Nutrient (re)-cycling in agroecosystems

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We study nutrient cycling in several agro-ecosystems, using multiple approaches

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P cycling in forets ecosystems - 2nd phase

The main objective of the 2nd phase of German priority program (SPP 1685) on ‘Ecosystem Nutrition’ is to investigate the importance of soil organic matter turnover on P cycling under environmental change. This will be tested in a field experiment studying the effect of N, P and N+P additions on P dynamics on exemplary forest ecosystem.

The main goal of our contribution within the SPP 1685 is to investigate to which extent soil biological processes are affected by mineral N and P additions and how this further translates into plant nutrition. We will use molecular microbiological tools and 31P nuclear magnetic resonance (NMR) analysis together with stable and radioactive isotope techniques.

Radioisotopes and stable isotopes will allow us to quantify fluxes among soil pools and investigate processes behind those fluxes. Isotopic tools will be also used to identify the contribution of different sources for plant nutrition. NMR will be used to characterise the molecular nature of organic P under the different treatments.

We will analyse the phosphatase gene harbouring microbial communities after N, P and N+P addition in soils. This will provide information on how the bacterial and fungal community composition and function change after nutrient addition. Potential alkaline and acid phosphatase activities and efficiencies will be determined.

Contact

ETH Zurich

Professur f. Pflanzenernährung

Chiara Pistocchi

FMG C 19

Eschikon 33

8315 Lindau

Switzerland

  • phone +41 52 354 92 26 
  • fax +41 52 354 91 19 

Improved phosphorus resource efficiency in organic agriculture

The main objective of this project is to identify alternative P fertilizers, i.e. obtained via recycling, for organic agriculture and evaluate agronomic measurements to improve P mobilization through enhanced biological activity in the soil.

We characterize P forms in recycled P fertilizers using chemical and spectroscopic methods, while the P mobilization by a bio-inoculant is determined using radioisotopic methods. The use of 33P in pot experiments and the isotopic dilution principle will allow the quantification of P taken up by the plants from the fertilizers.

Supervisors: Astrid Oberson, Paul Mäder

Collaboration with: K. Möller (Univ. of  Hohenheim, DE), J. Friedel (BOKU, AT)

Funding source: ERA-net CORE Organic II

Contact

ETH Zurich

Professur f. Pflanzenernährung

Gregor Meyer

FMG C 13.1

Eschikon 33

8315 Lindau

Switzerland

  • phone +41 52 354 91 43 

Nutrient Use and Dynamics in Conservation Agriculture in Madagascar (MoETH)

Full Project title: Nutrient Use and Dynamics in Conservation Agriculture Including Legumes in the Midwest of the Malagasy Highlands (MoETH)

Objectives: Understand how direct seeding with permanent soil cover by the legume Stylosanthes guianensis (Stylo) affects, under tropical conditions, rainfed cereal production and the fluxes and dynamics of nitrogen (N).

Activities/approaches: A three-year field trial was installed in Ivory in the district of Mandoto, region of Vakinankaratra, at 900 m altitude, on a ferralsol that is representative for the region of the Midwest Malagasy Highlands. Micro-plots were installed to assess N uptake and fertilizer use efficiency by upland rice. Direct 15N isotope labelling was used to trace the fate of N added as mineral fertilizer and Stylo, while an indirect 15N isotope-labelling technique was applied to trace the fate of N added with manure. To quantify symbiotic N2 fixation of Stylo the natural abundance technique was used.

