mined in several western states including Idaho, where mining is near the dairy production areas.

This paper showcases an on-farm project that explored the effects of adding clinoptilolite to dairy manure at the time of composting as a tool to reduce NH3 emissions, retain N in the final composted product, and evaluate its effect on the final product.

What did we do?

This on-farm research was conducted at an open-lot dairy in Southern Idaho with 100 milking Jersey cows. Manure stockpiled during the winter and piled after the corral’s cleaning was mixed with fresh pushed-up manure from daily operations and straw from bedding and old straw bales, in similar proportions for each windrow. The compost mixture was calculated using a compost spreadsheet calculator (WSU-Puyallup Compost Mixture Calculator, version 1.1. Puyallup, WA). Moisture was adjusted by adding well water to reach approximately 50% to 60% moisture on the initial mix. Windrows were mixed and mechanically turned using a tractor bucket. Three replications were made for control and treatment. The control (CTR) consisted of the manure and straw mix as described. The treatment (TRT) consisted of the same mix as the control, plus the addition of 8% w/w (15%DM) of clinoptilolite zeolite during the initial mix. Windrows were actively composted for 149 days on average. Ammonia emissions were measured using passive samplers (Ogawa & Co. Kobe, Japan) and results were described in a previous Waste to Worth proceeding paper (de Haro Martí, et al. 2017). Complete initial manure (compost feedstock mix) and final screened compost nutrient lab analyses were performed for each windrow. Compost maturity tests were performed using the SOLVITA® test (Woods End Laboratories, Mt Vernon, ME). Statistical analyses were conducted using SAS 9.4 (SAS Institute, Cary, NC). Analyses included ANOVA (PROC MIXED) and paired t-test when applicable.

What have we learned?

The initial mix lab analysis revealed no significant differences in all parameters between control and treatment, except for ammonium (NH4+) where a tendency was observed. Many of the most stable parameters were very close to one another numerically, indicating a good management of the on-farm feedstock formulation and mixing. Ammonium at 553.4±100 mg/kg for CTR and 256.77±100 mg/kg for TRT showed a tendency (0.05<p≤0.1, Figure 1).

Figure 1. Ammonium ppm before and after composting   
Figure 1. Ammonium ppm before and after composting

This difference from the beginning of the process indicates that clinoptilolite has an immediate impact on NH4+ when added to the compost mix, changing the NH4+ and NH3 behavior and volatilization even during the construction of the windrow.

Nitrate (NO3) concentration in the TRT compost, 702±127 mg/kg was three times higher than the CTR, 223±127 (p= 0.05, Figure 2).

Figure 2. Nitrate ppm before and after composting
Figure 2. Nitrate ppm before and after composting

The presence of such high amount of NO3 compared to the control indicates a strong prevalence of nitrification processes (Sikora and Szmidt, 2001; Weil and Brady, 2017). Elevated NO3 concentrations are desirable in high quality compost used in plant nurseries, green houses, and horticulture, and are usually obtained from feedstock with much higher carbon content than the one used in this research. The NO3 to NH4+ ratio (NO3:NH4) in the treated windrows is also indicative of a much more stable compost than what is to be expected in a dairy compost with such low initial C:N (Sikora and Szmidt, 2001). High NO3 concentrations in compost could, however, generate a concern for NO3 leaching if the compost is not managed properly during storage and at the time of application (Miner et al., 2000; Weil and Brady, 2017). Total nitrogen (TN) on the compost was 14,933±1,379 mg/Kg (1.5%) for CTR and 11,300±1,379 mg/Kg (1.1%) for TRT (p=0.13), showing no significant difference.

