Records 1 - 20 / 2048
Trafficking intensity index for soil compaction management in grasslands
Bondi, Giulia ; O‘Sullivan, Lilian ; Fenton, Owen ; Creamer, Rachel ; Marongiu, Irene ; Wall, David P. - \ 2020
Soil Use and Management (2020). - ISSN 0266-0032
compaction - grazing - machinery - soil - soil structural quality - trafficking pressure
Good soil structure provides multiple benefits for society but in grass-based production systems is underpinned by trafficking management regime. For Irish soils, there is no soil trafficking intensity index that considers the effect of geo-climatic variability or differences in drainage classes on soil compaction risk. Grazing and machinery activity data were compiled across 38 managed grasslands along with common soil structural quality indicators in order to develop and validate a ‘soil trafficking intensity index for compaction (STICi)’. Two component indices of STICi were developed: (a) a grazing trafficking index (Gi, kg × year ha−1) and (b) a machinery trafficking index (Mi, kg × year ha−1). The average annual grazing trafficking pressure observed was 213,914 kg × year ha−1, and the average annual machinery trafficking pressure was 4,412 kg × year ha−1. These figures represent thresholds above which soils are at higher risk of compaction. Mi spanned a wider range (−2.1 ≤ Mi ≤ 2.8) compared with Gi (−1.32 ≤ Gi ≤ 1.06). STICi and components, when disaggregated by soil drainage class, were able to detect changes in direct indicators of soil structural quality, such as bulk density, total porosity, water holding capacity, water conductivity and visual soil assessment. STICi (Mi and Gi) were also related to indirect indicators, such as, soil carbon content, earthworms and microbial biomass. In general, poorly drained sites showed higher vulnerability to machinery trafficking intensity compared with grazing trafficking pressure. At national scale, STICi can be utilized to identify soils at risk of compaction and underpin targeted management advice for supporting sustainable grassland production.
WoSIS snapshot - September 2019
Batjes, Niels ; Carvalho Ribeiro, Eloi ; Oostrum, Ad van - \ 2019
soil - standard - bulk density - cation exchange capacity (CEC) - soil classification - coarse fragments - clay - effective cation exchange capacity (ECEC) - electrical conductivity - organic carbon - pH - sand - silt - calcium carbonate equivalent - texture - water retention - WoSIS - WoSIS snapshot
The World Soil Information Service (WoSIS) provides quality-assessed and standardised soil profile data to support digital soil mapping and environmental applications at broad scale levels. Since the release of the first ‘WoSIS snapshot’, in July 2016, many new soil data were shared with us, registered in the ISRIC data repository, and subsequently standardised in accordance with the licences specified by the data providers. Soil profile data managed in WoSIS were contributed by a wide range of data providers, therefore special attention was paid to measures for soil data quality and the standardisation of soil property definitions, soil property values (and units of measurement), and soil analytical method descriptions. We presently consider the following soil chemical properties (organic carbon, total carbon, total carbonate equivalent, total Nitrogen, Phosphorus (extractable-P, total-P, and P-retention), soil pH, cation exchange capacity, and electrical conductivity) and physical properties (soil texture (sand, silt, and clay), bulk density, coarse fragments, and water retention), grouped according to analytical procedures (aggregates) that are operationally comparable. Further, for each profile, we provide the original soil classification (FAO, WRB, USDA, and version) and horizon designations insofar as these have been specified in the source databases. Measures for geographical accuracy (i.e. location) of the point data as well as a first approximation for the uncertainty associated with the operationally defined analytical methods are presented, for possible consideration in digital soil mapping and subsequent earth system modelling. The present snapshot, referred to as ‘WoSIS snapshot - September 2019’, comprises 196,498 geo-referenced profiles originating from 173 countries. They represent over 832 thousand soil layers (or horizons), and over 6 million records. The actual number of observations for each property varies (greatly) between proﬁles and with depth, this generally depending on the objectives of the initial soil sampling programmes.
