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Discrete element modelling (DEM) is widely regarded as one of the most effective methods for simulating the soil-to-tool interaction. Discrete element simulations were carried out to evaluate the performance of mouldboard plough in paddy soil. The Hertz-Mindlin bonding contact model was applied to develop the bonding between soil particles. Maximum soil draught force (3.64 N) was obtained at 15 cm depth. The force decreased from 1.98 to 1.10 N as the depth decreased from 10 cm to 5 cm. From the results, the DEM have the potential to predict cutting forces of mouldboard plough in all direction draught, vertical and side (Fx, Fy and Fz. A linear relationship was observed throughout the simulation process between working depths. It is concluded that the EDEM model has the potential to serve as a reliable tool for determining the soil-tool interaction. [ABSTRACT FROM AUTHOR]

Determination of the mechanical properties (rupture force, deformation, hardness, and toughness) of maize grain could be a significant concern for designing the harvester, thresher, and handling, processing, and storage equipment. Thus, the present research was conducted to assess the vertical and lateral rupture force, deformation, hardness, and toughness of maize grain (Beijing Denong, Lianchuang, Suyu 20, Liyu 88 and Suyu 29) influenced by different moisture contents (11.2%, 17.5%, and 21.3%) and compressive loading speeds (5, 10, 15, 20, and 25 mm/min, respectively). Besides, the mean length, width, thickness, geometric mean diameter, equivalent diameter, arithmetic diameter, sphericity, grain volume, surface area, and aspect ratio of the selected varieties were measured. The results showed that the highest length, width, thickness and sphericity, grain volume, surface area, and aspect ratio were obtained at moisture of 21.3%, whereas the lowest was at 11.2%. Moreover, it was observed that as increasing the loading speed from 5 to 25 mm/min, the vertical and lateral rupture forces decreased. However, as increasing moisture contents from 11.2% to 21.3%, the vertical and lateral rupture forces, hardness, and toughness decreased noticeably. Furthermore, the maximum correlation (R2=0.9957) between rupture force and loading speed was found for Liyu 88 at moisture of 17.5% and minimum correlation (R2=0.7002) was found for Suyu 29 at moisture of 11.2%. Moreover, the highest lateral and vertical rupture force was noticed (p<0.05) at a loading speed of 5 mm/min. Based on the experimentally obtained results, it was concluded that the properties of maize grain evaluated were relevant to the design of planter, harvesters, thrashers, and processing machine. [ABSTRACT FROM AUTHOR]

A knowledge-based fuzzy logic model was developed on experimental data and used to predict the draft, side and vertical forces and soil disturbance area by disc tillage tool operation. The laboratory research work was conducted to evaluate the performance of the disc tool at three working speeds (1.25 m/s, 1.98 m/s and 2.47 m/s, respectively) and depths (0-5 cm, 5-10 cm and 10-15 cm, respectively) on paddy soil under soil-bin environment. Further, draft (Fx), side (Fz) and vertical (Fy) forces of disc and soil disturbance area were assessed and predicted towards working speeds and depths. A fuzzy prediction model with two input variables (speed and depth) and four output variables was developed and the Mamdani inference approach was used. Draft, side and vertical forces of disc and soil disturbance area were positively responded 0.97, 0.95 and 0.84 and 0.99, respectively. The prediction results showed a close relationship between measured and predicted data. Similarly, the measured and predicted results revealed that the draft, side, vertical forces, and soil disturbance area slightly increased, while increasing the speed and depth of the disc tool. Furthermore, disc forces and soil disturbed area were highly significant (p<0.05) for higher speed towards depth. It was concluded that the fuzzy model may be introduced for predicting the disc forces and soil disturbance area during the disc tillage tool operation with high accuracy. [ABSTRACT FROM AUTHOR]

Biochar can play an important role in improving the soil health and crop yield by sequestering the soil carbon and improving the soil structure, soil fertility. An incubation trial was conducted with the hypothesis that application of maize and wheat biochar washed with hot water may affect the performance of macronutrient availability (P, K, NH4+-N, NO3-- N) and carbon fractions [soil organic carbon (SOC), microbial biomass carbon MBC] in the soil. Results indicated that washed and unwashed biochars application improved the available macronutrients (P, K), soil pH, SOC, MBC and soil cation exchange capacity (CEC) significantly compared to the control. However, washed maize- and wheat-biochars significantly reduced the ammonium and nitrate contents in the soil. The activity of urease enzyme was noticed obviously improved compared to control of the washed and unwashed biochar treatments. And no changes in the activity of invertase enzyme were found across washed and unwashed biochar treatments as compared to control. Overall, wheat and maize derived biochars with and without washing were effective in improving the macronutrients and organic carbon status of the soil. [ABSTRACT FROM AUTHOR]

