Feature Presentation | INI 2016

Putting an economic value on nitrogen pollution in Europe: can we improve the unit N cost method using results of the Eurobarometer?

2016 INI, Feature Presentation, Nitrogen science and policy

Hans J.M. van Grinsven¹

¹Department: Water, Agriculture and Food, PBL Netherlands Environmental Assessment Agency, PO box 303 | 3720 AH, The Hague, The Netherlands

Abstract

The unit N cost method was applied for the European Nitrogen Assessment (ENA) to monetize the social cost of impacts of N pollution on human health, ecosystems and climate stability for the European Union. Unit costs are based on Willingness To Pay (WTP) of people to prevent these impacts by reducing N pollution. Underlying cost-impact data for various impacts came from diverse sources, apply to different periods and sometimes regions. Incompatibility of data sources may have created artefacts, like an apparent five time higher unit N cost to prevent impacts of N on aquatic ecosystems than on terrestrial ecosystems. This paper explores if we can validate and improve the unit N cost method using the Eurobarometer surveys by the European Commission. This survey polls societal concerns in the European Union including those for environment. A preliminary estimate of the social cost of N pollution in 2013-2014 for the European Union based on the Eurobarometer is more than three times lower than the value for 2008 as derived in ENA and differences in this cost between low and high GDP countries are larger than reported in ENA.

Options to decrease N losses from our global food system

2016 INI, Feature Presentation, Nitrogen science and policy

J.G. Conijn¹, J.J. Schröder¹, P.S. Bindraban²

¹Wageningen University and Research centre, Droevendaalsesteeg 4, 6708 PB, Wageningen, the Netherlands, http://www.wageningenur.nl. Email address of corresponding author: sjaak.conijn@wur.nl.

² VFRC-IFDC, 1901 Pennsylvania Ave., NW. Washington, DC 20006. USA.

Abstract

Food production causes losses of reactive nitrogen (N) to the detriment of the environment but the current level of losses per unit food leaves room for improvement. Due to feedback mechanisms a comprehensive analysis is needed and we developed a quantitative model of the whole food system to assess the effects of improvement measures on the required amount of N fertilizer and resulting N losses as function of food demand. For 2010 we calculate a total N loss from agricultural soils and ammonia volatilization of 172 Mt N y^-1 and an amount of 32 Mt N y^-1 entering households in food items. This implies a N loss ratio of 5.4 kg N lost per kg N purchased by households. Due to higher food demand and changed diet as projected for 2050, the N loss ratio increases to almost 6.0 if equal N use efficiencies are used as in 2010 and the total N loss amounts to 293 Mt N y^-1. The effects of a number of improvement measures are explored, such as less animal-based products in the human diet and reduced N loss from agricultural soils. Single measures can reduce this ratio to as low as 3.8 but when all measures are combined, the ratio drops to 2.0 with a total N loss of 84 Mt N y^-1 without affecting the projected food demand for 2050. Our results clearly illustrate that the effectiveness of measures cannot be realistically estimated without taking the whole system into account and that the N loss ratio is a better indicator to estimate environmental impacts of N use than N use efficiency.

Nitrogen and the Sustainable Development Goals

2016 INI, Feature Presentation, Nitrogen science and policy

David R. Kanter, Xin Zhang, Clare M. Howard³

¹Department of Environmental Studies, New York University, 285 Mercer Street, New York, NY, 10003, USA, david.kanter@nyu.edu

² University of Maryland Center for Environmental Science, 301 Braddock Rd., Frostburg, MD, 21532, USA, xin.zhang@umces.edu

³Centre for Ecology and Hydrology, Bush Estate, Scotland, EH26 OQB, UK, inms@ceh.ac.uk, www.inms.international

