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Abstract No-tillage (NT) is a conservation practice adopted by 60% of the Brazilian farmers. Due to unsuitable management, compaction problem reported in soils under NT has increased. The study aimed to evaluate the influence of different soil tillage and different winter cover crops in long-term on crops biomass and maize yield and on soil penetration resistance (PR), in two crop seasons. The long-term experiment is located at the UTFPR Dois Vizinhos experimental station, with a combination of five soil tillage: NT; NT chiseled up to 0.35 m deep (Jumbo), annually (NTCa) and triennially (NTCt); NT with minimum tillage chiseled up to 0.35 m deep (Terrus), annually (NTMTa) and triennially (NTMTt); and four winter cover crops: black oats, common vetch, forage radish, and a mixture of oats + vetch + radish (mix). Dry matter production of cover crops was higher in oats and the mix, and in NTMTa in both years (2021 and 2022). Soil chiseling reduces PR, however over time, an increase was observed. NT showed higher PR, especially in the 0.15-0.20 m soil layer, but it did not impact crop production. Maize yield was not influenced by cover crops or soil tillage. NT proved to be the most efficient soil management, as its performance in maize yield was similar to the others, indicating the way forward in the pursuit of a more sustainable agriculture.

Gear drives are widely used in various fields and applications due to their properties and capacity. Their versatility, durability, and ability to transmit high torques as well as precision and reliability make them extremely useful in many fields of technology. They are widely used in industrial and energy machinery, vehicle drive systems, aerospace, medical devices, and many other areas. Gears can be manufactured using many technologies. This work focuses mainly on machining with particular emphasis on high-performance new technologies. The process of mathematical modeling of the gear and the machined profile is strongly related to CNC machining technologies. A robust correlation of systems supporting the design and modeling of sliding gears needed for the manufacturing process is presented in the article. It is very important to properly assess gears with correct manufacturing in accordance with a specific standard. The article presents an analysis of available methods for controlling gears using coordinate measurement techniques. Gear machining methods were assessed in terms of the technologies used as well as their productivity and manufacturing tolerance. [ABSTRACT FROM AUTHOR]

In agrotechnologies postcut crops of intermediate cultures are placed after harvesting annual grasses for green mass, and stubble crops after harvesting early grain crops. Annual herbs at the April sowing dates reach mowing maturity and are harvested for green mass in the third decade of June – the first decade of July. However, after harvesting the main crop of the crop rotation, there are still about 70–90 days left until the end of the growing season, which is quite enough to obtain a full-fledged harvest in the hay crops, and thereby increase the index of arable land use [1; 6]. In this regard in 2020–2022 in the foothill zone of the Kabardino-Balkarian Republic (the Baksansky district), the scientific research was carried out on the irrigated Ciscaucasian chernozems (according to B.A. Dospekhov “Methodology of field experience”) in order to study the elements of improving the technology of growing corn in hay crops, providing a reduction in energy costs and optimization of the main parameters of soil fertility. Recently, agricultural production has been operating in the conditions of a resource deficit and an increasingly complex structure of economic relations and an ever-increasing problem of soil and water conservation. The dominance of economic mechanisms fundamentally changes many generally accepted ideas and approaches in the field of agricultural land use. The overall objective is to maximize crop production per unit of input. As a result of the research, it has been found that the cultivation of corn for grain by cutting, after winter rapeseed by chisel processing to a depth of 28–30 cm and the application of fertilizers at a dose of N120P90, contributes to the stabilization of the agrophysical properties of the soil and the optimization of the energy balance

ABSTRACT Off-season crops diversification and gypsum under minimal tillage can improve soil fertility and reduce soil compaction. The objective of this work was to evaluate changes on soil physical and chemical properties and soybean yield grown over off-season crops in combination with gypsum and chiseling. Treatments consisted of gypsum application (0 and 3,5 t ha-1), two tillage systems (no tillage [NT] and minimal tillage [MT] with chiseling) and four soybean off-season crop successions: maize (M); maize+brachiaria (M+B); millet+crotalaria/wheat (Mi+C/W) and maize+black oats (M+O). Gypsum application reduced resistance to penetration (PR) by 12% in M+B system (1.12 kPa), when compared to the same treatment without gypsum. Gypsum increased surface soil Ca contents, mainly in M/O (from 3.81 to 5.66 cmolc dm-3). MT decreased PR in M+B, Mi+C/W and M/O, from 1.28 kPa in NT to 0.98 kPa. MT lowered total soil porosity from 66.9 to 63.1%, but reduced Ca contents compared to NT. Cultivation of crotalaria in the off-season reduced Al levels on the soil surface and grasses increased K and P in depth. Despite the improvements in the soil properties, crop rotations, chiseling and gypsum were not able to increase soybean yields in this 18-month experiment, averaging 3904 kg ha-1.

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High-aspect-ratio metallic surface microstructures are increasingly demanded in breakthrough applications, such as high-performance heat transfer enhancement and surface plasmon devices. However, the fast and cost-effective fabrication of high-aspect-ratio microstructures on metallic surfaces remains challenging for existing techniques. This study proposes a novel cutting-based process, namely elliptical vibration chiseling (EV-chiseling), for the high-efficiency texturing of surface microstructures with an ultrahigh aspect ratio. Unlike conventional cutting, EV-chiseling superimposes a microscale EV on a backward-moving tool. The tool chisels into the material in each vibration cycle to generate an upright chip with a high aspect ratio through material deformation. Thanks to the tool’s backward movement, the chip is left on the material surface to form a microstructure rather than falling off. Since one microstructure is generated in one vibration cycle, the process can be highly efficient using ultrafast (>1 kHz) tool vibration. A finite element analysis model is established to explore the process mechanics of EV-chiseling. Next, a mechanistic model of the microstructured surface generation is developed to describe the microstructures’ aspect ratio dependency on the process parameters. Then, surface texturing tests are performed on copper to verify the efficacy of EV-chiseling. Uniformed micro ribs with a spacing of 1–10 μ m and an aspect ratio of 2–5 have been successfully textured on copper. Compared with the conventional EV-cutting that uses a forward-moving tool, EV-chiseling can improve the aspect ratio of textured microstructure by up to 40 times. The experimental results also verify the accuracy of the developed surface generation model of microstructures. Finally,the effects of elliptical trajectory, depth of cut, tool shape, and tool edge radius on the surface generation of micro ribs have been discussed.