The dryland region of the loss of stability is subject to developing strategies for sustainable crop production by the variation of field executive affecting soil properties and crop production. In this study, a field experiment was carried out and the effect of straw incorporation rates by different tillage implement combinations (T1= Reduced tillage at 10 cm + wheat straw incorporation rate 02 t.ha-1, T2 = Conventional tillage at depth 10 cm + straw incorporation rate 02 t.ha-1, T3 = Reduced tillage at depth 20 cm + wheat straw incorporation rate 04 t.ha-1 and T4= Conventional tillage at depth 20 + wheat straw rate 04 t.ha-1) were evaluate the pre and post harvesting physic-chemical properties, plant traits and maize yield. The results revealed that the EC and pH of soil significant decreased significantly (P<0.05) towards all treatments after the harvesting crop at depths 0-45 cm. Moreover, average organic matter and bulk density were highest improved significant towards T3 and T4 at depth 0-15 cm, while lowest at 15-30 and 30-45 cm respectively. Plant height, thousand grains weight, and crop yield was increased significantly in T3 treatment as compared to T1, T2, and T4 treatments. It is concluded that (T3) Reduced tillage at depth 20 cm + wheat straw incorporation rate 04 t.ha-1 to soil for the sustainability of the soil fertility, physico-chemical properties plant traits and maize yield under the combinations of tillage practices. [ABSTRACT FROM AUTHOR]

Mechanical shear resistance of wheat grain is a significant concern for the designers and researchers related to the design of threshing, handling and processing machinery of the field crops. The grain mechanical properties directly affect the machine geometry and its operational parameters. The present study was carried out to determine the shear resistance of five wheat varieties (Locally names; TD-02, Sindhu-1105, Benazir, China and SKD-118) influenced by moisture content (16.7%, 18.7% and 19.5%) and loading rate (3 mm/s, 6 mm/s and 9 mm/s). However, some physio-dimensional properties (length, width, thickness, slenderness ratio, surface area and sphericity) were obtained at different moisture contents. The results showed that the shear resistance reduced by increasing the moisture content and loading rate. The average shear resistance decreased from 10.45 N to 3.74 N for 3-9 mm/s loading rate at moisture content of 16.7% to 19.5%. Thus, the maximum correlation (r = 0.905) of shear resistance obtained at 16.7%, whereas minimum correlation (r = 0.692) obtained at 19.5%. The shear resistance of wheat grain was highly significant (p<0.05) at 9 mm/s for 19.5%. Shear resistance decreased with an increase in the moisture content in the grain whereas deformation is increasing with the increase of moisture content. However, the maximum bulk density of wheat grain obtained at 19.5% for SKD-118, while the minimum obtained at 16.7% for TD-02. It is recommended that the design and modification of wheat grain processing equipment should be executed on the physio-mechanical properties of grain varieties. [ABSTRACT FROM AUTHOR]

The overall objective of this paper is to analyze the long-term spatio-temporal patterns of precipitation and temperature especially under changing climatic conditions. A comprehensive study of different non-parametric trend techniques for serially correlated data were performed. Four variants of Mann Kendall, Spearmen's rho and Theil Sen's approach were utilized to quantify the significance of precipitation and temperature trends and their magnitude. Furthermore, to investigate the non-stationary behavior of these trends, Sequential Mann Kendall technique has been used. Besides, inter-annual and seasonal variations in the precipitation and temperature patterns were analyzed to understand the climatic conditions of the study area along with their spatial fluctuating characteristics. Abrupt changes in precipitation and temperature patterns were also illustrated to understand the hydrological behaviors. It is concluded that the Modified Mann Kendall technique is more reliable for trend detection of serially correlated data. The results indicated that generally no significance trend in annual and seasonal precipitation data series exist. However, for temperature except during summer, a significant increasing trend in annual and seasonal data series has been observed with a change up to 0.17 °C decade. Results of Sequential Mann Kendall indicated that change in trend for annual and seasonal precipitation except for autumn season began in 1955-1965, whereas it started in 1965-1975 for annual and seasonal temperature for majority of the study regions. [ABSTRACT FROM AUTHOR]

