Impact Presentation | INI 2016

Field evaluation of N2O, CO2 and CH4 emissions and enzyme activities under corn-soybean intercropping system

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

Artemio A. Martin, Jr ¹, Diane S, Stott²

Isabela State University, Echague, Isabela, Philippines

NRS-USDA, Purdue University, West Lafayette, Indiana, USA

Abstract

The effect of cover crops (ryegrass, hairy vetch, and oilseed radish) in terms of microbial biomass carbon (MBC), C and N mineralization, and enzymatic activities in a corn-wheat-soybean cropping systems under a Mollisol was evaluated. The distributions of total organic C (TOC), total Kjeldahl N (TKN), microbial biomass C (MBC), readily mineralizable C and N, and five enzyme activities (β-glucosidase, β-glucosamidase, acid phosphatase, arylamidase, and fluorescein diacetate hydrolysis) involved in the cycling of C, N, P and S were studied in three soil depths (0-5. 5-10, 10-20 cm) while soil surface fluxes of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) were estimated. Rye grass showed higher activity in acid phosphatase, β-glucosidase and β-glucosaminidase. Rye grass and hairy vetch significantly increased organic C and N, and MBC. Level of mineralized C and N were the same in rye grass and hairy vetch. There was no clear variation in CO₂, N₂O and CH₄ fluxes from the cover crop treatments. N₂O fluxes increased with an increase in soil moisture. The negative CH₄fluxes manifest the soil as CH₄sink. No significant differences among cover crop treatments in terms of CO₂-C, N₂O-N and CH₄C emissions, a reflection that their emissions are highly variable.

Empirical data on carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) fluxes are important in management systems to evaluate mitigation strategies, while microbial biomass and enzyme activities can be used as sensitive indicators of ecological stability.

Agriculture Victoria’s unique distribution channel for nutrient balances

2016 INI, Impact Presentation, Modelling and decision support

Gemma Heemskerk¹, Hayden Lewis ², Andrew McAllister ² , Cameron Gourley ³, Muhammad Islam⁴

¹Agriculture Research, Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria, 32 Lincoln Square North, Carlton Victoria 3053. Website: http://farmbuild.github.io/farmbuild/ Email: Gemma.Heemskerk@ecodev.vic.gov.au
²Agriculture Research, Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria, 255 Ferguson Road, Tatura Victoria 3616. Email: Andy.McAllister@ecodev.vic.gov.au; Hayden.Lewis@ecodev.vic.gov.au
³Agriculture Research, Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria, 1301 Hazeldean Road, Ellinbank Victoria 3821. Email: Cameron.Gourley@ecodev.vic.gov.au
⁴Agriculture Research, Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria, Cnr Taylor St and Midland Hwy, Epsom Victoria 3551. Email: Muhammad.Islam@ecodev.vic.gov.au

Abstract

Victorian agriculture faces significant challenges to meet the demands of growing markets and continue to deliver production gains, while also demonstrating responsible management of resources. Nutrient resources are a key management consideration for Victorian agriculture. Translation of our science into practical, everyday decision support is achieved with FarmBuild that delivers algorithms, calculators, and key agricultural datasets as freely available online functions.

Agriculture industry service providers and software developers can utilise FarmBuild web services, Application Programming Interfaces (APIs), integrated data sources and open source JavaScript API sample code, to build their own digital tools. This will enable providers to support their own clients, and be customised for their specific needs. Whole farm nutrient balance models, as well as farm mapping and soil information, are currently available as on-line FarmBuild functions.

FarmBuild is a unique distribution channel for Agriculture Victoria’s science. Decades of scientific research and data collation to understand whole farm nutrient balances is being delivered as web services and API’s. This allows third-party users to integrate this science into their own digital tools with free and open access via GitHub. Providing third-party users the opportunity to embrace the significant advances in digital technology, together with access to the best and current science for Victorian agriculture, will encourage evidence-based decision making on-farm.

