Archive for the category: 2016 INI

Zhi Quan¹, Shanlong Li¹, Feifei Zhu¹, Yunting Fang^{1, *}, Peipei Li², Limei Zhang², Rong Sheng³, Wenxue Wei³, Jizheng He²

¹Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China

²State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China

³Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China

*Correspondence: fangyt@iae.ac.cn,

http://research.iae.ac.cn/web/ShowArticle.asp?ArticleID=2442

http://www.researcherid.com/rid/G-4456-2012

Abstract

A better understanding of the fates of fertilizer N is critical to design appropriate N management strategies in intensively cultivated croplands. In this study, we evaluated the fates of ¹⁵N-urea in a field experiment on a black soil-maize system and their responses to straw incorporation in Gongzhuling, Northeast China. In order to get realistic results, we adopted the field management used by local farmers. Results showed that the crop N uptake was the main sink, recovering 52-53 % of the fertilizer N. Total ¹⁵N recoveries in plant organs followed the order: grain (27-29%) > leaf (11-12%) > stem (6%) > tassel, silks, leaf sheath, husks, etc. (5%) > root (2%) > cob (1%). Tracer N remaining in soil was the second largest sink (25-33%), and most (18-29%) was located in the ridge 0-20 cm layer (fertilized area). The total loss of fertilizer N was 13-23%. Straw incorporation increased the retention of applied fertilizer N and decreased its losses, although there was no significant difference in  plant N uptake. The contribution of fertilizer N to total  N uptake was 36-37% at the physiological maturity stage of maize. Fertilizer N was an important N source for maize growth but soil N was still the main N source. Our results indicate that Nitrogen Use Efficiency (NUE) in maize cultivation system in northeast China is not as low as that reported by many previous studies using difference or balance method. Considering the low NUE in China, our next aim is to find out which region, and which kinds of crops lowered the overall NUE in Northeast China.

Bruce Smith

Technical Director, Eko360 Limited, PO Box 87039, Auckland 1742, New Zealand

Email: bruce@eko360.com    website: www.eko360.com

Abstract

In New Zealand the use of nitrogen fertiliser has in past 25 years increased 600% while dairy production, where much of the nitrogen fertiliser is used, has increased by 270%. The unintended consequences of the excessive use of nitrogen have been a cost to the overall environment.

A paradigm shift is needed to achieve sustainable farming systems. Much of the science to support this shift has been published and it is time to dust off these research papers   re-educate and share the established knowledge with industry leaders taking responsibility.

Sustainability is a journey. It is about the People, the Planet and Profit. Practices must change to ensure they meet today’s needs while ensuring future generations have the ability to meet their needs.

Priit Kaal¹, Richard Vines²

¹ DEDJTR, 1 Spring Street, Melbourne, Vic, 3000, priit.kaal@ecodev.vic.gov.au

² DEDJTR, 1 Spring Street, Melbourne, Vic, 3000, richard.vines@ecodev.vic.gov.au

Abstract

Since September 2012, knowledge management specialist staff within Agriculture Victoria, (Department of Economic Development, Jobs Transport and Resources and its predecessor institutions) have been developing a number of different digital applications to foster more effective online collaborations across the public, research, private service provider, community and education sectors. Adoption of these work practices and systems, including governance systems has the potential to improve the means by which those involved in the design, deployment and monitoring of research, development and extension programs and projects can reach and engage audiences, facilitate co-design of solutions with target audiences and improve access to information and expertise.

In this paper, we explore these possibilities and articulate the benefits for adopting these innovations in line with the overarching theme of this conference: that is through the aspiration of developing solutions to enhance nitrogen use efficiency for the world. The context will be the Victorian dairy sector and in particular a project called: Manure Technologies To Drive Resource Efficiencies.  This project is situated within a policy context that intensification of all agricultural industries including the Victorian dairy industry is desirable and inevitable. This global trend towards agricultural intensification is increasing place-based conflicts involved with securing a social license to underpin a ‘right to farm’. The Victorian Government State Government in Australia is grappling with the complexity of the trade-offs between these two policy objectives.

The central claim of the paper is this. Embedding principles of good practice knowledge management into the way programs and projects are designed and managed will do much to ameliorate the tensions inherent between the policy objectives of enabling agricultural intensification and securing a social license underpinning any ‘right to farm’. The complexity associated with the trade-offs between these dual objectives involve many technical challenges. To enhance nitrogen use efficiency in the dairy sector, solutions are required across many domains –for example in facilitating the re-use of nutrients, addressing soil nutrient accumulation, reducing gaseous emissions and odour and eliminating nutrient contamination of water and air, particularly those where there are larger herds and intensive operations involved.

It will be concluded that effective knowledge management needs to address two overarching challenges (Snowden 2003). The first is to create the conditions within which innovation can emerge via effective sense-making, collaboration and innovation systems thinking that apply in both face to face and online environments. Practical examples from other sectors will be discussed to highlight how technology can be harnessed to create the conditions within which representatives of “communities of practice” (CoPs) can co-learn and co-evolve with representatives of “communities of interest” (CoIs)  in order that solutions to problems involve principles of co-design. It will be emphasised that such approaches have significant potential in the realm of manure technologies and enhancing nitrogen use efficiency. The second is to enhance the quality of decision support systems. In the case of agriculture such support systems need to be flexible and extensible enough to apply at different levels in integrated ways (i.e. across farms, catchments, industry development, community based and public policy levels). The problem at the moment is that current decision support systems do not take into account the need to integrate and value the many different types of evidence to support decision making across these different levels.