A fuzzy algorithm was designed for the evaluation of wheat straw mechanical properties such as shear strength, bending strength and young's modulus under influence of moisture contents and loading rates. Wheat straw mechanical properties were measured under controlled moisture contents, i.e. 9.5%, 15.1% and 22.8%, on distinguished internode positions, i.e. IN1, IN2 and IN3 (first, second and third internode, respectively), and with three loading rates, i.e. 10, 20 and 30 mm/min, respectively during year 2013. The results showed that moisture content, loading rate at various internode regions significantly (P<0.05) influenced the shear strength, bending strength and young's modulus. Shear strength (yang mai 16, verity) increased with escalating moisture content and loading rate toward third internode. Whereas bending strength and young's modulus dropped off with the raise of moisture content and loading rate in the direction of the third internode. The proposed mamdani min- max 27 rule based fuzzy model was evaluated with a sub data set from experimental results. Coefficients of determination of relationships for shear strength, bending strength and young's modulus were 0.96, 0.92 and 0.75j, respectively, indicating that the fuzzy logic algorithm for mechanical properties prediction of wheat straw could be regarded as an substitute under the selected experimental conditions. [ABSTRACT FROM AUTHOR]

Straw cover protects soil from erosion caused by wind and water. For this purpose, small amount of straw is needed be incorporation into soil. Tillage was done by disc in a soil-bin filled with paddy field soil with straw cover (100 g.m-2) at three speeds and depths to study forces acting on disc, burial straw rate of different lengths of straw (7,13, and 19 cm), soil disturbance and change in bulk density. Results showed draft, vertical and side forces of the disc increased from 533 to 1236, 243 to 632, and 418 to 1063 N. Disc tillage tool brought 47 to 86% of the straw buried in the 0-15 cm layer having smallest straw length (7cm) share of 39 % as maximum. Further soil bulk density was improved from 8.5 to 26.9 % as depth and speed was increased. Moreover, soil disturbance area was highest at 15 cm while lowest at 5 cm. Forces of disc, burial straw, soil disturbance area and bulk density were highly significantly (p<0.05) at higher speed and depth. Present research indicated that powered disc has provided constant and horizontal flow of furrow wedge to the side with more soil disturbed area. [ABSTRACT FROM AUTHOR]

The grouser height and soil conditions have a considerable influence on the tractive performance of single-track shoe. A soil bin-based research was conducted to assess the influence of grouser height on the tractive performance of single-track shoe at different moisture contents of clay loam soil. Eight moisture contents (7.5, 12, 16.7, 21.5, 26.2, 30.7, 35.8, and 38%) and three grouser heights (45, 55, and 60 mm) were comprised during this study. The tractive performance parameters of (thrust, running resistance, and traction) were determined by penetration test. A sensor-based soil bin was designed for penetration tests, which was included penetration system (AC motor, loadcell, and displacement sensor). The test results revealed that soil cohesion was decreased, and adhesion was increased after 16.7% moisture content. Soil thrust at lateral sides and bottom of grouser were increased before 16.7%, and then decreased for all the three heights but the major decrease was observed at 45 mm height. The motion resistance was linearly decreased, the more reduction was on 45 mm at 38% moisture content. The traction of the single-track shoe was decreased with a rise in moisture content, the maximum decrease was on 45 mm grouser height at 38% moisture content. It could be concluded that an off-road tracked vehicle (crawler combine harvester) with 45 mm grouser height of single-track shoe could be operated towards a moderate moisture content range (16.7–21.5%) under paddy soil for better traction. [ABSTRACT FROM AUTHOR]

The proper selection of the atomizer (droplet size) and nutrient solution spray interval is one of the most important factors to be investigated in aeroponics system for sustainable agriculture. The aim of this study was to research the effects of four aeroponics atomizing nozzles (one air-assisted; A1, two air-less; A2 and A3, and one ultrasonic fogger; A4) with droplet sizes of 11.24 µm, 26.35 µm, 17.38 µm, and 4.89 µm, respectively, four spray intervals (15 min (I1), 30 min (I2), 45 min (I3) and 60 min (I4)) at a 5 min of constant spray time by atomizing the Hoagland's nutrient solution on growth, root-to-shoot ratio, photosynthesis characteristics, pigments, and nutritional quality of the aeroponically grown lettuce. The experimental results demonstrated that in A1 atomizer and I2 interval, the growth, photosynthesis efficiency, chlorophyll, carotenoids, and nutritional values of the lettuce were significantly higher compared to that grown in A2 and A3 atomizers at all spray intervals. The shoot developments were more constrained than root, prominent to the alteration of root-to-shoot ratio (fresh and dry) in the influence of different droplet sizes and spray intervals. Moreover, the plants did not grow well in A4 atomizer associated with proposed spray intervals. The results disclosed that there was an obvious interaction between droplet sizes (atomizers) and spray intervals for growth, the ratio of root to shoot, photosynthesis efficiency, pigments, and nutritional quality of the aeroponically grown lettuce. This research study increases the awareness of the proper droplet size (atomizer) and the regulation of nutrient solution spray interval for leafy vegetables grown in an aeroponics system. [ABSTRACT FROM AUTHOR]