Table 1. Solvita® test results on finished compost
Sample TRT or CTR

CO2
Index

NH3
Index

Maturity Index Compost Condition O2 depletion Phytotoxicity Noxious hazard pH NH4+ Estimate (ppm) N-Loss potential
W 1 CTR 6.5 3.5 5.5 Curing 1.60% Medium/ Slight Moderate /Slight 9.1 500 Moderate/Low
W 2 CTR 6.5 2 4.5 Active 2.50% High Severe 9.3 1500 M/ High
W 5 CTR 6.5 2 4.5 Active 2.50% High Severe 9.8 1500 M/ High
W 3 TRT 7 5 7 Finished 0.70% None None 9.5 <200 V Low-None
W 4 TRT 7 5 7 Finished 0.70% None None 8.9 <200 V Low-None
W 6 TRT 6 5 6 Curing 1.20% None None 9.3 <200 V Low-None

The Solvita® test results from the screened composts (Table 1) show a significant difference (p=0.007) in the NH3 test results between CTR, index 2.5±0.35 and TRT, index 5.0±0.35. Carbon Dioxide (CO2) test results showed no significant differences between CTR and TRT. All other calculated parameters showed a significant difference between control and treatment. Maturity index was 4.8±0.33 for CTR and 6.7±0.33 for TRT (p<0.02). Oxygen depletion was 0.022±0.002 for CTR and 0.009±0.002 for TRT (p<0.02). NH4+ estimate was 1167 for CTR and <200 for TRT (p=0.05). Other estimated test parameters indicate a significant difference between CTR and TRT results. Control windrows showed more unstable conditions, reaching the active or curing status, medium to high phytotoxicity, moderate to severe noxious hazard, and moderate to low N-loss potential. In contrast, treatment windrows showed more stable conditions, including reaching finished and curing status, no phytotoxicity or noxious hazard, and very low to no N-loss potential.

These results, coupled with the NO3:NH4 ratio and much higher NO3 values in the zeolite amended compost, indicate that the addition of clinoptilolite zeolite to a dairy manure compost mix in this study induced nitrification processes, produced NH4+ retention, NH3 emissions reduction, and lower oxygen depletion without significantly modifying the CO2 production. It also led to compost maturity characteristics that are regularly achieved only in compost mixes with much higher carbon content  and C:N ratios, usually associated with high quality composts. No negative effects were observed in the composting process or final product.

Future Plans

A greenhouse trial on silage corn comparing treatment and control compost effects followed. Results need to be analyzed and published.

Authors

Mario E. de Haro-Martí. Extension Educator. University of Idaho Extension, Gooding County, Gooding, Idaho. mdeharo@uidaho.edu  

Mireille Chahine. Extension Dairy Specialist. University of Idaho Extension, Twin Falls R&E Center, Twin Falls, Idaho.

Additional information

 

References:

de Haro-Martí, M.E., H. Neibling, M. Chahine, and L. Chen. 2017. Composting of dairy manure with the addition of zeolites to reduce ammonia emissions. Waste to Worth, Advancing Sustainability in Animal Agriculture conference. Raleigh, North Carolina.

Fabian, E. E., T. L. Richard, D. Kay, D. Allee, and J. Regenstein. 1993. Agricultural composting: a feasibility study for New York farms. Available at:  http://compost.css.cornell.edu/feas.study.html . Accessed 04/28/2011.

Lorimor, J., W. Powers, A. Sutton. 2000. Manure Characteristics. Manure Management System Series. Midwest Plan Service. MPWS-18 Section 1. Iowa State University.

Magdoff, F., & Van Es, H. (2009). Building soils for better crops – Sustainable soil management (3rd ed.). Brentwood, MD, USA: Sustainable Agriculture Research and Education program.

Miner, J. R., Humenik, F. J., & Overcash, M. R. 2000. Managin livestock wastes to preserve environmental quality (First ed.). Ames, Iowa, USA: Iowa State University Press.

Mumpton, F.A. 1999. La roca magica: Uses of Natural Zeolites in Agriculture and Industry. Proceedings of the National Academy of Sciences of the United States of America, Vol.     96, No. 7 (Mar. 30, 1999), pp. 3463-3470

Ndegwa, P. M., Hristov, A. N., Arogo, J., & Sheffield, R. E. 2008. A review of ammonia emission mitigation techniques for concentrated animal feeding operations. Biosystems Eng. (100), 453-469.

Rink, R., M. van de Kamp, G.B. Willson, M.E. Singley, T.L. Richard, J.J. Kolega, F.R. Gouin, L.L. Laliberty Jr., D.K. Dennis. W.M. Harry, A.J. Hoitink, W.F.Brinton. 1992. On-Farm Composting Handbook. NRAES-54. Natural Resource, Agriculture, and Engineering Service. Cooperative Extension. Ithaca, New York.