Different soil management systems can change the sugarcane yield and quality parameters for sugar/ethanol production. The objective of this study was to evaluate the effects of subsoiling on the inter-row of sugarcane ratoons after the second harvest on productivity and technological quality. Productivity was estimated in tonnes of sugarcane per hectare (TSH), and technological quality parameters were apparent sucrose percentage (Pol) and total sugar recoverable per hectare (TRS). The apparent sucrose percentage and total recoverable sugar were measured in tonnes per hectare, corresponding to the parameters TSH and total recoverable sugar in tonnes per hectare (TTRSH), respectively. This research was carried out at the Experimental Sugarcane Station at the Federal Rural University of Pernambuco in the northeast region of Brazil. A randomized complete block design was used, with two treatments: conventional tillage and inter-row subsoiling. Subsoiling provided a significant gain of stalk yield of 5.53 tonnes per hectare. The other parameters evaluated did not differ significantly.

Copyright of Dyna is the property of Universidad Nacional de Colombia, Medellin, Facultad de Minas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The present study proposes an advanced force display control system for a surgical training simulator with virtual reality. In oral and orthopedic surgeries, a surgeon uses a chisel and mallet for chiseling and cutting hard tissue. To enable the representation of force sensation for the chiseling operation in a virtual training simulator, the force display device has been constructed with the ball-screw mechanism to obtain high stiffness. In addition, two-degrees-of-freedom (2DOF) admittance control has been used to react instantaneously to the impactive force caused by pounding with the mallet. The virtual chiseling operation was realized by the force display device with a single axis in the previous studies. In the current study, we propose the design procedure for the force display control system with the 2DOF admittance control approach to virtual operation in three-dimensional space. Furthermore, we propose the design method for the PD controller with imperfect derivative using frequency characteristics for the 2DOF admittance control system. The efficacy of the proposed control system is verified through the virtual experience from manipulating the chisel using the developed force display device in the current study.

Understanding the soil-plant relationship is important to determine critical limits of soil properties that influence crop growth and yield. The objectives were to quantify the influence of soil compaction levels on physical properties and crop growth and yield in a clayey Oxisol. An experiment was performed having in the main plots, levels of soil compaction (NT: no-tillage during six years, NTC: NT + four passes of a 10 Mg machine in the agricultural year 2003/2004, and Chisel: NT + chiseling and harrowing in the agricultural year 2003/2004), and in the sub-plots, the summer crops soybean and corn, and wheat in the winter season. We measured soil physical and mechanical properties, along with yield of corn, soybean and wheat, and root growth of that last two crops. After four passes of a 10 Mg machine, the soil resistance to penetration increased to a 0.12 m depth, while Chisel disrupted the 0–0.20 m soil layer, with the effects persisting for at least nine months. Soil compaction in no-tillage concentrated in the 0.05–0.15 m layer. Corn yield was similar among the treatments, soybean yield was highest in NT, and the highest yield of wheat was in the sequence with soybean under NT. [ABSTRACT FROM AUTHOR]

The results of multi-year research on the study of unconventional methods of tillage on fused leached chernozems of the south-foothill zone of Adygea are presented. The following tillage methods have been compared: mouldboard tillage with the PN-4-35 plow, nonmouldboard tillage with the PCh-2.5 chisel plow and the alternation of these methods; single deep slitting, shallow treatment with an anti-erosion KPE-3.8 cultivator – plane cutter; surface treatment with a heavy BDT-3 disk harrow. As a result of the studies the influence of energy-saving methods of tillage on the agrophysical parameters of the soil and crop productivity has been revealed. The content of productive moisture in a meter soil layer on options with constant chisel cultivation is slightly inferior to the options with constant plowing under all crop rotation crops. In the summer growing season a higher moisture content is observed in areas with constant plowing under all crop rotation crops. The bulk soil weight under continuous sowing cultures in a 0-40 cm soil layer is somewhat denser (1.13-1.12 g / cm3) in surface and mouldboard processing than in chisel processing (1.09 g / cm3). The agronomically valuable fraction of soil aggregates (0.25-3.0 mm) is contained in a larger number in crops of row crops, cereal crops, clover in the soil layer of 0-40 cm with constant plowing (26.9 %, 17.0 %, 25,0 %). Excessive crop yields have been noted for variants with permanent chisel processing (275.8 TZE / ha) and at alternating different processing methods compared to the variant with constant plowing (288.3 TZE / ha). In order to reduce erosion processes on sloping lands, when cultivating crops, it is possible to use subsurface tillage: chiseling for six years, shallow and shallow for 2-3 years. According to the results of an economic analysis of the studied methods of soil cultivation, the replacement of the main processing (plowing) with energy-saving methods have provided fuel savings of 20-25 % and an increase in labor productivity by 27-28 %.

