This study aims to evaluate the efficiency of a new type of corn header equipped with flail knives that shreds corn stubble close to the ground. A field trial was carried out to quantify the influence of the shredding tool design (flail knives, standard knives, horizontal choppers disengaged), harvesting speed (1.5, 3.0, 4.5, 6.0 km/h) and cutting height (approx. 20 cm variation, 4 levels) on the power consumption of the corn header, engine load and fuel consumption of the combine harvester. The regression analyses revealed that modifications of the shredding tool assembly have significant effects on the parameters of the functional relationships. The power consumption of the flail knives configuration was 15 kW/row unit at 6 km/h at the lowest cutting height setting, making it compatible with most current combine harvester models. The additional power demand and fuel consumption that arise when switching to the new shredding tool design (flail knives) show a wide range, depending on the initial situation. Compared to the standard knives at 6 km/h, the additional power consumption was 3.6–5.5 kW/row unit and the additional fuel consumption was 2.6–3.9 L/ha. Compared to the configuration with disengaged horizontal choppers, it was 5.3–6.6 kW/row unit and 3.9–5.1 L/ha, respectively. At 90% engine load the additional power requirement was 1.6–3.1 kW/row unit and the additional fuel consumption was 2.9–5.6 L/ha compared to the standard knives configuration and 2.6–3.6 kW/row unit and 5.6–7.2 L/ha respectively, compared to the configuration with disengaged horizontal choppers.
Providing pigs with organic enrichment material is important for satisfying pigs' natural explorative behavior to prevent injurious tail biting and thus increase animal welfare in general. The aim of this study was to investigate the effects of automatically supplied enrichment material of three different types (alfalfa pellets, oat bran pellets, or a mixture of both) and different enrichment frequencies (2, 4, or 6 supplies/day) on the behavior, the occurrence of tail biting, and daily weight gains of weaner pigs. The results showed significant effects and interactions of enrichment material, frequency and the time of day on the exploratory behavior, the occurrence of tail biting, and daily weight gains. Higher probabilities for pigs using the enrichment material were observed for groups provided with only two supplies/day or receiving oat bran pellets. Additionally, more pigs explored the material when supplied in the afternoon compared to the morning. Tail lesions began to increase in week 4 of the rearing period. Higher probabilities of having a tail lesion were recorded in groups provided with two supplies/day compared to four or six supplies per day. Furthermore, the highest probabilities for pigs having a tail length loss at the end of the rearing period were shown by groups receiving two supplies/day, with 0.170 for alfalfa pellets, 0.342 for mixture, and 0.486 for oat bran pellets. For daily weight gains, only alfalfa groups differed significantly from mixture groups in the case of two supplies/day. No differences were observed for the other factor combinations. These results showed the potential of an automatic enrichment device supporting pigs in performing their natural exploratory behavior in a conventional housing system. Higher numbers of daily enrichment supplies show beneficial effects to reduce the occurrence of tail biting and tail length losses.
Plant-derived protein sources are the most relevant substitutes for fishmeal in aquafeeds. Nevertheless, the effects of plant based diets on the intestinal microbiome especially of juvenile Rainbow trout (Oncorhynchus mykiss) are yet to be fully investigated. The present study demonstrates, based on 16S rDNA bacterial community profiling, that the intestinal microbiome of juvenile Rainbow trout is strongly affected by dietary plant protein inclusion levels. After first feeding of juveniles with either 0%, 50% or 97% of total dietary protein content derived from plants, statistically significant differences of the bacterial gut community for the three diet-types were detected, both at phylum and order level. The microbiome of juvenile fish consisted mainly of the phyla Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria, and thus fits the salmonid core microbiome suggested in previous studies. Dietary plant proteins significantly enhanced the relative abundance of the orders Lactobacillales, Bacillales and Pseudomonadales. Animal proteins in contrast significantly promoted Bacteroidales, Clostridiales, Vibrionales, Fusobacteriales and Alteromonadales. The overall alpha diversity significantly decreased with increasing plant protein inclusion levels and with age of experimental animals. In order to investigate permanent effects of the first feeding diet-type on the early development of the microbiome, a diet change was included in the study after 54 days, but no such effects could be detected. Instead, the microbiome of juvenile trout fry was highly dependent on the actual diet fed at the time of sampling.