Sikora, L. J., & Szmidt, R. A. 2001. Nitrogen sources, mineralization rates, and nitrogen nutrition benefits to plants from composts. In P. J. Stofella, & B. A. Kahn (Eds.), Compost utilization in horticultural cropping systems (pp. 287-306). Boca Raton, Florida, USA: CRC Press LLC.

Weil, R. R., & Brady, N. C. 2017. The nature and properties of soils (Fifteenth. Global Edition ed.). Harlow, Essex, England: Pearson Education Limited.

Acknowledgements

This project was made possible through a USDA- ID NRCS Conservation Innovation Grants (CIG) # 68-0211-11-047. The authors also want to thank the involved dairy farmer and colleagues that helped during this Extension and research project. Thanks to USDA-ARS Kimberly, ID for the loan and sample analysis of the Ogawa passive samplers.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

 

Composting of Dairy Manure with the Addition of Zeolites to Reduce Ammonia Emissions

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Purpose

The purpose of this project was to demonstrate the effects of adding natural clinoptilolite zeolites to a dairy manure compost mix at the moment of initiating the composting process on ammonia emissions, nitrogen retention, composting performance, and characteristics of the final compost product. A typical dairy cow in the U.S. produces approximately 148 lb of manure daily (feces and urine, not counting bedding; Lorimor et al., 2000). This amounts to millions of tons of monthly manure production. On-farm composting of manure is one of the most-used practices to manage dairy manure in Idaho. Composting reduces manure volume between 35 and 50%, which allows the material to be significantly more affordable to transport than fresh, wet manure. Composting converts the nitrogen (N) present in the raw manure into a more stable form, which is released slowly over a period of years and thereby not totally lost to the environment. Composting contributes to alleviating problems associated with ground and surface water contamination and also reduces odor complaints (Rink et al., 1992; Fabian et al., 1993). During the manure handling and composting process, between 50 and 70% of the nitrogen can be lost as ammonia if additional techniques are not used to increase nitrogen retention. In most cases, manures from dairies and other livestock operations don’t have the proper carbon to nitrogen (C:N) ratio to be composted efficiently without added carbon (usual straw bedding has a C:N of 60 to 90). Dairy cow manure is rich in nitrogen (C:N ratios below 18:1), causing a great proportion of the available nitrogen to be lost as ammonia due to the lack of carbon to balance the composting process. The loss of nitrogen from manures as ammonia reduces the nutrient value of the manure, produces an inefficient composting process, and generates local and regional pollution. Lack of carbon also results in a lower-grade compost that can carry elevated concentrations of salts, potassium and phosphorous. In many arid zones there are not enough sources of carbon to balance the nitrogen present in the manure.

Zeolite is a mineral defined as a crystalline, hydrated aluminosilicate of alkali and alkaline earth cations having an infinite, open, three-dimensional structure. Zeolites are able to further lose or gain water reversibly and to exchange cations with and without crystal structure (Mumpton, 1999). Zeolites are mined in several western U.S. states where dairy production also is concentrated. This paper showcases a project that explored the effects of adding natural zeolites to dairy manure at the time of composting as a tool to reduce ammonia emissions and retain nitrogen in the final composted product.

What did we do?

This on-farm research and demonstration study was conducted at an open-lot dairy in southern Idaho with 100 milking Jersey cows. Manure stockpiled during the winter and piled after the corral’s cleaning was mixed with freshly collected manure from daily operations and straw from bedding and old straw bales, in similar proportions for each windrow. The compost mixture was calculated using a compost spreadsheet calculator (WSU-Puyallup Compost Mixture Calculator, version 1.1.; Puyallup, WA). Moisture was adjusted by adding well water to reach approximately 50% to 60% moisture on the initial mix. Windrows were mixed and mechanically turned using a tractor bucket. Three replications were made on control and treatment. The control consisted of the manure and straw mix as described. The treatment consisted of the same mix as the control, plus the addition of 8% of clinoptilolite zeolite by weight during the initial mix. Windrows were actively composted for four months or more. Ammonia emissions were measured using passive samplers (Ogawa & Co., Kobe, Japan) for the first five to seven days after building each windrow (called turn 1 in Figure 1) and after the two subsequent turns. Ammonia emissions per measurement period and per turn were obtained. Three periods of one to three days at the time of building each windrow and after the first turn were measured. After the second turn, two measurement periods of three to four days were made. Values of mg NH3-N/m3 are time-corrected by minutes of sampling (Figure 1). Complete initial manure (compost feedstock mix) and final screened compost nutrient lab analyses were performed for each windrow. Analyses of variance (ANOVA) on lab data and on ammonia samples were performed using SAS 9.4 (SAS Institute, Cary, NC).

