Impact of Surface Improvement Measures on Low-yielding Summer Pastures on Pasture Productivity and Forage Quality

Cultivation of soil on the slopes of mountainous areas leads to a decrease in organic matter and nutrients in the soil and severe soil erosion. Grazing is one of the main reasons for the degradation of pastures and natural landscape, which increases the sensitivity of the soil to erosion. Soil erosion, in turn, pollutes water by increasing its turbidity and sometimes causes atrophy due to leakage of phosphorus and nitrogen. An average of 30.6 quintals of green mass or 7.8 quintals of dry grass per hectare was produced in the variant of grass seed sowing (without fertilizer), compared to the control variant, in the variant of grass seed sowing + N60P60K40 this indicator averaged 39.9 centners/ha of green mass. or more than 15.0%, resulting in the production of 10.0 quintals of dry or 14.7% more dry grass. Experimental field studies to improve pastures have shown that the fodder produced in each of the tested variants; green mass and dry grass supply and their nutritional value were higher than control.

Dynamics of the Species Composition of Phytocenoses of Floodplain Mountain Meadows of the Carpathians Subject to Superficial Improvement

The conducted research of various authors has developed a number of measures for surface improvement of meadowland in various soil and climatic conditions. However, studies on the influence of such surface improvement measures as the use of organic and mineral fertilizers and sowing of perennial grasses and legumes in the sod on the dynamics of the species composition of Floodplain Mountain meadows of the Carpathians have not yet been conducted, which confirms the relevance of this study. The article presents the results of three-year studies conducted during 2017-2019 in the peasant farm of V.F. Martyshchuk (the Verkhovinsky District of the Ivano-Frankivsk region) to study the features of transformation of the species composition of natural phytocenoses of floodplain Meadows of the Black Cheremosh river of the mountain and forest belt of the Carpathians under the influence of their surface improvement with the use of organic and mineral fertilizers and sowing of a cereal mixture for haymaking use and Tribolium repens L. for multipurpose use. It was found that floodplain Meadow phytocenoses were mainly cereals and mixed grasses with a share of wild cereals of 57-58% (up to 15 of them % Festuca rubra L. s. str. and 5-6% of low-value ones in feed terms Calamagrostis arundinaceae (L.) Roth and Deschampsia caespitosa (L.) Beauv.), mixed grasses – 35-38% and unseeded Fabaceae 5-7%. When applying a set of measures for surface improvement of cereals and mixed grasses, low productive (within 1.95-2.15 t/ha of dry weight) floodplain mountain meadowlands, their species composition improved. For making P30K60 the content of wild plants increased by 2-5% Fabaceae, and N60P30K60 – by 9-10% unseeded Poaceae. For haymaking use, Poaceae with Phleum pratense L. and Festuca pratensis Huds. against the background of making N60P30K60 for sowing a mixture in the sod in the spring, their share increased to 74%, and for multi-year use and sowing Trifolium repens L. against the background of making P30K60 the quantity of Fabaceae increased to 44% or by 32%. The highest floral saturation (43 species from 19 families and 93-98% from perennials) was observed in variants without fertilization and with the introduction of P30K60 for multi-year use, which is 4-14 species more compared to haymaking use, or with the introduction of N60P30K60 and or with sowing a mixture of cereals on the background of N60P30K60 for haymaking use, or sowing Trifolium repens L. against the background of P30K60 for multipurpose use

Productivity of mountain bows of the carpathians depending on surface improvement measures

