MEASURING PRECIPITATION, INFILTRATION AND WATER DISCHARGE ON A CATCHMENT SCALE FOR SOIL EROSION MODELING IN THE SOUTH PACIFIC REGION

Abstract The work presented here was done in the framework of the CROPPRO project. CROPPRO aims to provide assistance to Pacific Island countries with the development of integrated farming approaches for sustainable crop production in environmentally constrained systems. The project focuses on the development of tailor-made farming approaches for major crop-soil units aiming at maximizing agricultural production and minimizing environmental deterioration. Special attention is paid to knowledge transfer and participatory, culture-sensitive training for stakeholders and end-users. One aspect of the work within the framework of CROPPRO projects is the continuous measurement of the dynamic features of the catchment hydrology. These data are needed to calibrate the LISEM model that is used to evaluate different land use scenarios. The work presented in this paper focuses on methods used and results obtained using various measuring methods and equipment, with respect to precipitation, slope hydrology, and catchment discharge. Two catchments on Fiji and Samoa were instrumented with automatic rain gauges to measure precipitation and precipitation intensity spatially, with data loggers equipped with Frequency Domain Reflectometry (FDR) sensors installed on a slope to measure the water content profile and sub-surface flow. At the outlet of the catchments a flume was constructed to measure outflow using ultrasonic water level sensors, and sediment content using automatic samplers. A sample of data collected using these systems is presented

Use of Clay Dispersed in Water for Decreasing Soil Water Repellency

In this study, we examined the efficiency of a kaolinite clayey soil to mitigate water repellency of a sandy soil with olive trees. The treatment was applied to the soil zone below the tree canopy, which displayed the highest degree of water repellency [average water drop penetration time (WDPT) value = 820 s]. Both dry (incorporated onto the top soil) and wet clay applications (after dispersion in irrigation water) were examined in a replicated experiment, with control trees being used for comparison. The application rate of the clayey soil was maintained in both cases (wet and dry mode) equal to 1 kg m−2, while the effect of subsequent wetting and drying cycles on the treatment performance was evaluated. The results of the study verify that clay application was effective to mitigate soil water repellency. Dry supplementation displayed low efficiency (26% reduction of the air-dry WDPT compared with the control soil) within the first week of application. The efficiency of the dry-clay treatment increased to 76% after applying three subsequent wetting and drying cycles. In comparison with the dry mode, the wet clay was efficient immediately after application (74% reduction of the WDPT), indicating that the limiting step in the overall process was clay dispersion. Based on the findings of this study, it was proposed that wet clay application is of interest for controlling soil water repellency in agricultural land

The effects of wildfire frequency on post-fire soil surface water dynamics

Increasing wildfire frequency in the Mediterranean Basin could affect future plant-soil–water-dynamics. The capacity of soils to retain water is a key parameter affecting plant post-fire regeneration. Yet, few research has looked at how different soil properties related to water retention is affected by increasing wildfire frequency. This study aimed at understanding the relationship between wildfire frequency, soil–water-related properties and the dynamics of surface water in soils. To this, after a 2012-summer wildfire in Portugal, three sets of three replicate maritime pine stands with contrasted wildfire frequency were selected (0 vs. 1 vs. 4 fires since 1975). At each of the nine study sites, three re-sprouter shrubs and neighbouring bare soil were chosen (54 microsites). There, soil cover, soil–water retention curves and surface (0–5 cm) soil–water-related properties (texture, bulk density, organic matter content, soil moisture, soil surface water repellency) were monitored for one year. Furthermore, records of post-fire soil moisture dynamics were analysed continuously using 72 probes installed at 2.5 and 7.5 cm depth. The hillslopes affected by 1 fire showed higher plant recovery than the 4 fires hillslopes. During the dry season, the threshold for water stress was reached 17 days sooner in the 4 fires hillslopes, and also 10 days sooner on bare microsites. Periods of plant water stress were longer and bare soil patches size bigger. The increase in wildfire frequency promoted high soil organic matter contents but less available water content, stressing the importance of soil organic matter quality characterization in water-related properties.Open access funding provided by FCT|FCCN (b-on). This work was funded and performed within the scope of the CASCADE-PROJECT (Catastrophic shifts in drylands: how can we prevent ecosystem degradation? Grant agreement: 28306), funded by the European Commission (FP7-ENV.2011.2.1.4-2-Behaviour o ecosystems, thresholds and tipping points). We acknowledge financial support to CESAM by FCT/MCTES thought national funds (UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020). We also acknowledge financial support the University of Aveiro through the assistant research contract of Oscar González-Pelayo (CDL-CTTRI-97-ARH/2018 (REF. 190-97-ARH/2018), and to the MED & CHANGE-University of Évora through the auxiliary research contract (Ref. UIDB/05183/2020). Thanks are also due to FCT for the research contract of Sérgio Prats (CDL-CTTRI-88-ARH/2018 REF.-138-88-ARH/2018) and auxiliary research contract (CEECIND/01473/2020), and Maruxa Malvar (SFRH/BPD/97977/2013), and the IF research grant of Jacob Keizer (IF/01465/2015) funded by national funds (OE), through the Portuguese Foundation for Science and Technology (FCT/MCTES)

