Location: Northwest Irrigation and Soils Research2014 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).
Objective 1. Gas samples were collected for the second year in GRACEnet plots that were fertilized with manure, compost, urea or slow release fertilizer. Since the project was delayed one year, barley was planted in 2014 and alfalfa will be planted after the barley is harvested. Soil samples were obtained in the Fall of 2013 after corn harvest. Nutrient uptake by barley will be determined after harvest in 2014. Two studies were initiated in 2014 to evaluate current nitrogen fertilizer recommendations. A study was established to evaluate the effect of manure and commercial nitrogen fertilizer application on sugar beet production to potentially revise commercial nitrogen fertilizer recommendations. Eight commercial nitrogen fertilizer rates were applied to soils that had received dairy manure or commercial fertilizers from 2004 to 2009. Sugar beet plant growth, root yield, sucrose yield, and quality are being measured. The second study was initiated to update commercial nitrogen fertilizer recommendations for irrigated corn in the Pacific Northwest and evaluate alternative application timing and controlled release nitrogen fertilizers. Several locations in the Pacific Northwest, representing different soils and micro-climates, will be selected each year for three years. At each site, nitrogen fertilizer will be applied at five rates. For selected rates, an alternative timing and nitrogen source will be compared to the conventional timing and nitrogen source. Corn silage and grain yield, and soil nitrogen will be monitored. A long term study was initiated in the fall of 2012 in cooperation with the University of Idaho to examine nutrient cycling and greenhouse gas emissions from irrigated cropping fields receiving either commercial fertilizer or annual or biannual dairy manure applications at three rates. Manure was applied in the fall each year and incorporated into the soil with a crop rotation of wheat, potatoes, barley and sugar beet. Greenhouse gas emissions (nitrous oxide, carbon dioxide, and methane) from the soils were monitored throughout the year, excluding times when temperatures were below freezing. In addition, soil sampling, plant sampling, and harvest data are used to determine the amounts of nutrients and salts that are utilized by the crops, removed from the fields, remain in the soil, and leached through the soil profile. This information will be used to better estimate nutrient cycling and losses from cropping systems that utilize manure. Objective 2. Monitoring of biochar field research plots was completed. The smaller scale outdoor pot study was continued for another season to determine interacting effects of biochar and manure on crop nutrient uptake. Greenhouse gas emission and nitrogen cycling results from the field experiment were submitted for publication. Protocols for measuring greenhouse gas emissions from freezing and thawing soil cores under controlled conditions have been tested and data collection initiated. Preliminary results indicated that nitrous oxide emissions decreased by a factor of four as manured soil was frozen. This fall, intact soil cores will be collected from manured and control plots of a long-term field experiment for additional freeze/thaw experiments. Emission data from these cores will provide both a check and real-world validation of data already collected.
1. Carbon budget for an irrigated corn field. Because soils store more than three-quarters of the earth’s terrestrial carbon, small changes in agricultural management practices can cause large environmental mass transfers of soil carbon. Yet few studies have evaluated the entire carbon budget for an agricultural system. For the first time, a study by ARS researchers at Kimberly, Idaho, determined the total carbon budget in an irrigated corn field, including organic and inorganic carbon inputs from the atmosphere, irrigation water, and amendments, and outputs from gas emissions, crop biomass removal, irrigation runoff, and deep percolation. Although soil carbon gas emissions were 18% greater from manure treated plots, these plots had a net carbon increase at the end compared to a net carbon loss for commercial fertilizer plots. This information defines critical pathways that remove and store carbon in a cropped system, which will better focus future carbon research to reduce atmospheric greenhouse gas concentrations.
2. Fertilizers and manure alter carbon transfers in an irrigated corn field. It is difficult to determine how fertilizer and manure differ in their effect on soil carbon storage because of the numerous carbon transfers that occur in agricultural systems. An ARS study at Kimberly, Idaho, comprehensively examined the carbon budget in irrigated corn plots treated with either fertilizer (low carbon) or dairy manure (high carbon) amendments. Applying manure added more carbon to the soil but did not increase carbon in furrow irrigation runoff or water percolating through the soil. The indirect effect of manure on soil properties, such as aggregate stability, was an important factor that promoted soil retention of manure-supplied carbon. This information will help develop management practices that increase carbon storage in agricultural soils and potentially reduce greenhouse gas accumulations in the atmosphere.
3. Biochar application improves soil water retention without altering microbial communities. Applying biochar to soil may improve the soil nutrient and water status. Based on results from a field study, ARS researchers at Kimberly, Idaho, conducted controlled laboratory studies to investigate biochar effects on nutrient cycling, microbial populations, and water relations. Biochar application increased plant available iron and manganese, carbon, microbial respiration and bacterial populations, and decreased soil nitrate-nitrogen. While biochar application at 10 and 20 tons per acre increased soil water retention, biochar applications greater than 20 tons per acre significantly altered the microbial community structure. A recommended biochar application rate of 10 tons per acre was established to improve soil water retention without altering microbial community composition. This provides a target biochar application to improve nutrient and water use efficiency in crop production settings.
Biswas, S., Shapiro, C.A., Kranz, W.L., Mader, T.L., Shelton, D.P., Snow, D.D., Bartelt-Hunt, S.L., Tarkalson, D.D., Van Donk, S.J., Zhang, T.C., Ensley, S. 2013. Current knowledge on the environmental fate, potential impact, and management of growth-promoting steroids used in the US beef cattle industry. Journal of Soil and Water Conservation. 68(4):325-336.
Ducey, T.F., Ippolito, J.A., Cantrell, K.B., Novak, J.M., Lentz, R.D. 2013. Addition of activated switchgrass biochar to an aridic subsoil increases microbial nitrogen cycling gene abundances. Applied Soil Ecology. 65:65-72.
Moore, A., Hines, S., Brown, B., Falen, C., De Haro Marti, M., Chahine, M., Norell, R., Ippolito, J.A., Parkinson, S., Satterwhite, M. 2014. Soil-plant nutrient interactions on manure-enriched calcareous soils. Agronomy Journal. 106:73-80.
Ippolito, J.A., Stromberger, M., Lentz, R.D., Dungan, R.S. 2014. Hardwood biochar influences calcareous soil physicochemical and microbiological status. Journal of Environmental Quality. 43(2):681-689.
Lentz, R.D., Lehrsch, G.A. 2014. Manure and fertilizer effects on organic and inorganic carbon losses and budget for an irrigated corn field. Soil Science Society of America Journal. 78:987-1002.
Spokas, K.A., Novak, J.M., Masiello, C.A., Johnson, M., Colosky, E., Ippolito, J.A., Trigo, C. 2014. Physical disintegration of biochar: An overlooked process. Journal of Environmental Science and Technology. 1(8):326-332.