Purpose. To determine the peculiarities of formation of productivity, as well as the chemical composition, nutritional value and energy intensity of grass forage, depending on the measures of surface improvement of the meadows of the Carpathian mountain forest zone. Methods. Field works, laboratory, mathematical-statistical. Results. Productivity of haymaking and perennial mowing fluctuated on the range of 2.15–4.77 t/ha and 1.95–4.11 t/ha during the 3-year research of dry mass yield. Compared to the variants without additional sowing of grasses and fertilizer use, the highest productivity of haymaking was upon the additional sowing of cereal grass mixtures and applying of N60P30K60 – 12 % and 85 %, respectively. Productivity of perennial mowing increased upon the additional sowing of Trifolium repens and applying of P30K60 on 85 % and 111 % respectively. The best uniformity of distribution of biomass crop by slopes was obtained by the use of multifaceted use of creeping clover with the introduction of P30K60, when the proportion of 1st slope was 39%, 2nd - 33 and 3rd – 28% with unevenness, which is expressed by the coefficient variation - 18%. Among the measures of surface improvement on the quality of feed by chemical composition, increasing, first of all, the content of crude protein, influenced by the introduction of N60P30K60 or 15 t / ha of manure, and in the case of multi-grade use - the sowing of clover on the background P30K60. Irrespective of the measures of surface improvement, higher crude protein content, better energy consumption and nutritious nutritional value of feed were characterized by a multi-use (pasture imitation) mode of use than hay. Conclusions. For surface improvement of the meadows of the Carpathian mountain forest belt with natural herbage, the annual application of N60P30K60, or 15 t / ha of manure, or – N60P30K60 + sowing of a mixture of grass meadows and sapwood with sapwood, on the grass meadows, is a factor of increasing their productivity and improving the quality of herbage. use or – P30K60 + clover seeding for high quality use. The best positive effect is the application of mineral fertilizers in combination with sowing of perennial grasses.

Study for Improvement in the Surface Properties and Wear Behavior of Mild Steel

Surface of a material can be improved by depositing the filler metal for the enhancement of various properties. Surface should be harder than substrate material for surface improvement. This surface improvement is also known as surfacing. In present research Mild steel specimens of size 140×35×40 were used to deposit surfacing layers and study the feasibility of iron/aluminum with varying compositions on low carbon steel deposited by GTAW process. Specimens for hardness and oxidation resistance were prepared. While studying oxidation of surfaced and un-coated area (base material), oxidation test resulted that the oxidation occurred on surface of base metal (un-coated area) after heating at different temperatures and time intervals. Specimens kept at 500˚C, 700˚C temperatures for 3, 6, 9 hours to get oxidized from un-coated surface but no mark of oxidation and pitting was visible at surfaced area but pitting of un-coated area occurred at 700˚C temperature. Oxidation had no effect to surfaced area. Low temperature oxidation test specimens gave only weight loss from un-coated portion but high temperature oxidation gave high amount of weight reduction due to pitting occurred on un-coated portion. The amount of weight loss of specimens increased with increase in furnace holding time at constant temperature. With increase in temperature oxidation of un-coated area of specimens also increased and pitting action occurred on un-coated area of specimens at high temperature. Further, for the various wear tests the cylindrical pins of 8 mm diameter with spherical tip 4 mm radius was made. Wear tests were carried out on pin on disc sliding wear testing machine. The comparison of wear rate loss was studied with constant sliding distance, varying load and sliding velocity of different compositions of iron/aluminum surfacing and substrate material. Hardness and wear resistance of composition were increased with increase in percentage of Fe element in composition. Composition C1 (Fe:Al/70:30) had high hardness and high wear resistance as compared to composition C2 (Fe:Al/30:70) and C3 (Fe:Al/50:50). Composition C3 (Fe:Al/50:50) had better hardness and wear resistance as compared composition C2 (Fe:Al/70:30). Keywords: Surface improvement, Fe-Al intermetallic, GTAW process, Sliding wear.

A Novel Laser-Aided Machining and Polishing Process for Additive Manufacturing Materials with Multiple Endmill Emulating Scan Patterns

In additive manufacturing (AM), the surface roughness of the deposited parts remains significantly higher than the admissible range for most applications. Additionally, the surface topography of AM parts exhibits waviness profiles between tracks and layers. Therefore, post-processing is indispensable to improve surface quality. Laser-aided machining and polishing can be effective surface improvement processes that can be used due to their availability as the primary energy sources in many metal AM processes. While the initial roughness and waviness of the surface of most AM parts are very high, to achieve dimensional accuracy and minimize roughness, a high input energy density is required during machining and polishing processes although such high energy density may induce process defects and escalate the phenomenon of wavelength asperities. In this paper, we propose a systematic approach to eliminate waviness and reduce surface roughness with the combination of laser-aided machining, macro-polishing, and micro-polishing processes. While machining reduces the initial waviness, low energy density during polishing can minimize this further. The average roughness (Ra=1.11μm) achieved in this study with optimized process parameters for both machining and polishing demonstrates a greater than 97% reduction in roughness when compared to the as-built part.