Naar een klimaatneutrale bedrijfsvoering: hoe doe je dat?

De huidige landbouw draagt bij aan het broeikaseffect en daarmee aan de klimaatverandering. Tegelijk heeft de landbouw goede mogelijkheden om tot vermindering van broeikasgasemissies te komen. Zestien agrariërs nemen daarvoor het voortouw in het project BoerenKlimaat.nl. Samen met Wageningen UR en het Louis Bolk Instituut werken zij aan een klimaatneutrale bedrijfsvoering door mogelijkheden in de praktijk te benutten en te optimaliseren. Dit BioKennisbericht belicht deze kansen en reikt de varkenshouder, akkerbouwer en pluimveehouder suggesties aan om het eigen bedrijf verder te verduurzamen

Gasvormige emissies uit het melkveebedrijf van de familie Spruit. I. Praktijkmetingen in een ligboxen en grupstal

In 2004 zijn verschillende metingen gestart om de nutriëntenstromen op het melkveebedrijf Spruit (Zegveld) te karakteriseren. Gedurende enkele korte meetperioden in 2004 en 2005 werden onder andere de gasvormige emissies (ammoniak, broeikasgassen, geur) uit verschillende bronnen (stal, mesttoediening, mestopslag) gemeten. Dit rapport is deel I van het project dat door Agrotechnology and Food Innovations werd uitgevoerd om de gasvormige emissies van het melkveehouderijbedrijf van de familie Spruit te meten. Hier worden de emissies uit de ligboxenen grupstal gepresenteerd. Doordat de ligboxen- en grupstal tegen elkaar zijn geplaatst ontstaat een gecompliceerd luchtbewegingspatroon waarbij lucht tussen beide stallen kan worden uitgewisseld. Dit bemoeilijkt het nauwkeurig vaststellen van de stalemissies. In dit rapport wordt daarom uitgebreid aandacht besteed aan de gekozen meetstrategie. Daarnaast worden de resultaten van de metingen gepresenteerd. Dit betreft de emissie van ammoniak, methaan, lachgas en geur

HAPEX-Sahel : a large-scale study of land-atmosphere interactions in the semi-arid tropics

The Hydrologic Atmospheric Pilot EXperiment in the Sahel (HAPEX-Sahel) was carried out in Niger, West Africa, during 1991 - 1992, with an intensive observation period (IOP) in August - October 1992. It aims at improving the parameterization of land surface atmosphere interactions at the Global Circulation Model (GCM) gridbox scale. The experiment combines remote sensing and ground based measurements with hydrological and meteorological modelling to develop aggregation techniques for use in large scale estimates of the hydrological and meteorological behaviour of large areas in the Sahel. The experimental strategy consisted of a period of intensive measurements during the transition period of the rainy to the dry season, backed up by a series of long term measurements in a 1° by 1° square in Niger. Three "supersites" were instrumented with a variety of hydrological and (micro) meteorological equipment to provide detailed information on the surface energy exchange at the local scale. Boundary layer measurements and aircraft measurements were used to provide information at scales of 100 - 500 km2. All relevant remote sensing images were obtained for this period. This programme of measurements is now being analyzed and an extensive modelling programme is under way to aggregate the information at all scales up to the GCM grid box scale. The experimental strategy and some preliminary results of the IOP are described

Methods for measuring gas emissions from naturally ventilated livestock buildings: Developments over the last decade and perspectives for improvement

[EN] The objectives of this paper are: 1) to give an overview of the development of methods for measuring emission rates from naturally ventilated livestock buildings over the last decade, 2) to identify and evaluate strengths and weaknesses, 3) to summarise and conclude the current state-of-art of available measurement concepts and their perspectives for improvement. The methods reviewed include determination of concentration and air exchange rate separately, tracer gas ratio, passive flux samplers, flux chambers, and combined downwind measurement and dispersion modelling. It is concluded that passive flux samplers, flux chambers and combined measurement and dispersion modelling are useful, but for limited fields of application only and require further development and validation against reference methods. The most robust method to investigate emission rates available at this stage is the tracer gas ratio method, but improvements are required. They include more detailed estimates of CO2 release rates (when using CO2 as a tracer) and research into optimising dosing performance of tracer gas release systems. The reliability of tracer gas ratio methods applied in buildings with large ventilation openings needs to be improved by a more profound understanding of tracer-pollutant ratios and their spatial variability, and the development of improved sampling methods for concentration ratios. There is a need for a field reference method against which other methods can be evaluated. None of the diicussed measurement methods can be marked as a solid reference for all conditions; tracer gas ratio methods are the most likely candidate but need further improvement. (C) 2012 IAgrE. Published by Elsevier Ltd. All rights reserved.The contribution to this paper of N. Ogink and J. Mosquera was financially supported by the Netherlands Ministry of Infrastructure and Environment.Ogink, NWM.; Mosquera, J.; Calvet Sanz, S.; Zhang, G. (2013). Methods for measuring gas emissions from naturally ventilated livestock buildings: Developments over the last decade and perspectives for improvement. Biosystems Engineering. 116(3):297-308. https://doi.org/10.1016/j.biosystemseng.2012.10.005S297308116

Preface paper to the Semi-Arid Land-Surface-Atmosphere (SALSA) Program special issue

The Semi-Arid Land-Surface-Atmosphere Program (SALSA) is a multi-agency, multi-national research effort that seeks to evaluate the consequences of natural and human-induced environmental change in semi-arid regions. The ultimate goal of SALSA is to advance scientific understanding of the semi-arid portion of the hydrosphere–biosphere interface in order to provide reliable information for environmental decision making. SALSA approaches this goal through a program of long-term, integrated observations, process research, modeling, assessment, and information management that is sustained by cooperation among scientists and information users. In this preface to the SALSA special issue, general program background information and the critical nature of semi-arid regions is presented. A brief description of the Upper San Pedro River Basin, the initial location for focused SALSA research follows. Several overarching research objectives under which much of the interdisciplinary research contained in the special issue was undertaken are discussed. Principal methods, primary research sites and data collection used by numerous investigators during 1997–1999 are then presented. Scientists from about 20 US, five European (four French and one Dutch), and three Mexican agencies and institutions have collaborated closely to make the research leading to this special issue a reality. The SALSA Program has served as a model of interagency cooperation by breaking new ground in the approach to large scale interdisciplinary science with relatively limited resources