Economies of scale in farms and environmental inequalities through the lenses of nitrogen fertilizer use: Concept development

2016 INI, Impact Presentation, Modelling and decision support

Luciano B. Mendes & Wilfried Winiwarter

International Institute of Applied Systems Analysis, Schlossplatz 1, Laxenburg, A-2361, Austria, www.iiasa.ac.at, mendes@iiasa.ac.at, winiwart@iiasa.ac.at

Abstract

In this paper, we develop the framework of a system dynamics-based model for future studying the equity of resource distribution in rural areas, at a country scale and farm resolution. Our main hypothesis for conceptual development of the model is the following: the unequal spatial distribution of N fertilizer availability and use within a country might be linked to an unbalanced distribution of income to farms (in terms of farm size, i.e. economies of scale), which at the same time, might lead to exacerbated pollution. In such a context, our target variables are: nitrogen fertilizer use, farm size (both in land area and herd size) and emissions of NH₃, N₂O and CH₄, all disaggregated in a per-country basis. The Causal Loop Diagram (CLD) approach was used for this study, for visual representation of our ‘model concept’ on how target and intermediate variables are related. In order to allow future calibration and/or validation of the dynamic model, all variables utilized in construction of the CLD are commonly used indicators of social and rural development, economies of scale at farm level and environmental impacts. The representation of our model into a CLD revealed that a more sophisticated representation of wealth distribution in farms may be needed to extend beyond trivial outcomes in modelling effects of N fertilizer use.

Spatial analysis of nitrogen strip trials in sugarcane

2016 INI, Impact Presentation, Modelling and decision support

Anthony Webster¹, Rob Bramley²

¹CSIRO Agriculture, McGregor Road, Smithfield, Qld, 4878, tony.webster@csiro.au

² CSIRO Agriculture, Waite Campus, Urrbrae, SA, 5064

Abstract

Nitrogen losses from sugarcane farms pose a threat to the Great Barrier Reef. Applying differential rates of nitrogen within blocks is one proposed management practice to reduce this threat by matching nitrogen rates to crop demand at the within-block scale. Farmers need practical methods to determine the appropriate nitrogen rate to apply to differing yielding parts of their blocks when employing variable rate application. We implemented a nitrogen strip trial with rates of 37, 132, and 170 kg N/ha in a plant crop of sugarcane, in comparison to the farmers normal rate of 153 kg N/ha. The block was harvested with a yield monitor fitted harvester. From the resultant yield map, yield values were extracted every three metres along the centre line of each strip. Rolling groups of ten extracted yield values were compared for each test strip to an adjacent area that received the farmer’s normal application via a paired two tail t-test. Yield was found to be significantly different for portions of each test strip and the normal N application rate. This information, used in conjunction with the yield map, was able identify areas of the block where lower application of N could be justified. In different parts of the block each of 37, 132 and 153 kg N/ha would achieve maximum yield. The farmer could use this information to apply lower than normal rates to areas where these lower rates do not compromise yield. Applying N differentially at the within-block scale at rates that match crop demand would be the optimal strategy in this block, and will lead to reduced N losses to the Great Barrier Reef.

The ‘Dairy Nitrogen Fertiliser Advisor’ – a web-based tool to assist farmer decisions

2016 INI, Impact Presentation, Modelling and decision support

Kerry Stott¹, Bill Malcolm¹ and Cameron Gourley²

¹Agriculture Victoria, Parkville Centre, Department of Economic Development, Jobs, Transport and Resources, Carlton, Victoria 3053. kerry.stott@ecodev.vic.gov.au

²Agriculture Victoria, Ellinbank Centre, Department of Economic Development, Jobs, Transport and Resources, Ellinbank, Victoria 3821.

Abstract

Decisions about using N fertiliser rely typically on rules based on expected average pasture responses to N applied. Such rules are mute on the economic limit to N use. In this paper, a new web-based application called the ‘Dairy Nitrogen Fertiliser Advisor’ (the ‘N-Advisor’) is presented. The tool uses marginal analysis and profit-maximising principles to inform dairy farmers and their advisors when they are considering how much N to apply to a particular paddock for a particular grazing rotation. The tool embodies response functions that have been derived from nearly 6,000 data sets from experiments in pasture yield response to N undertaken across Australia over the past 40 years. The response functions exhibit the diminishing returns required for marginal economic analysis. Recommendations about nitrogen fertiliser based on information from using the N-Advisor derive from (i) the expected marginal product of a response function for a particular Australian state and season calibrated to the paddock in question, (ii) the cost of the fertiliser (as spread) and (iii) the value of the extra pasture consumed. The N-Advisor enables users to perform ‘what-if’ analyses, exploring the effect on the profit maximising level of N of changing the cost of N fertiliser, or changing the value of the dry matter consumed. The N-Advisor also enables risk associated with production outcomes to be considered. The production and profit information that can be estimated using the N-Advisor has sufficient rigour and relevance to add value to decisions dairy farmers make about applying N.