Jun Shan¹, Xu Zhao¹, Shutan Ma¹, Xiaoyuan Yan¹

¹ State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China, Email: shanjun@issas.ac.cn or yanxy@issas.ac.cn

Abstract

Paddy fields are one of the most important N sinks in terrestrial ecosystems, and considerable N loss is caused by denitrification. Biochar has been recognized as useful soil amendment to paddy field in mitigating nitrous oxide (N₂O) emission. However, the key mechanisms responsible for the reduced N₂O emissions by biochar in paddy soils are still obscure. Here, using two paddy soils with contrasting pH, the denitrification and N₂O emission were investigated in soil amened with different amounts of biochar (0%, 0.5% and 5%) via soil slurry incubation combined with N₂/Ar technique. The results showed that biochar amendment significantly increased the pH values both in the alkaline and acidic soils. Biochar at 5% amendment rate significantly increased denitrification and significantly decreased N₂O emission in soils. In the alkaline soil, biochar at 0.5% amendment rate significantly increased denitrification, but had no effect on N₂O emission. Conversely, in the acidic soil, biochar at 0.5% amendment rate did not affect denitrification, but significantly reduced N₂O emission. The N₂O/(N₂+N₂O) ratio was significantly reduced by biochar amendment irrespective amendment rate both in alkaline and acidic soils. In the alkaline soil, biochar at 5% amendment rate significantly increased the abundance of nosZ genes, whereas biochar had no effect on the abundance of nosZ genes in the acidic soil irrespective of amendment rate. Our results suggested biochar effects in the alkaline soil were attributed to increase of denitrifying community, whereas biochar effects in the acidic soil was attributed to increase of pH.

Anuga Liyanage¹², Peter R Grace¹, David W Rowlings¹   Clemens Scheer¹

¹ Institute for Future Environments, Queensland University of Technology, 2 George Street, Brisbane, QLD 4000, Australia.     anuga.liyanage@ hdr.qut.auanuga.liyanage@hdr.qut.edu.au anuga.liyanage@hdr.qut.edu.au

² Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya, 81100, Sri Lanka.

Abstract 

The application of organic amendments (OA) is a strategy to improve soil fertility and offset the high cost of mineral fertilizers used in agricultural systems. However, information on the interaction of OAs with synthetic fertilizers and the resulting greenhouse gas emissions from these combinations are not well understood for different soil types. A 36 day laboratory incubation experiment (3 compost x 3 N rates) was conducted to quantify soil N₂O emissions along with CO₂ and mineral N from subtropical soils in Gatton, Australia. Nitrous oxide emissions  decreased by 68% and 57% in  60N and 120N treatments respectively with the increase in compost applications  rates up to 30 t/ha and 60 t/ha. Adding 60 t/ha compost and 120 kg N/ha is considered  as the optimum fertilizer rate to minimize N₂O and CO₂ emissions from  a sub-tropical Vertosol and potentially conserving soil physical, chemical and biological properties for a sustainable crop growth.

Ziyin Shang¹, Feng Zhou¹, Shuoshuo Gao ¹, Yan Bo¹, Philippe Ciais ², Kentaro Hayashi ³, James Galloway ⁴, Dong-Gill Kim ⁵, Changliang Yang ⁶, Shiyu Li ⁶, Bin Liu ⁶

¹ Sino-France Institute of Earth Systems Science, Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, P.R. China, Email: zyshang@pku.edu.cn

²Laboratoire des Sciences du Climat et de l’Environnement, CEA CNRS UVSQ, 91191 Gif-sur-Yvette, France

³Carbon and Nutrient Cycles Division, National Institute for Agro-Environmental Sciences, 3-1-3, Kannondai, Tsukuba, Ibaraki 305-8604, Japan

⁴Environmental Sciences Department, University of Virginia, Charlottesville, Virginia 22904, USA

⁵Wondo Genet College of Forestry and Natural Resources, Hawassa University, PO. Box 128, Shashemene, Ethiopia

⁶Research Institute of Engineering Technology, Yunnan University, Kunming, 650091, P.R. China

Abstract

Ammonia (NH₃) released to the atmosphere leads to a cascade of impacts on the environment, yet estimation of NH₃ volatilization from cropland soils (V_NH3) in a broad spatial scale is still quite uncertain in China. This mainly stems from non-linear relationships between V_NH3 and relevant factors. Based on 495 site-years of measurements at 78 sites across Chinese croplands, we developed a nonlinear Bayesian Tree Regression model to determine how environmental factors modulate the local derivative of V_NH3 to nitrogen application rates (N_rate) (VR, %). V_NH3-N_rate relationship was non-linear. VR of upland soils and paddy soils depended primarily on local water input and N_rate, respectively. Our model demonstrated good reproductions of V_NH3 compared to previous models, i.e., more than 91% of the observed VR variance at sites in China and 79% of those at validation sites outside China. The observed spatial pattern of V_NH3 in China agreed well with satellite-based estimates of NH₃ column concentrations. The average VRs in China derived from our model were 14.8 ± 2.9% and 11.8 ± 2.0% for upland soils and paddy soils, respectively. The estimated annual NH₃ emission in China (3.96 ±0.76 TgNH₃·yr^-1) was 40% greater than that based on the IPCC Tier 1 guideline.