Foliar nitrogen dynamics of representative woody plants seedlings grown under elevated ozone with a free-air system

Cong Shi1, Fankang Meng1,2, Toshihiro Watanabe1, Fuyuki Satoh3, Takayoshi Koike1*

Graduate School of Agriculture, Hokkaido University, Sapporo 060-8689, Japan

  1. College of Life Science, Nankai University, Tianjin 300071, China
  2. Hokkaido University Forests, Sapporo 060-0809, Japan

*Corresponding author: Takayoshi Koike:



To clarify effects of ozone (O3) on foliar nitrogen (N) contents dynamics in three representative woody plant seedlings: birch (Betula platyphylla var. japonica), oak (Quercus mongolica var. crispula), and beech (Fagus crenata) grown in elevated O3 (eO3), we investigated N contents in live and senescing leaves, the relation of N content differences and leaf mass per area (LMA) of each species. The 3 species seedlings were planted in a free-air O3 enrichment system for one growing season with 3 replicated plots exposed to the air or O3 at about 2.5 times the ambient. In our study, about 60 % of foliar N was retranslocated under eO3 conditions in birch; nearly 70 % of N in live leaves of oak was decreased by O3; and negative correlations were found between LMA and N at ambient. Based on the results, we discussed plausible understanding physiologically and biochemically to conclude that foliar N contents of birch is more sensitive than beech in response to O3, especially for the senescing leaves; on the other hand, LMA may be considered as an index parameter in speculation of the changes in foliar N contents at ambient O3 concentrations.


Setting and reaching institutional N Footprint reduction goals: a case study at the University of Virginia

Elizabeth S. Milo1, Elizabeth A. Castner1, Lia R.Cattaneo1, James N. Galloway1, Allison M. Leach2

1University of Virginia, 291 McCormick Rd, Charlottesville, VA, 22904 USA,

2University of New Hampshire, 131 Main Street, 107 Nesmith Hall, Durham, NH, 03824 USA


Reactive nitrogen is both essential and detrimental to life on Earth. While nitrogen is a key component of protein, it is also a pollutant that can cause climate change, eutrophication, and more. The University of Virginia (UVA) is the only university that has approved a nitrogen footprint reduction goal. This goal was approved by UVA’s governing board in 2013 and aims to reduce the University’s nitrogen footprint by 25% below 2010 levels by 2025. Note that for this study, the boundaries of the N footprint calculation at UVA include on-campus university operations but excludes the food component of the universities’ health system.  UVA has calculated its footprint for 2010 and 2014 and will continue to complete a benchmark calculation every four years. The UVA N footprint group and the Office for Sustainability have determined a number of scenarios to reduce the University’s N footprint. Examples of these include implementing a Meatless Mondays program, composting all food waste at the University and switching from coal to natural gas at the heating plant. Since the 2010 baseline year, UVA’s N footprint has changed from a total of 403 to 393 MT N; the total reduction needs to be to 303 MT N. The decrease in the universities N footprint can be partially attributed to the decrease in coal use in the universities’ heating plant.   UVA hopes to serve as a model for other universities and institutions that want to reduce their environmental impact by setting and achieving N reduction goals.

Monitoring and modeling of nitrogen leaching caused by nitrogen fertilizer application to green tea fields in Japan

Yuhei Hirono1, Shigekazu Nakamura2, Tomohito Sano3, Kunihiko Nonaka3

1 National Agriculture and Food Research Organization, 2769, Kanaya-Shishidoi, Shimada, Shizuoka, 428-8501, Japan, E-mail:

2 Shizuoka Prefectural Research Institute of Agriculture and Forestry, Mobata, Shimizu, Shizuoka, 424-0101, Japan

3 National Agriculture and Food Research Organization, 2769, Kanaya-Shishidoi, Shimada, Shizuoka, 428-8501, Japan


Large amounts of nitrogen fertilizer are required in the cultivation of tea (Camellia sinensis (L.)), relative to other crops, resulting in nitrate contamination of surrounding water systems and high rates of nitrous oxide emissions. In response to these problems, the amount of nitrogen fertilizer applied to tea fields in Japan has been decreased by the improvement of fertilizer application methods in recent years. In this study, we aimed to assess the changes in water quality due to the reduction of nitrogen input and determine the environmental response to improved fertilizer application methods in tea fields. First, we analyzed 21-year water quality monitoring data in an intensive tea-growing area in Japan. We found nitrate concentrations significantly decreased at most studied sites in water systems in the tea-growing area, indicating that water quality was improved by reducing nitrogen fertilizer application in tea fields. Second, we modeled nitrogen leaching from tea field soil based on the data obtained by lysimeter experiments. This showed that the calculated amounts of water and nitrogen leachate agreed well with the observed results.

Extending “SafeGauge for Nutrients” to high rainfall cropping in Australia

Kirsten Barlow1, Thabo Thayalakumaran2, Philip Moody3

1 Agriculture Victoria, DEDJTR,124 Chiltern Valley Road, Rutherglen, Victoria, 3685,

2 Agriculture Victoria, DEDJTR, 32 Lincoln Square North, Carlton, Victoria, 3053

3 Department of Science, Information Technology and Innovation, Brisbane, Queensland, 4000


As agricultural systems continue to intensify there is a need for farmers and farm advisors to understand how soil, climate and management interact to affect nitrogen (N) losses at the paddock scale. Computer-based decision support tools have been widely used to build farm advisors’ capacity to understand the risks of N losses to the environment. However, existing tools often only provide an average annual risk of nitrogen loss from a paddock, even though nitrogen export is dependent on daily interactions between soil water content, water movement through deep drainage and runoff pathways and N availability. In this paper we present the design of a decision support tool for high rainfall cropping systems building on SafeGauge for Nutrients (developed for the sugarcane industry in Queensland, Australia). This tool (SG_Grains), allows users to define the system including location, cropping season, soil type and management decisions (e.g. fertiliser rate and timing, cultivation, stubble management). Information on management practices is combined with relevant modelled daily crop growth, soil water, drainage and runoff sourced from a library of simulation runs for various soil types and climates. Taking account of  N uptake and cycling, the daily nitrogen balance and risks of nitrogen losses via the various pathways are calculated. The risks are then modified to account for differences in slope and paddock position in the landscape. The results are presented as a risk gauge for all three loss pathways (runoff, leaching and denitrification), as well as a summary report on nitrogen input/output balance for the selected paddock. SG_Grains will be used as part of the training for advisors within the Fertcare Program, allowing the investigation of how management affects the risk of N export through various pathways.

Nitrogen Budget on Township Scale in North China Plain

Xinsheng NIUa  Baojing GUb  Xiaotang JUc[1]

a Qu Zhou Experimental Station, China Agricultural University, Quzhou 057250, PR China.

b Department of Land Management, Zhejiang University, Hangzhou 310058, PR China.

c College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, PR China.


To find out the critical problems of reactive nitrogen (Nr) on township scale and ascertain Nr flows in basic agricultural farming unit, we carried out a research of Nr budget at the township scale in North China Plain (NCP). Results showed that chemical N fertilizer dominants the Nr imported into a town, which was concerning with complex economic, social and conventional issues. Low Nr using efficiency in cropland subsystem was found in ecotone of agriculture-animal husbandry due to natural condition dependent and meteorological changes adaptive crop. Environmental Nr loads mainly derived from cropland subsystem due to excessive N fertilizer application and irrational applying universally used in NCP. Thus, application rates of N fertilizer synchronized to demand of crop and alternatives of scientific and advanced application measurements were necessary. Huge losses of Nr during storage of human feaces and manure due to inaccessible to treatment facilities and ignoring the rational management on wastes should be given a priority consideration. The extension of new extensive technologies of livestock husbandry for achieving higher converting ratio of feed and provided with facilities of treating manure with great efforts seem necessity especially in ecotone of agriculture-animal husbandry.