The article presents the results of research on the impact of three farming systems with different resource content - industrial, environmental, and organic, and four systems of basic tillage - plowing 20-22 cm, chisel plowing 20-22 cm, disking 10-12 cm and disking 6-8 cm on bulk density of typical chernozem and yield of spring wheat in the right-bank Forest-Steppe of Ukraine. Given the results of research by scientists around the world, it is important to improve the agrophysical properties of soils, including their bulk density. According to the results of a three-year field experiment conducted in the field crop rotation of the experimental field of NULES of Ukraine, the increase in soil bulk density occurred gradually from the upper to lower layers and from the pre-sowing period to harvesting in all variants of farming and tillage systems. There was a significant decrease in the bulk density of the soil before sowing to 1.06 g/cm3 in 0-10 cm layer in environmental farming and up to 1.05 - organic. While in the control, this figure was 1.12 g/cm3. A similar trend was observed in the layers of 10-20 and 20-30 cm. On average, this decrease was 4.5 % for the environmental farming and 5.1 % for the organic farming. The advantage of these systems remained until the harvest of spring wheat. According to ANOVA the conservation tillage variants provided significantly lower parameters of the bulk density before sowing the crop in the upper - 0-10 cm layer of soil, compared to plowing. In the deeper layers of the soil - 10-20 and 20-30 cm, no significant differences between plowing and chisel plowing were found. Variants with disking led to a significant increase in the soil bulk density to 1.21 g/cm3 at a depth of 10-20 cm and 1.24-1.25 g/cm3 - 20-30 cm preserved until the harvest of the culture. The application of organic fertilizers in combination with the cultivation of green manure crops in crop rotation allows to limit the impact of minimizing the primary tillage on its bulk density. Regardless of the variant of soil tillage in environmental and organic farming, the bulk soil density on average over the years of research did not exceed 1.3 g/cm3, which indicates the important role of organic matter in improving the agrophysical parameters of chernozems. [ABSTRACT FROM AUTHOR]

The present study proposes an advanced force display control system for a surgical training simulator with virtual reality. In oral and orthopedic surgeries, a surgeon uses a chisel and mallet for chiseling and cutting hard tissue. To enable the representation of force sensation for the chiseling operation in a virtual training simulator, the force display device has been constructed with the ball-screw mechanism to obtain high stiffness. In addition, two-degrees-of-freedom (2DOF) admittance control has been used to react instantaneously to the impactive force caused by pounding with the mallet. The virtual chiseling operation was realized by the force display device with a single axis in the previous studies. In the current study, we propose the design procedure for the force display control system with the 2DOF admittance control approach to virtual operation in three-dimensional space. Furthermore, we propose the design method for the PD controller with imperfect derivative using frequency characteristics for the 2DOF admittance control system. The efficacy of the proposed control system is verified through the virtual experience from manipulating the chisel using the developed force display device in the current study. [ABSTRACT FROM AUTHOR]

The result of the study was an establishment of dependence of winter wheat productivity on a method of a primary tillage. There has been identified an advantage of deep chiseling on 0.35–0.37 m over moldboard plowing on 0.20–0.22 m, over disk tillage on 0.12–0.14 m and direct sowing. Plots with deep chiseling showed the best performance compared with other methods of primary tillage in density, porosity, humidity and, consequently, winter wheat productivity.

Copyright of Plant & Soil Science is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study explores the technology of chilling from the point of view of anthropogenic impact on soil. The influence of the arrangement of workers on technological rocessing is analyzed. The efficiency of resource-saving deep cultivation technology in production of row crops on example of sunflower growing in Volgograd region is estimated. We give technical and economic assessment of sunflower cultivation depending on the technological process of chilling. We defined a competitive technology of basic soil cultivation. Analysis of data obtained shows that the largest area of cross-section of the formation is produced when soil is treated with chisel tools as working organs are arranged such that they form a zone of continuous loosening, accordingly, it has the greatest anthropogenic impact. Field experiments also showed that deep loosening belts to a depth of 0.25...0.35 m, alternating with strips without treatment, are characterized by positive processes. Unprocessed areas become overcrowded (more than 1.3 g/cm3), so they create less favorable, in comparison with processed, conditions for the development of some species of perennial weeds. Studies have shown that, with the main soil-free tillage of the soil to a depth of 0.3 m, from the stubble of winter wheat, stubble conservation was consistent: 69.67% - over the treated band using striptill technology; 76.33% - on the processed strip by a chisel with a trail of 0.7 m; 68.67% for a chisel with a trail of 0.35 m. After the passage of the aggregates on the soil surface, all stubble remains within the requirements for SRT AIST 4.6-2010 (more than 60%). The use of striptill technology reduces fuel costs by 35.5% relative to the classical chiesel, and by 27.3% relative to the minimum technology. Accordingly, the cost of wages is reduced by 37.5% compared to the classical chisel and by 24.8% compared to the minimum chisel technology.

ABSTRACT Farming systems may affect soil properties and crop production of components, decreasing yields. This study aimed to assess penetration resistance (PR) and agronomic traits of soybeans under no-tillage (NT) and chiseling (CP). The experiment was carried out in a randomized block with two treatments (tillage and scarification) with 12 repetitions; yet soil penetration resistance (PR) was assessed in a factorial block, considering farming systems and sampling sites (row and interrows). PR was measured with an impact penetrometer, sampling in row and interrows within a 22.5 x 0.1 m2 mesh grid up to 0.60 m depth. The obtained values were higher for NT in the 0.10-0.20 m layer. Great PR values in interrows were only registered within the surface layer. This is because there was no soil mobilization by seeder chisel plow. In chiseled soil, compaction was reduced, however, the first tractor passings were able to compact the soil to a depth of 0.50 m. Therefore, scarification reduced the plant stand and penetration resistance, allowing greater growth and soybean yield.

ABSTRACT In Brazil, there are several available models and systems to measure soil compaction; however, the data generated by such equipment have to be processed and interpreted, making the process expensive. Our study aimed to evaluate a prototype of instrumented rods to identify soil compacted layers and control chiseling depth, and compared it to a conventional system at a fixed depth of 0.35 m. In order to compare them, we assessed the following parameters: hourly fuel consumption, operational fuel consumption, drawbar power, average power, average speed, slipping, tractor effective field capacity and response time. Our results showed that mechanical chiseling at variable depths reduced in 26% the operational fuel consumption and increased in 14% the effective field capacity. Furthermore, the prototype of chisel plow automated control generated maps displaying spatial variability of soil mechanical resistance with resolution, sampling density and high operating capacity.