Figure 1. Ammonia emissions per period and turn

What have we learned?

The addition of 8% w/w natural zeolites to the dairy manure compost mix on a mechanically turned system using a tractor bucket reduced cumulative ammonia emissions by 11% during the first three turns (Figure 2) and showed a significant reduction trend in ammonia emissions. Figure 1 shows the differences and trend line in ammonia emissions per monitoring period and per turn. Treated windrows’ cumulative emissions were significantly lower (P<0.05) at 2.76 mg NH3-N/m3 from control windrows at 3.09 mg NH3-N/m3. Nitrates (NO3) on the composted treatment (702 ppm) were 3 times greater (p=0.05) than the control (223 ppm) (Figure 3). These results demonstrate that the addition of natural zeolites has a positive effect on reducing ammonia emissions during the composting process and increasing the conversion to nitrates, retaining nitrogen in the compost in a form that is more available to crops.

Figure 2. Cumulative ammonia emissions

Figure 3. Nitrate, ppm before and after composting

Future Plans

Field days and journal publications about this project are expected to occur within the next year.

Corresponding author, title, and affiliation

M. E. de Haro-Martí. Extension Educator. University of Idaho Extension, Gooding County, Gooding, Idaho.

Corresponding author email

mdeharo@uidaho.edu

Other authors

M. Chahine. Extension Dairy Specialist. University of Idaho Extension, Twin Falls R&E Center, Twin Falls, Idaho. H. Neibling. Extension Irrigation Engineer. University of Idaho Extension, Kimberly R&E Center, Kimberly, Idaho. L. Chen. Extension Waste Management Specialist,

Additional information

References:

Fabian, E. F., T. L. Richard, D. Kay, D. Allee, and J. Regenstein. 1993. Agricultural composting: a feasibility study for New York farms. Available at: http://compost.css.cornell.edu/feas.study.html . Accessed 04/28/2011.

Lorimor, J., W. Powers, A. Sutton. 2000. Manure Characteristics. Manure Management System Series. Midwest Plan Service. MPWS-18 Section 1. Iowa State University.

Mumpton, F.A. 1999. La roca magica: Uses of Natural Zeolites in Agriculture and Industry. Proceedings of the National Academy of Sciences of the United States of America, Vol. 96, No. 7 (Mar. 30, 1999), pp. 3463-3470

Rink, R., M. van de Kamp, G.B. Willson, M.E. Singley, T.L. Richard, J.J. Kolega, F.R. Gouin, L.L. Laliberty Jr., D.K. Dennis. W.M. Harry, A.J. Hoitink, W.F.Brinton. 1992. On-Farm Composting Handbook. NRAES-54. Natural Resource, Agriculture, and Engineering Service. Cooperative Extension. Ithaca, New York.

Acknowledgements

This project was made possible through a USDA- ID NRCS Conservation Innovation Grants (CIG) # 68-0211-11-047. The authors also want to thank the involved dairy farmer and colleagues that helped during this Extension and research project. Thanks to Dr. April Leytem and her technicians at USDA-ARS in Kimberly, ID, for the loan of the Ogawa passive samplers and for sample analysis.

Composting of Dairy Manure and Grape Vine Prunings as a Tool to Better Manage Both Industries Waste and Reduce Their Environmental Impact


Why Look at Grapevine Prunings As a Compost Feedstock?

The objectives of this research and Extension project were:

  • To determine the impact of mixing grape vine prunings with dairy manure in a compost mix on the composting process and final product.
  • In particular, we were interested in determining if nitrogen gets fixated into the compost mix with increased carbon content.
  • To evaluate if composting is a workable alternative to annual grape vine prunings burning. Stopping this annual burning will reduce vineyards environmental footprint.
  • To demonstrate three different on-farm composting techniques. Mechanically turned (MT), passive aerated (PA), and forced aerated composting (FA).

