Christof Kluß

The study investigated how the concentration and composition of purified tannin extracts, at various inclusion rates, affect the ruminal in vitro fermentation parameters. Tannin extracts were isolated from four different forage species, birdsfoot trefoil (Lotus corniculatus), sulla (Hedysarum coronarium), big trefoil (Lotus pedunculatus), and salad burnet (Sanguisorba minor). Plants extracts were purified by Sephadex LH-20 gel chromatography and analyzed by UPLC-ESI-MS/MS. The results showed a large variation among the extracts from different species in terms of tannin composition and structural features. The extracts from salad burnet were dominated by hydrolysable tannins (HTs), comprising mainly ellagitannins. The extracts derived from sulla and big trefoil contained predominantly proanthocyanidins (PA), primarily composed of prodelphinidins (PDs) with high mean degree of polymerisation (mDP). Birdsfoot trefoil extracts comprised procyanidin-rich PAs with low mDP. To determine whether the combined presence of tannins and flavonoid together lead to synergistic or antagonistic effects, the tannin extracts were incubated both with or without rutin at concentrations of 10, 20, and 30 g/kg DM, using a base substrate of perennial ryegrass (Lolium perenne, control). In general, all the tannin extracts decreased methane (CH 4) production compared to the control, while no significant effect of rutin was observed on both gas (GP) and CH 4 production, neither pure, nor in the simultaneous presence of tannins. The highest CH 4 reduction (15%, at 30g/kg DM) was observed from sulla and big trefoil extracts compared to control, but this was also …

There is a pressing need to support farmers' decisions on grassland renovation, based on sound scientific evidence regarding its effects on productivity, herbage quality and soil organic carbon stocks. To quantify these effects a long-term experiment with grass/white clover swards was set up at the Lindhof research farm in Northern Germany in 1995. Treatments included control plots of undisturbed grassland as well as 10 grassland renovations starting after 10 (2005) years and repeated on different plots 10 times until 2019, and without and with addition of slurry (equivalent to 240 kg N ha−1 yr−1). Grassland renovation resulted in a significant drop in biomass production in the first year after renovation, and the slightly higher yields in the third year after renovation could not compensate for this drop. Yields from the year of renovation to three years afterwards were generally lower, with average reductions over the …

The integration of cover crops (CCs) in low-input systems is a widely adopted practice to re-capture surplus nitrogen (N) and avoid excessive losses to the environment by leaching or N2O emissions. Closing the N cycle within an agricultural system is therefore economically beneficial and lowers the negative impact of inorganic N on soil and water bodies. However, it is debated if pollution swapping occurs to some extent and if N2O emissions increases as a result of decreased N leaching. An experiment was conducted to systematically evaluate grass vs. non-grass CCs, frost tolerant vs. non-frost tolerant CCs as well as high residual N vs. low residual N from the pre-crop, in a low input system which receives no additional fertilizer. Furthermore, the extent to which N2O losses occur from different seeded CC species and mixtures (Sinapis alba/Vicia sativa, Brassica rapa/Vicia villosa and Lolium perenne/Trifolium …

The effect of slurry application techniques and slurry N stabilizing strategies on nitrous oxide emission from grasslands is poorly understood and, therefore, can result in large uncertainties in national/regional inventories. Field experiments were, thus, conducted to estimate the effect of different fertilization techniques on nitrous oxide (N2O) emissions. Fertilizer was applied (135–270 kg N ha−1 year−1) as calcium ammonium nitrate (CAN), untreated or treated cattle slurry. The slurry was either treated with sulfuric acid (target pH = 6.0), applied using trailing shoes or treated with 3,4‐dimethyl pyrazole phosphate and applied via slot injection. N2O fluxes were sampled using the closed chamber technique. Cumulative N2O emissions ranged 0.1–2.9 kg N ha−1 year−1 across the treatment, sites and years. The N application techniques showed inconsistent effects on soil mineral N content, cumulative N2O …