The seed bank is characterized by the amount of seeds and other viable reproductive structures in the soil and it is changed by the input and output of seeds, being classified by its permanence in the soil as transient or permanent. The tillage and crops used decisively influence this dynamic and more disturbed areas tend to have richer seed banks. The purpose of this study was to test different soil tillage and crop systems, aiming to reduce or eliminate the ryegrass in the area. The experiment was conducted from 2010 to 2012. In the first year, the effect of chemical tillage was assessed, compared to the area without tillage. From the second year on, in the area that received chemical tillage, the second experiment was installed, where it was assessed the effect of soil tillage and crop rotation in the ryegrass seed yield. The soil tillage treatment was chisel plow and non-chisel plow. The crop rotation was: fallow/soybean; wheat/soybean; black oat/maize. The samples of soil were taken three times a year and split in 0-5, 5-10, 10-15 and 15-20 cm. After sampling, the seeds were separated from the soil and sterilized. Afterwards, germination and tetrazolium test were conducted. In the same plots used for soil sampling, the emergence flow of ryegrass was assessed in the winter 2011 and 2012. In the first year it was observed that chemical tillage had considerably reduced the amount of ryegrass in the soil. The crop rotations used were more effective than soil tillage in reducing the seed banks in the soil. The rotation oat/maize and wheat/soybean, in only two years, practically zeroed the ryegrass seed banks in the area.

This study aimed to characterize soil carbon dioxide (CO2) emission associated with soil pore distribution in an Oxisol and Ultisol under chiseling in the planting row and in total area for sugarcane (Saccharum officinarum) cultivation. The experimental design was a large paired-plot design. Treatments consisted of chiseling in the planting row (CPR) and chiseling in total area (CTA) in an Oxisol and Ultisol. Soil CO2 emission, soil temperature, and soil moisture were assessed over 12 days in the Oxisol and 11 days in the Ultisol at a depth of 0-0.10 m. Organic carbon associated with minerals (OCAM) and particulate organic carbon (POC) were also assessed. OCAM, pore class C2 (0.05 ≤ ɸ < 0.1 mm), soil moisture, and soil temperature explained 72 and 53% of the variability of soil CO2 emission in CPR and CTA, respectively. In the Ultisol, pore class C1 (ɸ ≥ 0.1 mm) and OCAM explained 82% of the variability of soil CO2 emission in CPR. In CTA, soil moisture, OCAM, and POC explained 67% of the variability of soil CO2 emission. In the Oxisol, CPR and CTA affected soil structure, causing changes in both soil porosity and soil CO2 emission. In the Oxisol, the lowest average value of soil CO2 emission (2.8 μmol m−2 s−1) was observed in CPR whereas its highest value (3.4 μmol m−2 s−1) was observed in CTA. In the Ultisol, soil tillage (CPR and CTA) did not affect soil CO2 emission. These results indicate that the intensity of soil tillage in more clayey textured soils favors soil CO2 emission possibly due to a higher carbon availability for microbial activity when compared to more sandy textured soils. A less intensive soil tillage can be considered as an efficient strategy to reduce soil CO2 emission and hence soil organic carbon losses. Thus, this management strategy proved to be efficient in terms of mitigating greenhouse gas emissions, reducing the contribution of agriculture to global climate change. [ABSTRACT FROM AUTHOR]

Energy balance is a way of evaluating the efficiency of the management of agricultural production systems. The objective of this work was to compare, from the energy point of view, two forms of soil management and with variation in the management of different winter cover crops. The experiment was conducted in a family-based property located in the municipality of Anta Gorda/ RS, in 2010/2011 and 2011/2012, in Neossolo Regolítico distrófico típico. The experimental design was in randomized blocks with subdivided plots and three replicates. The main treatments consisted of two forms of soil management: no-tillage and no-tillage and chiseling at two-year intervals, being subdivided in winter by crops of black oats (Avena strigosa), vetch (Vicia sativa L.) and grazed black oats. As a result, it was verified that all management systems had a positive energy balance. No-tillage resulted in lower intake, higher output, net energy and energy efficiency in relation to no-tillage and chiseling every two years. Among the winter cover crops, oats without grazing were those whose cultivation resulted in higher net energy and energy efficiency. [ABSTRACT FROM AUTHOR]

O tráfego de máquinas agrícolas é considerado uma das principais fontes da compactação do solo. Uma prática utilizada para minimizar os efeitos da compactação é a escarificação, porém a haste escarificadora pode causar compactação subsuperficial. O objetivo deste trabalho foi avaliar a influência do tráfego de máquinas na compressibilidade de um Argissolo Vermelho-Amarelo distrófico arênico, de textura franco arenosa e avaliar o comportamento mecânico desse solo abaixo da linha de atuação da haste escarificadora. Os tratamentos investigados foram: semeadura direta há 13 anos, semeadura direta há 13 anos com tráfego adicional (intensidade de tráfego de 24,67Mg km ha-1), cultivo mínimo recém implantado e cultivo mínimo recém implantado com tráfego adicional. Para a determinação da densidade do solo, de índice de vazios, da pressão de preconsolidação e do coeficiente de compressão, foram coletadas amostras nas camadas de 0,0-0,10m, 0,10-0,20m, 0,20-0,30m e 0,30-0,40m. O tratamento semeadura direta há 13 anos apresentou a menor capacidade de suporte e maior suscetibilidade à compactação. A intensidade de tráfego de 24,67Mg km ha-1 aumentou a densidade do solo e reduziu o índice de vazios até 0,20m. A escarificação não afetou a pressão de preconsolidação e o coeficiente de compressão do solo na camada abaixo da linha de atuação da ponteira do escarificador.Farm machinery wheeling is considered a major source of soil compaction. The use of chisel plow can minimize such effects, but the chisel can cause subsurface compaction. The aim of this study was to evaluate the effect of traffic and is present below the compaction layer thought compressive parameters of soil. The treatments investigated were: no-tillage, no-tillage with additional traffic (traffic intensity of 24.67Mg km ha-1), no-tillage chiseling recent implanted, no-tillage with additional traffic and chiseling recent implanted. For the density, void ratio, preconsolidation pressure and coefficient of compressibility determination in the layers 0.0-0.10m, 0.10-0.20m, 0.20-0.30m and 0.30 to 0.40m samples were collected. The treatment no-tillage showed the lowest load support capacity and greater susceptibility to compaction. The traffic intensity of 24.67Mg km ha-1 increased bulk density and decreased void ratio until 0.30m depth. The chisel plow did not affect the preconsolidation pressure and coefficient of compressibility of soil layer below the line of action of the chisel tip.

