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De interesse voor kruidenrijk grasland neemt toe. In een tweejarig onderzoek werden twee typen kruidenrijk grasland – ‘productief’ en ‘extensief kruidenrijk’ – vergeleken met blijvend grasland. Hoe verschillen hun productie, hun bodemkwaliteit en de biodiversiteit van de flora en fauna? Het onderzoek werd uitgevoerd door het Louis Bolk Instituut, Wageningen Environmental Research, Wageningen Plant Research en De Vlinderstichting.

Marsh horsetail (Equisetum palustre L.) is harmful to livestock and it increases in grassland when fertilisation is reduced. The combination of being a toxic feed and having few options to reduce its population brings challenges, especially for organic dairy farming. In a field trial on grassland with marsh horsetail infestation, electrical weed control (Zasso Xpower) was compared to no control of marsh horsetail and aboveground control using a chain harrow. Three replicates were placed in a field with high infestation and three in low infestation. Before treatments were applied, ground cover of marsh horsetail was between 8 and 15% in the high infestation plots and between 0.5 and 4% in the low infestation plots. Chain harrowing showed an initial reduction between 17 and 21%, while electrical control showed a reduction between 42 and 94%. Although initial reduction through electrical control was promising, in the next year marsh horsetail levels returned to that of the control treatment. The reduction through use of the chain harrow was not significant. Therefore, we conclude that a Zasso Xpower, as a single application, to control of marsh horsetail did not result in the desired level of reduction in the longer term. More frequent applications could provide a desirable effect.

In Nederland ligt een groot areaal kruiden- en faunarijk grasland (N12.02). Het overgrote deel heeft een slechte natuurkwaliteit. Er komen te weinig doelsoorten voor en ze worden gedomineerd door witbol of pitrus. Vanwege het grote areaal heeft het beheertype echter veel potentie voor verbetering van de biodiversiteit. Maar hoe beoordeel je eigenlijk de kwaliteit van kruiden- en faunarijk grasland en hoe kan die beoordeling in dienst staan van een goed beheer? Deze vragen proberen we aan de hand van een praktijkcasus te beantwoorden., In Nederland ligt een groot areaal kruiden- en faunarijk grasland (N12.02).Het overgrote deel heeft een slechte natuurkwaliteit. Er komen te weinigdoelsoorten voor en ze worden gedomineerd door witbol of pitrus. Vanwegehet grote areaal heeft het beheertype echter veel potentie voor verbetering vande biodiversiteit. Maar hoe beoordeel je eigenlijk de kwaliteit van kruiden- enfaunarijk grasland en hoe kan die beoordeling in dienst staan van een goed beheer?Deze vragen proberen we aan de hand van een praktijkcasus te beantwoorden.

The expanded usage of white clover has increased the importance of understanding white clover dynamics in pastures. It is assumed that clover plants have a higher tolerance for moisture and nutrient deficiencies when the taproot is still present. Therefore, the survival of the seminal taproot can influence the dynamics of clover. Past breeding efforts in countries like New Zealand have focussed on increasing the taproot longevity through hybridisation with a close relative of white clover. However, there is no direct evidence whether increased survival of the taproot results in increased performance of white clover. In this study, we aimed to (i) assess the relationship between taproot volume and taproot survival, and (ii) whether the timing of death of the seminal taproot influences the population dynamics of white clover varieties. In a two-year field experiment with 18 white clover varieties grown in monoculture and in mixture with Lolium perenne L, the taproot characteristics and population dynamics were studied. It was shown that taproot volume was positively correlated to both leaf size and taproot presence during autumn 2017, 1 year after sowing. The combination of the timing of death of the seminal tap root and the development of stolons seems to play a more important role in increasing the persistence of white clover than the absolute survival of the seminal taproot. Future research should focus on understanding the transition from a taprooted white clover to a stolonous white clover plant in relation to specific weather events such as winter frost conditions.

In three dairy grasslands on peat, minerals were added to manipulate the soil Ca:Mg ratio with or without effect on pH. The responses of soil properties and grass N yield were measured. CaCO3 application led to higher soil Ca:Mg ratio and pHKCl compared to the untreated control, decreased Ntotal and Ctotal, and increased P availability. Grass N yield increased in the first year by only 6% of the reduction in soil Ntotal, but not in the second year. A higher pH increased SOM decomposition, especially in soils with high P availability. MgCO3 reduced the Ca:Mg ratio, had little influence on soil parameters and no effect on grass N yield. In contrast, CaSO4 and MgSO4 did not influence pHKCl but reduced grass N yield in most cases. Results suggest stabilisation of organic matter by Ca binding in treatments with added Ca. We conclude that grass N yield was not linked with changes in Ca:Mg ratio but with soil pH. The pH effects on SOM decomposition depended on P availability and Ca binding. Hence, to avoid potentially large soil losses of C and N, the current agricultural advice on pH management in peat grasslands should be better adapted to local edaphic characteristics.

