N2O emission in maize-crops fertilized with pig slurry, matured pig manure or ammonium nitrate in Brittany

Posted in: Environment by admin on January 1, 2008 | No Comments

N2O is a potent greenhouse gas and solutions have to be sought to reduce its emission from agriculture. This work evaluates N2O emission from maize-crop (Zea mays) fields submitted to different organic or mineral fertilizers (pig slurry, matured pig manure or ammonium nitrate) in Brittany (France). N2O emission was evaluated along a year in two experimental sites receiving 110 or 180 kg N ha1 as ammonium nitrate or pig slurry and 180 or 132 kg N ha1 as ammonium nitrate or matured pig manure at Champ Noel and Le Rheu experimental plots, respectively. N2O emission was evaluated by interpolation method of periodic fluxes on the field scale and by simulation with NOE algorithm using measured soil characteristics such as N content and gravimetric moisture and other soil biological properties determined in a previous study (potential denitrifying activity, N2O/[N2O + N2] ratio during denitrification) or drawn from literature. On the whole N2O emissions vary between 0.3 kg N ha1 year1 in an unfertilized plot and 2–4 kg N ha1 year1 under ammonium nitrate fertilization. They were higher under N fertilizer application than without N fertilizer but no significant effect of type of N fertilizer was observed on either site. However, N2O losses immediately after fertilizer application were higher under pig slurry and matured pig manure, while measured and predicted fluxes showed that greater N2O losses occurred from summer to winter under ammonium nitrate application. This could be mainly explained by higher mineral N contents at Le Rheu and higher N2O/(N2O + N2) ratio at both sites. The NOE model predicted higher annual N2O emission and emission factor with ammonium nitrate at Champ Noe¨l only and similar emissions for both treatments at Le Rheu. These results suggest that in this climate and soil context the use of pig slurry or matured pig manure did not have a stimulating impact on N2O emissions in comparison with a plot receiving a mineral fertilization.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/01678809

Bringing the Soil Back

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Manure from a Missouri hog operation set up by the Brinker brothers – Kenny, Dale and Ronnie – has been an integral part of bringing back soil that had been depleted of nutrients and severely eroded. When it comes to environmental stewardship, and nutrient management, the Brinker brothers of Missouri were instrumental in literally bringing a farm back from the brink. In 1993, the three brothers – Kenny, Dale and Ronnie Brinker – set up a hog operation, Harrison Creek Farm, near Auxvasse, Missouri, about two hours west of St. Louis. The land the hog operation was located on, however, was depleted of nutrients and severely eroded. It has been a long, steady climb back since then, but good soil conservation practices and a comprehensive nutrient management plan have taken what was barren soil to high levels of productivity. And an integral part of bringing some of the acreage back involved the use of manure effluent from the swine operation. Harrison Creek Farm has built up a relationship with the University of Missouri, which is basically down the road in Columbia. They had the assistance of nutrient specialists John Lorey and Charlie Fulhage in laying out operations on the farm, and determining the best site for the hog barns and the lagoon. There have been other significant improvements to the farm. Some 36 different waterways have been installed on their total acreage through Missouri’s Continuous CRP and federal EQIP programs. Six miles of terraces have been built, draining water into the waterways, helping to prevent erosion. There have been subsequent land purchases since they first set up the farm – the Brinkers now farm 4400 acres, mostly a corn soybean rotation, all no-till. Kenny noted they purchased a nearby farm in the last several years, and they’ve since carried out grid sampling on that acreage and – for the first time – are trying variable rate fertilization. There may be further land purchases, Kenny added. “A lot of financial advisors would tell you to spread your investment out, buy a little of this and a little of that. But from our perspective, we’ve grown up knowing how to farm and are very comfortable with that. “If we have the ability and things work out well, we would probably buy other farmland in the area. We take great enjoyment in taking a piece of ground like we had here that was a little neglected and bringing it back into productivity and making it a nice looking place.”

Forage Subsurface Drip Irrigation Using Treated Swine Wastewater

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The overall study objective was to determine the feasibility of using subsurface drip irrigation (SDI) for treated wastewater effluent applications. It was found that treatments using wastewater effluent had significantly higher hay yields and significantly higher nutrient biomass removal rates than the commercial fertilizer treatments. Nitrate-N observed in soil water lysimeters increased with depth, indicating the potential for leaching without proper management. Soil nitrogen and carbon were not significantly different for any of the treatments but did vary slightly over the life of the project.