Supervisors: Emmanuel Frossard (ETH Zurich), Astrid Oberson (ETH Zurich)

Collaboration with: University of Antananarivo; International Research Unit on Sustainable Farming and Rice Cropping Systems (SCRID), Laboratoire des Radioisotopes (LRI), Madagascar

Funding source: Swiss Science Foundation (SNF) – Swiss Development Cooperation (SDC)

Contact

ETH Zurich

Institut für Agrarwissenschaften

Dr. Oliver Zemek

FMG B 20

Eschikon 33

8315 Lindau

Switzerland

Drivers of sustainable soil use in yam systems for improved food security in West Africa (YAMSYS)

Full Project title: Biophysical and socio-economic drivers of sustainable soil use in yam cropping systems for improved food security in West Africa (YAMSYS)

Background: Yams are tuber crops essential for food security in West Africa. They are an important source of income for the actors involved in the yam chain value (producers, traders, processors) as their tubers are highly appreciated by urban populations. They are also a very important part of West African culture and are present in many rites and ceremonies. Traditionally yams are grown without input as the first crop after a long-term fallow or natural vegetation with strong negative impacts on the environment. However, the traditional cropping systems have very low tuber productivity. Given the high prevalence of food insecurity, poverty and environmental degradation in West Africa, measures to improve the sustainability of yam cropping systems should be developed and implemented as soon as possible

Objectives and approach: YAMSYS aims at developing sustainable methods for soil management that will allow settling yams in long-term crop rotations, increase tuber yields and increase income of the actors working along the yams chain values. To reach these goals we will carry out research both on biophysical aspects to assess the effects of soil management options on soil fertility and yams yield and on the socio-economic and institutional settings to understand the drivers of soil use and the role of these crops. Innovation platforms gathering the most important stakeholders of the project will be installed at each of the 4 pilot sites (2 in Côte d’Ivoire and 2 in Burkina Faso). Based on continuous discussions and on results delivered by the research, these platforms will elaborate and validate innovations that will have a sustainable impact in the region.

Collaboration with: Emmanuel Frossard (ETH Zurich), Beatrice Aighewi (International Institute of Tropical Agriculture, Nigeria), Séverin Aké (Université Felix Houphouët Boigny, Côte d’Ivoire), Dominique Barjolle (FiBL, Switzerland), Hassan Bismarck Nacro (Université polytechnique de Bobo-Dioulasso, Burkina Faso), Daouda Dao (CSRS, Côte d’Ivoire), Lucien N. Diby (World Agroforestry Centre, ICRAF), François Lompo (INERA, Burkina Faso), Johan Six (ETH Zurich)

Funding source: YAMSYS is funded by the Swiss National Science Foundation and the Swiss Agency for Development and Cooperation

http://www.r4d.ch/E/food-security/projects/sustainable-yam-cropping/Pages/default.aspx

www.yamsys.org

Yamsys logo

Contact

ETH Zurich

Institut für Agrarwissenschaften

Delwende Innocent Kiba

FMG C 18

Eschikon 33

8315 Lindau

Switzerland

On-farm study on maize-based conservation agriculture systems in Southern Africa

PhD Thesis: Finding the truth in wishful thinking: an on-farm study on maize-based conservation agriculture systems in Southern Africa

Background: Conservation agriculture (CA) – a cropping system based on the three principles of (1) minimum soil disturbance, (2) permanent organic soil cover and (3) crop rotations or associations – has successfully spread under large-scale agriculture in the Americas and Australia, contributing to reduce erosion and halt soil degradation. Since the early 2000s CA has been widely promoted, mainly through donor funded projects, among Southern Africa’s smallholder farmers. It was proposed as an option to halt soil fertility depletion while stabilizing or increasing productivity. Result for on-station and on-farm research on soil fertility and productivity improvements under CA have been variable and adoption has been (s)low in Southern Africa. In 2009 a controversial publication “Conservation agriculture and smallholder farming in Africa: The heretic's view” has strongly questioned this promotion of CA, highlighting a series of knowledge gaps. Among the concerns raised were (1) observations of deceased yields, especially in the first years after adoption, (2) little evidence of increases in soil carbon (C) stocks and (3) the question of how/if possible benefits at field level would translate into benefits to the farming system and livelihood of smallholders.