Nitrogen budget in South America: observation and modeling

2016 INI, Impact Presentation, Regional impacts of reactive nitrogen

Jean Pierre Ometto¹; Nnet Project team²

¹National Institute for Space Research (INPE)

Av dos Astronautas, 1758

12227-010 – São José dos Campos, SP, Brazil

²http://nitrogen.ccst.inpe.br

Abstract

This paper, mirrored in the project report, presents a regional initiative, in South America, which aims to synthesize scientific information, acquire new data and informing the policy processes on the nitrogen budget and nutrient management in a broad region. The goal of this network is to examine human impact in natural and modified ecosystems across a wide range of climates, and ranging from direct measurements to regional modeling. The up-scaling of local nitrogen studies aims to constrain regional atmospheric chemistry and transport modeling, feeding global models, greatly enhancing our understanding of global patterns of alterations to the nitrogen cycle. In the study sites, defined according to physiographic and/or socio-economic attributes, the following inputs and outputs of nitrogen are being reviewed and analyzed: (i) Inputs: Natural-BNF and cultivation induced-BNF, fertilizer use, atmospheric deposition; (ii) Outputs: Net exports of agricultural products at regional level and estimates at site scale of gaseous emissions from land use (fertilizer volatilization, biogenic soil emissions and burning) and export of N to groundwater and surface waste (domestic, agricultural and industrial).

Canadian-US Project Towards an International Nitrogen Management System

2016 INI, Impact Presentation, Regional impacts of reactive nitrogen

Jill Baron¹, Shabtai Bittman², Robert Black³, Richard Sheibley³, Jana Compton⁴, Cliff Snyder⁵, Daniel Wise⁶

¹U.S. Geological Survey, Colorado State University, Fort Collins CO, 80523-1499, jill.baron@usgs.gov

²Agriculture and Agri-Food Canada, P.O. Box 1000, Agassiz, British Columbia, V0M 1A0

³U.S. Geological Survey, Washington Water Science Center, Tacoma WA 98402

⁴U.S. EPA Office of Research and Development, Corvallis OR 97333

⁵International Plant Nutrition Institute, Conway AR 72034

⁶U.S. Geological Survey, Oregon Water Science Center, Portland OR 97201

Abstract

Bellingham Bay and the Nooksack River Basin will provide the test case for an international nitrogen (N) management system for North America. Spanning a portion of the western interface of the U.S. and Canada, the region supports intensive agriculture, freshwater and estuarine fisheries, diverse wildlife, cities and towns, and to the east, North Cascades National Park that is protected by the US Wilderness Acts. Using abundant data and model activities from a well-established scientific community, our project seeks to create knowledge, build regional capacity, and forge collaborations toward creation of regional N management solutions that protect or restore ecosystems and human health affected by excess reactive N while maintaining a vibrant agricultural community.

Nitroportugal – Strengthening Portuguese research and innovation capacities in the field of excess reactive nitrogen

2016 INI, Impact Presentation, Regional impacts of reactive nitrogen

Cláudia Marques-dos-Santos Cordovil¹, Tommy Dalgaard² and Mark A. Sutton³

¹Research Centre Linking Landscape, Environment, Agriculture and Food (LEAF), School of Agronomy, University of Lisbon, Tapada da Ajuda 1349-017 Lisbon, Portugal. cms@isa.ulisboa.pt.

² Department of Agroecology, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark.

³NERC Centre for Ecology & Hydrology, Bush Estate, Penicuik Midlothian EH26 0QB Scotland, UK.

Abstract

Nitrogen (N) is a key nutrient, indispensable for the survival of all living organisms on earth, including Man. However, due to human pressure, the N cycle has become the most altered among the element cycles, highlighting the N problem as one of the most pressing environmental issues faced today. Despite the recent work on N in Europe and the rest of the world, Portugal has not so far utilized its full capacity to integrate the available scientific, technical or practical knowledge. NitroPortugal addresses how to improve the Science and technology skills and the scientific output of Portugal, at the same time strengthening the potential for N policy implementation. The project develops around the consensus that N is an emerging issue, that it impacts all the environmental compartments, and has both human health and social implications. This twinning effort on N is divided into five key areas which coincide with the whole N concept WAGES (Water, Air, Greenhouse gases, Ecosystems and biodiversity and Soil) launched by the European Nitrogen Assessment. Based on bringing together existing data on data analysis and on training in new methods for each of the five key topics, a comprehensive analysis will be delivered that prioritizes the key gaps in knowledge. These gaps will then serve as themes for different types of training activities. Emerging questions will feed brainstorming workshops to be held at key points through the project, which will strengthen the Portuguese skills base and enhance peer-review publication. Based on the new skills of the host country team, the basis for preparing a Portuguese Nitrogen Assessment will be obtained that will strengthen Portuguese engagement within the EU and in UNECE Air and Water Conventions. The resulting increase in scientific productivity, associated with strengthened networking between the Portuguese and international partners will be measurable through objective indicators of publication output, policy support and the public engagement.

