scholarly journals Study of the Mechanics and Micro-Structure of Wheat Straw Returned to Soil in Relation to Different Tillage Methods

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 894
Author(s):  
Yanpeng Wang ◽  
Adnan Abbas ◽  
Xiaochan Wang ◽  
Sijun Yang ◽  
Morice R. O. Odhiambo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wheat Straw ◽  
Decomposition Rate ◽  
Morphological Changes ◽  
Micro Structure ◽  
Dynamic Changes ◽  
Straw Decomposition ◽  
Nylon Mesh ◽  
Mesh Bag ◽  
Tillage Methods

A field experiment was conducted to study the effects of different tillage methods, and their interaction on the dynamic changes of straw decomposition rate, mechanical properties, and micro-structure of the stalk. A nylon mesh bag technique was used. An obvious change was observed in the decomposition rate of straw, and its mechanical, and micro-structural properties. The decomposition rate of straw was increased in all tillage treatments. Specifically, it increased consistently in conventional and dry rotary tillage, and sharply in wet rotary tillage. Furthermore, for all tillage, the mechanical properties like shear and bending strengths decreased sharply while compressive strength first decreased linearly and then increased, whereas the micro-structure of wheat straw showed a fluctuating trend, i.e., it changed neither regularly nor consistently over time. Moreover, the micro-structure of the stalk explained the morphological changes to the straw that returned to the field, which may impact the mechanical properties. However, these changes could not explain the degradation trend of straw directly. The findings of the study could be used as a theoretical reference for the design of tillage and harvesting machinery keeping in view soil solidification and compaction dynamics.

Nutrient Recycling, Wheat Straw Decomposition, and the Potential Effect of Straw Shear Strength on Soil Mechanical Properties

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 314 ◽  
Author(s):  
Yanpeng Wang ◽  
Abbas Adnan ◽  
Xiaochan Wang ◽  
Yinyan Shi ◽  
Sijun Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Wheat Straw ◽  
Decomposition Rate ◽  
Nutrient Recycling ◽  
Potential Effect ◽  
Straw Decomposition ◽  
Rapid Decomposition ◽  
Nylon Mesh ◽  
Straw Return

This study aimed to explore the release rate (RR) of wheat straw nutrients during straw return to a paddy field and examined the possible relationship between wheat stalk shear strength and the content of the remaining components in wheat straw. We used the nylon mesh bag technique to study the decomposition of straw nutrients such as total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), lignin, and cellulose over time. During the time span of 0–90 days, results showed a rapid decomposition rate with a diverse trend under different tillage operations. Furthermore, the decomposition rate was higher under the plough (PRP) conditions than under dry conditions (RP) or water rotation (PR). Moreover, under PRP conditions, the RR of TOC, TK, lignin, and cellulose increased, while the RR of TK was higher than 95% initially and then increased slightly. However, the carbon to nitrogen ratio was first increased and then decreased; similarly the RR of TP first increased and then decreased; a fluctuating pattern was observed for TN. Additionally, we found a strong correlation between wheat stalk shear strength and the remaining contents of lignin, hemicellulose, and cellulose, with R2 ≥ 0.91, which was higher than 0.82 after computing adjustments. Furthermore, the changing trend of nutrients and components and the relationship between shear strength and the content of the remaining components in wheat straw were used to evaluate the release characteristics of nutrients under straw return. The potential effects of the straw shear strength on soil mechanical properties were determined, providing a remarkable opportunity for acquiring nutrients for sustainable application of soil.

