Method and timing of grassland renovation affects herbage yield, nitrate leaching, and nitrous oxide emission in intensively managed grasslands

Managed grasslands are occasionally ploughed up and reseeded in order to maintain or increase the sward productivity. It has been reported that this renovation of grassland is associated with a flush of soil organic nitrogen (N) mineralization and with a temporary increase in soil mineral N contents. Here, we report on the effects of method and time of grassland renovation on herbage yield, nitrate (NO3 -) leaching and nitrous oxide (N2O) emission. Field experiments were carried out at three sites (two sandy soils and a clay soil) in the Netherlands for three years. Renovation of grassland increased the percentage of Perennial ryegrass from 48–70% up to more than 90%. However, averaged over three years, dry matter yields were higher for the reference (not reseeded) swards (on average 13.6 Mg ha-1 for the highest N application rate) than for the renovated grasslands (12.2–13.1 Mg ha-1 dry matter). Grassland renovation in April did not increase N leaching in comparison to the reference. However, renovation in September increased the risk of leaching, because mineral N contents in the 0–90 cm were in November on average 46–77 kg N ha-1 higher than in the reference. Contents of dissolved organic N (DON) in the soil were not affected by renovation. Renovation increased N2O emissions by a factor of 1.8–3.0 relative to the reference grassland. Emissions of N2O were on average higher after renovation in April (8.2 kg N2O-N ha-1) than in September (5.8 kg N2O-N ha-1). Renovation without ploughing (i.e. only chemically destruction of the sward) resulted in a lower percentage of perennial ryegrass (60–84%) than with ploughing (>90%). Moreover, N2O emissions were higher after renovation without ploughing than with ploughing. Clearly, farmers need better recommendations and tools for determining when grassland renovation has beneficial agronomic effects. Losses of N via leaching and N2O emission after renovation can probably not be avoided, but renovation in spring in stead of autumn in combination with ploughing and proper timing of fertilizer application can minimize N losses

Nitrogen in current European policies

Europe, and especially the European Union (EU), has many governmental policy measures aimed at decreasing unwanted reactive nitrogen (N_r) emissions from combustion, agriculture and urban wastes. Many of these policy measures have an "effects-based approach", and focus on single N_r compounds, single sectors and either on air or waters. This chapter addresses the origin, objectives and targets of EU policy measures related to N_r emissions, considers which instruments are being used to implement the policies and briefly discusses the effects of the policy measures

Indicatoren kwaliteit landelijk gebied : uitwerking van een methode, toepassingsmogelijkheden en een set van indicatoren

Een studie naar indicatoren voor een integrale, systematische, overzichtelijke en inzichtelijke beschrijving van de kwaliteit van het landelijk gebied. Deze kwaliteit is daarbij opgevat als een combinatie van natuurkwaliteit, landbouwkwaliteit, landschapskwaliteit, recreatiekwaliteit, veiligheid en gezondheid en leefbaarheid. Deze uitwerking is beschreven in Oenema et al., 2009 (WOt-werkdocument 130). De definiëring en interpretatie van de ‘impact’, de zogenoemde ‘eindpunten’ (natuurkwaliteit, landbouwkwaliteit, landschapskwaliteit, recreatiekwaliteit, veiligheid en gezondheid en leefbaarheid) bleek echter gecompliceerd en onbevredigend omdat de eindpunten van ongelijke orde zijn en ze door elkaar worden beïnvloedt. Daarom is besloten om de zoektocht naar geschikte indicatoren voor de kwaliteit van het landelijk gebied voort te zetten in 2009. De aandacht is hierbij vooral gericht op het vinden van een alternatief van de zogenoemde ‘eindpunten’

Are neighbourhood social capital and availability of sports facilities related to sports participation among Dutch adolescents?

