Distributed hydrological modelling of total dissolved phosphorus transport in an agricultural landscape, part I: distributed runoff generation

International audienceSuccessful implementation of best management practices for reducing non-point source (NPS) pollution requires knowledge of the location of saturated areas that produce runoff. A physically-based, fully-distributed, GIS-integrated model, the Soil Moisture Distribution and Routing (SMDR) model was developed to simulate the hydrologic behavior of small rural upland watersheds with shallow soils and steep to moderate slopes. The model assumes that gravity is the only driving force of water and that most overland flow occurs as saturation excess. The model uses available soil and climatic data, and requires little calibration. The SMDR model was used to simulate runoff production on a 164-ha farm watershed in Delaware County, New York, in the headwaters of New York City water supply. Apart from land use, distributed input parameters were derived from readily available data. Simulated hydrographs compared reasonably with observed flows at the watershed outlet over a eight year simulation period, and peak timing and intensities were well reproduced. Using off-site weather input data produced occasional missed event peaks. Simulated soil moisture distribution agreed well with observed hydrological features and followed the same spatial trend as observed soil moisture contents sampled on four transects. Model accuracy improved when input variables were calibrated within the range of SSURGO-available parameters. The model will be a useful planning tool for reducing NPS pollution from farms in landscapes similar to the Northeastern US

Distributed hydrological modeling of total dissolved phosphorus transport in an agricultural landscape, part II: dissolved phosphorus transport

International audienceReducing non-point source phosphorus (P) loss to drinking water reservoirs is a main concern for New York City watershed planners, and modeling of P transport can assist in the evaluation of agricultural effects on nutrient dynamics. A spatially distributed model of total dissolved phosphorus (TDP) loading was developed using raster maps covering a 164-ha dairy farm watershed. Transport of TDP was calculated separately for baseflow and for surface runoff from manure-covered and non-manure-covered areas. Soil test P, simulated rainfall application, and land use were used to predict concentrations of TDP in overland flow from non-manure covered areas. Concentrations in runoff for manure-covered areas were computed from predicted cumulative flow and elapsed time since manure application, using field-specific manure spreading data. Baseflow TDP was calibrated from observed concentrations using a temperature-dependent coefficient. An additional component estimated loading associated with manure deposition on impervious areas, such as barnyards and roadways. Daily baseflow and runoff volumes were predicted for each 10-m cell using the Soil Moisture Distribution and Routing Model (SMDR). For each cell, daily TDP loads were calculated as the product of predicted runoff and estimated TDP concentrations. Predicted loads agreed well with loads observed at the watershed outlet when hydrology was modeled accurately (R2 79% winter, 87% summer). Lack of fit in early spring was attributed to difficulty in predicting snowmelt. Overall, runoff from non-manured areas appeared to be the dominant TDP loading source factor

Process evaluation of two environmental nutrition programmes and an educational nutrition programme conducted at supermarkets and worksite cafeterias in the Netherlands

This article describes the process evaluation of two environmental programs and a educational nutrition program, implemented at supermarkets and worksite cafeterias. Studies conducted earlier, indicated that the programs had no effect on consumers’ eating behavior. Consequently, the more specific purpose of the present study was to identify explanations for the ineffectiveness of the programs and to formulate recommendations for future programs. Materials and Methods The environmental programs included labeling of healthy products and increasing the range of healthy foods on offer. The education program consisted of several elements, such as brochures and a self-help guide. Semi-structured interviews were conducted with twenty-one managers of supermarkets and worksite cafeterias where the programs were implemented. Results Although materials were not always entirely compatible with the different supermarkets and worksite cafeterias, the degree of implementation was satisfactory. According to the managers, the programs were not striking enough, the labeling would have been more effective if it had discriminated between different brands of a product, and the number of new products was too small compared to the total range of foods on offer. Discussion The results can be used to help design and check future intervention programs for use at supermarkets or worksite cafeterias. Recommendations for future programs and research are given

Improved water and land management in the Ethiopian highlands and its impact on downstream stakeholders dependent on the Blue Nile

Improved water and land management in the Ethiopian highlands and its impact on downstream stakeholders dependent on the Blue Nile – short title Upstream-Downstream in Blue Nile River project is one of the projects in the Nile Basin supported by the CPWF. It was implemented during from 2007 to 2009 through a partnership of 8 institutions. The Blue Nile is the major tributary of the Nile River, contributing about 62% of the Nile flow at Aswan. About two thirds of the area of this densely populated basin is in the highlands and hence receives fairly high levels of annual rainfall of 800 to 2,200 mm. However, the rainfall is erratic in terms of both spatial and temporal distribution with prolonged dry spells and drought often leading to crop failures. Currently, water resources are only marginally exploited in the upper basin but are much more developed in the downstream reaches. The population, located in the downstream part of the Blue Nile, is dependent on the river water for supplementary irrigation and energy production. Canal and reservoir siltation is a major problem, adding the burdens of poor riparian farmers. This project was envisaged to improve the scientific understanding of the land and water resources of the basin, and hypothesized that with increased scientific knowledge of the hydrological, watershed, and institutional processes of the Blue Nile in Ethiopia (Abbay), constraints to up-scaling adaptable best practices and promising technologies (technical, socio-economic, institutional) could be overcome, which will result in significant positive impacts for both upstream and downstream communities and state

The impact of educational and environmental interventions in Dutch worksite cafeterias