Wheat straw decomposition in subtropical Australia .I. A comparison of 14C labeling and two weight loss methods for measuring decomposition

Soil Research ◽  
1987 ◽  
Vol 25 (4) ◽  
pp. 473 ◽  
Author(s):  
AL Cogle ◽  
PG Saffigna ◽  
WM Strong ◽  
JN Ladd ◽  
M Amato
Keyword(s):  
Weight Loss ◽  
Wheat Straw ◽  
Nitrogen Transformations ◽  
Straw Decomposition ◽  
Percent Recovery ◽  
14C Labelling ◽  
Mesh Bags ◽  
Mesh Bag ◽  
14C Labeling ◽  
Subtropical Australia

Three techniques for measuring straw decomposition in the field were compared. They were 14C labelling, weight loss from unconfined straw, and weight loss from straw held in mesh bags. The effect of these techniques on nitrogen transformations was also considered. The percent recovery by weight of straw held in mesh bags was greater than that which had been left unconfined in microplots, and also was greater than the percent recovery of 14C from 14C-labelled straw. This suggested that the mesh bag technique gave an underestimate of decomposition. Unconfined straw in microplots provided results in general agreement with 14C recoveries. Straw decomposition under the conditions of the different treatments had little effect on nitrogen transformations.

Teknologi Inokulasi Besi Cor Kelabu FC-250 Untuk Mencegah Pengerasan Pada Dove Tale Produk Ragum Tipe 125

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Amin Suhadi ◽  
Seodihono
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Treatment Process ◽  
Gray Cast Iron ◽  
Spare Parts ◽  
Gray Cast ◽  
Micro Structure ◽  
Control Factors ◽  
Seed Inoculation ◽  
Casting Industry

Production technology of metal casting industry in Indonesia needs to be improved, especially in the manufacturing of spare parts and box engine made of gray cast iron which has various wall thick such as dove tale construction. Microstructure of gray cast iron is influenced by cooling rate during casting, chemical composition and melting treatment process (inoculation). The part which has the thinnest thickness has the fastest cooling therefore, the grain boundary is smaller compared to other section. As a result this part has highest hardness and difficult to be machined. This research is conducted to solve this problem by modifying melting and solidification treatment process. The research starting from micro structure analysis, composition and mechanical properties tests on the product, and then conducting modification treatment through Taguchi method approach. Experimental results obtained show that the best level settings to control factors which affect to the uniformity of the microstructure and mechanical properties in gray cast iron is the addition of seed inoculation super ® 75, as much as 0.25% with the method of inoculation material entering into the Transfer Ladle.Teknologi produksi pada industri pengecoran di Indonesia masih membutuhkan perbaikan terutama dalam pembuatan komponen mesin perkakas dan peralatan pabrik yang terbuat dari besi tuang kelabu yang mempunyai variasi ketebalan yang besar seperti konstruksi ekor burung (dove tale). Pada pengecoran, struktur mikro dari besi tuang kelabu sangat dipengaruhi oleh kecepatan pendinginan, komposisi kimia dan proses perlakuan pada logam cair (inokulasi). Bagian yang mempunyai ukuran paling tipis mempunyai kecepatan pendinigan paling tinggi karena itu ukuran butirnya jauh lebih kecil dari bagian lain, akibatnya bagian ini mempunyai kekerasan lebih tinggi dan sulit dilakukan pengerjaan mesin. Penelitian ini bertujuan untuk memperbaiki hal ini yang terjadi pada dove taledengan cara memodifikasi proses perlakuan pada cairan besi dan proses pendinginan. Penelitian dimulai dari analisa struktur mikro, pengujian komposisi kimia, pengujian sifat mekanis pada produk kemudian dilakukan modifikasi menggunakan pendekatan metode statistik Taguchi. Hasil penelitian menunjukkan bahwa pengaturan terbaik yang dapat diperoleh untuk mendapatkan keseragaman struktur mikro dan sifat mekanis pada pengecoran besi tuang kelabu adalah penambahan seed inoculation super ® 75, sebesar 0.25% dengan metode pemasukan inokulasi kedalam Ladle pengangkut logam cair.Keywords: carbon, micro structure, hardness, inoculation

scholarly journals Effects of different returning method combined with decomposer on decomposition of organic components of straw and soil fertility

