We investigated differences between forage species with regard to micronutrients that are essential to sustain livestock health. Five grasses (timothy, perennial ryegrass, meadow fescue, tall fescue and cocksfoot), three legumes (red clover, white clover and birdsfoot trefoil) and four forbs (ribwort plantain, salad burnet, caraway and chicory) were grown on one micronutrient-poor/low pH soil and one micronutrient-rich/high pH soil (outdoor pot experiment). In addition, six grasses (timothy, perennial ryegrass, meadow fescue, tall fescue, Festulolium hybrid and cocksfoot) and one legume (red clover) were field-grown on the micronutrient-poor soil. Of the twelve pot-grown species, herbage of chicory, red clover and white clover generally had the highest micronutrient concentrations (maximum Co, Cu, Fe and Zn concentrations were 0Á23, 9Á8, 233 and 109 mg kg À1 DM, respectively), except for Mo, which was highest in the clovers (10Á6 mg kg À1 DM), and Mn, which was highest in cocksfoot (375 mg kg À1 DM). Soil type had the strongest effect on plant Mo and Mn concentrations. We also investigated differences in micronutrients between varieties, but they were generally few and negligible. The results indicate that choice of forage species is of major importance for micronutrient concentrations in herbage and that soil type exerts a major effect through pH. Forage of chicory, red clover and white clover generally met the requirements of high-yielding dairy cows with regard to most micronu-trients; therefore, diversification of seed mixtures so as to include these species could increase micronutrient concentrations in forage.

Abbreviations: LOD, limit of detection; LOQ, limit of quantification; OMK, organic environmental chemistry; PTI, Pesticide Toxicity Index; WQO, water quality objective.

The main aim of this study was to examine how concentrations of the micronutrients cobalt, copper, iron, manganese, molybdenum, nickel and zinc change with phenological development in red clover, perennial ryegrass and timothy. An additional aim was to investigate micronutrient concentrations and the dry matter (DM) proportions of the leaves, stems and flowers at the flowering stage. The plants were harvested at five phenological stages, ranging from stem elongation to flowering, in a greenhouse pot experiment. The results show that micronutrient concentrations generally decreased with phenological development of the grasses, but that the reduction was larger in timothy than in perennial ryegrass. Concentrations of cobalt, iron, manganese and nickel were more constant in red clover than in the other species. Flowers and leaves had higher concentrations than stems. The generally low concentrations found in timothy were largely due to the high DM proportion of micronutrient‐poor stems. Our results suggest that harvest at an early phenological stage is not only preferred due to high digestibility but also with regard to micronutrient concentrations. They also highlight the importance of considering phenological development and DM harvested when comparing forage species with regard to micronutrient concentrations.

16Highlights: 17• Four grass-clover-chicory mixtures were grown on three contrasting sites. 18• Chicory and clovers had higher micronutrient concentrations than grasses. 19• Mixture micronutrient concentrations increased with red clover proportion. could be explained by differences in pH and micronutrient concentrations of the soils at the 41 sites. We conclude that increased red clover proportion in the sward has the potential to 42 increase the overall micronutrient concentrations but that the effect of the soil is also a 43 controlling factor.

35A renewed interest in trace elements (TE), as micronutrients as well as potentially toxic 36 elements, and new options for multi-element analysis has led to an increased number of 37 scientists engaging in TE studies. Accreditation, certification and quality control of TE

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Phosphorus (P) leaching from agricultural soils is a serious environmental concern. Application of aluminium water treatment residuals (Al-WTRs) at a rate of 20 Mg ha(-1) to clay soils from central Sweden significantly increased mean topsoil P sorption index (PSI) from 4.6 to 5.5 μmol kg(-1) soil. Mean degree of P saturation in ammonium lactate extract (DPS-AL) significantly decreased from 17 to 13%, as did plant-available P (P-AL). Concentrations of dissolved reactive P (DRP) decreased by 10-85% in leaching water with Al-WTR treatments after exposure of topsoil lysimeters to simulated rain. Soil aggregate stability (AgS) for 15 test soils rarely improved. Three soils (clay loam, silty loam and loam sand) were tested in greenhouse pot experiments. Aluminium-WTR application of 15 or 30 ton ha(-1) to loam sand and a clay loam with P-AL values of 80-100 mg kg(-1) soil significantly increased growth of Italian ryegrass when fertilised with P but did not significantly affect growth of spring barley on any soil. Al-WTR should only be applied to soils with high P fertility where improved crop production is not required.