Background There is a great need for simple and inexpensive methods to quantify ammonia emissions in multi‐plot field trials. However, methods that meet these criteria have to be thoroughly validated. In the calibrated passive sampling approach, acid traps placed in the center of quadratic plots absorb ammonia, enabling relative comparisons between plots. To quantify ammonia emissions, these acid trap samplings are scaled by means of a transfer coefficient (TC) obtained from simultaneous measurements with the dynamic tube method (DTM). However, dynamic tube measurements are also comparatively costly and time‐consuming. Aims Our objective was to assess the best practice for using calibrated passive sampling in multi‐plot field trials. One particular challenge in such experiments is to evaluate the influence of ammonia drift between plots. Methods In a series of eight multi‐plot field trials, acid traps …

Significant greenhouse gas emissions during substrate cultivation reduces the potential environmental benefits of biogas production. This study investigates the productivity of different cropping systems and their environmental impact in terms of nitrous oxide (N2O) emissions under the environmental conditions of the coastal marsh regions (Northern Germany) with heavy clay soils, in a 2-year field trial (April 2009-March 2011). Treatments included four cropping systems (perennial ryegrass (Lolium perenne, PR) ley, continuous maize (Zea mays), a rotation (CR1) of spring wheat (Triticum aestivum), Italian ryegrass (Lolium multiflorum, IR) and maize, and a rotation (CR2) of maize, winter wheat and IR; two sources of N (nitrogen) fertilizers (calcium ammonium nitrate, and biogas residue (BR)), and three levels of N fertilizer applications (control, moderate, high). Nitrous oxide emissions were determined for the unfertilized and highly fertilized cropping systems comprising PR ley, CR1 and CR2. Cumulative annual N2O emissions varied across the treatments, ranging from 0.82 to 3.4 kg N2O-N ha−1 year−1. Under high N fertilizer applications, PR ley incurred higher N2O-N losses compared to other tested cropping systems, and IR cover crop caused relatively high N2O-N emissions in a short vegetation period. The study observed wide range of yield-scaled emissions (0.00–5.60 kg N2O-N (Mg DM)−1) for different crops, emphasizing the variability in N2O emissions linked to cropping systems. The N2O-N emission factors for the three cropping systems were found to be low to moderate for all treatments, ranging from 0.03% to 0.53% compared to …

Studies evaluating the complexity of models, which are suitable to simulate grass growth at regional scales in intensive grassland production systems are scarce. Therefore, two different grass growth models (GrasProg1.0 and APSIM) with different complexity and input requirements were compared against long-term observations from variety trials with perennial ryegrass (Lolium perenne) in Germany and Denmark. The trial sites covered a large range of environmental conditions, with annual average temperatures ranging from 5.9 to 10.3 °C, and annual rainfall from 536 to 1154 mm. The sites also varied regarding soil type, which were for modelling categorised into three different groups according to their plant available water (PAW) content: light soils with a PAW of 60 mm, medium soils with a PAW of 80 mm, and heavy soils with a PAW of 100 mm. The objective was to investigate whether the simple model performed equally well with the given low number of inputs, namely climate and PAW group. Evaluation statistics showed that both models provided satisfactory results, with root mean square errors for individual cuts ranging from 0.59 to 1.28 t dry matter ha−1. The model efficiency (Nash–Sutcliffe efficiency) for the separate cuts were also good for both models, with 81% of the sites having a positive Nash–Sutcliffe efficiency value with GrasProg1.0, and 72% with APSIM. These results reveal that without detailed site-specific descriptions, the less complex GrasProg1.0 model can be incorporated into a simple decision support tool for optimising grassland management in intensive livestock production systems.

The specialisation of agricultural systems in Western Europe and the intensification of livestock and cropping production are intrinsically linked to substantial resource inputs. This intensified approach frequently leads to nutrient surpluses and biodiversity loss, resulting in detrimental environmental impacts. A transformative agricultural shift is imperative in light of climate and environmental protection objectives. Addressing this need, the Lindhof eco‐efficient pasture‐based milk production initiative, initiated in 2016, is a tangible manifestation of a productive and profitable dairy system integrated within a ley‐based Integrated Crop‐Livestock System (ICLS). Operational at the organically managed Lindhof farm, this approach involves a rotational stocking system of spring‐calving Jersey cows stocked on grass‐clover‐herb leys embedded within a cash crop rotation. The dairy cows benefit from these highly productive …