C.J. Koopmans

C.J. Koopmans

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49
Publications
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2,478
Citations

Publications

Publications (49)
Article
Full-text available
Sustainable agriculture is an important component of many of the 17 Sustainable Development Goals agreed upon by the UN in 2015 (https://sustainabledevelopment.un.org/sdgs). However, the trend in agriculture is moving in the opposite, non-sustainable direction. Agriculture is one of the major drivers of biodiversity loss. Next to biodiversity loss...
Article
In deze studie zijn de mogelijkheden verkend om natuur en biodiversiteit op biologische melkveebedrijven te vermarkten. Er is consumentenonderzoek uitgevoerd, er zijn pakketten van maatregelen opgesteld en getoetst op hun bijdrage aan biodiversiteit en de haalbaarheid voor de biologische melkveehouders. De burger verwacht van boeren en tuinders dat...
Article
Full-text available
This paper introduces and explores the possibilities of a concept that may bridge apparent divergences within the sustainable agriculture approach. Sustainable agriculture concepts may depart from different paradigms, varying from securing global and local resource availability, to maintaining functional integrity of farming systems. Likewise, many...
Article
Full-text available
Een vergelijkende studie naar Europese biologische pluslabels. De onderwerpen en aanvullende eisen van Biogarantie, Bioland, Naturland en Biosuisse zijn naast elkaar geplaatst en vergeleken met de EU normen en specifieke Nederlandse interpretatie tot nu toe.
Article
Full-text available
Onfarm nitrogen fixation is a driving force in organic agriculture. The efficiency with which this nitrogen is used can be increased by using lucerne (Medicago sativa) or grassclover directly as sources of fertilizer on arable land: cutandcarry fertilizers. In two arable crops, the use of lucerne and grassclover as fertilizers was compared with the...
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Bij de ontwikkeling van een integraal duurzame landbouwsector is veel nieuwe kennis en innovatie nodig. Kenmerkend voor Nederland is dat bij het oppakken van deze uitdagingen voor de toekomst nauw wordt samengewerkt tussen overheid, bedrijfsleven en de kennisinstellingen; de zogenaamde ‘gouden driehoek’. In de biologische sector is de afgelopen jar...
Article
Full-text available
On-farm nitrogen fixation is a driving force in organic agriculture. The efficiency with which this nitrogen is used can be increased by using alfalfa or grass-clover crops directly as fertilizer on other fields: cut-and-carry fertilizers. In two crops in two years, the use of several types of alfalfa and grass-clover as fertilizer is compared with...
Article
Full-text available
White clover has a lower root biomass and a higher abundance of earthworms than grass. This might have an impact on the ecosystem services soil structure maintenance and water regulation when white clover is introduced in the grassland on organic dairy farms. We investigated the root biomass, the abundance of earthworms and a selection of soil phys...
Article
After 8 years, the MAC field trial in Lelystad, the Netherlands, shows the effects of different fertiliser strategies, ranging from animal manure to plant compost to mineral fertiliser. The impact on yield, soil quality, soil health, environment and climate change is discussed. The trial is unique in monitoring the effect of so many types of fertil...
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Voor een duurzame landbouw is maatwerk nodig op bedrijfsniveau. Het rapport “Biodiversiteit en bodembeheer in de landbouw” maakt op dit niveau zichtbaar hoe een duurzaam bodembeheer, inclusief de optimalisering van het mineralenmanagement, hand in hand kan gaan met het benutten van bodembiodiversiteit. De onderbouwing van dit perspectief is mogelij...
Article
Verslag van een proef in het Biokas project. Het blijkt dat na het stomen van de bodem, om ziekteverwekkers in de kasteelt te bestrijden, het bodemleven drastisch vermindert. Wanneer daarna organische mest wordt toegediend, kunnen onschuldige schimmels de schadelijke verdringen, maar omgekeerd is ook mogelijk. Het is belangrijk goed verteerde compo...
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Door de hoge gewasbehoefte bij intensieve glasteelten in combinatie met de wettelijke beperkingen aan het gebruik van stalmest, is aanvullende bemesting met snelwerkende meststoffen noodzakelijk. In het kader van het BIOKAS-project is de werkzaamheid onderzocht van een groot aantal hulpmeststoffen, zowel van plantaardige als dierlijke oorsprong. De...
Article
The validation of the carbon and nitrogen model NDICEA ( Nitrogen Dynamics in Crop rotations in Ecological Agriculture) is presented. The model allows one to estimate how crop rotations and manure applications affect the amount of mineral nitrogen in different phases of a crop rotation. The model was tested on 8 organic farms and research sites. Th...
Article
Voor het schatten van de beschikbare hoeveelheid minerale stikstof uit organische mest zijn drie berekeningssystemen met elkaar vergeleken door gebruik te maken van gegevens die afkomstig waren van diverse praktijk- en proefpercelen uit de biologische akkerbouw, vollegrondsgroenteteelt en bollenteelt. NDICEA en ROTASK zijn dynamische simulatiemodel...
Article
Nadelhoffer et al. reply - Jenkinson et al. and Sievering are justifiably concerned that our 15N additions to forest floors do not account for the potential uptake of nitrogen input by forest canopies. We agree that canopies can remove nitrogen from the atmosphere, resulting in inputs to forest floors that are less than the total nitrogen depositio...
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Humans have altered global nitrogen cycling such that more atmospheric N2 is being converted (`fixed') into biologically reactive forms by anthropogenic activities than by all natural processes combined. In particular, nitrogen oxides emitted during fuel combustion and ammonia volatilized as a result of intensive agriculture have increased atmosphe...