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to explore whether availability of sports facilities, parks, and neighbourhood social capital (NSC) and their interaction are associated with leisure time sports participation among Dutch adolescents.</p> <p>Methods</p> <p>Cross-sectional analyses were conducted on complete data from the last wave of the YouRAction evaluation trial. Adolescents (n = 852) completed a questionnaire asking for sports participation, perceived NSC and demographics. Ecometric methods were used to aggregate perceived NSC to zip code level. Availability of sports facilities and parks was assessed by means of geographic information systems within the zip-code area and within a 1600 meter buffer. Multilevel logistic regression analyses, with neighborhood and individual as levels, were conducted to examine associations between physical and social environmental factors and leisure time sports participation. Simple slopes analysis was conducted to decompose interaction effects.</p> <p>Results</p> <p>NSC was significantly associated with sports participation (OR: 3.51 (95%CI: 1.18;10.41)) after adjustment for potential confounders. Availability of sports facilities and availability of parks were not associated with sports participation. A significant interaction between NSC and density of parks within the neighbourhood area (OR: 1.22 (90%CI: 1.01;1.34)) was found. Decomposition of the interaction term showed that adolescents were most likely to engage in leisure time sports when both availability of parks and NSC were highest.</p> <p>Conclusions</p> <p>The results of this study indicate that leisure time sports participation is associated with levels of NSC, but not with availability of parks or sports facilities. In addition, NSC and availability of parks in the zip code area interacted in such a way that leisure time sports participation is most likely among adolescents living in zip code areas with higher levels of NSC, and higher availability of parks. Hence, availability of parks appears only to be important for leisure time sports participation when NSC is high.</p

Sturen op nitraat: waar zitten de knoppen?

Bemesting, beweiding en scheuren van grasland hebben een groot effect op de nitraatconcentratie in het grondwater. Op maïsland heeft het achterwege laten van kunstmest, maar ook het achterwege laten van de bemesting van het vanggewas, behoorlijk effect. Dit blijkt uit een analyse van melkveebedrijven op zandgronden in het project Koeien & Kansen. De analyse omvat de effecten van bedrijfsvoering en van bodem, waterhuishouding en weer op de nitraatconcentrati

Associations of Children's Appetitive Traits with Weight and Dietary Behaviours in the Context of General Parenting

Background: Individual variations in child weight can be explained by genetic and behavioural susceptibility to obesity. Behavioural susceptibility can be expressed in appetite-related traits, e.g. food responsiveness. Research into such behavioural factors is important, as it can provide starting points for (preventive) interventions. Objectives: To examine associations of children's appetitive traits with weight and with fruit, snack and sugar-sweetened beverage intake, and to examine whether parenting style interacts with appetite in determining child weight/intake. Methods: Data were used from 1275 children participating in the INPACT study in 2009-2010, with a mean age of 9 years in 2009. Their height and weight were measured to calculate body mass index (BMI). Parents completed a questionnaire to measure children's appetitive traits, children's dietary intake and parenting style. Child BMI z-scores, fruit, snack and sugar-sweetened beverage intake were regressed on appetitive traits. Moderation by parenting style was tested by adding interaction terms to the regression analyses. Results: Food-approaching appetitive traits were positively, and food-avoidant appetitive traits were negatively related to child BMI z-scores and to child fruit intake. There were no or less consistent associations for snack and sugar-sweetened beverage intake. Authoritative parenting voided the negative association between food fussiness and fruit intake, while neglecting parenting strengthened the positive association between food-approaching appetitive traits and weight. Conclusions: Early assessment of appetitive traits could be used to identify children at risk for overweight. As parenting style can moderate the associations between appetitive traits and weight/intake in a favourable way, parents are a promising target group for preventive interventions aimed at influencing the effect of appetitive traits on children

Parental and child fruit consumption in the context of general parenting, parental education and ethnic background

This study examines the association between parental and child fruit consumption in the context of general parenting, parental education and ethnic background. A cross-sectional study was performed among 1762 parent-child dyads. Mean age of the children was 8. years. One parent completed a questionnaire to measure their own and their child's fruit consumption, parenting style, education level and ethnicity. In mediation and moderation analyses, child fruit consumption was regressed on parental fruit consumption, parenting style, parental education and ethnicity. Participating children consumed on average 7.5 pieces of fruit per week. Fourteen percent met the recommended Dutch norm of two pieces of fruit per day. Parental and child fruit consumption were positively associated. The association was more pronounced under higher levels of psychological control and behavioural control, and among ethnic groups. Additionally, parental education and child fruit consumption were positively associated. Parental fruit consumption partially mediated this association. Interventions are needed to increase child fruit consumption. Interventions should focus on increasing parental fruit consumption and positive parental modelling, with particular focus on low-SES families. Additionally, interventions that combine positive modelling with positive general parenting skills (e.g. increasing behavioural control) may be more effective than interventions that focus on parental modelling alone