Data from: Variation in home-field advantage and ability in leaf litter decomposition across successional gradients
Veen, Ciska G.F. ; Keiser, Ashley D. ; Putten, W.H. van der; Wardle, David A. - \ 2018
decomposition - functional breadth - succession - soil - plant-litter feedback
1. It is increasingly recognized that interactions between plants and soil (a)biotic conditions can influence local decomposition processes. For example, decomposer communities may become specialized in breaking down litter of plant species that they are associated with, resulting in accelerated decomposition, known as ‘home-field advantage’ (HFA). Also, soils can vary inherently in their capacity to degrade organic compounds, known as ‘ability’. However, we have a poor understanding how environmental conditions drive the occurrence of HFA and ability. 2. Here, we studied how HFA and ability change across three types of successional gradients: coastal sand dunes (primary succession), inland drift sands (primary succession), and ex-arable fields (secondary succession). Across these gradients, litter quality (i.e., nutrient, carbon and lignin contents) increases with successional time for coastal dunes and decreases for the other two gradients. 3. We performed a 12-month reciprocal litter transplant experiment under greenhouse conditions using soils and litters collected from early-, mid-, and late-successional stages of each gradient. 4. We found that HFA and ability did not consistently shift with successional stage for all gradients, but were instead specific for each type of successional gradient. In coastal dunes HFA was positive for early-successional litter, in drift sands it was negative for mid-successional litter, and for ex-arable fields, HFA increased with successional time. Ability of decomposer communities was highest in mid-successional stages for coastal dunes and drift sands, but for ex-arable fields ability decreased throughout with successional time. High HFA was related to high litter C content and soil and organic matter content in soils and to low litter and soil nutrient concentrations. Ability did not consistently occur in successional stages with high or low litter quality. 5. Synthesis: Our findings show that specific environmental conditions, such as changes in litter or soil quality, along environmental gradients can shape the influence of HFA and ability on decomposition. In sites with strong HFA or ability, interactions between plants, litter and decomposer communities will be important drivers of nutrient cycling and hence have the potential to feedback to plant growth.
Comparison of ecosystem services provided by grasslands with different utilization patterns in China’s Inner Mongolia Autonomous Region
Du, Bingzhen ; Zhen, Lin ; Hu, Yunfeng ; Yan, Huimin ; Groot, Rudolf de; Leemans, Rik - \ 2018
Journal of Geographical Sciences 28 (2018)10. - ISSN 1009-637X - p. 1399 - 1414.
ecosystem services - grasslands utilization pattern - household livelihoods - natural resource management - soil - vegetation
Although several previous studies in Inner Mongolia examined the effects of ecological conservation on the delivery of ecosystem services, they were often limited in scope (few ecosystem services were assessed) and often suffered from confounding by spatial variation. In this study, we examined the impact of conservation measures (changes in grassland utilization patterns) on the provision of selected ecosystem services in three types of grasslands (meadow steppe in Hulun Buir, typical steppe in Xilin Gol, and semi-desert steppe in Ordos) in Inner Mongolia. We examined five utilization patterns: no use (natural grasslands), light use, moderate use, intensive use, and recovery sites (degraded sites protected from further use). Through household surveys and vegetation and soil surveys, we measured the differences in ecosystem services among the different grassland utilization patterns. We also identified spatial factors that confounded the quantification of ecosystem services in different types of grasslands. We found that light use generally provided high levels of ecosystem services in meadow steppe and typical steppe, with the main differences in the supporting ecosystem services. Surprisingly, we found no consistently positive impacts of strict conservation activities across the sites, since the results varied spatially and with respect to differences in the land-use patterns. Our study suggests that appropriate grassland utilization patterns can enhance the supply of ecosystem services and reduce negative effects on both household livelihoods and the environment.
Efficiency of phosphorus resource use in Africa as defined by soil chemistry and the impact on crop production
Magnone, Daniel ; Bouwman, Alexander F. ; Zee, Sjoerd E.A.T.M. Van Der; Sattari, Sheida Z. ; Beusen, Arthur H.W. ; Niasar, Vahid J. - \ 2017
Energy Procedia 123 (2017). - ISSN 1876-6102 - p. 97 - 104.
DPPS - modelling - phosphorus - soil - soil resources
By 2050 the global population will be 9.7 billion, placing an unprecedented burden on the world's soils to produce extremely high food yields. Phosphorus (P) is crucial to plant growth and mineral fertilizer is added to soil to maintain P concentrations, however this is a finite resource, thus efficient use is critical. Plants primarily uptake P from a labile (available) P pool and not from the stable solid phase; transfer between these pools limits bioavailability. Transfer is controlled by soil properties which vary between soil types. The dynamic phosphorus pool simulator (DPPS) quantifies crop production and soil P relationships by utilising the transfer. This approach effectively models crop uptake from soil inputs, but it does not quantify the efficiency use. This study incorporates geochemical techniques within DPPS to quantify the efficiency of fertilizer-P use based on soil chemistry.