Soil management influences water erosion and sediment size in runoff. With the objective of quantifying sediments in runoff and their relation to runoff velocity (Rv), random roughness (RR), and Ir index, this experiment was carried out from 2003 to 2006, on a typical Hapludox with the following soil management systems submitted to chiseling: i) bare soil with plowing+two disking tillage (BSC); ii) plowing+two disking tillage (CTC); iii) no tillage with crop residues burned (BNTC); and iv) traditional notillage (TNTC). CTC, BNTC and TNTC treatments were cultivated with crop rotation and the BSC treatment was not cultivated. Five simulated rainfall tests were applied, with intensity of 64 mm h-1 and duration of 20, 30, 40, 50 and 60 min. RR was influenced by the residual effect of soil management and by simulated rainfall, and affected the Rv in the three initial rainfall tests. Sediments carried by runoff were influenced by soil management and by simulated rainfall. Most of the sediments were in the size range from 0.5 to > 2 mm, with a higher quantity of fine sediment in BNTC and TNTC treatments than in the other treatments. The D50 index of sediments changed with soil management system and with rainfall tests, decreasing with the increase of the RR and increasing with the increment of Rv and Ir index.O manejo do solo influencia a erosão hídrica e o tamanho de sedimentos na enxurrada. Com o objetivo de quantificar os sedimentos na enxurrada e relacioná-los com sua velocidade (Ve), com a rugosidade (RR) e com o índice Ir, conduziu-se este estudo entre 2003 e 2006, em um Nitossolo, sob sistemas de manejo do solo submetidos a uma escarificação: i) solo descoberto com aração e duas gradagens (SCE); ii) aração e duas gradagens (PCE); iii) semeadura direta em solo nunca preparado e com resíduos queimados (SQE); e iv) semeadura direta tradicional (STE). Os tratamentos PCE, SQE e STE foram cultivados com rotação de culturas e o SCE não foi cultivado. Foram aplicados cinco testes de chuva simulada, com intensidade constante de 64 mm h-1 e durações de 20, 30, 40, 50 e 60 minutos cada um. A RR foi influenciada pelo efeito residual do manejo do solo e pelas chuvas simuladas e afetou a Ve nos três testes iniciais de chuva. Os sedimentos transportados pela enxurrada foram influenciados pelo manejo do solo e pelas chuvas simuladas; tais sedimentos ocorreram em maior quantidade no tamanho entre 0,5 e > 2 mm do que nos tamanhos menores, com maior quantidade de sedimentos menores nos tratamentos SQE e STE do que nos demais tratamentos. O índice D50 dos sedimentos variou com o manejo do solo e com os testes de chuva, diminuindo com o incremento de RR e aumentando com o incremento de Ve de Ir.

O objetivo deste trabalho foi avaliar o efeito de coberturas de inverno e da descompactação mecânica do solo sobre o desempenho de soja e milho, em sistema de plantio direto. Foram conduzidos dois experimentos em Eldorado do Sul, RS, sobre Argissolo Vermelho compactado, nas safras 2005/2006 e 2006/2007. No primeiro, o delineamento experimental foi em blocos ao acaso, com parcelas subdivididas. Os tratamentos consistiram de duas profundidades teóricas de atuação da haste sulcadora da semeadora (0,06 e 0,12 m, subparcela) e de três tipos de coberturas do solo no inverno (parcela): pousio, aveia-preta (Avena strigosa) e aveia-preta+ervilhaca (Vicia Sativa). Em 2006, a cobertura aveia-preta+ervilhaca foi substituída por nabo-forrageiro (Raphanus sativus). No segundo experimento, realizado em blocos ao acaso, o solo foi escarificado e os tratamentos consistiram do uso de aveia-preta ou nabo-forrageiro como cobertura de inverno. Os cultivos de cobertura reduziram a compactação superficial do solo (0-0,06 m) em comparação ao pousio e, na safra 2006/2007, sob condições de baixa disponibilidade hídrica, proporcionaram maior produtividade de milho e soja. Isso não se repetiu em 2006/2007, quando a disponibilidade hídrica foi adequada. O aumento da profundidade de atuação das hastes sulcadoras não influenciou a produtividade da soja e do milho. A escarificação reduziu a produtividade da soja e do milho em relação ao SPD contínuo.The objective of this work was to evaluate the effect of soil winter covers and soil mechanical loosening on soybean and corn yield, in no-tillage system. Two experiments were carried oud in Rio Grande do Sul state, Brazil, in a compacted Argissolo Vermelho (Haplic Acrisol), in the 2005/2006 and 2006/2007 crop seasons. The first experiment was carried out in a complete block design, with a split plot arrangement. The treatments were two theoretical working depths of a driller chisel-type furrow opener (0.06 and 0.12 m, split plot), and three soil winter covers (main plot): fallow, black oat (Avena strigosa), and black oat+common vetch (Vicia sativa). In 2006, the soil cover black oat+common vetch was replaced by oilseed radish (Raphanus sativus). In the second experiment, in a complete block design, the soil was chiseled and treatments consisted of black oat or oilseed radish as winter cover crops. Cover crops reduced soil superficial (0-0,06 m) compaction compared to fallow and, in the 2005/2006-crop season, under low water availability, provided higher soybean and corn yields. In the 2006/2007-crop season, when water availability was higher, the same did not happen. Increasing working depths of the chisel-type furrow opener did not affect soybean or corn yields. Soil chiseling reduced soybean and corn yields in comparison to the continuous no-tillage system.