Precision planters are important machines in the regime of modern technological agriculture. Field conditions, seed metering system and machine operating parameters affect the pneumatic planter performance. The pneumatic planter was evaluated to determine the effect of three tillage levels (L1, L2, and L3) and four travel speeds (S1, S2*, S3 and S4). The sowing uniformity of the planter was observed with respect to the horizontal distribution of seeds within a row and described by using the precision index (Ip), the multiple index (Imult), the miss-seeding index (Imiss) and the quality of feed index (Iqf). The results revealed that the tillage levels (L) and travel speed (S) had a significant effect (p<0.05) on dependent variables. The maximum Imiss (22.12%) was observed at L1 and S4 whereas the maximum Imult was observed at L1 and S1. The mean values of missing-, multi-, quality- feed and precision indices were 5.14%, 5.833%, 89.03% and 17.85% at L3, respectively. The mean values of multi-index 17.59%, 14.44%, 12.40% and 10.18%, quality feed index 74.07%, 75.92%, 75.74% and 74.07% and precision indices 21.47%, 23.26%, 25.51% and 28.53% were at S1, S2, S3 and S4, respectively. The study showed that maize could be seeding within an acceptable precise range by bed-type pneumatic planter subjected to the proper seedbed preparation level. [ABSTRACT FROM AUTHOR]

For granular materials, discrete element modeling is one of the best computer tools to simulate their behavior and interactions. A field experiment was carried out to evaluate the performance of disc furrow openers in paddy soil. Discrete element simulation was done to develop a 3D DEM model for notched, toothed and double disc furrow openers using EDEM software. Hertz Mindlin contact model with bonding was applied for simulation to fulfill the obligations of the soil moisture and bonding between the cohesive particles. Simulated and field experimental data were compared to determine the applicability in the different working conditions. The results of the simulation validated the applicability of the Hertz-Mindlin contact model with bonding to simulate the no till paddy soil using an extremely narrow tillage tool. The calibrated value of normal and shear stiffness was 5x107 N/m, and the calibrated value of bond normal and shear strength was 3x107 Pa. The relative error (-1.7% to 20.6%) for the double disc furrow opener was lower as compared with that notch typed (29.2% to 44.4%) and toothed type (31.5% to 45.9%) furrow openers. [ABSTRACT FROM AUTHOR]

The current rapid increase in irrigation water consumption is considered unsustainable and threatens the world food production. Therefore, it is mandatory to promote modern techniques and to manage existing conventional irrigation methods. The present study was attempted to determine the effects of different irrigation frequencies and rice straw incorporation rates on yield and water productivity of the wheat crop. The experiment was arranged with randomize complete block design involving nine treatments (RS0I7, RS0I15, RS0I22, RS1I7, RS1I15, RS1I22, RS2I7, RS2I15 and RS2I22) under three replications. Results exposed that the incorporation of rice straw with different irrigation frequencies significantly improved physico-chemical properties of soil. Moreover, soil bulk density, infiltration rate, pH, electrical conductivity significantly decreased and soil porosity significantly increased under all treatments. Furthermore, maximum crop yield and crop water productivity of 7706.4 kg/hm2 and 1.92 kg/m3 respectively were found under RS1I15 treatment. Based on experimental results it can be concluded that irrigation frequency and incorporation of rice straw had significant effects on the physico-chemical properties of soil, total grain yield and water productivity of the wheat crop. However, this study suggested that the wheat crop yield and water productivity could be increased by incorporating 1 t/hm2 rice straw with 15 d of irrigation frequency. [ABSTRACT FROM AUTHOR]

Traditionally, crops are cultivated in soil-based open field systems. Seasonality, environmental degradation, urbanization, and food security issues have replaced open-field systems with modern plant production systems. Soilless culture is one of the modern plant production systems, which involves much higher use of available resources. The presented study provides information about currently accessible soilless systems and discussed the aeroponic system. Compared to other soilless systems, aeroponic reduce water usage through continuous water circulation. However, the aeroponic is not entirely implemented among local farmers, and very few farmers have adopted the system due to the lack of research and technical information available in the literature. Therefore, this study was planned to provide information about the development and maintenance tasks required for practicing the aeroponic system. This study could provide knowledge to the researchers, farmers, and those people interested in practicing the aeroponic system. [ABSTRACT FROM AUTHOR]