Pionieren : De impact van innovatieve maatschappelijke initiatieven op een natuur-inclusieve samenleving
Salverda, I.E. ; Dam, R.I. van; Pleijte, M. - \ 2017
Wageningen : Wageningen Environmental Research (Pionieren ) - 64
natuur - samenleving - participatie - stedelijke gebieden - sport - lopen - burgers - fondsgelden - weidevogels - bodem - nederland - nature - society - participation - urban areas - sport - walking - citizens - funding - grassland birds - soil - netherlands
Biochar boosts tropical but not temperate crop yields
Jeffery, Simon ; Abalos Rodriguez, Diego ; Prodana, Marija ; Bastos, Ana Catarina ; Groenigen, Jan Willem van; Hungate, Bruce A. ; Verheijen, Frank - \ 2017
Environmental Research Letters 12 (2017)5. - ISSN 1748-9318
biochar - crop yield - meta-analysis - soil
Applying biochar to soil is thought to have multiple benefits, from helping mitigate climate change [1, 2], to managing waste  to conserving soil . Biochar is also widely assumed to boost crop yield [5, 6], but there is controversy regarding the extent and cause of any yield benefit . Here we use a global-scale meta-analysis to show that biochar has, on average, no effect on crop yield in temperate latitudes, yet elicits a 25% average increase in yield in the tropics. In the tropics, biochar increased yield through liming and fertilization, consistent with the low soil pH, low fertility, and low fertilizer inputs typical of arable tropical soils. We also found that, in tropical soils, high-nutrient biochar inputs stimulated yield substantially more than low-nutrient biochar, further supporting the role of nutrient fertilization in the observed yield stimulation. In contrast, arable soils in temperate regions are moderate in pH, higher in fertility, and generally receive higher fertilizer inputs, leaving little room for additional benefits from biochar. Our findings demonstrate that the yield-stimulating effects of biochar are not universal, but may especially benefit agriculture in low-nutrient, acidic soils in the tropics. Biochar management in temperate zones should focus on potential non-yield benefits such as lime and fertilizer cost savings, greenhouse gas emissions control, and other ecosystem services.
De effecten van gereduceerde grondbewerking : groenbemesters beschermen bodem in winter en verminderen onkruiddruk in groeiseizoen
Balen, D.J.M. van; Leeuwen-Haagsma, W.K. van - \ 2017
Ekoland 37 (2017)5. - ISSN 0926-9142 - p. 12 - 13.
groenbemesters - biologische landbouw - bodemkwaliteit - bodem - bodembiologie - organische stof - gereduceerde grondbewerking - green manures - organic farming - soil quality - soil - soil biology - organic matter - reduced tillage
Binnen de biologische landbouw was er altijd extra aandacht voor bodemkwaliteit. De bodem voedt de plant tenslotte. Intussen beginnen wat meer te leren over welke processen er zich in de bodem afspelen. En over de rol die planten spelen. Naast gewas- en rassenkeuze kunnen groenbemesters en mengsels van gewassen en groenbemesters een belangrijke rol spelen. Zo kan ook de plant de bodem voeden.
Biotic interactions and trait-based ecosystem functioning in soil
Sechi, Valentina - \ 2017
Wageningen University. Promotor(en): L. Brussaard, co-promotor(en): R.G.M. de Goede; C. Mulder; M. Rutgers. - Wageningen : Wageningen University - ISBN 9789463431316 - 176
soil - ecosystems - plant-animal interactions - interactions - soil biology - soil quality - grasslands - collembola - diversity - bodem - ecosystemen - plant-dier interacties - interacties - bodembiologie - bodemkwaliteit - graslanden - collembola - diversiteit
Recent emphasis on ecosystem services as a framework to evaluate ecosystems and to promote their sustainable use has drawn attention to how organisms contribute to the delivery of services. Soil attributes and biotic interactions play important roles in ecological processes (e.g. soil formation, nutrient turnover, carbon sequestration and transformation) and, consequently, in the related delivery of ecosystem services.
Therefore, understanding how soil organisms interact and how they respond to environmental conditions is fundamental to preserve soil functioning and provide a meaningful assessment of ecosystem services. Functional traits determine individual responses to pressures and their effects on ecosystem functioning hence, investigating soil ecosystems from a trait-based perspective offers an interesting opportunity to link the functional responses of the organisms to environmental pressures and to give insight into how the entire community influences ecological processes.
The main objective of this thesis is to develop and to test concepts for a trait-driven quantification of ecosystem services through the assessment of the effects of land management on soil processes. In particular, it focuses on exploring the potential of a trait-based approach in identifying and better understanding the response of the soil biota to environmental pressures and analyses the responses of soil organisms in terms of changes in functional trait distribution and trophic interactions.