A avaliação da qualidade física dos solos agrícolas tem assumido importância cada vez maior, principalmente em áreas sob sistema plantio direto, uma vez que nesse sistema de manejo ocorrem importantes alterações na estrutura do solo. A resistência mecânica do solo à penetração (RP), o intervalo hídrico ótimo (IHO) e a densidade relativa (DR) têm sido apresentados como opções para essa avaliação. Os objetivos deste trabalho foram avaliar e modelar a RP em função da umidade e densidade do solo e determinar o IHO em função da DR em dois sistemas de manejo. Amostras de solo com estrutura preservada foram coletadas na camada de 0-5cm, em solo sob plantio direto (PD) e plantio direto escarificado (PDE) há seis meses. Em laboratório, determinou-se a RP utilizando penetrômetro eletrônico e efetuou-se um ajuste estatístico individual para cada manejo à equação de Busscher. No PDE, para uma mesma densidade e umidade do solo, a RP foi menor que no PD, e a diferença na RP foi maior entre os dois manejos quando a umidade do solo no campo foi menor. O IHO foi maior no PDE até a DR 0,9. Os resultados permitem concluir que a RP é um parâmetro sensível para determinar a qualidade estrutural do solo e que o PDE reduziu significativamente a RP e aumentou o IHO, o que proporcionará melhores condições para o desenvolvimento radicular das plantas por um período de tempo maior.The assessment of the physical quality of agricultural soils has taken on added importance, especially in areas under no tillage, as important changes to soil structure occur as a result of this type of management. Soil resistance to penetration (RP), the least limit water range (LLWR) and relative density (RD) have been used as evaluation parameters. The aim of this study was to assess and model RP as a function of soil moisture and density and to determine the LLWR as a function of RD under two management systems. Samples of soils under no tillage (NT) and chiseled no tillage (CNT) for six months and whose structure had been preserved were collected at a depth of 0 to 5cm. In the laboratory, RP was assessed using an electronic penetrometer and each management system was statistically adjusted to Busscher's equation. In CNT soils, RP was lower for the same density and moisture, and lower than the PD, whereas the difference in RP was larger between the two management systems when soil moisture in the field was lower. The LLWR was higher under CNT up to an RD of 0.9. Results allow us to conclude that RP is a sensitive parameter for determining the physical quality of the soil and that CNT significantly reduced RP and increased the LLWR, providing favorable conditions for root growth for a longer time period.

Os objetivos deste trabalho foram determinar a variação temporal da porosidade, da densidade e da resistência à penetração do solo, em quatro sistemas de manejo, e estudar seus efeitos sobre o crescimento radicular do feijoeiro (Phaseolus vulgaris). O experimento foi conduzido em Argissolo, em delineamento experimental de blocos ao acaso, com três repetições. Os tratamentos foram: plantio direto há 10 anos, preparo convencional, plantio em solo escarificado recentemente (Esc. recente) e plantio direto sobre área escarificada há 1 ano (Esc. 1 ano). A escarificação reduziu a densidade média do solo e aumentou a porosidade total durante o ciclo do feijoeiro. A maior densidade ocorreu na camada de 0,10-0,15 m dos sistemas plantio direto e Esc. 1 ano. A resistência à penetração foi a propriedade que melhor caracterizou e diferenciou os sistemas de manejo, as camadas com impedimento e o efeito do tempo de amostragem, porém não afetou o crescimento radicular do feijoeiro. Os efeitos da escarificação sobre a densidade e a resistência à penetração desapareceram um ano após a escarificação, o que indica a reconsolidação do solo.The objectives of this work were to determine the temporal variation in soil porosity, bulk density and penetration resistance, in four soil management systems, and study their effects on the root growth of black beans (Phaseolus vulgaris). The experiment was conducted in a Hapludalf using three replicates. The treatments consisted of: long-term (10 years) no-tillage, conventional tillage, chiseling of the long-term no-tillage (Chi. recent), and no-tillage in area after one year since chiseling (Chi. 1 year) of the long-term no-tillage area. Chiseling reduced soil bulk density and increased total porosity during the bean growing cycle. The greatest bulk densities were observed at 0.10 to 0.15 m in the no-tillage and in Chi. 1 year. Soil resistance was the best property to differentiate the effects of the soil management systems, the restricted layers, and time of sampling. Howerver, soil resitance did not affect the root growth of black beans. The effects of the soil chiseling on bulk density and soil resistance disappeared after one year, which indicated soil consolidation.

A qualidade estrutural do solo é importante para a emergência das plântulas, bem como para o crescimento, desenvolvimento e produtividade das culturas. Uma ampla distribuição de valores de resistência tênsil do solo indica condições estruturais do solo para atender a estes pressupostos. O objetivo deste trabalho foi avaliar a resistência tênsil e a friabilidade de um Latossolo Vermelho distroférrico sob plantio direto com sucessão e rotação de culturas. Os tratamentos utilizados foram: plantio direto com sucessão das culturas de trigo e soja (SDS); plantio direto com rotação de culturas, utilizando em seqüência milho-aveia-soja-aveia-soja-trigo (SDR), e SDR associado à escarificação periódica do solo (SDE). Em duas épocas distintas (outubro de 2003 e abril de 2004), foram coletados dez blocos de solo (0,15 x 0,20 x 0,10 m) em cada tratamento na camada de 0-0,20 m de profundidade. Quatrocentos e cinqüenta agregados de cada tratamento e época de coleta foram utilizados para determinar a resistência tênsil e a friabilidade do solo, determinando-se, também, o conteúdo de C orgânico. Não foi verificada influência do C orgânico do solo na resistência tênsil e na friabilidade do solo. Verificou-se menor resistência tênsil em SDE para o ano de 2003. A sucessão de culturas (SDS) alternou temporariamente a friabilidade do solo entre a classe friável e a muito friável. A rotação de culturas (SDR) manteve temporalmente estável a estrutura do solo na classe de friabilidade do solo muito friável, assegurando melhor estrutura e qualidade física do solo. A resistência tênsil dos agregados e a friabilidade foram sensíveis na avaliação da qualidade estrutural do solo para os sistemas de manejo de solo e culturas estudados.The soil structural quality is important for plant emergence as well as for crop growth, development and yield. A wide range of soil tensile strength values indicates that soil structure conditions meet these requirements. The objective of this study was to evaluate the tensile strength and friability of an Oxisol (Acrudox) under no-tillage with crop rotation and crop succession. The soil management treatments consisted of: crop succession with wheat and soybean (SDS); crop rotation with corn-oats-soybean-oats-soybean-wheat (SDR) and SDR plus periodic soil chiseling (SDE). Ten soil blocks (0.15 x 0.20 x 0.10 m) were randomly collected from the 0-0.20 m layer for each treatment, on two sampling dates (October 2003 and April 2004). The soil tensile strength and soil friability was estimated in 450 soil aggregates from each treatment and sampling date. The soil organic carbon content of the aggregates was also measured. There was no effect of soil organic carbon on soil tensile strength and friability. Results showed lower tensile strength in SDE soil collected in 2003. Crop succession (SDS) temporarily changed the friability classification from very friable to friable. Crop rotation (SDR) was effective in maintaining the soil structure at the very friable class, resulting in a better structure and soil physical quality. The parameters tensile strength and friability proved sensitive enough to evaluate soil structural quality under the crop management systems studied.