Abstract

The United Nations’ new Sustainable Development Goals (SDGs) aim to maximize social, economic and environmental wellbeing, from ending hunger and poverty, to enhancing access to education and healthcare, to protecting biodiversity. The inevitable overlap between these broad goals call for implementation strategies that can exploit potential co-benefits. Improving nitrogen management provides a key opportunity for strengthening the three pillars of sustainable development, given nitrogen’s widespread uses and impacts. For example, nitrogen inputs are fundamental to modern food production and rural livelihoods, with Haber-Bosch nitrogen responsible for the existence of almost half the world’s current population. And yet nitrogen pollution is also one of the most important environmental issues of the 21^st century, contributing to air and water pollution, biodiversity loss, climate change and stratospheric ozone depletion. Consequently, improving humanity’s complex relationship with nitrogen could be a key component of implementing the SDGs from local to global scales, as well as measuring progress towards them. This study examines the links between nitrogen management and the SDGs. We identify 16 of the 17 goals as relevant to nitrogen management, and group them into three categories: those that require more nitrogen, those that require less nitrogen, and those that could help improve nitrogen management. The “Towards an International Nitrogen Management System” project has taken the first steps to create a science support system for the emerging nitrogen policy community, which could be used to better integrate nitrogen management into implementation strategies for the Sustainable Development Goals.

Nitrogen dynamics in deep ploughed soils of North Germany

2016 INI, Biological N fixation and cropping systems, Feature Presentation

Rolf Nieder¹, Zaur Jumshudov¹, Viridiana Alcántara², Axel Don², Reinhard Well²

¹Institute of Geoecology, Technische Universität Braunschweig, Langer Kamp 19c, Braunschweig 38106,

Germany, r.nieder@tu-bs.de

²Thünen Institute of Climate-Smart Agriculture, Bundesallee 50, Braunschweig 38116, Germany

Abstract

On average 45 years after the deep ploughing operation, deep ploughed soils contained 24±5% more total N compared to conventionally ploughed reference soils. However, the mean N stock in the new topsoils was still 8% lower compared to the reference soils. This indicates a long-term N accumulation potential lasting more than 4-5 decades. The potential N mineralization and nitrification capacities of loamy deep ploughed soils were higher compared to sandy deep ploughed soils. All sites showed very low N mineralization potentials and nitrification capacities in the buried Ap material compared to surface Ap horizons.

Reactive nitrogen releases and greenhouse gas emissions during the staple food production in China and their mitigation potential

2016 INI, Feature Presentation, Regional impacts of reactive nitrogen

Longlong Xia¹, Xiaoyuan Yan¹^*

¹Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China, llxia@issas.ac.cn, yanxy@issas.ac.cn

Abstract

Reactive N (Nr) releases are closely linked with greenhouse gas (GHG) emissions, and the simultaneous evaluation of them can help to develop overall effective mitigation options. In this study, we evaluated the characteristics of the Nr and GHG releases from staple food (rice, flour and corn-based fodder) production in China (2001-2010) and explored their mitigation potential. Results showed that there was a high spatial variation in the Nr and carbon footprints. Provincial Nr footprints had a significant linear relationship with carbon footprints, attributed to large contribution of N fertilizer use to both GHG and Nr releases. NH₃ volatilization and N leaching were the main contributors to the Nr footprints, while synthetic N fertilizer applications and CH₄ emissions dominated the GHG (carbon) footprints. About 10 (95% uncertainty range: 7.4–12.4) Tg Nr-N and 564 (404–701) Tg CO₂ eq GHG were released every year during 2001–2010 from staple food production in China. This caused the total damage costs of 325 (70–555) billion ¥, equivalent to nearly 1.44% of the Gross Domestic Product of China. A reduction of 92.7 Tg CO₂ eq yr⁻¹ and 2.2 Tg Nr-N yr⁻¹ could be achieved by reducing synthetic N inputs by 20%, increasing grain yields by 5% and implementing off-season application of straw and mid-season drainage practices for rice cultivation.

Understanding the variability in performance of the nitrification inhibitor 3,4-Dimethylpyrazole phosphate in Australian agricultural soils

2016 INI, Crop management to improve nitrogen efficiency, Feature Presentation

Helen Suter¹, Charlie Walker², Deli Chen¹

¹Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Burnley Campus, 500 Yarra Boulevard, Richmond, Victoria 3121, http://fvas.unimelb.edu.au/ Email: helencs@unimelb.edu.au