This work shows that approaches taking the whole soil community into consideration are more suitable to give insight into the effect of anthropogenic pressure on ecosystem functioning than approaches based on single taxonomic groups. Moreover, performing combined analysis (e.g. analysing body-mass distribution and trophic grouping) helps to better identify community response to environmental pressure.
A clear methodology for the next step, i.e. quantification of ecosystem services, is still lacking due to the current difficulties to link and quantify the effect of anthropogenic pressure to ecosystem functioning in soil. For this reason, it is essential that methods analysed in this thesis will be further explored under different environmental pressures to enable the development of tools to be used at the interface of science and society for sustainable development.
The steering role of plant-soil interactions in natural community dynamics and nature restoration
Wubs, Engel Reinder Jasper - \ 2017
Wageningen University. Promotor(en): W.H. Putten; T.M. Bezemer. - Wageningen : Wageningen University - ISBN 9789463434447 - 242
soil plant relationships - soil - plants - ecological restoration - terrestrial ecosystems - soil inoculation - plant communities - soil ecology - bodem-plant relaties - bodem - planten - ecologisch herstel - terrestrische ecosystemen - bodeminoculatie - plantengemeenschappen - bodemecologie
Biodiversity is declining worldwide and many ecosystems have been degraded due to human actions. There have been many attempts to restore degraded ecosystems, but restoration success varies. Past human management has left important abiotic and biotic legacies and active intervention is needed to overcome these legacies. Legacy effects include altered abiotic conditions and limited availability of appropriate seeds. However, plants also have many interactions with the myriad organisms that inhabit the soil. Soil biota include e.g. bacteria, fungi, nematodes, collembolan, and mites. Restoring plant-soil interactions may be key to successful ecological restoration, because studies on natural succession in ecosystems show that both plant and soil communities develop in concert. In addition, late-successional soil communities promote the performance of late-succession plant species that are often the target species for restoration. The aims of my thesis were to 1) test whether inoculation of living soil can improve restoration of species-rich grasslands and dry heathlands, and 2) understand how plant-soil interactions affect plant composition and diversity.
In a large-scale field experiment, called “Reijerscamp-experiment”, I tested the potential of soil inoculation to speed up ecosystem restoration. On a former arable field large areas of on average 0.5 ha were inoculated with a thin layer of <1 cm living soil, which was taken either from a mid-succession grassland or a dry-heathland. After six years I monitored the species composition of the vegetation and the soil community. I found that both types of inoculum had substantially altered the community composition of both soil and vegetation. Moreover, the soil inocula had caused a shift in the direction of the respective donor communities. In a parallel mesocosm experiment I repeated the experiment while sowing a standardized species-rich seed mixture to ensure that seed availability was the same in all treatments. Also in this case the sown plant community developed towards the respective communities found in the donor sites. Consequently the soil community is, at least in part, able to steer plant community composition in the field.
I also tested how mixtures of inocula from different donor systems affect restoration success. In a greenhouse experiment I made replacement series of soil inocula sourced from arable fields, mid-succession grasslands and dry heathlands and monitored the responses of target and ruderal plant species. The target species all responded positively to higher proportions of heathland material in the inoculum, while the responses of the ruderal species were variable. Interestingly, a 50:50 mixture of arable and heathland inoculum strongly reduced the growth of the ruderal species. Soil inoculation may be considered as a way of microbiome engineering, which is a newly emerging field mainly used to improve human health and agricultural production. My results show that conceptually similar techniques can be applied to improve inocula for the restoration of ecological communities.
In a second field experiment I tested the long-term consequences of soil inoculation with and without sowing mid-successional plant species for plant and soil community composition. I found that sowing strongly altered plant community composition for over two decades. Soil inoculation, on the other hand, substantially altered the composition of the soil nematode community and that these effects persisted for at least 15 years. However, in contrast to the Reijerscamp experiment, the effect of soil inoculation on vegetation composition was transient. I propose that in this case the presence of an intact arable top soil, as well as perhaps a too minimal difference between the composition of the donor and recipient soil communities may have limited the impact of the soil inocula.
In general, the restoration of plant cover and a number of common (‘matrix’) plant species can be achieved using standard approaches, e.g. reducing site fertility and providing seed material, but creating conditions that allow for coexistence of both locally dominant and rare subordinate species proves much more elusive. Fundamental knowledge on how biodiversity is regulated is needed to restore diverse plant communities including the rare species. Testing plant-soil feedback provides a way to directly study the net consequences of the myriad interactions between plants and soil biota for plant performance and community composition. However, while both plants and soil communities are strongly heterogeneous in space and time, spatiotemporally explicit tests of plant-soil feedback are rare.