Soil-Improving Cropping Systems for Sustainable and Profitable Farming in Europe

Soils form the basis for agricultural production and other ecosystem services, and soil management should aim at improving their quality and resilience. Within the SoilCare project, the concept of soil-improving cropping systems (SICS) was developed as a holistic approach to facilitate the adoption of soil management that is sustainable and profitable. SICS selected with stakeholders were monitored and evaluated for environmental, sociocultural, and economic effects to determine profitability and sustainability. Monitoring results were upscaled to European level using modelling and Europe-wide data, and a mapping tool was developed to assist in selection of appropriate SICS across Europe. Furthermore, biophysical, sociocultural, economic, and policy reasons for (non)adoption were studied. Results at the plot/farm scale showed a small positive impact of SICS on environment and soil, no effect on sustainability, and small negative impacts on economic and sociocultural dimensions. Modelling showed that different SICS had different impacts across Europe-indicating the importance of understanding local dynamics in Europe-wide assessments. Work on adoption of SICS confirmed the role economic considerations play in the uptake of SICS, but also highlighted social factors such as trust. The project's results underlined the need for policies that support and enable a transition to more sustainable agricultural practices in a coherent way

Soil-Improving Cropping Systems for Sustainable and Profitable Farming in Europe

Soils form the basis for agricultural production and other ecosystem services, and soil management should aim at improving their quality and resilience. Within the SoilCare project, the concept of soil-improving cropping systems (SICS) was developed as a holistic approach to facilitate the adoption of soil management that is sustainable and profitable. SICS selected with stakeholders were monitored and evaluated for environmental, sociocultural, and economic effects to determine profitability and sustainability. Monitoring results were upscaled to European level using modelling and Europe-wide data, and a mapping tool was developed to assist in selection of appropriate SICS across Europe. Furthermore, biophysical, sociocultural, economic, and policy reasons for (non)adoption were studied. Results at the plot/farm scale showed a small positive impact of SICS on environment and soil, no effect on sustainability, and small negative impacts on economic and sociocultural dimensions. Modelling showed that different SICS had different impacts across Europe—indicating the importance of understanding local dynamics in Europe-wide assessments. Work on adoption of SICS confirmed the role economic considerations play in the uptake of SICS, but also highlighted social factors such as trust. The project’s results underlined the need for policies that support and enable a transition to more sustainable agricultural practices in a coherent way

The role of multixenobiotic transporters in predatory marine molluscs as counter-defense mechanisms against dietary allelochemicals

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 152 (2010): 288-300, doi:10.1016/j.cbpc.2010.05.003.Multixenobiotic transporters have been extensively studied for their ability to modulate the disposition and toxicity of pharmacological agents, yet their influence in regulating the levels of dietary toxins within marine consumers has only recently been explored. This study presents functional and molecular evidence for multixenobiotic transporter-mediated efflux activity and expression in the generalist gastropod Cyphoma gibbosum, and the specialist nudibranch Tritonia hamnerorum, obligate predators of chemically defended gorgonian corals. Immunochemical analysis revealed that proteins with homology to permeability glycoprotein (P-gp) were highly expressed in T. hamnerorum whole animal homogenates and localized to the apical tips of the gut epithelium, a location consistent with a role in protection against ingested prey toxins. In vivo dye assays with specific inhibitors of efflux transporters demonstrated the activity of P-gp and multidrug resistance-associated protein (MRP) families of ABC transporters in T. hamnerorum. In addition, we identified eight partial cDNA sequences encoding two ABCB and two ABCC proteins from each molluscan species. Digestive gland transcripts of C. gibbosum MRP-1, which have homology to vertebrate glutathione-conjugate transporters, were constitutively expressed regardless of gorgonian diet. This constitutive expression may reflect the ubiquitous presence of high affinity substrates for C. gibbosum glutathione transferases in gorgonian tissues likely necessitating export by MRPs. Our results suggest that differences in multixenobiotic transporter expression patterns and activity in molluscan predators may stem from the divergent foraging strategies of each consumer.Financial support was provided by the Ocean Life Institute Tropical Research Initiative Grant (WHOI) to KEW and MEH; the Robert H. Cole Endowed Ocean Ventures Fund (WHOI) to KEW; the National Undersea Research Center – Program Development Proposal (CMRC-03PRMN0103A) to KEW; and the National Science Foundation (Graduate Research Fellowship to KEW and DEB-0919064 to EES)

A new design to assess Land Degradation Neutrality (LDN) in the Netherlands : How can we better report to the UNCCD for SDG 15.3?

The Netherlands is party to the UNCCD (United Nations Convention to Combat Desertification) and is, thereby, committed to report about the progress made towards the objectives of this convention. This project explored the shortcomings of the existing UNCCD methodology, and how it could be adapted to take the specific conditions in the Netherlands into account. In this project, we aimed to assess the suitability of the UNCCD SDG 15.3 monitoring and reporting methodology for the Dutch context, and which additional tools could be added to this methodology to enable a more realistic assessment of the actual Land Degradation Neutrality (LDN) status and evolution in the Netherlands