² Incitec Pivot Fertilisers, PO Box 54, North Geelong, Victoria 3215, Australia

Abstract

The nitrification inhibitor 3,4-Dimethylpyrazole phosphate (DMPP) is being widely used across Australian agricultural systems to reduce nitrogen loss from soils, particularly targeting the greenhouse gas nitrous oxide, and to improve nitrogen use efficiency. However, the effectiveness of DMPP is variable and the reason for this has been unclear. A laboratory investigation was undertaken using 30 soils collected from a range of agricultural land uses to identify the key drivers influencing the performance of DMPP. Average nitrification over 14 days across all treatments ranged from -4.61 to 26.89, with a median of 2.57 mg NO₃^–N produced/g soil/day. Cumulative N₂O emissions ranged from 0.01 to 7.74 mg N₂O-N/g soil. However only 3 soils contributed to high emissions and the remaining soils had < 0.63 mg N₂O-N/g soil. DMPP effectively reduced average nitrification by 9-100% (average of 42%) and N₂O emissions by 0-100% (average of 55%) Only manganese and the interaction between organic C and clay influenced DMPP’s efficacy at reducing nitrification, having a negative impact. The efficacy of DMPP at inhibiting N₂O emissions was positively related to pH, Cu and Zn and negatively related to Fe. The results suggest that further investigation of the soil metal-inhibitor interaction, and the role of metals in soil microbial function (nitrifiers and denitrifiers) is required to understand when the DMPP will work best.

Effect of a new urease inhibitor on ammonia volatilization and nitrogen utilization in maize in North China Plain

2016 INI, Crop management to improve nitrogen efficiency, Feature Presentation

Li Qianqian¹, Liu Xuejun¹, Chen Xinping¹, Zhang Fusuo¹

¹College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, website: http://www.cau.edu.cn/, Email: lilli@cau.edu.cn; liu310@cau.edu.cn

Abstract

Maize field experiments were conducted over two years at Quzhou site (Hebei Province, North China Plain) to investigate ammonia (NH₃) volatilization from urea and from urea amended with 0.12% (w/w) Limus^® (a new urease inhibitor). Grain yields and nitrogen (N) budgets of all N treatments were evaluated to investigate the effects of urea-N application rates and Limus during two summer maize seasons. Cumulative NH₃ losses after two weeks for conventional urea ranged from 42 to 108 kg N ha^-1(20-57% of applied N), while the new urease inhibitor Limus significantly reduced NH₃ losses by 65 to 90%. However, maize grain yields (9.5-10.1 t ha^-1) were not significantly (P<0.05) increased by Limus compared to conventional urea without Limus (9.0-10.1 t ha^-1). A clear increase in apparent N recovery efficiency (RE_N) with Limus (ranging from 11 to 17 percentage points during two consecutive maize seasons) compared to equal amounts of optimized urea-N. A further 20% reduction in urea N rate amended with Limus led to the same maize yield but substantially decreased NH₃ losses and increased RE_N compared with optimized urea treatment. Our study also demonstrates the role of Limus in reducing NH₃ losses and improving N use efficiency in maize production in the North China Plain.

Improving nitrogen efficiency of maize (corn) using crop sensors

2016 INI, Crop management to improve nitrogen efficiency, Feature Presentation

Peter Scharf ¹

¹University of Missouri, 108 Waters Hall, Columbia, MO, 65211, U.S.A., http://plantsci.missouri.edu/nutrientmanagement/, http://nvisionag.com/, scharfp@missouri.edu

Abstract

Nitrogen fertilizer has a tremendous impact on crop growth and is essential for feeding the 7.4 billion people on Earth. It is also the most energy-intensive input to crop agriculture, has a proclivity to escape from ag systems, and has negative off-site impacts when it escapes. For all of these reasons, efficient use of N fertilizer is essential. Crop sensors are a promising approach to optimize N fertilizer application rate and timing. Three separate experiments with maize (corn) helped to define the N efficiency gains to this approach. One experiment group involved 55 field-scale experiments in which the farmer’s N rate was compared to variable-rate N based on crop sensors. System efficiency (N removed in grain/[N applied as fertilizer + manure]) was 0.68 with the farmer’s chosen rate, and increased to 0.78 with sensor-chosen N rates. A second experiment was initiated in 2007 to compare N fertilizer rate and timing decision systems. For 2007-2014, the most profitable pre-plant N rate (200 kg N ha^-1) gave system N efficiency of 0.43, while sensor-based N rate gave system N efficiency of 0.74. The third experiment was initiated in 2012 and compared a pre-plant N rate of 155 kg N ha^-1 with sensor-based variable-rate N. System efficiency for pre-plant N was 0.51, and for sensor-based N was 0.57. In the latter two experiments, pre-plant N treatments had low efficiency in years with high spring rainfall. Timing of N probably improved N efficiency more than improved N rate.