Integrating nitrogen footprints across scales: from institution to watershed

Elizabeth A. Castner1, Allison Leach2, Beth McGee3, James N. Galloway4

1 University of Virginia, Charlottesville, VA, 22903,,

2 University of New Hampshire, Durham, NH

3Chesapeake Bay Foundation, Annapolis, MD

4 University of Virginia, Charlottesville, VA


Nitrogen footprints provide an important link between the body of work concerning human alteration of the global nitrogen cycle and the actions that can be taken by individuals, institutions, and policy-makers. The nitrogen footprints calculated for institutions of higher education serve as a link between research, education, and management. The research component demonstrates which activities of the institution contribute most heavily to nitrogen pollution in the form of a data-intensive sustainability metric, which in turn is used to educate the community and promote management strategies that reduce the institution’s impact. Nitrogen footprints for individuals also serve as education and management tools, and can be applied in regions where nitrogen pollution has the most effect. A nitrogen footprint calculation tool for residents of the Chesapeake Bay watershed (USA) aims to teach users how their actions impact water quality in the bay and suggests actions that individuals can employ to reduce their impact. In both institutional and individual N footprints, the most important sector is food production. Broad changes in consumption patterns have the most potential for reduction. The Nitrogen Footprint Network addresses the needs of multiple communities at different scales, and data collected from novel footprint calculations for institutions and individuals informs how best to reduce their N pollution.

NBudget: A simple tool for farmers and advisors for N management in Australia’s northern grain cropping

David Herridge1

1 School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351,,


Effective management of plant-available nitrogen (N) by farmers will generally have beneficial productivity, economic and environmental consequences. The reality is that farmers may be unsure of plant-avalable N levels in cropping soils at sowing and by necessity make decisions about how much fertiliser N to apply with limited information about soil N supply. NBudget is an excel-based decision-support (DS) tool developed to assist farmers/advisors in Australia’s northern grains region estimate (i) plant-available soil N and water levels pre-sowing, (ii) target yields, (iii) fertiliser N requirements for cereals and oilseed crops and (iv) N2 fixation by legumes. NBudget does not rely on soil testing either for nitrate-N, organic carbon or water. Rather, the tool relies on rainfall data plus basic descriptions of soil texture and fertility, tillage practice, information about the previous two years paddock use plus rules-of-thumb values and stand-alone or linked algorithms. Winter and summer versions of NBudget cover the major crops of the region. Groundtruthing of NBudget against three independent data sets (n=55) indicated generally close agreement between measured and predicted values for sowing soil nitrate (r2=0.76). A limitation of the tool is that it does not account for denitrification losses of soil N. The usefulness of NBudget would be enhanced by transforming the current Excel-based tool to a stand-alone app or web-based tool.

What is the nitrogen footprint of organic food in the United States?

Laura Cattell Noll1, Allison M. Leach2, Verena Seufert3, James N. Galloway1, Brooke Atwell1, Jan Willem Erisman4, Jessica Shade5

1 University of Virginia, 291 McCormick Rd, Charlottesville, VA, 22903,, 22903 USA,

2 University of New Hampshire, 131 Main Street, 107 Nesmith Hall, Durham, NH, 03824 USA

3 University of British Columbia, 6476 NW Marine Drive, Vancouver, BC, V6T 1Z2, Canada

4 Louis Bolk Institute, Hoofdstraat 24, 3972 LA, The Netherlands; VU Amsterdam, The Netherlands

5 The Organic Center, 444 N. Capitol St. NW, Suite 445, Washington D.C. 20001 USA


Using a nitrogen (N) footprint model, we estimated the Nr lost per unit Nr consumed for organic food production in the United States and compared it to conventional production. Additionally, we quantified the types of Nr inputs (new versus recycled) that are used in both production systems.