In a greenhouse experiment I studied how spatial heterogeneity in plant-soil feedbacks influence plant communities. I found that when multiple species conditioned the soil, plant performance was reduced compared to mono-specific soil conditioning. This reduction in competitive ability led to a higher plant diversity in the experimental communities. The plant responses were not related to differences in abiotic conditions, but soil conditioning induced clear changes in fungal community composition. Recent meta-analyses and experiments have shown that spatial heterogeneity in abiotic conditions only promotes plant diversity when the grain of the heterogeneity is larger than the size of individual plants. When it is smaller, heterogeneity simply selects for those species that have the highest root plasticity and this leads to lower plant diversity. Together, these results suggest that spatial heterogeneity in abiotic conditions only promotes plant beta diversity, while interaction with the soil community, primarily soil-borne antagonists, maintains plant alpha diversity.
Finally, I used repeated soil conditioning by conspecific and heterospecific species to show that soil feedbacks may carry over across soil conditioning periods. In contrast to what is commonly assumed my data show that heterospecific soil-conditioning can result in equally negative PSF as repeated conspecific soil-conditioning and repeated conspecific soil-conditioning does not always lead to stronger negative feedback. Instead, the particular sequence of plant species that successively condition the soil strongly determines the sign and magnitude of PSF. These results highlight the need to incorporate sequential soil-conditioning in models of plant communities and effective crop-rotations.
In conclusion, plant-soil interactions are a key aspect in the natural dynamics of plant communities and can be used to improve restoration of semi-natural ecosystems. Abiotic conditions and dispersal ability determine which species may occur in a given site. However, at small spatial scales plant-soil feedbacks and particularly interactions with soil borne antagonists can enhance plant species diversity. Manipulation of the soil community, through inoculation of soil from well-developed donor sites can speed up natural succession and even steer its direction in the field. However, soil inoculation success will not be universal and depends on the match in abiotic conditions of donor and recipient sites, as well as the community composition of the inoculum and the resident communities. Future studies are needed to test the success of introducing soil communities across environmental gradients.
Technical documentation of the soil model VSD+ : Status A
Mol-Dijkstra, J.P. ; Reinds, G.J. - \ 2017
Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 88) - 88
soil - soil acidity - models - nutrient availability - soil carbon sequestration - climatic change - precipitation - bodem - bodemaciditeit - modellen - voedingsstoffenbeschikbaarheid - koolstofvastlegging in de bodem - klimaatverandering - neerslag
VSD+ is een model om de gevolgen te berekenen van atmosferische depositie en klimaatverandering voorbodemverzuring, de beschikbaarheid van voedingsstoffen en het vastleggen van koolstof. Het model isontwikkeld ter onderbouwing van strategieën om de uitstoot van zwavel (S) en stikstof (N) in Europa teverminderen. Dit document biedt een samenvatting van de theorie waar het model op gestoeld is, detechnische documentatie hiervan alsmede een beschrijving van het testen, het valideren en de sensitiviteitsanalysevan het model. De processen zoals beschreven in het artikel over VSD+ zijn met goed gevolg getest.De gevoeligheidsanalyse gaf aan dat de constante voor het evenwicht tussen H+ en Al3+ in de bodemoplossingen de Ca-verweringssnelheid de parameters zijn, die voor een groot gedeelte de waarde van degesimuleerde pH bepalen. Voor basenverzadiging zijn de belangrijkste parameters de uitwisselingsconstantetussen H+ en basische kationen en de verwering van Ca. Voor de C/N ratio van bodemorganische stof zijn Cen N in het strooisel en de opname van N zeer bepalende factoren. De nitraatconcentratie hangt sterk samenmet het nerslagoverschot en de netto input van N---VSD+ is a model to calculate effects of atmospheric deposition and climate change on soil acidification,nutrient availability and carbon sequestration. The model has been developed to support emission abatementstrategies of sulphur (S) and nitrogen (N) in Europe. This document contains a summary of the modeltheory, technical documentation and descriptions of testing, validations and the sensitivity analysis of themodel. The processes described in the paper about VSD+ have been tested successfully. The sensitivityanalysis showed that the constant for the equilibrium between H+ and Al3+ in the soil solution and theweathering rate of Ca are the parameters that to a large extent determine the value of the simulated pH. Forbase saturation, most important parameters are the exchange constant between H+ and base cations andthe weathering of Ca. For the C/N ratio of soil organic matter, litterfall of C and N and the uptake of N areimportant influencing factors. The nitrate concentration strongly depends on the leaching flux and the net N input
Bodemhydrofysische gegevens in BRO en BIS : update 2016
Bakker, G. ; Heinen, M. ; Wesseling, J.G. ; Groot, W.J.M. de; Assinck, F.B.T. ; Hummelink, E.W.J. - \ 2017
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2789) - 77
bodemfysica - hydrologie - water - bodem - soil physics - hydrology - water - soil
Lift up of Lowlands : beneficial use of dredged sediments to reverse land subsidence
Figueiredo Oliveira, Bruna Raquel - \ 2017
Wageningen University. Promotor(en): Huub Rijnaarts, co-promotor(en): Tim Grotenhuis. - Wageningen : Wageningen University - ISBN 9789462578838 - 229
dredgings - dredging - sedimentation - soil - sediment - subsidence - recycling - environmental engineering - bagger - baggeren - sedimentatie - bodem - sediment - bodemdaling - recycling - milieutechniek
In this thesis, the beneficial use of dredged sediments to reverse land subsidence in lowlands and delta areas is explored. The major constraints for beneficial use of sediments are the contaminant concentrations, and the proper managing of supply and demand of sediments (Chapter 1).