Proporcionar condições ótimas ao desenvolvimento das plantas deve ser um dos objetivos do manejo do solo. O sistema plantio direto é um manejo conservacionista por excelência, mas tem apresentado problemas de compactação, afetando o desenvolvimento e à produtividade das culturas. A escarificação esporádica do solo nessas áreas tem-se apresentado como uma alternativa para minimizar os efeitos negativos do aumento da sua densidade. Neste estudo, avaliou-se a densidade do solo, a porosidade total e de aeração, a densidade máxima e a relativa do solo e o rendimento de grãos de trigo num Latossolo em duas áreas: plantio direto há 6 anos (PD) e plantio direto escarificado (PDE). Durante todo o ciclo da cultura do trigo, monitorou-se o potencial de água no solo por meio de sensores eletrônicos e "datalogger". A escarificação esporádica do solo sob sistema plantio direto diminuiu (5%) a densidade e a densidade relativa do solo, aumentou a porosidade total e alterou a dinâmica da água no solo, proporcionou maior volume de poros livres de água (7,6%) durante todo o ciclo da cultura do trigo e aumentou significativamente o rendimento de grãos (682kg ha-1).The soil management should be aimed at providing optimal conditions for plant growth and development. No-tillage is a quintessential conservative system; however, it has caused compaction, thus affecting crop development and yield. Sporadic soil chiseling in these areas has been used as an alternative to minimize the negative effects of an increase in bulk density. The soil bulk density, total porosity, air-filled porosity, maximum density, relative density, and wheat grain yield of an oxisol were assessed in two areas: under no-tillage for 6 years and under no tillage chiseled. Soil water potential was monitored throughout the wheat crop cycle by using electronic sensors and a datalogger. Results show that sporadic chiseling of the soil under no-tillage reduced soil density and relative density by 5%, increased total porosity and changed the soil water dynamics, resulting in a higher volume of water-free pores (7.6%) throughout the wheat crop cycle, remarkably increasing grain yield (682kg ha-1).

O intervalo hídrico ótimo (IHO) é um método que integra vários fatores que afetam o desenvolvimento das plantas, e corresponde ao intervalo de umidade do solo no qual não ocorre restrição de aeração (porosidade de aeração mínima de 0,10 m³ m-3) nem de resistência mecânica à penetração das raízes (RP) dentro da faixa de água disponível às plantas, isto é, entre a capacidade de campo (CC) e o ponto de murcha permanente (PMP). O objetivo deste trabalho foi determinar o IHO em um Latossolo Vermelho sob plantio direto (PD) e plantio direto escarificado (PDE), bem como o rendimento de grãos de soja. Avaliou-se a densidade do solo, o IHO, a variação da umidade do solo durante o ciclo da soja e o rendimento de grãos. Os resultados indicaram que a densidade do solo foi menor no PDE, o que acarretou maior amplitude do IHO. A densidade crítica, na qual IHO = 0, foi semelhante entre o PD e o PDE. Durante o ciclo da cultura da soja, em vários momentos, a sua umidade ficou fora do IHO, quando assumida RP limitante de 2 MPa. Como o rendimento de grãos da soja não apresentou diferença significativa, deduz-se que a RP de 2 MPa não é limitante para a soja.The least limiting water range (LLWR) was used to determine several factors that influence plant growth. The LLWR is defined as the water content range in which aeration (AFP) and soil resistance to root penetration (RP) are not restrictive, within the field capacity (FC) and permanent wilting point (PWP). The aim of the present study was to determine the LLWR and soybean grain yield in an Oxisol under non-tillage (NT) and chiseled no-tillage (CNT) systems. The soil density, LLWR, soil water content range throughout the soybean crop cycle and grain yield were assessed. Soil density was lower in the CNT system, which resulted in a wider LLWR. Critical density (LLWR=0) was similar in the NT and CNT systems. The soil water content decreased to values outside the LLWR at different periods during the crop cycle when a limiting RP of 2 MPa was considered. It was concluded that an RP of 2 MPa is not limiting for soybean because there were no significant differences in grain yield between the two tillage systems.

Reduced tillage, as well as the most reduced tillage – No-till – every year are becoming more important in our region. Unfortunately, the areas under reduced tillage are still very small. In order to establish optimal system of reduced soil tillage, the experimental trials were set on Chernozem soil type in northern Baranja during three vege¬tation seasons (1998/1999-2000/2001) and five soil tillage systems: CT) Conventional Tillage (primary soil tillage by moldboard ploughing at 30-35 cm depth), DH) Multiple Diskharrowing at 10-15 cm as primary tillage, CH) Chiseling and diskharrowing (chiseling at 30-35 cm and diskharrowing at 10-15 cm as primary tillage), PD) One diskharro-wing pass (diskharrowing at 10-15 cm as primary tillage, and NT) No-tillage system. The highest yields were recor¬ded at CT with three-year average of 9.29 t/ha, followed by CH with 8.37 t/ha, DH with 8.07 t/ha, PD with 6.99 t/ha, whereas the lowest yields were recorded at NT treatment, with three-year average of 5.94 t/ha. The highest profit was achieved at CT treatment (665,34 HRK/ha), followed by CH (189,24 HRK/ha), DH (77,20 HRK/ha), PD (-334,95 HRK/ha) and NT (-459,81 HRK/ha).