Technical efficiency and impact of environmental regulations in farrow-to-finish swine production in Taiwan

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This article demonstrates how technical efficiency and the impact of environmental regulations of Taiwanese farrow-to-finish swine production can be estimated in the presence of undesirable outputs. The issue of measuring technical efficiencies while considering undesirable outputs has been addressed by past studies. But the proper method of including undesirable outputs has always been a subject of debate. This article develops a data envelopment analysis (DEA)-based model that includes undesirable outputs. The technologies of desirable output production and undesirable
output control are considered simultaneously. This allows one to transform undesirable output into desirable output, whereby a traditional Shephard distance function can be used to measure technical efficiencies. An approach to measuring the impacts due to environmental regulations is then derived. Empirical results show that larger farms are more technically efficient than small-sized farms, but no clear conclusions can be reached for the measures of regulatory impact among farms with different sizes. On average, the sample farms incurred an opportunity cost due to  evironmental regulations equivalent to 9.8% of market value. Opportunity costs rise with efficiency.

For more information the full article can be found at http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1574-0862/issues

Best Management Practices to Improve the Productivity and Environmental Sustainability of Grassland Pasture Systems

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Expansion of the hog sector in Manitoba from less than 2 million head in 1980 to more that 8 million head in 2006 (Knowledge Management, Manitoba Agriculture, Food and Rural initiatives); has created opportunities for the beef and dairy cattle industries to improve forage productivity through the application of hog manure. Although the use of hog manure as a fertility source in grassland pasture systems may be mutually beneficial to hog and cattle producers, there are still many aspects of this practice that require further study in the Manitoba production environment including both productivity and environmental sustainability as measured by greenhouse gas production (including enteric methane emissions and soil nitrous oxide/methane emissions), as well as the potential for nutrient accumulation/ movement within the soil and movement of pathogens from hog manure to soil, forage and cattle. To accomplish these objectives, a research/demonstration site was established in September 2003. Treatments examined were i) manure application and ii) method of forage removal. Three strategies for manure application were used: i) no manure; ii) manure applied as a single application of 110 lbs of available N delivered in the spring; iii) manure applied as a split application with 55 lbs available N applied in the spring and 55 lbs of available N applied in the fall. Soil nutrient profiles were examined prior to manure application and in the fall of each study year (prior to the Split manure application) to determine if elements in the applied manure moved through the profile towards groundwater. The elements of interest included available nutrients, nitrogen and phosphorus, as well as chloride. Nutrient profiles in soil up to 120 cm did not show an accumulation of available nitrogen or phosphorus with manure application. Chloride, which served as a marker to determine if nitrate leaching occurred, tended to be highly variable under manured plots. An increase in Cl- concentration at 60-90 and 90-120 cm depths for replicate 1 of the Control-hayed and replicate 2 of the Control-grazed plots occurred following the very dry summer and fall of 2006. Detailed sampling and analysis of plant available nitrogen and phosphorus clearly showed an increase in phosphorus in the near soil surface (0-5 cm) of manure-treated soil (>44 ppm Olsen-P compared to <12 ppm in Control treatments). It is important to note that these projections are based on a relatively small data set. In contrast to available P, available nitrogen (ammonium and nitrate) did not increase in the near soil surface layer. The influence of cattle on nutrient distribution near watering and mineral supplement sites was also examined. Surface soil nutrient concentrations were much greater for bare earth areas (area of high animal traffic around waterers and supplements) compared to grassed areas in 2005 and in 2006. Phosphorus, nitrate and chloride were all very high in the bare earth areas. In 2006, phosphorus levels were highest in the 0.5 cm depth of the bare earth zone. The results indicate that urine and dung deposition in high traffic areas can create areas within grazed land that have extremely high nutrient levels. Movement of waterers and mineral supplement to a new location is advised to prevent the establishment of nutrient accumulation in bare earth areas. Application of hog manure on hayfields increased forage yield relative to hayfields receiving no fertility. Average standing forage biomass generated in Control, Split and Full hayfields were 2.9, 7.0 and 6.7 ± 0.21 t ha, respectively. In addition to increased yield, nutrient profile