Assessing controlled release and deep placement N fertilizer technologies in subtropical sugarcane

2016 INI, Crop management to improve nitrogen efficiency, Feature Presentation

Lukas Van Zwieten^1,2, Josh Rust¹, Terry J Rose², Stephen Joseph³, Rick Beattie⁴, Scott Donne³, Greg Butler⁵, Robert Quirk⁶, Stephen Kimber¹, Stephen Morris¹

¹NSW Department of Primary Industries, 1243 Bruxner Highway, Wollongbar, NSW, 2480 www.dpi.nsw.gov.au

²Southern Cross Plant Science, Southern Cross University, Military Road, East Lismore, NSW, 2480

³ Discipline of Chemistry, University of Newcastle, Callaghan NSW 2308

⁴ Sunshine Sugar, Suite 1, Level 1, Cnr River and Martin Streets Ballina, NSW, 2478

⁵ South Australia No-Till Farmers Association, PO Box 930 Berri, SA,5343

⁶ 30 Duranbah Road, Duranbah, NSW 2487

Abstract

Maintaining adequate nitrogen (N) nutrition in sugarcane requires matching supply with demand. The NSW sugarcane system predominantly grows sugarcane over 2 years, with fertiliser N supplied within a couple of months after planting cane or harvesting the previous crop and ratooning. We evaluated alternate N fertiliser technologies; a) that supply N deeper into the soil profile (ca. 50-200mm) via ultra-high pressure, and b) slow release products. Preliminary results indicate that polymer coated urea is able to lower nitrous oxide (N₂O) emissions during peak events, presumable by limiting mineral N in soil at any given time. This lower soil NO₃^– was observed at site 1 in the 2015/16 season only. The N fertiliser based on a modified charcoal pellet gave lower cumulative N₂O emissions than farmer practice urea (matching N rate) at only one of six field sites. The emissions of N₂O did not appear to depend upon the dose of fertiliser N applied, but were site specific, and highly dependent upon rainfall events.

Controlled release nitrogen fertilizer use in potato production systems of eastern Canada

2016 INI, Crop management to improve nitrogen efficiency, Feature Presentation

Noura Ziadi¹, Mervin St.Luce¹, Athyna N. Cambouris¹, and Bernie J. Zebarth²

¹Agriculture and Agri-Food Canada, 2560 Hochelaga Blvd, Quebec, QC, Canada, G1V 2J3, Noura.Ziadi@agr.gc.ca

²Agriculture and Agri-Food Canada, PO Box 20280, 850 Lincoln Rd., Fredericton, NB, Canada E3B 4Z7

Abstract

Nitrogen (N) is the most limiting essential nutrient for potato (Solanum tuberosum L.) and its management is important from both economic and environmental standpoints. Controlled-release N fertilizers, such as polymer-coated urea (PCU), could reduce N losses and increase N use efficiency (NUE) by matching the release of N with potato N uptake. During the last 10 years, different studies were conducted in eastern Canada (Quebec and New-Brunswick) to evaluate the effectiveness of PCU in potato production. A total of nine site-years were conducted between 2006 and 2012 to compare the PCU to the most used conventional N sources. Their effects were assessed on various parameters including yield, specific gravity, NUE, chlorophyll meter readings nitrate (NO₃) leaching, and nitrous oxide (N₂O) emissions along with soil nitrate availability during growing seasons and at harvest. Our results showed that PCU can maintain or increase marketable tuber yield and quality, increase NUE, and reduce NO₃ leaching, particularly in excessively wet years. However, higher N availability from PCU may have implications for N₂O emissions and non-growing season N losses. Evidence of the overall economic advantages of using the PCU in potato production, if any, will be needed to influence a more widespread adoption of PCU by producers.