There is an urgent global need for the ecological intensification of agricultural systems to reduce negative impacts on the environment while meeting the rising demand for agricultural products. Enriching grasslands with floral species is a tool to promote diversity and the associated services at higher trophic levels, and ultimately, to enhance the agricultural landscape matrix. Here, we studied an organic pastures-based dairy production system with plant species enhanced grass–clover pastures with respect to the effect on the activity density, functional traits, carabid assemblages, and species richness of carabid beetles. To understand the effect of land management on carabid beetles, we studied two types of grass–clover pastures with low and relatively high plant diversities in an integrated crop–livestock rotational grazing system (ICLS). As a comparison, organic permanent grasslands and conventionally managed maize were studied. We installed pitfall traps for three weeks in early summer, and for two weeks in autumn. In total, 11,347 carabid beetles of 66 species were caught. Grass–clover pastures did not differ in activity density, functional traits, habitat guilds, or species richness, but conventional maize did show a higher activity density in autumn and a higher proportion of eurytopic species and mobile species compared to grass–clover pastures. On grass–clover pastures, we found more endangered species, Carabus beetles, and a distinct carabid assemblage compared to maize. However, we attribute the lack of an effect of increased plant diversity of the grass–clover pastures on carabid species richness and functional traits to the intensive grazing regime, which resulted in the compositional and structural homogeneity of vegetation. Still, the presence of specialized and endangered species indicated the potential for organically managed grass–clover pastures to promote dispersal through an otherwise depleted and fragmented agricultural landscape. By increasing crop diversity in ICLS, more resources for foraging and nesting are created; therefore, organically managed grass–clover pastures add to the multi-functionality of agricultural landscapes.
In previous experiments, Trichoderma sp. BI 7376 and Pseudomonas chlororaphis subsp. aurantiaca BI 7439, applied as seed treatments, controlled soilborne Fusarium culmorum on maize. The current paper is focused on a deeper characterization of the effects of both strains. The experiments were conducted as pot tests with artificial inoculation of the substrate with F. culmorum, or with maize seed lots infected with Fusarium spp. When seeds were treated with Trichoderma strain BI 7376, Pseudomonas strain BI 7439 or with the chemical active ingredient thiram and stored before they were sown in substrate inoculated with F. culmorum, the protection by all agents declined. During the storage period of 211 days, the activity of thiram and Trichoderma strain BI 7376 dropped by about 38% and 57%, respectively. After 36 days of storage, Pseudomonas strain BI 7439 failed to provide any protection, which was obviously related to the observed total loss of viable cells of this agent. Moreover, we observed that both strains protected against soilborne F. subglutinans and F. verticillioides, showing that their activity was not limited to F. culmorum which was used in the previous experiments. Further, experiments with seed lots suspected or known to be infected with Fusarium species indicated that Trichoderma strain BI 7376 also controlled seedborne inoculum. When electron seed treatment was followed by application of Trichoderma strain BI 7376, both seed- and soilborne infections were controlled, showing that the concept of using a combination of a physical seed treatment and microbial antagonists appears feasible.
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 4-year periods of 2600 kg DM ha−1 for the treatments without slurry and 1500 kg DM ha−1 for the slurry treatments. Differences in herbage quality between permanent and renovated grassland were negligible and generally not statistically significant. The soil organic carbon showed a rapid and significant drop in the year of renovation, followed by a gradual increase. Without slurry application, the initial levels of soil organic carbon stocks could not be reached even after a period of 18 years following renovation, and with slurry application, it took about 8–10 years. Deep ploughing to a depth of 30 cm did not increase the SOC stocks compared with the undisturbed permanent grasslands, suggesting that the topsoil has not reached the carbon saturation level. We conclude that maintaining productivity of permanent grassland without renovation measures is a promising way towards yield stability and natural climate solutions.
The European corn borer is a major pest of corn that overwinters in corn stubble and stalks. Shredding these residues disrupts the larvae’s habitat or directly harms them. A corn header has been engineered with a new type of cutting tool on its horizontal choppers, featuring sharp edges and dulled flails, to shred corn stubble near the soil surface. This study investigated the effect of the dulled flails on the shredding intensity of corn stover. Field trials compared flail knives with standard knives for particle size distribution of corn stover and structural integrity of corn stalk segments. Additionally, a common two-step method, which involved a standard knives-equipped corn header followed by tractor-driven flail mowers, was tested. The flail knives reduced the mean particle size by 3.6 mm compared to the standard knives. Subsequent processing with tractor-driven flail mowers, following the corn header using standard knives, led to a reduction in mean particle size by 11.8 mm. It also further reduced the number of incompletely destroyed stalk segments. However, completely intact internodes were scarce in all methods. Given that flail knives enhance shredding intensity without a second processing step, this concept is concluded to be effective for corn stover shredding.