When sediments are transferred from waterways to upland conditions, a series of processes take place that transform the waterlogged sediments into aerated soils, a process known as ripening. To understand the relation between the sediments and the soils formed, physical/chemical and biological processes were studied at three scales: laboratory scale, mesoscale, and field scale. The knowledge obtained with these experiments can provide guidelines to effectively use dredged sediments to reverse land subsidence.
In the laboratory experiments, the environmental conditions were controlled, leading to constant water content and optimal oxygen concentration for biological processes. In the mesoscale experiment, the environmental parameters such as wind, precipitation and temperature, were not controlled as the 1 m3 containers used for these experiments were placed outside, in open air conditions. Still, the water level could be monitored and controlled, and the subsidence of the dredged sediment could be monitored. In the field experiment, the environmental and filling conditions could not be controlled but the changes occurring in the deposit were monitored.
In the first laboratory experiment (Chapter 2) the behaviour of dredged sediments with varying particle size distribution and organic matter content was studied. The dredged sediments were dewatered using suction chambers and then submitted to biochemical ripening during 141 days. The five types of dredged sediments had similar overall behaviour. The most significant observation was that most volume lost during dewatering and biochemical ripening was due to shrinkage and not to organic matter mineralization. Furthermore, the type of organic matter changed in the direction of humification, i.e., more stable compounds were formed. The soils formed from biochemical ripening of dredged sediments had very stable aggregates and the load-bearing capacity was enough to sustain cattle and tractors.
The second laboratory experiment (Chapter 3) was designed to investigate the influence of mixing compost and the solid fraction of swine manure (low in nutrients) with dredged sediments on dewatering and biochemical ripening. When the supply of dredged sediments is too low to compensate for land subsidence, bio-wastes, such as compost and manure, can be mixed with the sediments to reverse land subsidence. The results of this experiment confirm that most volume lost during ripening was due to shrinkage and not due to organic matter mineralization. Adding compost or the solid fraction of manure to the dredged sediments enhances the changes in the type of organic matter and CO2 production, i.e., the addition results in increased rates of organic matter mineralization which is described in the literature as the priming effect. In addition, the undrained shear strength of the mixtures of sediments with compost or manure was three times higher than the measured values for the sediments alone, meaning that organic amendments will improve the characteristics of the soil formed from ripening of sediments.
The mesoscale experiment (Chapter 4) was performed during 400 days in 1m3 containers which allowed to control the water level. Two scenarios were tested: upland deposits in which the sediments are allowed to dry; and underwater deposits in which the water level is always 2 cm above the sediments. It was expected that the upland deposit conditions would lead to a higher subsidence than the underwater conditions. However, subsidence of the sediments was very similar for the two scenarios. Also in these experiments it was observed that most subsidence could be attributed to shrinkage and not organic matter mineralization, and the type of organic matter changed in the direction of humification. Furthermore, the water balance indicated that evapotranspiration results in higher loss of water than drainage. Still, in this case the undrained shear strength after 400 days of experiment was not enough to sustain cattle or tractors even though it increased with time.
The monitored field scale upland deposit of dredged sediments (Chapter 5) is located in the Wormer- en Jisperveld area – North Holland, the Netherlands. The deposit was filled in two stages reaching a maximum height of sediments of 195 cm. After 17 months of monitoring, the subsidence of the sediments was 119 cm to which an extra subsidence of 19.5 cm of the underlying soil due to the overburden pressure was added. The results observed in the upland deposit are in line with the laboratory and mesoscale results since subsidence could also be attributed to shrinkage and no significant changes in the organic matter content were observed. However, in the case of the upland deposit, the type of organic matter changed in the direction of humification during the first 8 months (March to November), then stabilized during 7 months (November to June), and changed in the direction of mineralization afterwards.
