[en] For biomass combustion to become a sustainable energy production system, it is crucial to minimise landfill of biomass ashes, to recycle the nutrients and to minimise the undesirable impact of hazardous substances in the ash. In order to test the plant availability of phosphorus (P) and cadmium (Cd) in four biomass ashes, we conducted two pot experiments on a P-depleted soil and one mini-plot field experiment on a soil with adequate P status. Test plants were spring barley and Italian ryegrass. Ash applications were compared to triple superphosphate (TSP) and a control without P application. Both TSP and ash significantly increased crop yields and P uptake on the P-depleted soil. In contrast, on the adequate-P soil, the barley yield showed little response to soil amendment, even at 300–500 kg P ha"−"1 application, although the barley took up more P at higher applications. The apparent P use efficiency of the additive was 20% in ryegrass - much higher than that of barley for which P use efficiencies varied on the two soils. Generally, crop Cd concentrations were little affected by the increasing and high applications of ash, except for relatively high Cd concentrations in barley after applying 25 Mg ha"−"1 straw ash. Contrarily, even modest increases in the TSP application markedly increased Cd uptake in plants. This might be explained by the low Cd solubility in the ash or by the reduced Cd availability due to the liming effect of ash. High concentrations of resin-extractable P (available P) in the ash-amended soil after harvest indicate that the ash may also contribute to P availability for the following crops. In conclusion, the biomass ashes in this study had P availability similar to the TSP fertiliser and did not contaminate the crop with Cd during the first year. - Highlights: • Effects of four biomass ashes vs. a P fertiliser (TSP) on two crops were studied. • Ashes increased crop yields with P availability similar to TSP on P-depleted soil. • Barley biomass and Cd uptake did not respond to high ash rates on a normal P soil. • Cd concentration of crops on ash-amended soil was in the range of TSP treatments. • High levels of soil available P remained after harvest at high ash applications.

[en] Highlights: • Storage of S biogas filter materials is often required prior application to crops. • Storage in manure can induce S loss and reduce the subsequent S fertilizer value. • A high amount of sulfide was formed during storage of filter S in manure. • Sulfate reduction to sulfide was less during storage in digested manure. • S filter materials are valuable fertilizers even after 6 months storage in manure. Residues from hydrogen sulfide (H₂S) removal in biogas filters contain sulfur (S) in various forms (sulfate, sulfide, elemental S) that, if properly stored, is potentially valuable as crop fertilizer. We investigated 1) the turnover of the S compounds from filter materials during storage in untreated and digested cattle manure (CM), and 2) the S fertilizer replacement value (SFRV) of the filter materials applied in pure form or mixed manure with and without storage. The S filter materials from four H₂S removal processes (biological and physical-chemical) containing mostly sulfate and/or elemental S were added to untreated CM or digested CM and stored at 10 °C for six months. Afterwards, a pot experiment was established to assess the S availability in an oil-seed rape (Brassica napus) crop. Microbial reduction of sulfate into sulfide took place rapidly after 69 days storage of untreated CM. A lower reduction rate was observed in digested CM mixtures. After six months, 68% and 32% of the initial sulfate content were still present in mixtures containing the S filter materials from biological desulfurization with digested CM and untreated CM, respectively. Sulfate reduction was inhibited for 120 days when digested CM was mixed with S saturated solution from an ash filter, probably due to high pH (≥8.2) and redox potential (>−100 mV) levels. Oppositely, elemental S was immediately and simultaneously both reduced and oxidized. Relatively low losses of total S were observed during the present storage conditions. Despite S turnover, the SFRV of CM and digested CM significantly increased from 15–19% (of total S applied) to 56–90% when S filter materials were added. The storage of S filter materials in digested manure reduced the risk of sulfide production and potential S volatilization. The S filter materials were a valuable source of plant-available S.

[en] A novel diffusion method was used for preparation of NH₄⁺- and NO₃^--N samples from soil extracts for ¹⁵N determination. Ammonium, and nitrate following reduction to ammonia, are allowed to diffuse to an acid-wetted glass filter enclosed in polytetrafluoroethylene tape. The method was evaluated with simulated soil extracts obtained using 50 ml of 2 M potassium chloride solution containing 130 μg of NH₄⁼-N (2.3 atom% ¹⁵N) and 120 μg of NO₃^--N (natural ¹⁵N abundance). No cross-over in the ¹⁵N abundances of NH₄⁺-N and NO₃^--N was observed, indicating a quantitative diffusion process (72 h, 25 deg C). Owing to the presence of inorganic nitrogen impurities in the potassium chloride, the ¹⁵N enrichments should be corrected for the blank nitrogen content. (author). 8 refs.; 1 tab

[en] The dynamics of coherent elliptic states in time-dependent electric and magnetic fields has been studied and it is shown that a linear Stark state may be transformed adiabatically into a circular Zeeman state through a continuous range of coherent elliptic states provided the fields vary slowly and are not parallel. The orientation vectors of the elliptic states rotate relative to the fields during the adiabatic transformation except when the fields are orthogonal. The condition for adiabatic behaviour is established for an easily realizable choice of field variation. (author)

No abstract available

[en] The study investigated the effect of co-ensiling of cover crops (CC) and barley straw (BS) on biogas production. Blends containing chopped CC and BS (mix ratios of 1:0, 2:1, 3:1, 6:1; 10:1 and 19:1 (w:w)) were prepared and stored for 4 months prior to the biogas batch assay. Results show that CC is feasible for producing biogas with reasonable CH₄ yield (330 mL CH₄ gVS⁻¹) and has good storability. Using of co-ensiling blends showed advantages over CC as it elevated the hydrolysis rate (k) from 0.024 to 0.061 d⁻¹ and decreased the lag phase (from 5 to 0.8 days) during the thermophilic (51 °C) batch test. Synergistic effects were observed from both CH₄ yield and hemi-cellulose removal. The finding provided an alternative strategy for integrated straw management and CC utilization for improved biogas production.

[en] Reutilizing biomass ashes in agriculture can substitute inputs of P from finite primary sources. However, recycling of ashes is disputed due to their content of toxic substances such as heavy metals. This study evaluates the potential risk of replacing easily soluble inorganic P fertilizer with P in biomass ashes in a barley crop grown on soil with adequate P status. Two contrasting doses of three different types of ashes were applied to an agricultural field with spring barley and compared to similar doses of triple-superphosphate fertilizer. In the second growing season after biomass ash application, grain, straw and root dry matter yield, and P and Cd uptake were determined. Resin-extractable P was measured in soil and the symbiotic arbuscular mycorrhizal fungal activity, colonization, and community composition were assessed. Crop yield was not affected by ash application, while P-uptake and mycorrhizal status were slightly enhanced with high ash applications. Changes to the mycorrhizal community composition were evident with high ash doses. Cadmium uptake in aboveground plant tissue was unaffected by ash treatments, but increased in roots with increasing doses. Consequently, we conclude that fertilization with biomass ashes can replace conventional fertilizers without risk to barley crops in the short term. - Highlights: • A conventional fertilizer was compared with biomass ashes. • Barley yield, nutrition, cadmium accumulation and mycorrhizal status were evaluated. • P availability was similar for treatments while Cd accumulated only in roots. • Mycorrhizal status was not negatively affected. • The biomass ashes tested can maintain the available P in agricultural soils.