Location: Northwest Irrigation and Soils Research2015 Annual Report
Objective 1. Determine the effects of fertilizer source and fertilizer additives on nutrient budgets in irrigated agricultural systems. (Tarkalson 0.5, Leytem 0.5, Dungan 0.2, Ippolito 0.15). Subobjective 1.1. Identify effects of fertilizer source, and nitrification and urease inhibitors on ammonia and greenhouse gas emissions from soils under irrigation. Subobjective 1.2. Identify effects of fertilizer source, and nitrification and urease inhibitors on carbon, nitrogen, and phosphorus cycling and losses from soils under irrigation. Subobjective 1.3. Identify effects of fertilizer source, and nitrification and urease inhibitors on crop nutrient removal from soils under irrigation. Objective 2. Develop utilization practices for agricultural byproducts to increase nutrient and water use efficiency. (Lentz 0.5, Lehrsch 0.4, Ippolito 0.1). Subobjective 2.1. Identify effects of biochar and other amendments on soil carbon, nitrogen, and micronutrient budgets and water availability over time. Subobjective 2.2. Identify the effects of agricultural byproducts and soil water content on the emissions of carbon dioxide and nitrous oxide gases from freezing and thawing soils.
The research for all objectives will be conducted at the ARS Northwest Irrigation and Soils Laboratory in Kimberly, ID. Project objectives will be achieved through three main studies conducted at different scales to improve our understanding and management of soil nutrients. Research for Objective 1 involves a five year field study comparing soil ammonia and greenhouse gas emissions, soil nutrient cycling and crop nutrient uptake from selected fertilizer or manure treatments combined with nitrification and urease inhibitors. More detailed field and laboratory studies will be used for Objective 2.1 to identify the effects of biochar and other amendments on nutrient cycling. Research in Objective 2.2 entails a laboratory study to collect detailed information about greenhouse gas emissions from soils during freeze thaw cycles. This project will broaden scientific knowledge of nutrient cycling in the agricultural fields to which dairy manures and fertilizers are applied, determine if selected agricultural byproducts and amendments can assist in managing nutrients and reducing emissions in arid agricultural systems, and help us better understand nutrient cycling within the broader system through validated process based models. Data from this project will be provided to scientists and organizations to improve and validate nutrient cycling models, and for other related analysis (USDA and USEPA greenhouse gas inventories, the Integrated Farm System (IFSM) model, the Voluntary Reporting of Greenhouse Gases Carbon Management Evaluation Tool (COMET-VR), the Daily Century Model (DayCent), and Dairy Management Inc. life cycle analysis).
Gas, soil and plant samples were collected for the third year in GRACEnet (Greenhouse gas Reduction through Agricultural Carbon Enhancement network) plots receiving manure, compost, commercial fertilizer or SuperU, an enhanced-efficiency nitrogen fertilizer. Data from the previous two years demonstrate that SuperU can reduce nitrous oxide emissions from irrigated cropping systems compared to conventional urea nitrogen fertilizer. Alfalfa was planted in the spring of 2015 and will remain for at least two years without any fertilizer applications. A long term crop rotation study, initiated in 2012 in cooperation with the University of Idaho, is examining nutrient cycling and greenhouse gas emissions from irrigated cropping fields receiving annual or biennial dairy manure applications. Sugar yields from sugar beet grown in 2014 were highest for biennial manure applications. Soil samples show increasing phosphorus concentrations in the soil profile with the highest manure application rates. The small scale container study with biochar and manure treatments was continued for another season to obtain a one-time measurement of soil physical properties. Greenhouse gas emissions and nitrogen cycling results from the field experiment showed that amending soils with biochar, a byproduct of bio-oil production, potentially could remove excess atmospheric carbon dioxide while improving soil quality. The laboratory incubation microcosm experiments showed that increasing biochar application rates improves the soil water holding capacity, yet excessive biochar application rates led to significant decreases in plant-available soil nitrogen. Applying biochar with manure eliminated the decreases in plant-available nitrogen. A freeze-thaw study with soil columns revealed that greenhouse gas emissions during light freezes, typical of spring and fall, may substantially contribute to the non-growing season emissions. Protocols to simulate these emissions are being planned. This study will continue with intact soil cores collected from a long-term field experiment with and without manure applications.
1. Biochar increases available nitrogen from manure amendments. Amending soils with biochar, a byproduct of bio-oil production, could remove excess atmospheric carbon dioxide while improving soil quality. ARS researchers at Kimberly, Idaho, and St. Paul, Minnesota, measured plant-available nitrogen and greenhouse gas emissions from plots treated with biochar and/or manure. Although biochar decreased carbon dioxide emissions from soil, it also decreased corn yields under particular soil conditions. Combining biochar with manure eliminated potential yield reductions from biochar while increasing nitrogen availability from manure. This demonstrated the synergy of applying biochar and manure to soil.
2. Sugar beet yields are similar between manure and urea fertilizer. Manure is frequently applied to many fields in southern Idaho due to the large number of dairy farms in the area. Farmers often avoid applying manure before planting sugar beet because they are concerned about effects on crop quality and sucrose content. ARS researchers at Kimberly, Idaho, in collaboration with University of Idaho researchers at Parma and Moscow, Idaho, determined that applying dairy manure, composted dairy manure or urea fertilizer resulted in similar sucrose yields. At one site, impurities in sugar beet roots increased with higher manure or compost application rates but were not different at the second site. Thus, producers can use manure and compost for sugar beet production.
Ippolito, J.A., Spokas, K.A., Novak, J.M., Lentz, R.D., Cantrell, K.B. 2015. Biochar elemental composition and factors influencing nutrient retention. In: Lehmann, J., Joseph, S., editors. Biochar for Environmental Management: Science, technology, and implementation. 2nd edition. New York, NY: Routledge. p. 137-161.
Koehn, A.C., Lehrsch, G.A., Busscher, W.J., Evans, D.E., King, B.A., Stieneke, D.L., Sojka, R.E. 2014. Aggregate tensile strength and friability characteristics of furrow and sprinkler irrigated fields in Southern Idaho. Communications in Soil Science and Plant Analysis. 45:2712-2720.
Lehrsch, G.A., Brown, B., Lentz, R.D., Johnson-Maynard, J.L., Leytem, A.B. 2014. Sugarbeet yield and quality when substituting compost or manure for conventional nitrogen fertilizer. Agronomy Journal. 107(1):221-231.
Barbarick, K.A., Ippolito, J.A., Mcdaniel, J. 2015. Uptake coefficients for biosolids-amended dryland winter wheat. Journal of Environmental Quality. 44:286-292.
Ippolito, J.A., Barbarick, R.B., Brobst, R.B. 2014. Copper and zinc speciation in a biosolids-amended, semiarid grassland soil. Journal of Environmental Quality. 43:1576-1584.
Lentz, R.D., Ippolito, J.A., Spokas, K.A. 2014. Biochar and manure effects on net nitrogen mineralization and greenhouse gas emissions from calcareous soil under corn. Soil Science Society of America Journal. 78:1641-1655.
Blecker, S., Stillings, L., Decrappeo, N., Ippolito, J.A. 2014. Soil-plant-microbial relations in hydrothermally altered soils of Northern California. Soil Science Society of America Journal. 78:509-519.