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiao Wang ◽  
Xuexin Wang ◽  
Peng Geng ◽  
Qian Yang ◽  
Kun Chen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Fertility ◽  
Decomposition Rate ◽  
Microbial Biomass Carbon ◽  
No Tillage ◽  
Short Term ◽  
Straw Decomposition ◽  
Short Period ◽  
Straw Return ◽  
Forms Of Carbon

AbstractIn view of the problems of low straw decomposition rates and reduced soil fertility in southern Liaoning, China, we investigated the effects of no-tillage mode (NT), deep loosening + deep rotary tillage mode (PT), rotary tillage mode (RT) and the addition of decomposing agent (the next is called a decomposer) (NT + S, PT + S, RT + S) on the decomposition proportion of straw, respectively, by using the nylon net bag method in combination with 365-day field plot experiments. The decomposition rules of cellulose, hemicellulose and lignin as well as the dynamics of soil organic carbon (SOC), soil microbial biomass carbon (MBC) and soil dissolved organic carbon (DOC) in straw returned to the field for 15, 35, 55, 75, 95, 145 and 365 days were analyzed. The results showed that in the short term, the decomposition of straw was better in both the rotray tillage and deep loosening + deep rotary modes than in the no-tillage mode, and the addition of decomposer significantly promoted the decomposition of straw and the release of carbon from straw, among them, the RT + S treatment had the highest straw decomposition proportion and carbon release proportion in all sampling periods. After a one year experimental cycle, the RT + S treatment showed the highest proportion of cellulose, hemicellulose and lignin decomposition with 35.49%, 84.23% and 85.50%, respectively, and soil SOC, MBC and DOC contents were also higher than the other treatments with an increase of 2.30 g kg−1, 14.22 mg kg−1 and 25.10 mg kg−1, respectively, compared to the pre-experimental soil. Our results show that in the short term, to accelerate the decomposition rate of returned straw and increase the content of various forms of carbon in soil, rotary tillage can be used to return the straw to the field, while also spraying straw decomposer on its surface. This experiment used a new straw decomposer rich in a variety of microorganisms, combined with the comparison of a variety of straw return modes, and in-depth study of straw decomposition effects of cellulose, hemicellulose and lignin. Thus, a scheme that can effectively improve the decomposition rate of straw and the content of various forms of organic carbon in soil within a short period of time was explored to provide theoretical support for the southern Liaoning.

scholarly journals Winter Wheat Straw Decomposition under Different Nitrogen Fertilizers

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 83
Author(s):  
Gabriela Mühlbachová ◽  
Pavel Růžek ◽  
Helena Kusá ◽  
Radek Vavera ◽  
Martin Káš
Keyword(s):  
Winter Wheat ◽  
Wheat Straw ◽  
Soil Surface ◽  
Weather Conditions ◽  
Mineral Nitrogen ◽  
Nitrogen Fertilizers ◽  
Pig Slurry ◽  
Straw Decomposition ◽  
Rainy Weather ◽  
N Fertilisers

The climate changes and increased drought frequency still more frequent in recent periods bring challenges to management with wheat straw remaining in the field after harvest and to its decomposition. The field experiment carried out in 2017–2019 in the Czech Republic aimed to evaluate winter wheat straw decomposition under different organic and mineral nitrogen fertilizing (urea, pig slurry and digestate with and without inhibitors of nitrification (IN)). Treatment Straw 1 with fertilizers was incorporated in soil each year the first day of experiment. The Straw 2 was placed on soil surface at the same day as Straw 1 and incorporated together with fertilizers after 3 weeks. The Straw 1 decomposition in N treatments varied between 25.8–40.1% and in controls between 21.5–33.1% in 2017–2019. The Straw 2 decomposition varied between 26.3–51.3% in N treatments and in controls between 22.4–40.6%. Higher straw decomposition in 2019 was related to more rainy weather. The drought observed mainly in 2018 led to the decrease of straw decomposition and to the highest contents of residual mineral nitrogen in soils. The limited efficiency of N fertilisers on straw decomposition under drought showed a necessity of revision of current strategy of N treatments and reduction of N doses adequately according the actual weather conditions.