O trabalho comparou o desempenho de um trator agrícola 4x2 TDA de 89 kW (121cv) em função do tipo de pneus (radial, diagonal e de baixa pressão), a condição de lastragem (com e sem água nos pneus) e quatro velocidades [V1 (1,84km h-1), V2 (3,18km h-1, V3 (4,57km h-1), V4 (5,04km h-1)]. O experimento foi realizado na UNESP-Jaboticabal-SP, em condição de preparo do solo com escarificador de sete hastes a 30cm de profundidade. Os pneus foram do tipo R1, com as seguintes características: [radial (dianteiros-14.9 R 26; traseiros-620/75 R 30) diagonal (dianteiros-14.9-26, traseiros-23.1-30) e BPAF (dianteiros-500/60-26.5; traseiros-700/55-34)]. O delineamento experimental foi blocos casualizados, em esquema fatorial 3x2x4, com 24 tratamentos e três repetições. Os resultados evidenciaram vantagens para o trator equipado com pneus radiais.The objective of this study was to compare the performance of the FWD agricultural tractor, equipped with three types of tires (bias ply, radial and low pressure), with and without tire water ballasting, operating in four forward speed. The research was carried out at UNESP, SP, Brazil, with the tractor pulling a chisel plow. A tractor with 89kW (121cv) engine power equipped with FWD, was used in the experiment, and the tires used had the following characteristics: radial (front: 14.9R26 and rear: 620/75R30), bias ply (front: 14.9-26 and rear: 23.1-30) and low pressure (front: 500/60-26.5 and rear: 700/55-34). The experiment was conducted in a completely randomized block, design (3x2x4), with 24 treatments and three replications. The results evidenced advantages for the tractor equipped with radial tires.

Abstract: Diamond Micro Chiseling (DMC) is a new machining process to generate discontinuous microstructures, such as miniaturized cube corner retroreflectors or V-shaped grooves with defined endings. After a brief introduction to the process itself, this paper presents an in-depth analysis of factors that determine the achievable size and performance of such microstructures. The capability for generating discontinuous microstructures is assessed theoretically by considering the process kinematics and the diamond tool design by geometrical calculations. Thereafter, an experimental evaluation of the process is presented by showing measured data for cutting forces, achievable shape accuracy and surface finish for different structure sizes. [Copyright &y& Elsevier]

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The innovative method for ameliorative treatment of low-fertility soils that are in an active phase of soil formation has been substantiated: by combination of periodic local deep close chiseling and phytoamelioration and, if necessary, by application of ameliorants. Such method excludes the erosion processes and output of unfertile layer to the surface. [ABSTRACT FROM AUTHOR]

Farm machinery wheeling is considered a major source of soil compaction. The use of chisel plow can minimize such effects, but the chisel can cause subsurface compaction. The aim of this study was to evaluate the effect of traffic and is present below the compaction layer thought compressive parameters of soil. The treatments investigated were: no-tillage, no-tillage with additional traffic (traffic intensity of 24.67Mg km ha-1), no-tillage chiseling recent implanted, no-tillage with additional traffic and chiseling recent implanted. For the density, void ratio, preconsolidation pressure and coefficient of compressibility determination in the layers 0.0-0.10m, 0.10-0.20m, 0.20-0.30m and 0.30 to 0.40m samples were collected. The treatment no-tillage showed the lowest load support capacity and greater susceptibility to compaction. The traffic intensity of 24.67Mg km ha-1 increased bulk density and decreased void ratio until 0.30m depth. The chisel plow did not affect the preconsolidation pressure and coefficient of compressibility of soil layer below the line of action of the chisel tip. [ABSTRACT FROM AUTHOR]

The assessment of the physical quality of agricultural soils has taken on added importance, especially in areas under no tillage, as important changes to soil structure occur as a result of this type of management. Soil resistance to penetration (RP), the least limit water range (LLWR) and relative density (RD) have been used as evaluation parameters. The aim of this study was to assess and model RP as a function of soil moisture and density and to determine the LLWR as a function of RD under two management systems. Samples of soils under no tillage (NT) and chiseled no tillage (CNT) for six months and whose structure had been preserved were collected at a depth of 0 to 5cm. In the laboratory, RP was assessed using an electronic penetrometer and each management system was statistically adjusted to Busscher's equation. In CNT soils, RP was lower for the same density and moisture, and lower than the PD, whereas the difference in RP was larger between the two management systems when soil moisture in the field was lower. The LLWR was higher under CNT up to an RD of 0.9. Results allow us to conclude that RP is a sensitive parameter for determining the physical quality of the soil and that CNT significantly reduced RP and increased the LLWR, providing favorable conditions for root growth for a longer time period. [ABSTRACT FROM AUTHOR]

Soil compaction is a worldwide problem in agricultural areas, and it is important to define soil properties and reference values that allow knowledge of the compaction level for decision making. The objective of this study was to define the critical values of physical properties associated with the compaction of soils. Three Ultisols and two Oxisols, under different management systems, were collected at different depths for an evaluation of particle size, volumetric moisture, bulk density, and porosity. In the field, soil resistance to penetration and the root length of the soybean and edible black bean crop were measured. The soil profiles presented horizontal layers with similar resistance, but in some cases, there is discontinuity of these layers, which allows the roots to use the zones of lower resistance to deepen in the profile. The values of bulk density and resistance to penetration critical to soybean and edible black bean (only in sandy loam soil) root growth, according to soil textural class, are: sandy loam = 1.66 Mg m−3 and 1.5 to 2 MPa; loam and clay loam = 1.52 Mg m−3 and 1 to 1.5 MPa; silty clay loam and silty clay = 1.32 Mg m−3 and 1.5 to 2 MPa; and clay = 1.33 to 1.36 Mg m−3 and 2 to 3.5 MPa. [ABSTRACT FROM AUTHOR]