What did we do?

field day at compost pilesWe teamed up with a grape and a dairy producer and we built a series of windrows to showcase the three different composting techniques and to research the effects of mixing both waste streams. Grape vine prunings were grounded and mixed with open lot dairy manure. Carbon content of the mix was adjusted to meet organic production standards since the vineyard hosting the project was certified organic. Since the carbon to nitrogen ratio (C:N) of the grounded grape vine prunings was on the low side (80:1), horse stable sawdust and straw from the local county fairgrounds were also used to help increase the C:N. Three replications of each system (MT, PA, and FA) were built with the enhanced carbon mix. A third set of three replications with dairy manure as received (some straw but no added carbon) were built using the mechanically turned system (MTMA) to serve as a control and comparison for that system. In addition to collecting data to evaluate th e effects of the added carbon, the project included two field days where all the systems, how to construct them, and their advantages and challenges were showcased.

What have we learned?

carbon to nitrogen rationThe initial feedstock mix C:N was significantly higher in the carbon enhanced windrows as expected, but the final C:N ratio of the compost was not significantly different among most systems and between the enhanced mix and the just manure mix (Figure 1). The C:N reduction between the initial mix and the final compost was significant in all systems of the carbon enhanced windrows, but not significant in the just manure mix (MTMA).

total nitrogenAs expected, the initial mix total nitrogen (TN) was significantly lower in the carbon (C) enhanced windrows compared to the just manure windrows (Figure 2). TN in the finished compost had no significant difference among all the systems. The difference between the initial mix and final compost TN wasn’t significant among C enhanced windrows, but highly significant in net values (10.08 Lb/T of N on dry weight basis; p<0.0001) on the just manure windrows. This difference in TN, coupled with the no significant difference in C:N, suggests the loss of nitrogen as ammonia during the composting process in the windrows made of just manure. Net nitrogen loss was significantly lower in the C enhanced windrows (1.45 Lb/Ton).

saltsSalts concentrations (mmhos) difference between initial mixes and final compost was significant in all windrows, with higher values in the final compost as expected due to the concentration effect that composting volume reduction has (Figure 3). Salt concentrations in the just manure windrows were significantly higher compared to the carbon enhanced mix. There is a dilution effect when carbon is added in the initial mix (lower manure mass per initial mix unit). Similar dilution trends were observed for phosphorous (P), potassium (K), and micronutrients. Carrying this dilution effect in the final compost can be beneficial when land applying compost since application rates can be increased, increasing the nitrogen and carbon content of the application (desirable conditions) by the time the limiting components in our soils (usually P, K, or salts) are reached.

Screening of the carbon enhanced windrows generated a refuse (bigger size particles) containing pieces of grape prunings that can be used as mulch to control weeds in the vineyard or other production units. When PFRP is achieved, plant pathogens in the mulch can be considered absent or inhibited, and the mulch will be usable on the same or similar plant species.

The PA and MT windrows with enhanced carbon mix reached USEPA-PFRP. FA system didn’t reach PFRP and had an incomplete composting process because of the lack of moisture in the initial mix due to problems with water supply during their construction. Other studies conducted by the authors using FA with similar feedstock had reached PFRP. MTMA windrows didn’t reach PFRP, a common event in the region due to the low carbon content of dairy manure.

Future Plans

This project demonstrated that composting of dairy and potentially other livestock manures mixed with woody wastes from the grape industry or similar agricultural products is not only feasible but beneficial for both industries. Further research is necessary to determine how different carbon and animal manures sources, especially harder woods, will affect the composting process and the final product.

Authors

Mario E. de Haro-Martí. Extension Educator. University of Idaho. mdeharo@uidaho.edu

Mireille Chahine, Extension Dairy Specialist
Tony McCammon, Extension Educator
Ariel Agenbroad, Extension Educator. University of Idaho

Additional information

Unpublished data. Please contact the author, Mario E. de Haro-Martí at mdeharo@uidaho.edu or 208-934-4417.

Acknowledgements

The authors want to thank the participating grape and dairy producers for their collaboration. This project was funded by an Idaho USDA-NRCS Conservation Innovation Grant (CIG).

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.