of the forage was also significantly improved. Mean standing forage crude protein (CP) was lowest in unmanured standing forage (7.5 ± 0.26 % CP), while Split and Full hayfields had CP concentrations of 10.2 and 11.0%, respectively. Neutral detergent fibre was higher in Split hayfields (61.8 ± 1.05 %) than in Control (57.3%) but not different than Full (59.6%) due to its advanced state of maturity at cutting. Gross energy was highest in manured hayfields (18.3, 18.7 and 18.6 ± 0.06 kJ g-1 DM, in Control, Split and Full hayfields, respectively. Application of hog manure also increased nutrient profile of pasture forages relative to those receiving no fertility. Mean forage CP was almost doubled with manure application. Serum urea nitrogen was measured in the grazing cattle to determine overall protein status of the animals. Steers grazing unmanured pastures had lower serum urea N values compared to steers grazing manured pastures. Animal intake and enteric methane emissions (% GEI) were unaltered by the changes in forage quality as a result of manure application. The addition of hog manure increased pasture carrying capacity over the grazing season by more than three-fold compared to unmanured pastures, which averaged 89 grazing days ha yr. Animal productivity increased from 100 kg gain ha for unfertilized to 319 and 339 kg gain ha for Split and Full pasture treatments, respectively. Nitrogen and phosphorus (P) removal efficiencies based on nutrients applied were significantly greater in the hayed system compared to the pastoral system, in which only 4.9 % of applied N and 5.0 % of the applied P were removed. Greenhouse gas emissions as affected by manure application and timing were also measured from soil. Nitrous oxide from soil was clearly the most important of the greenhouse gases produced in 2004 and 2006 while methane predominated in 2005, a year which was characterized by increased precipitation. Over the three study years, average net N2O and CH4 emissions, expressed as kg CO2 equivalent ha, increased from 63 for the Control treatment to 196 and 250 for the Split and Full hayed treatments, respectively. However, net N2O and CH4 emissions were unaffected by manure treatment when expressed as kg CO2 equivalent kg live weight gain ha over the study period (0.633 Control, 0.613 Split and 0.738 Full kg CO2 eq. kg live weight gain ha). Root mass C in the 0-5 cm depth was 2,695 and 3,588 kg C ha for the Control- and Full-hayed plots in replicate 1 (Figure 19). As such, manure application resulted in 900 kg C ha or about 3,300 CO2 eq. ha; a value significantly higher than the 897 CO2 eq. ha associated with emissions of CH4 from soil, direct N2O emission from soil and indirect emission of N2O from volatilization of ammonia in the Full-hayed plots. Presence of Salmonella, Yersina and E. coli were examined using both standard culture and DNA techniques. Salmonella and E. coli were present in hog manure at the time of application to the experimental plots during both years studied. Yersinia enterocolitica was not detected in hog manure at anytime during the study. Salmonella and E. coli were detected on forage two days after manure application but were not detected on forage before cattle were grazed. Salmonella was not detected in soil at any time before or after manure application during both years of the study. During this study, Salmonella and E. coli present in hog manure did not appear to have been transferred to cattle grazing manure-treated fields. Low numbers of E. coli and Salmonella on vegetation and in soil at the time cattle started to graze may have been the main reason cattle did not acquire organisms from the applied hog manure. Research data gathered from this site has resulted in the submission of three scientific publications, with five others in preparation. The site has also served as an excellent location for student training at both the graduate and undergraduate level. Two students have successfully completed graduate programs with data collected from the site while three more students are in the process of completing their postgraduate degrees. Finally, the site has served as an excellent means of communicating information regarding productivity and environmental sustainability of grassland systems to the agricultural sector and the community at large.

Development and Comparison of Backpropagation and Generalized Regression Neural Network Models to Predict Models to Predict Diurnal and Seasonal Gas and PM10 Concentrations and Emissions From Swine Buildings

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The purpose of this study was to employ backpropagation neural network (BPNN) and generalized regression neural network (GRNN) techniques to model GPCER generated and emitted from swine deep‐pit finishing buildings as affected by time of day, season, ventilation rates, animal growth cycles, in‐house manure storage levels, and weather conditions. Good results were found which indicated that the artificial neural network (ANN) technologies were capable of accurately modeling source air quality within and from the animal operations. However, it was also found that the process of constructing, training, and simulating the BPNN models was very complex. Thus, the GRNN was characterized as a preferred solution for its use in air quality modeling.