How did chemical nitrogen efficiency evolve under agricultural intensification process in northern China from 1980 to 2014?

2016 INI, Impact Presentation, Regional impacts of reactive nitrogen

Xin Zhang¹, Guangmin Xiao¹, Roland Bol², Wenliang Wu¹, Fanqiao Meng¹

¹College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanming Xilu, Haidian, Beijing, 100193, China, mengfq@cau.edu.cn

²Institute of Bio- and Geosciences, Agrosphere (IBG–3), Research Centre Jülich, Jülich, 52425, Germany

Abstract

During the past three decades of agricultural intensification in China, crop production has increased greatly. However, intensive agriculture is under pressure to reduce environmental pollution and improve nutrient use efficiency. We undertook a 35-year study in the Huantai county to analyse the temporal dynamics of N efficiency, losses and driving factors during this process. From 1982 to 2002, N partial factor productivity (PFPN) and N uptake efficiency (NUpE) increased 2.0-fold and 1.8-fold, and then stabilised from 2003 to present (PFPN at 36.4 kg grain kg^-1 N_fert, and NUpE at 0.57 kg N_plant kg^-1 N_fert+min). Similarly, decreases were observed in reactive N losses intensity (32.0 to 10.7 kg N Mg^-1 grain), land intensity (0.13 to 0.06 ha Mg^-1 grain) and N uses intensity (49.2 to 24.6 kg N Mg^-1 grain), and then were stable from 2002 to 2014. Nitrogen utilization efficiency (NUtE) was stable at about 42 kg grain kg^-1 N_plant during the 35 years. Apparent N use efficiency (ANUE) increased from 42.1% in the 1980s to 60% in 2010s. The increase of N use efficiency and decrease of N losses depended much on optimized fertilization, mechanization farming and crop straw incorporation. This highlighted that with the introduction of improved farming practices, a sustainable agricultural intensification was achieved in developing countries like China.

Dynamics and mineralisation of nitrogen in soil fertilised with brown coal-urea blends

2016 INI, Impact Presentation, Inhibitors to improve N efficiency

Biplob K. Saha^1*, Michael T. Rose², Vanessa Wong³, Timothy R. Cavagnaro⁴ and Antonio F. Patti¹

¹School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia

²NSW Department of Primary Industries, Wollongbar Primary Industries Institute, Wollongbar, NSW 2477, Australia

³School of Earth, Atmosphere & Environment, Monash University, Clayton, Victoria, 3800, Australia

⁴School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, South Australia, 5064, Australia

^*Corresponding author. Email: biplob.saha@monash.edu

Abstract

Increasing the efficiency of nitrogenous fertilisers is becoming more important due to detrimental effects of N loss on the environment. The addition of humic rich brown coal (BC) as an organic amendment can alter N cycling by reducing its losses in different ways. However, the effect of brown coal-urea (BCU) blends on N cycling is poorly understood. Therefore, a glasshouse incubation study was conducted to assess the effects of BCU blends on the transformation and transport of N in soil. Blending of urea with BC slowed down the fertiliser N release resulting in higher N retention over a longer period of time compared to urea. Over the two-month study, compared to urea, BCU blends generally suppressed total N₂O and NH₃ emissions by 31% and 43%, respectively. Incorporation of BCU blends in soil maintained significantly higher amounts of mineral and mineralisable N in soil compared to urea application only. This is supported by the leachate analysis data, which showed that less mineral N was leached from soil in the BCU blends compared to urea. The blends with higher proportions of BC had lower NH₃ emissions and maintained higher mineral N in soil compared to the blend with lower proportion of BC. Moreover, addition of BCU blends increased the organic carbon content of soil. The overall results suggest that blending of urea with BC can strongly reduce N losses via leaching and gaseous emissions. As a result, greater amounts of fertiliser N will be available to crops over a longer time period, increasing the fertiliser N use efficiency and soil health.