Objectives and approach: This thesis investigated field but also farm level impacts of CA in Southern Africa. The main topics investigated were changes in productivity (maize yields) and soil carbon stocks (and other nutrients) when moving from conventional practice (CP) to CA systems as well as the adoptability of CA by smallholders. The study area comprised 125 on-farm validation trials across 23 sites in Zimbabwe, Zambia, Mozambique and Malawi. In 2011 yield data and soil samples were collected on a CP and a CA treatment of each validation trial. Soil samples were analysed for soil physical (texture, bulk density, aggregate distribution) and chemical (carbon, nitrogen, phosphorus, potassium, calcium, magnesium, zinc and sodium concentrations) parameters. Adoptability was investigated through focus group discussions and individual interviews with farmers that were hosting validation trials on their farm.

Supervisors: Emmanuel Frossard (ETH Zurich), Christian Thierfelder (International Center for Maize and Wheat Improvement: CIMMYT, Southern Africa regional office, Harare, Zimbabwe), Neal Eash (Department of Biosystems Engineering and Soil Science, Institute of Agriculture, University of Tennessee, Knoxville, TN, USA)

Collaboration with: CIMMYT, University of Knoxville

Funding source: SDC and CIMMYT

Contact

ETH Zurich

Professur f. Pflanzenernährung

Dr. Stephanie Cheesman

FMG B 20

Eschikon 33

8315 Lindau

Switzerland

Forms and dynamics of soil phosphorus along a climosequence on basalt-derived soils (CLIMP)

Background

Climate is beside parent material, biota, topography, time, and human impact a state-factor controlling soil and ecosystem development. Whereas a lot of research has been carried out on the effect of most of these factors on phosphorus (P) cycling, less has been done on the effect of climate and, more in particular, precipitation. One of the reasons for that is the difficulty of finding suitable soil climosequences, i.e. sites on a given parent material of a given age exposed for the same time to different climates with little impact of human activity . Soils found on the Kohala Mountain, Hawaii, provide ideal conditions to investigate the effect of increased precipitation on processes affecting the distribution and cycling of P in soils. These soils have developed on the same parent material, the 150 ky old Hawi lava flow, which consists of alkali basalts with high contents of apatite. Along the climosequence, mean annual precipitation ranges from <200 to >3000 mm. The distribution of minerals, macro- and micronutrients, and the abrupt changes in soil chemical properties are strongly influenced by the precipitation gradient. Organic matter and non-crystalline minerals increase along the climosequence, with amorphous minerals dominating at high rainfall.

Objectives and approch

The overall objective of CLIMP is to obtain a better understanding of the linkage of pedogenic processes to the dynamics of P, a master element in tropical ecosystem development affecting a wide range of processes. This objective will be reached by studying forms and fluxes of P using the most up-to-date isotopic and spectroscopic methods in soils from a sequence of sites on the Kohala Peninsula in which there are sharp transitions emerging on a continuous gradient in climate forcing. The discontinuity in soil properties observed along the climosequence will provide the opportunity to understand controls of P species and cycling valid not only for the studied climosequence but also for other tropical soils.

Our hypotheses are that i) the distribution of P forms are determined by intertwined abiotic (related to soil mineralogy) and biotic (related to living organisms) factors driven by the climate gradient, ii) that P fluxes can be observed between each pool, although at different rates also controlled by abiotic and biotic factors, and iii) that the isotopic composition of O bound to P (δ18O-P) is mostly impacted by biological activity.

climosequence

Supervisors

Emmanuel Frossard & Federica Tamburini (ETH Zurich)

Collaboration with:

Peter Vitousek (Stanford University), Oliver Chadwick (UC Santa Barbara), Christian von Sperber (Bonn University)

Funding

SNF project 162422

Contact

ETH Zurich

Professur f. Pflanzenernährung

Julian Helfenstein

FMG C 18

Eschikon 33

8315 Lindau

Switzerland

  • phone +41 52 354 91 44 
 
 
Page URL: http://www.plantnutrition.ethz.ch/research/nutrient-agroecosystems.html
Wed Jun 28 16:53:52 CEST 2017
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