Principal Components Analysis to Evaluate Secondary and Tertiary Ponds For Piggery Waste Treatment

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Stabilization ponds have been used to treat piggery waste. In order to better understand the interactions among
the variables and the factors governing the process of degradation in the ponds and to identify the predominant factors in every stage (pond) of the treatment system, the principal components analysis (PCA) was employed in this study. The work was performed in an experimental treatment system comprising a primary (an equalizer, a settling tank, and two anaerobic ponds), a secondary (a high rate algal pond), and a tertiary treatment step (two maturation ponds and one water hyacinth pond), in series. The PCA was applied for the secondary and the tertiary steps of the treatment. It was evident that in the high rate algal pond (HRAP), the main artificial factors were: nutrient removal, algae growth and stabilization process; in the first maturation pond (MP1), nutrient removal, aerobic conditions and organic matter concentration; in the second maturation pond (MP2), nutrient removal and algae growth; and in the water hyacinth pond (WHP), nutrient removal, temperature, and algae growth. The PCA showed the importance of the aerobic conditions associated with the efficient performance of the treatment system.

For more information the full article can be found at http://asae.frymulti.com/toc.asp

Scale model experiments to determine the effects of internal airflow and floor design on gaseous emissions from animal houses

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Odours and gases emitted from animal houses are strongly related to airflows. Knowledge of the exchange mechanisms between air and the manure surface in the slurry pit, and between air and the soiled surfaces and animals within the building may lead to novel and efficient ways of reducing the odour emission. To investigate the effects of airflow patterns, and floor and slurry channel designs, on gaseous emissions, four 1:10 scale models were built; each identical except for their floor and slurry channel layouts. The floor types investigated were two configurations of partly
solid and two configurations of fully slatted floors. Ammonia water was circulated from a storage tank to a reservoir of ammonia water at the bottom of each model with an air space between the water surface and the floor. Provision was made for enough ammonia to be available for prolonged evaporation. Ventilation air was supplied under the ceiling at one end wall. The air outlet was placed in the ceiling halfway between the two end walls and about 1/3rd from one of the sidewalls.  Ammonia concentration was measured in the outlet air. The results showed that the average NH3 concentration in the outlet air was significantly affected by the different airflow patterns created by the floor type and slurry channel layout. Using a partly solid, dry floor as a reference the effect of soiling the solid floor resulted in more than double the NH3 concentration in the outlet air. The use of fully slatted floors with slurry channels parallel to the supply air jet resulted in a 57% increase in the emission values compared with the reference model whilst using slurry channels under the fully slatted floor perpendicular to the supply air jet increased the emission values by only 22%.
It is hypothesised that the effects on gas emissions are as a consequence of changing airflow patterns and different types of flow in the boundary layer between the slurry and ventilation air. The results from the scale model experiments need to be validated with fullscale experiments.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/15375110

Models for Manure Distribution in Soil Following Liquid Manure Injection

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In this study, manure distribution in soil was measured by characterizing the manure‐soil mix zone following liquid manure injection. The results showed that for both winged and simple tools, the zone was significantly greater at an increased micro‐rate of manure application, as indicated by the increased zone area, perimeter, major axis, and minor axis.

Meeting environmental requirements for the land application of manure

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In an effort to save regulatory resources, the US Environmental Protection Agency and individual
states have interpreted the Clean Water Act in a manner that authorizes discharges from concentrated
animal feeding operations without the review of nutrient management plans. Environmental groups have
objected to the abbreviated regulatory procedures, and courts have ruled that permitting agencies must review
substantive documentation of effluent limitations contained in nutrient management plans. Proposed new federal regulations prescribing the requirement of a meaningful review of appropriate documentation by the permitting agency respond to the judicial mandates. To facilitate regulatory approval, regulators might use a state certification program to achieve the obligatory meaningful review. Independent certifiers would ensure that an operation’s land application of
manure meets federal water quality requirements.

For more information the full article can be found at http://jas.fass.org/