To evaluate the performance of organic and inorganic fertilizers for regeneration of ecosystem services in peat grasslands with biodiversity goals, we carried out a field experiment in the western peat district in the Netherlands. The fertilizers tested represent the current practice and potential alternatives for regenerative grassland management on drained peat. Experimental setup The field experiment (2013 – 2015) was conducted on a permanent grassland on peat soil (Terric Histosol; SOM 56 g 100 g−1 and pHKCl of 4.5 in 0-10 cm) at the experimental dairy farm at Zegveld (the Netherlands). In March 2013, a randomized block experiment (six blocks) was laid out with six fertilizer treatments and a control treatment (no fertilizer: “Contr”). The fertilizer used were: conventional dairy cattle slurry manure (“Slurry”), mature compost of kitchen and garden waste (“Comp”), dairy cattle farmyard manure (“FYM”), solid fraction of the cattle slurry manure (“SFrac”, obtained by pressurized filtration), inorganic N fertilizer (“IF”; calcium ammonium nitrate, 27% N) and a combination of inorganic N fertilizer and sawdust (“IF+SD”). Plot size was 4 × 10 m; for the Slurry treatment plots were 5.2 × 10 m. Slurry was applied by slit injection, the other fertilizers were applied by hand. Target application rate was 120 kg total N ha−1 yr−1, divided in two applications per year (February/March and May). This is relatively low for conventional grasslands but usual for grasslands with biodiversity goals (Kleijn et al., 2004). The amount of Ctotal applied in Comp was taken for the rate of sawdust to be applied. All plots were fertilized with 200 kg K2O ha−1 yr−1 (applications in March and May) (Commissie Bemesting Grasland en Voedergewassen, 2019). Fertilizer application quantities and organic matter and nutrient inputs are provided in Fertilizer_intput.csv (dataset). The grassland had an history of conventional management with mainly cutting, winter grazing with sheep and a normal fer

An important motivation for farmers to renew grassland swards (by ploughing and reseeding) is to introduce the most recent grass cultivars that give high yields and high forage quality. However, grassland renewal may affect soil quality negatively due to ploughing. The aims of this study were (1) to compare grass productivity and soil chemical quality of young and old grasslands, and (2) to investigate the relation between soil chemical quality and grass productivity. On clay soil in the north of the Netherlands we measured grass productivity and soil parameters of ‘young’ (5-15 years without grassland renewal) and ‘old’ (>15 years without grassland renewal) grasslands, located as pairs at ten different dairy farms. We selected grasslands with at least 70% desirable grasses (i.e. Lolium perenne and Phleum pratense). We found a lower herbage nitrogen (N) yield in young grassland and no significant difference compared with old grassland in terms of herbage dry matter yield and fertilizer N response. The soil of young grassland contained less soil organic matter (SOM), carbon (C-total) and nitrogen (N-total) compared to the old grassland soil. Grass productivity was positively correlated with SOM, N-total and C-total. The current management practice of renewing grassland after 10 years without considering the botanical composition is counter-productive.

Permanent grassland soils can act as a sink for carbon and may therefore positively contribute to climate change mitigation and adaptation. We compared young (5-15 years since latest grassland renewal) with old (>15 years since latest grassland renewal) permanent grassland soils in terms of carbon stock, carbon sequestration, drought tolerance and flood resistance. In old grassland soils we found a higher carbon stock (62 Mg C ha-1) than in young grassland soils (51 Mg C ha-1). The carbon sequestration rate tended to be higher (not statistically significant) in young (average 3.0 Mg C ha-1 year-1) than old (1.6 Mg C ha-1 year -1) grassland soils. Regarding potential drought tolerance, we found larger soil moisture and lower soil bulk density in old than in young grassland soils. Old grassland soils were also more resistant to heavy rainfall. We conclude that by extending grassland age on clay soil, farmers can contribute to climate change mitigation and adaptation ecosystem services.

Begin jaren nul deden biologische akkerbouw- en veebedrijven mee aan provinciale stimuleringsprojecten voor zogenoemde koppelbedrijven. Biologische akkerbouwers wilden de aanvoer van biologische mest veiligstellen, veehouders wilden voer uit de regio. Terugkijkend stellen akkerbouwers dat ze gras-klaver als rustgewas en het kunnen intensiveren van het overige deel van het bouwplan waardeerden.