The outcomes of this research indicate that dredged sediments have the potential to reverse land subsidence. This statement is supported by the consistent results showing that the decrease in volume of dredged sediments is caused by shrinkage and not to organic matter mineralization as traditionally reported (Chapters 2, 3, 4, and 5).
In addition, in places where composted and stable bio-wastes are available, these can be added to dredged sediments to further reverse land subsidence. Still, in this case special attention should be given to the potential priming effect (Chapter 3).
Finally it is recommended to adapt the current practices of disposal of dredged sediments in upland deposits, since 19.5 cm of subsidence observed for the underlying soil in the upland deposit (Chapter 5), was caused by the overburden pressure of the dredged sediment. From the point of view of avoiding/reversing land subsidence it is recommended to spread thin layers (in the order of cm) of sediments over the land, although this might lead to an increase in the time and costs for the stakeholders involved in dredging and in managing the water boards.
Cadmium in soil, crops and resultant dietary exposure
Rietra, R.P.J.J. ; Mol, G. ; Rietjens, I.M.C.M. ; Römkens, P.F.A.M. - \ 2017
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2784) - 39
cadmium - soil - food intake - crops - exposure - fertilizers - food safety - toxicology - cadmium - bodem - voedselopname - gewassen - blootstelling - kunstmeststoffen - voedselveiligheid - toxicologie
Report of DG AGRI Conference on Agriculture and Innovation - Pre-Event on International Soil Research: Opportunities for Synergy and Cooperation with FACCE-JPI, 27 January 2016, Brussels
Aller Moran, P. ; McKhann, H. ; Boekhorst, D. te - \ 2016
FACCE-JPI - 6 p.
agriculture - food security - climate change - innovation - soil - FACCE-JPI - agriculture - food security - Climate change - soil - innovation - DG AGRI - conference - FACCE JPI - Bioeconomy
Mais en bodem rapport 2015
Riemens, M.M. ; Huiting, H.F. ; Deru, J.G.C. ; Schooten, H.A. van; Weide, R.Y. van der - \ 2016
Wageningen Plant Research - 76
zea mays - maïs - bodem - bodembeheer - teeltsystemen - zea mays - maize - soil - soil management - cropping systems
Hoe kunnen veetelers met minder input meer resultaten halen bij snijmaïsteelt? Dat is de centrale vraag van het project “Duurzaam bodembeheer maïs” (BO-31.03-001-003). Veel melkveehouderijbedrijven telen snijmaïs, een gemakkelijk te telen ruwvoergewas met een goede productie van constante hoge kwaliteit. Als zetmeelbron met een ruime energie/eiwitverhouding past het goed in het runderdieet, naast gras en graskuil. De maïsteelt kan echter nadelige effecten hebben voor de bodem door gewasbeschermingsmiddelen en het uit- en afspoelen van nutriënten. Wageningen UR en het Louis Bolk Instituut onderzoeken in opdracht van het ministerie van EZ duurzame en praktisch haalbare verbeteringen en vernieuwingen. Teeltsystemen die zorgen voor een gezonde bodem worden daarbij gezien als sleutel tot duurzame teelt. Op drie locaties worden diverse teeltsystemen vergeleken in meerjarige proeven uitgevoerd op zand- en kleigrond. Daarbij wordt onder andere gekeken naar opbrengst, onkruiddruk, bodemstructuur, aanwezigheid van regenwormen, indringingsweerstand, waterinfiltratie, stikstofdynamiek en economische aspecten. Deze kennis wordt vervolgens doorgegeven aan de praktijk middels o.a. de beslisboom snijmaïs, een instrument om praktische kennis naar veetelers en erfbezoekers te brengen.