The promise of an off-the-shelf, microparticulate diet for first feeding marine larval fish is still one of the ‘holy grails’ of the hatchery manager. Replacing the laborious live feed production facilities with high-quality microdiets will greatly increase marine larval production, improve hatchery consistency and will help in cost reduction in fry production. Over the last decades, many scientific and industrial efforts have focussed on developing microparticulate diets to reduce or replace the use of live feed for growing marine fish larvae in hatcheries. However, in most professional hatcheries, an extended live feed period is still the standard procedure. Thus, this study aimed to compare the performance of four state-of-the-art commercially available microdiets used in an early weaning protocol to the standard Artemia-based feeding. European seabass larvae were used as a model organism. The three most relevant parameters, survival, growth and deformities were used for the performance-rating of the four different microdiets. The results of the study depict that early weaning of European seabass between 15 and 20 days post-hatching (dph) onto the commercially available microdiets still result in lower survival, reduced growth and an increase in deformities in the early-weaned treatments. Nevertheless, one microdiet outperformed the others in this study, resulting in significantly fewer deformed larvae and improved growth. However, larvae fed with Artemia only still yielded the best results considering growth, survival and deformities.
SUMMARY Phenological development and its variation during reproductive growth have important effects on the yield and quality of forage grasses. In perennial ryegrass ( Lolium perenne L.) genetic variation in heading date is well recognized, but there are no reliable studies about the variability in the length of the stem elongation phase. To determine the variation in phenological traits of single plants of perennial ryegrass genotypes, a field trial was conducted over three growing seasons (2011–2013) using plant material from eight different ecotype populations, sampled from old permanent grassland swards in Northern Germany. In addition to the phenological stages of jointing, heading and flowering, the critical phase of stem elongation was considered as a new phenological trait. It was hypothesized that the length of the critical phase between jointing and heading differs significantly among genotypes and thus offers a new tool for selecting for specific purposes, e.g. adaption to changing climatic conditions, cutting or grazing as well as yield and quality. The study revealed significant genotypic variation in the observed traits, which was highest for the critical phase (GCV = 0·21). Moderate heritability in jointing ( h 2 = 0·72) revealed a large environmental impact. In contrast, high heritability ( h 2 > 0·86) in heading, flowering and the critical phase imply a strong genetic effect. Moderate to high genotypic and phenotypic coefficients of correlation revealed a substantial linkage among the phenological traits. Results are discussed in the context of providing different approaches and strategies in forage crop production, especially with regard to regional weather conditions and future climate change. Significant differences among the tested ecotype populations indicate that existing diversity in permanent grassland can provide source material for further progress in grass breeding.
Abstract Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, is one of the most destructive diseases in oilseed rape growing regions. To date, there is no effective genetic resistance against S. sclerotiorum in the B. napus germplasm and knowledge of the molecular plant-fungal interaction is also limited. To identify new resistance resources, we screened a set of wild Brassica species and identified B. villosa (BRA1896) with a high Sclerotinia-resistance. Two segregating F2 populations for Sclerotinia-resistance, generated by interspecific crosses between the resistant B. villosa (BRA1896) and the wild susceptible B. oleracea (BRA1909) were assessed for Sclerotinia-resistance. Genetic mapping using a 15k Illumina Infinium SNP- array resulted in a high-density genetic map containing 1,118 SNP markers and spanning a total genetic length of 792.2 cM. QTL analysis revealed seven QTLs explaining 3.8 % to 16.5 % of phenotypic variance. Intriguingly, RNAseq-based transcriptome analysis identified genes and pathways specific to B. villosa, of which a cluster of five genes encoding putative receptor-like kinases (RLKs) and two pathogenesis-related (PR) proteins are co-localized within a QTL on chromosome C07. Furthermore, transcriptomic analysis revealed enhanced ethylene (ET)-activated signaling in the resistant B. villosa, which is associated with a stronger plant immune response, depressed cell death, and enhanced phytoalexin biosynthesis compared to the susceptible B. oleracea. Our data demonstrate that B. villosa represents a novel and unique genetic source for improving oilseed rape resistance against SSR.