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For a Douglas fir forest ecosystem subjected to an experimental decrease in nitrogen (N) deposition, N dynamics were simulated using the dynamic simulation model NICCCE. Meteorological driving variables and N concentrations in throughfall were input to the model, that simulated results of a 15N tracer experiment, C and N concentrations in the soil,...
Article
Chronic atmospheric N input may alter the rate of decomposition and N cycling during needle litter decomposition. Fresh needle litter from Douglas fir (Pseudotsuga menziesii (Mirb.) Franco.) and Scots pine (Pinus sylvestris L.) was exposed to high (>37 kg N ha−1 yr−1) and strongly attenuated rates of natural N deposition (4–6 kg N ha−1 yr−1), achie...
Article
Chronic atmospheric nitrogen deposition can alter the rate of internal nitrogen cycling and increase the magnitude of N leaching losses in forested ecosystems. As fractionation of nitrogen in favour of the lighter 14N occurs during various transformations associated with N-enrichment and nitrogen loss, it has been proposed that the 15N signal of ve...
Article
Impact of nitrogen (N) deposition was studied by comparing N fluxes, N concentrations and N pool sizes in vegetation and soil in five coniferous forest stands at the NITREX sites: Gårdsjön (GD), Sweden, Klosterhede (KH), Denmark, Aber (AB), Wales, UK, Speuld (SP), the Netherlands, and Ysselsteyn (YS), the Netherlands. The sites span a N- deposition...
Article
As part of four European ecosystem manipulation experiments in coniferous forests, field-scale 15N tracer experiments have been carried out. The experiments involved a year-long addition of 15NH4+ and/or 15NO3− to throughfall at experimental plots with different N inputs. The fate of this applied 15N in the important ecosystems pools (trees, ground...
Article
The results of two European field-scale manipulation projects (NITREX (nitrogen saturation experiments) and EXMAN (experimental manipulation of forest ecosystems)) were used to evaluate the effect of ecosystem disturbance on nitrate leaching in coniferous forest ecosystems. The first principle component (PC1) of a principle component analysis expla...
Article
Full-text available
Natural 15N abundance values were measured in needles, twigs, wood, soil, bulk precipitation, throughfall and soil water in a Douglas fir (Pseudotsuga menziesii (Mirb.) and a Scots pine (Pinus sylvestris L.) stand receiving high loads of nitrogen in throughfall (>50 kg N ha−1 year−1). In the Douglas fir stand δ15N values of the vegetation ranged be...
Article
The stable isotope15N was added as (15NH4)2SO4 to throughfall water for one year, to study the fate of the deposited nitrogen at different levels of N deposition in two “N saturated” coniferous forests ecosystems in the Netherlands. The fate of the15N was followed at high-N (44–55 kg N ha−1 yr−1) 1) and low-N (4–6 kg N ha−1 yr−1) deposition in plot...
Article
Nitrogen deposition in a nitrogen saturated ecosystem has been reduced to natural background levels by means of a roof construction. The same amount of 15N was applied to the throughfall water of a high and low nitrogen deposition plot leading to enrichments of 3400% and 43000% 15N, respectively. After nine months of manipulation with 15N major eco...
Article
Nitrogen transformations were studied in the forest floor and mineral soil (0–5 cm) of a Douglas fir forest (Pseudotsuga menziesii (Mirb.) Franco.) and a Scots pine forest (Pinus sylvestris L.) in the Netherlands. Curren nitrogen depositions (40 and 56 kg N ha-1 yr-1, respectively) were reduced to natural background levels (1–2 kg N ha-1 yr-1) by a...
Article
Atmospheric inputs of nitrogen and sulphur were reduced to pre-industrial levels in a nitrogen and sulphur saturated Scots pine (Pinus sylvestris) and Douglas fir (Pseudotsuga menziesii) stand in the Netherlands. Starting in 1989, throughfall water was intercepted by means of a roof and replaced by simulated, clean throughfall water. Underneath the...
Article
Full-text available
For organic farming systems, the challenge is to become more specific in practices to maintain high standards in sustainability. Soil processes need to be clearly understood if rotations and manure applications are to become more precise. Simulation models like the NDICEA model help in the design and maintenance of these farming systems. These mode...
Article
Full-text available
The TP Organics Strategic Research Agenda (SRA) was finalised in December 2009. The purpose of the Strategic Research Agenda (SRA) is to enable research, development and knowledge transfer that will deliver relevant outcomes – results that will contribute to the improvement of the organic sector and other low external input systems. The document...
Article
Full-text available
Understanding organic management practices is a key in developing sustainable organic farming systems. We report the results of four different organic fertilization strategies in a field trial on yields, soil quality and economic performance. We found highest yields and economic performance in two direct plant feeding strategies. One of these strat...

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Project (1)
Project
The aim of the Climate-CAFE project is to evaluate different adaptation strategies of agricultural systems in two IPCC scenarios in the near future (2050) and far (2100). Three broad categories of strategies were identified: (1) resistance strategies, minimizing the impact of short-term climate change with simple adjustments and easy to implement, (2) resilience, which will require a systemic adaptation cropping systems across the field or farm, (3) a drastic transformation of cropping and farming systems. The objective of its strategies is to increase the adaptability of European cropping systems. The alternatives will be built in participatory research by mobilizing 10 "adaptation pilots" (group of farmers, advisers and actors of the agricultural sector). These drivers are distributed in various European pedoclimates sweeping the wide range of agricultural situations of major European cultures, from Finland to the South of Spain (north-south gradient) and Scotland to the east of Germany ( West-East gradient).