Microbial Community Structure and Litter Decomposition in Stratified Soils of a Long Term Reduced Tillage Experiment

The aim of the present study was to examine decomposition of plant material (maize straw, green and rooibos tea) in stratified soils of the long-term tillage experiment, established in 1999 and shifted from conventional to organic farming system in 2015. The plowing in conventional tillage (CT) has been done by moldboard plow 20 cm deep, while in minimum tillage (MT), soil disturbance has been up to 10 cm deep by a Special disc harrow. More than 15 years of long term Minimum tillage, with reduced soil disturbances and improved residue management, resulted in stratification of soil organic carbon and nutrients with highest concentrations in the very topsoil

The effect of shielding gas composition on the toughness and crack growth parameters of AlMg4,5Mn weld metals

The experiment have been performed using samples of welded joints of the three components aluminium alloy AlMg4,5Mn. The welding was performed with GTAW in the shielded atmosphere of Ar+0,015N2, mixture of the inert gases Ar+50%He+0,015N2 and Ar+70%He+0,015N2. After welding has been completed, the metallographic tests, the tensile test and the tests of the hardness were performed. Also, the weld metal toughness was estimated, using the instrumental Charpy impact testing system, followed by estimating the crack initiation energy, crack growth energy and the fracture mechanics parameters. The goal was to establish the effects of shielding atmosphere composition on the mechanical properties and fracture mechanics parameters of weld metal

Patellar tendon ossification after partial patellectomy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Patellar tendon ossification is a rare pathology that may be seen as a complication after sleeve fractures of the tibial tuberosity, total patellectomy during arthroplasty, intramedullary nailing of tibial fractures, anterior cruciate ligament reconstruction with patellar tendon autograft and knee injury without fracture. However, its occurrence after partial patellectomy surgery has never been reported in the literature.</p> <p>Case presentation</p> <p>We present the case of a 35-year-old Turkish man with a comminuted inferior patellar pole fracture that was treated with partial patellectomy. During the follow-up period, his patellar tendon healed with ossification and then ruptured from the inferior attachment to the tibial tubercle. The ossification was excised and the tendon was subsequently repaired.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first report of patellar tendon ossification occurring after partial patellectomy. Orthopaedic surgeons are thus cautioned to be conscious of this rare complication after partial patellectomy.</p

Consequences of minimum soil tillage on abiotic soil properties and composition of microbial communities in a shallow Cambisol originated from fluvioglacial deposits.

A long-term field experiment was run for 12&nbsp;years to evaluate the impact of minimum tillage (MT) compared to conventional mouldboard ploughing (CT) on soil chemical, physical and microbial properties in a shallow Cambisol formed over fluvioglacial deposits of Drava river in Slovenia. Significant differences between MT and CT were found in vertical distribution of soil organic C (SOC) and nutrients (total N and plant available potassium); under MT, concentrations decreased from the soil surface to the lower layers, as opposed to CT which maintained rather uniform distribution down to the ploughing depth. MT in comparison with CT also increased the proportion of water-stable 2&ndash;4-mm-sized aggregates (80.9 and 61.3&nbsp;%, respectively), water holding capacity (24.8 and 22.2&nbsp;%, respectively) and plant available water (13.4 and 10.3&nbsp;%, respectively) in the upper 0&ndash;10-cm soil layer. Bulk density, porosity, the proportion of water-stable 1&ndash;2-mm-sized aggregates and infiltration rate showed no significant differences between the tillage treatments. SOC content in the upper 0&ndash;10-cm soil layer was not significantly different between MT and CT (1.60&thinsp;&plusmn;&thinsp;0.07 and 1.45&thinsp;&plusmn;&thinsp;0.05&nbsp;%, respectively), as well as the overall stock in the investigated soil profile (0&ndash;60&nbsp;cm) remained unaffected (57.4&thinsp;&plusmn;&thinsp;0.8 and 59.1&thinsp;&plusmn;&thinsp;2.2&nbsp;t&nbsp;ha&minus;1, respectively). Microbial biomass, estimated by the total soil DNA, was higher in MT than CT in the 0&ndash;10-cm layer. Furthermore, a positive linear dependence of microbial biomass on SOC content was observed. Fingerprinting of bacterial, fungal and archaeal communities indicated that microbial community composition changed by long-term MT, whereas changes in microbial diversity were not detected for any domain. The most pronounced shifts in the composition were found for bacterial communities in the 10&ndash;20-cm layer, while the composition of fungal communities slightly changed in the upper 0&ndash;10&nbsp;cm of MT soil. The composition of archaeal communities was not affected by the tillage or by the soil depth. Our results indicate that MT generates modest changes in soil structure and soil water retention properties and could support measures against erosion, drought and nutrient leaching. Considering increased microbial biomass in the topsoil of MT and shifts in microbial diversity, the impacts of MT on soil microbiome are also evident and need to be further investigated to identify the affected functional traits

Resilience of bacteria, archaea, fungi and N-cycling microbial guilds under plough and conservation tillage, to agricultural drought

Climate change causes droughts, which in turn cause significant physiological stress for soil microorganisms. In this study, we investigated how the abundance of total bacterial, crenarchaeal and fungal communities and the abundance of N-cycling microbial guilds responded to a severe agricultural drought event in a long-term experiment of minimum tillage (MT) and conventional ploughing (CT) at two soil depths. This study was financially supported by the European Commission within the EcoFINDERS project (FP7-264465), CORE Organic Plus funding bodies within the FertilCrop project, and by the Slovenian Research Agency within the programme P4-0085

The effect of shielding gas composition on the toughness and crack growth parameters of AlMg4,5Mn weld metals

The experiment have been performed using samples of welded joints of the three components aluminium alloy AlMg4,5Mn. The welding was performed with GTAW in the shielded atmosphere of Ar+0,015N2, mixture of the inert gases Ar+50%He+0,015N2 and Ar+70%He+0,015N2. After welding has been completed, the metallographic tests, the tensile test and the tests of the hardness were performed. Also, the weld metal toughness was estimated, using the instrumental Charpy impact testing system, followed by estimating the crack initiation energy, crack growth energy and the fracture mechanics parameters. The goal was to establish the effects of shielding atmosphere composition on the mechanical properties and fracture mechanics parameters of weld metal