Nr losses from organic crop and animal production are estimated to be of comparable magnitude to conventional production losses. While Nr losses from organic grains and vegetables are slightly higher (+13%, +43%, respectively), and from organic starchy roots and legumes slightly lower (-1%, -17% respectively), losses from organic poultry, pigmeat, beef and dairy production are generally higher than from conventional production (+40%, -7%, +58%, +81%, respectively). Due to high variability and high uncertainty in both systems, we cannot make conclusions yet on the significance of these differences. Conventional production relies heavily on the creation of new Nr (70-90% of inputs) whereas organic production primarily utilizes already existing Nr (0-50% of inputs from new Nr).

Consuming organically produced foods has little impact on an individual’s food N footprint, but it changes the percentage of new Nr in the footprint. Per unit N in product, Nr losses from organic production are comparable to conventional production, but organic production introduces less new Nr to the global pool.

For the full paper, please contact Laura Cattell Noll at

Nitrogen use efficiency as an indicator for monitoring the environmental sustainability of maize production in central Chile

Osvaldo Salazar1, Ricardo Cabeza1, Yasna Tapia1, Claudia Rojas1, Carla Soto1, Miguel Quemada2, Manuel Casanova1

1 Departamento de Ingeniería y Suelos, Facultad de Ciencias Agronómicas, Universidad de Chile, Santa Rosa 11315, Santiago, postcode 1004, Email:

2 Technical University of Madrid (UPM), Ciudad Universitaria, Madrid, 28040. Email:


The main purpose of this study was to evaluate the Nitrogen Use Efficiency (NUE) as an indicator for monitoring the environmental sustainability of maize production in the O’Higgins Region in central Chile. Additionally the NUE indicator was used for evaluating the extension services offered for a Clean Agreement Program (CAP) developed for the Chilean Government for the maize-farmers in this Region. A crop management survey was carried out in 80 maize fields during the season 2014-2015, where most of the NUE values were less than 50% using traditional farmer N fertilisation rates, being related to N over-fertilisation. For the 2016-2017 season, 85% of the NUE values would be between the two NUE references values of 50% and 90% if a N recommendation scenario based on a mass N balance by the CAP is applied by the maize-farmers. Thus NUE showed that it is necessary to reduce the N input for improving the environmental sustainability of maize production in this Region.

Nitrogen performance indicators on southern Australian grain farms

Robert Norton1, Elaina vanderMark2

1 International Plant Nutrition Institute, 54 Florence St, Horsham, Victoria, 3400, Australia,,

2 Southern Farming Systems, 23 High St, Inverleigh, Victoria 3321, Australia.


A survey was undertaken of 118 growers covering 474 fields over five years across south-eastern Australia. Crop type, grain and hay yield, residue management and fertilizer use were recorded and used to derive N partial nutrient balance (PNB) and N partial factor productivity (PFP). Estimates of the amount of N derived from biological fixation were made for pulse crops. Fertilizer N rates were higher for the higher rainfall regions, averaging 39 kg N/ha for cereals and 56 kg N/ha for oilseeds. Biological nitrogen fixation (BNF) was estimated for the fields based on legume seed or estimated pasture yields and BNF accounted for 16%, 29%, 14% and 50% of the N input for the High Rainfall Zone, Mallee, Southern New South Wales and Wimmera respectively.  The regional median values for both PNB and PFP were higher than the mean values, indicating that there were relatively more high values in all regional data sets. Median PNB was less than 1 of all regions, but there were over 10% of fields in the High Rainfall Zone and the Mallee where PNB was more than 2, and the mean N deficit was highest in those regions at 13 kg N/ha/y and 10 kg N/ha/y respectively. PFP values were highest in Mallee, possibly a consequence of the inherently lower soil N status there. These data demonstrate that understanding the inherent variability in nutrient performance indictors, and also linking soil fertility assessments, is important in developing strategies to improve nutrient management.