On farm comparison of two liquid dairy manure application methods
On-Farm Comparison of Two LiquidDairy Manure Application Methods inTerms of Ammonia Emission, OdorEmission, and CostsL. Chen, M. de Haro Marti, W. Gray, H. Neibling,M. Chahine, and S. K. R. Yadanaparthi.From Waste to Worth ConferenceDenver, ColoradoApril 3rd, 2013
Outline Introduction Objective What we did Results Summary Acknowledgements
Introduction Dairy production stands as the single largest agricultural pursuitin Idaho. Currently, Idaho is the third largest milk productionstate in the US. A number of dairies in Magic Valley use flushing systemsresulting in a huge amount of lagoon water which is applied tocrop land via irrigation systems. The volatilization of ammonia from irrigated lands is not only aloss of valuable N, but also cause air pollution.
Introduction Concentrated dairy production in a limited area such as theMagic Valley has caused air and water quality concerns. Manure direct injection has been proven in other regions toeffectively manage odors and manure nutrients.
Objective The purpose of this project was to demonstrate, evaluate, andencourage the widespread adoption of the manure directinjection method in southern Idaho for mitigating odor andammonia emissions.
What we did A manure application field day was held on adairy in Buhl, Idaho.
What we did On-farm manure application trials conducted attwo sites were comprised of two manureapplication methods: surface broadcast anddeep injection.
What we did At each of the sites, a square plot of about 3,600 m2(200 X 200 ft) was used for surface broadcast.200 m1.5 m towersPassive NH3 samplerSoil temperature probeswith a data logger
What we did Passive NH3 samplers were used to determine the NH3concentration at each location. Ammonia samplers werechanged approximately every 24 hours over a two-day period. Air samples were collected from test site 1 for odor evaluation. For each test site, one liter of liquid manure was collected forpH and total nitrogen analysis.
What we did A soil temperature probe with a data logger was used to recordsoil temperature data in 15-min increments. Weather data were obtained from local Buhl Airport. Cost analysis was carried out for four different manure landapplication systems.
ResultsTable 1. manure pH and total N concentrations and application rates of total N at the two test sitesSite and Application Method Manure pHManure total Nconcentration (mg/L)Manure Total NApplication Rate (kg/acre)Site 1 7.4 3433 257Site 2 7.3 3519 265Table 2. Ambient weather conditions and soil temperature at the test sitesSite 1 Site 2Item Day 1 Day 2 Day 1 Day 2Average wind speed, m/s 5.0 4.2 4.2 3.1Air temperature, average(minimum, maximum),˚F61 (42, 78) 49 (45, 63) 49 (45, 63) 47 (38, 61)Average relative humidity, % 28 53 53 51Soil temperature, average(minimum, maximum),˚F50.9 (51.1, 56.1) 47.3 (51.1, 51.2) 46.5 (51.5, 52.1) 66.7 (51.6, 69.1)
Results00.20.40.60.8126.96.36.199.8Broadcast Injection BackgroundAmmonia(mgofNH3-N/m3)Sampling location00.20.40.60.8188.8.131.52.8Broadcast Injection BackgroundAmmonia(mgofNH3-N/m3)Sampling locationFirst day from test site 1 Second day from test site 1The NH3 data from test site 1 showed 82% and 64% reduction in NH3concentration for first and second sampling days, respectively whenliquid manure was applied by subsurface injection vs. surface broadcast.
Results00.20.40.60.811.21.4Broadcast Injection BackgroundAmmonia(mgofNH3-N/m3)Sampling location00.20.40.60.811.21.4Broadcast Injection BackgroundAmmonia(mgofNH3-N/m3)Sampling locationFirst day from test site 2 Second day from test site 2The NH3 data showed 64% and 41% reduction in NH3 concentration forfirst and second sampling days, respectively when liquid manure wasapplied by subsurface injection compared with surface broadcast.
ResultsManure applicaiton system Total Cost ($/acre)Tank system with broadcasting $22.20*Tank injection using disk injection $29.89*Tank injection using knife injection $30.74*Drag hose system with knife injection $67.48*Time and equipment to refill the tank is not included in these calculations.The subsurface injection method has higher costs mainly due to theneed of larger tractor and lower operating speed.
Summary Subsurface injection can reduce both the odor and NH3 emissionscompared with surface broadcast; therefore, applying liquid dairymanure by subsurface injection could be recommended as one ofthe best management practices to control NH3 and odor emissions. The estimated costs associated with subsurface injection werehigher than surface broadcast. However, the higher costs could becompensated by the higher nitrogen fertilizer value captured in thesoil by the subsurface injection method.
AcknowledgementsThis project was supported by the USDA Natural ResourcesConservation Service through a Conservation InnovationGrant.We would also like to thank Dr. April Leytem and Mr. MylesMiller (USDA Northwest Irrigation and Soils Researchlaboratory (NWISRL) for their help with analysis of ammoniasamples.