Fosfaatonderzoek Noorderpark 2016 : bodemonderzoek t.b.v. realisatie soortenrijke schraallanden, uitbreiding bij onderzoek uit 2013
Delft, S.P.J. ; Brouwer, F. - \ 2016
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2775) - 51
bodem - fosfaten - bodemonderzoek - natuurontwikkeling - graslanden - eutrofiëring - soortenrijkdom - utrecht - soil - phosphates - soil testing - nature development - grasslands - eutrophication - species richness - utrecht
In het noordwestelijk deel van het Noorderpark is onderzoek gedaan naar de abiotische geschiktheid voor soortenrijke graslanden. Hierbij zijn de nutriëntentoestand en de zuurbuffer beoordeeld. Met profielbeschrijvingen is de veraardingsgraad van veenlagen vastgesteld. Er zijn 36 boringen gedaan waarbij twee lagen bemonsterd zijn. Van drie boringen is een derde laag bemonsterd. De bodemmonsters zijn voor analyse samengevoegd tot 25 mengmonsters waaraan de analyses zijn uitgevoerd. Voor het plannen van de bemonstering en het samenstellen van de mengmonsters is een stratificatie uitgevoerd op basis van de Landschapsleutel. De nutriëntentoestand is beoordeeld op basis van de fosfaattoestand en de kans op het vrijkomen van nutriënten door mineralisatie en interne eutrofiëring. Bij de beoordeling van de fosfaattoestand is ook beoordeeld in hoeverre deze verbeterd kan worden door verschralingsbeheer of door afgraven van een deel van de bovengrond. Afhankelijk van de realisatiekans voor natuurdoelen bij verschillende maatregelen is per deelperceel een inrichtingsadvies opgesteld.
Simulation nitrogen-limited crop growth with SWAP/WOFOST : process descriptions and user manual
Groenendijk, Piet ; Boogaard, Hendrik ; Heinen, Marius ; Kroes, J.G. ; Supit, Iwan ; Wit, Allard de - \ 2016
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2721) - 59
crops - growth - soil - nitrogen - organic matter - mineralization - leaching - simulation models - nitrates - gewassen - groei - bodem - stikstof - organische stof - mineralisatie - uitspoelen - simulatiemodellen - nitraten
This report describes a soil nitrogen module (Soil-N), which is combined with the agro-hydrological model, SWAP, and the crop growth model, WOFOST. The core of the Soil-N module is a description of the nitrogen cycle, which is coupled to the organic matter cycle based upon the RothC-26.3 model. Nitrogen can be supplied to the soil as different types of fertilizer applications and through mineralisation of organic nitrogen. Ammonium and nitrate balances are calculated including uptake by plant roots, de-nitrification and leaching of nitrate. Data exchange is on a daily base. The partitioning of nitrogen within crops and the nitrogen contents of crop residues are calculated by WOFOST and passed to the Soil-N module. SWAP generates the data for establishing the water balance of the soil compartment for which the Soil-N perform the simulations. Nitrogen uptake by the crop is calculated as the minimum of the demand by the crop and the availability of nitrogen in the soil. The crop production rate is reduced when the mineral nitrogen stock is limited. Nitrogen-fixation is based on a simple approach. An improved sub-model for phenological stages of soybean was implemented. Increasing atmospheric CO2 concentrations can be accounted for. The innovated integrated model was tested using data sets from The Netherlands, China and Argentina, for which examples are given. This new model can be used as a tool in studies, in which both water and nitrogen can be limited for crop growth.
De bodem onder ons Bestaan
Brussaard, Lijbert - \ 2016
Wageningen : Wageningen University & Research - ISBN 9789463430081 - 24
bodem - bodembiologie - bodemkwaliteit - soil - soil biology - soil quality
Chemisch-fysische schematisering van de bodem voor NHI-waterkwaliteit : naar een nieuwe fysisch-chemische schematisering van de Nederlandse bodem
Bolt, Frank van der; Walvoort, Dennis ; Vries, Folkert de; Hoogland, Tom ; Vroon, Henk ; Groenendijk, Piet ; Renaud, Leo ; Massop, Harry ; Veldhuizen, Ab ; Walsum, Paul van - \ 2016
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2753) - 34
bodem - bodemkwaliteit - hydrologie - bodemeigenschappen - bodemkarteringen - soil - soil quality - hydrology - soil properties - soil surveys
Voor de ontwikkeling van het Nationaal Hydrologisch Instrumentarium-waterkwaliteit is een aanpak opgesteld om de fysisch-chemische schematisering van de bodem in Nederland verder te ontwikkelen. Op korte termijn (2017-2018) is een pragmatische werkwijze nodig om de bodemchemische parameters met bijbehorende schematisering in representatieve eenheden voor de operationele toepassing voor landelijke beleidsstudies te actualiseren. Het gebruik van de huidige fysischchemische karakterisering voor de bodemkaart 1:50.000 vormt de geëigende methode. Op de langere termijn is het de wens om het Nationaal Hydrologisch Instrumentarium-waterkwaliteit ook te kunnen inzetten voor regionale toepassingen. Dit kan alleen als er een gedetailleerde geostatistisch gesimuleerde 3D-bodemkaart aan ten grondslag ligt die recht doen aan regionale variabiliteit van de bodem.