Environmental interventions as labeling of healthy foods and an increased availability of healthy foods may help consumers to meet the guidelines for a healthy diet. This article describes a study into the effectiveness of two environmental programs to be used in worksite cafeterias along with an educational program. The aim of the interventions was to reduce fat intake and increase fruit and vegetable intake. In the 'Labeling Program', low fat products were labeled. The 'Food Supply Program' comprised an increased availability of low-fat products and fruits and vegetables in worksite cafeterias. The 'Educational Program' consisted of information about healthy nutrition through brochures, table tents, a self help manual and posters. The design consisted of a pretest-posttest experimental control group design, with four conditions: the Educational Program, the Food Supply Program plus Educational Program, the Labeling Program plus Educational Program and a control group. Seventeen worksites were randomly assigned to one of the four research conditions. Total fat, fruit, and vegetable intake was measured with a quantitative, self-administered food frequency questionnaire (35 questions). Intake during lunch was measured by asking respondents to write down which food items they had purchased during their last lunch in the cafeteria. Furthermore, sales data for some targeted product categories were collected (milk, butter, cheese, meat products, desserts). For the whole study population, no significant effects on consumption data were found for any of the programs. The data showed a beneficial significant treatment effect of the Labeling Program on total fat intake, for respondents who believe they eat a high fat diet. Sales data revealed a significant effect of the labeling program on desserts, but not for the other products

Effects of behavioural parent training for children with attention-deficit/hyperactivity disorder on parenting behaviour:a protocol for an individual participant data meta-analysis

Introduction : Behavioural parent training (BPT) is a well-established treatment for children with attention-deficit/hyperactivity disorder (ADHD). BPT is based on the hypothesis that improvements in parenting are mediators of improvements in children's behaviours. However, meta-analyses show considerate heterogeneity in effects of BPT on child outcomes, and meta-analyses on parenting outcomes are scarce. Also, few studies have investigated parenting factors as mediators of child outcomes. This study aims to examine the effects and moderators of BPT on parenting outcomes and whether improvements in parenting mediate amelioration of behaviour and impairment in children with ADHD. Methods and analyses : We will conduct an individual participant data meta-analysis (IPDMA), making use of individual data of existing trials, and giving the opportunity for highly powered moderator analyses. This IPDMA will be performed by the Psychosocial ADHD INTervention (PAINT) collaboration. We will include randomised controlled trials of BPT, for individuals with ADHD below 18 years old. Systematic searches have been performed to locate relevant papers. Authors are currently contacted to share their data with the PAINT-IPDMA project. We will examine effects of BPT on parenting outcomes (eg, positive and negative parenting, management of affect, perceived parenting competence, parenting stress), moderators of these effects (eg, parental depression, parenting stress, severity of the child's ADHD symptoms) and subsequently perform mediation analyses where parenting outcomes are modelled as mediators of child outcomes (eg, symptoms and severity of ADHD, comorbid psychopathology and impairment). Ethics and dissemination : We will include data from randomised control trials for which ethical approval has been received and consent forms have been signed. Deidentified data will be provided by the original investigators. We aim to disseminate our findings through peer-reviewed scientific journals, presentations at (inter)national scientific meetings, newsletters, the website of our project and the Dutch academic workspace ADHD. PROSPERO registration number : CRD42017069877

Phloem-specific resistance in Brassica oleracea against the whitefly Aleyrodes proletella

The cabbage whitefly [Aleyrodes proletella L. (Hemiptera: Aleyrodidae)] is becoming a serious pest in Brassica oleracea L. (Brassicaceae) crops. However, almost nothing is known about the interaction of this insect with its host plants. Previous studies have shown differences in the natural occurrence of adults, eggs, and nymphs on the closely related B. oleracea cultivars Christmas Drumhead and Riviera grown in the field. In this study, we aimed to identify the nature of these differences and to gain insight into the resistance mechanisms against A. proletella. We used no-choice experiments on field- and greenhouse-grown plants to show that the differences between the two cultivars are mainly based on antibiosis (traits that reduce herbivore performance) and not on antixenosis (traits that deter herbivory). This was further supported by laboratory choice experiments that indicated little or no discrimination between the two cultivars based on plant volatiles. We showed that resistance is dependent on plant age, that is, resistance increased during plant development, and is mainly independent of environmental factors. Analysis of probing behaviour revealed that the resistance trait affects A. proletella at the phloem level and that morphological differences between the two cultivars are most likely not involved. We suggest that compounds present in the phloem reduce sap ingestion by the whitefly and that this explains the observed resistanc

Rainfall infiltration and runoff from an Alfisol in semi-arid tropical India. II. Tilled systems

Daily runoff data from a field experiment conducted at International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India, were analysed to quantify the benefits of shallow tillage to a depth of 10 cm and deep tillage to a depth of 20 cm and application of amendments (farmyard manure at 15 Mg/ha per year and rice straw (Oryza sativa) at 5 Mg/ha per year) on Alfisols, using a no-till, unamended system as a control. The no-till system is discussed in detail in Part I. Runoff from tilled plots declined sharply after tillage operation and reverted back to that from an untilled plot after a few storms totalling ~150 mm of rainfall. The effective period of tillage varied from 5 days in 1989, when a single storm of 115 mm rain occurred 5 days after tillage, to ~60 days during 1993 and 1994. Quantitative rainfall-runoff relationships were developed by dividing 633 rainfall-runoff events over 6 years into three groups, depending on time of occurrence: fallow period, from time of tillage operation to receipt of 150 mm of rain, and the remaining events during the cropping period after 150 mm of rain to crop harvest. More than 73% of the variation in runoff from bare and farmyard manure plots could be explained by either rainfall amount or by the product of rainfall amount and 30 min intensity. In addition, soil cover was important during the fallow period. Using the 5 min rainfall intensities, runoff of tilled systems were reduced from 35 to 10% of rainfall by adding straw. The implication is that organic amendments (such as straw or farmyard manure, if available) offer a sustainable way for Alfisols to maintain a high infiltration rate and, thereby, both reduce runoff and increase the amount of water available for crop production