Effect of Laser Shock Peening on micro-structure and mechanical properties of Friction Stir Welded CuCrZr sheets

2021 ◽  
pp. 142238
Author(s):  
Abhijit Sadhu ◽  
Sagar Sarkar ◽  
Angshuman Chattopadhyay ◽  
Omkar Mypati ◽  
Surjya K. Pal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Micro Structure ◽  
Friction Stir ◽  
Shock Peening

Diffusion-alloying sintering of Cr–Mo pre-alloyed iron powders with carbon: The effect of the carbon introduction method on the sinter’s properties

2021 ◽  
Vol 112 (1) ◽  
pp. 48-56
Author(s):  
Lubomir Anestiev ◽  
Jordan Georgiev ◽  
Seryozha Valkanov ◽  
Marcela Selecká ◽  
Sabine Cherneva ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dissolution Rate ◽  
Reasonable Assumption ◽  
Micro Structure ◽  
Iron Powders ◽  
Base Powder ◽  
Alloyed Iron ◽  
Iron Based

Abstract The influence of the carbon introduction method on the microstructure and the mechanical properties of sinters produced from iron-based powders by diffusion-alloying sintering has been studied. Two methods of carbon introduction were tested: (1) Premixing of the base powder with graphite, and (2) Coating of the base powder with a carbon-containing substance. The results obtained could be summarized as (1) The microstructure and the mechanical properties depend on the method of carbon introduction; (2) The sinters produced from coated powders possess finer micro-structure, improved homogeneity, and in two out of three of the studied compositions, better mechanical properties. Based on the results obtained, a reasonable assumption was made that the method of carbon introduction affects the dissolution rate of the carbon additive, thus affecting the micro-structure and the mechanical properties of the sinter.

scholarly journals Effect of Intercalation Structure of Organo-Modified Montmorillonite/Polylactic Acid on Wheat Straw Fiber/Polylactic Acid Composites

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 896 ◽  
Author(s):  
Qiqi Fan ◽  
Guangping Han ◽  
Wanli Cheng ◽  
Huafeng Tian ◽  
Dong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermogravimetric Analysis ◽  
Wheat Straw ◽  
Polylactic Acid ◽  
Low Cost ◽  
Interlayer Spacing ◽  
Positive Influence ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Ir Analysis

In this work, an easy way to prepare the polylactic acid (PLA)/wheat straw fiber (WSF) composite was proposed. The method involved uses either the dopamine-treated WSF or the two-step montmorillonite (MMT)-modified WSF as the filler material. In order to achieve the dispersibility and exfoliation of MMT, it was modified by 12-aminododecanoic acid using a two-step route. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to characterize the modified MMT and the coated WSF. As for the properties of PLA/WSF composites, some thermal (using Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis) and mechanical properties (flexural, tensile, and impact) were analyzed. The results showed that the dopamine was successfully coated onto the WSF. Furthermore, Na-MMT was successfully transformed to organo-montmorillonite (OMMT) and formed an exfoliated structure. In addition, a better dispersion of MMT was obtained using the two-step treatment. The interlayer spacing of modified MMT was 4.06 nm, which was 123% higher than that of the unmodified MMT. Additionally, FT-IR analysis suggested that OMMT diffused into the PLA matrix. The thermogravimetric analysis (TGA) showed that a higher thermal stability of PLA/WSF composites was obtained for the modified MMT and dopamine. The results also showed that both the dopamine treated WSF and the two-step-treated MMT exhibited a positive influence on the mechanical properties of PLA/WSF composites, especially on the tensile strength, which increased by 367% compared to the unmodified precursors. This route offers researchers a potential scheme to improve the thermal and mechanical properties of PLA/WSF composites in a low-cost way.

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