Search

Rotary tillage facilitates conservation agriculture in rice-based crop farming systems through minimal soil disturbance for seedbed preparation and crop residue management. However, efficiency of rotary tiller blades is hampered by degraded paddy soils and excessive crop residue conditions. Biomimetics presents an edge in the optimisation design of cultivation tools and can be employed to improve the efficiency of rotary tiller blades. This study was designed to evaluate the adaptability and performance of biomimetic rotary tiller blades inspired by the geometric structure of a mole rat’s claw. Field experiments were conducted to evaluate the blades’ torque and power requirements, soil fragmentation, displacement characteristics, and the rate of straw incorporation at three tillage depths (i.e., 40, 70, and 100 mm). Results revealed that the biomimetic blades minimised torque by up to 21.05%, had lower specific power requirements, and produced finer tilths with granular and more even clod sizes than conventional blades. It also achieved more redistribution of topsoil and improved the straw burial rate. The biomimetic rotary tiller blades are thus energy-efficient and can improve soil structure and the quality of seedbeds, besides managing crop residues through incorporation, and therefore advance conservation tillage in intensive farming systems.

HighlightsA whole-process experiment was done to incorporate both machine and peanut properties.Wetting and drying control for unbalanced moisture contents improved shelling performance.A Box-Behnken design and response surface method were used for system optimization on the small sheller.Unbalanced moisture contents resolved the controversial response between MDR and SE.System optimization quantified the optimum combination of moisture, drying time, and speed.Abstract. Improvement of peanut shelling performance for smallholders is challenging due to the numerous influential factors involved with both machinery and peanut properties. A Box-Behnken design (BBD) and response surface method (RSM) were used to simplify the experimental investigations. Sequential laboratory observations were made on wetting-and-drying pretreatments, single-factor tests, multiple-factor couplings, modeling and significance analysis, response surface analysis, and system optimization. Results showed that wetting-and-drying pretreatment can effectively mediate the physical properties of peanut pods for unbalanced moisture contents between the peanut shell and kernel, contributing to improved mechanical damage rate (MDR) and shelling efficiency (SE). Statistical analysis of MDR and SE models identified the rated effects as: moisture content (MC) > cylinder speed (CS) > drying time (DT) for MDR, and DT > CS > MC for SE. The coupling effects among the variables were: MC × CS > MC × DT > DT × CS for MDR, and DT × CS > MC × DT > MC × CS for SE. System optimization with RSM provided the optimal combination as MC = 11.63%, DT = 26.87 min, and CS = 234.78 rpm. This combination resulted in a minimum MDR of 3.94% and a maximum SE of 97.17%. The optimized results were evaluated in production trials, revealing the mean values of MDR and SE as 4.18% and 93.87%, respectively. It is suggested that a suitable wetting-and-drying pretreatment can be a powerful means to enhance the shelling performance of small shellers. Keywords: Mechanical damage rate, Optimization, Peanut, Response surface method, Shelling efficiency.

As an advanced agricultural production technology, conservation tillage has been developed rapidly and adopted widely for many crops all over the world, but challenges remain with regard to dealing with excessive residues, especially for intensive rice–wheat rotation systems. Most studies to date have been based on a single type of tool and the indoor bin test to explore its performance. Accurate field test data on the tillage performance of different types of tools for conservation tillage are lacking in this area. In this study, five tillage tools were tested in a paddy field with plenty of crop residues to compare their performance. They were three vertical discs with plain disc (PD), notched disc (ND), and rippled disc (RD) and two disc coulters with plain disc coulter (PDC) and notched disc coulter (NDC). All five tools were tested using a specific field test rig at two different working depths of 70 and 100 mm. Tillage forces, straw cutting efficiency, soil disturbance width, and soil cutting depth were measured. The results showed that tool geometry and working depth had a significant impact on tillage performance. The vertical disc performed a higher average straw cutting efficiency, as well as lower tillage forces and lower soil disturbance width than the disc coulter. For straw handling and furrowing operations, RD had the highest straw cutting efficiency, moderate tillage force, and appropriate soil disturbance width among the five tools. For all five tools, the 100 mm working depth results in 40% higher draught force, 39% greater vertical force, and 18% higher straw cutting efficiency on average. For no-tillage seeding in the intensive rice–wheat rotation system, the RD would be a more suitable rotary tool for conservation tillage practice.

The management of crop residues together with compacted soil under intensive farming systems requires highly efficient and well-adapted tools. The performance assessment of such tools requires proper definition of their technical designs as well as the tool-induced soil-straw dynamic interactions. Few studies have characterized the performance of toothed discs based on their design considerations and mechanical responses. This study evaluated the tillage forces, structural strength, straw-cutting performance, and tillage-depth uniformity of a curved-edged toothed disc in comparison to a straight-edged toothed disc. The design of the curved-toothed disc was inspired by the arc-shaped structure of the mole-rat's claw. 3D finite element analysis (FEA) was used to simulate the discs’ interactions with soil and straw. Field experiments were conducted to validate the FEA results. It was revealed that the curved disc reduced the tillage forces by up to 22.8%, and significantly reduced the stresses on the tool. The disc also achieved uniform tillage depths and improved the straw-cutting efficacy by up to 26.31%. Bionic curved cutting-profiles on toothed discs thus provide a structurally enhanced, energy-efficient option for effectively managing crop residues and improving seeding performance in no-till conservation farming.

High-yielding agriculture leads to plenty of residues left in the field after harvest, which not only makes seeding operations difficult, but also decreases residue decomposition rate. Thus, it is necessary to incorporate some residue into the soil by tillage operations. Providing the relation between tillage operations and residue incorporation, and establishing a mathematical model plays an important role in residue management and the design of tillage machinery. In order to obtain detailed data on the interaction between crop residue and tillage operations, an electric and multi-functional field testing bench with precise parameter control was developed to perform residue incorporation characteristics of rotary tillage, and investigated straw length, rotary speed and stubble height effect on the dispersion and burying of residue. Three experimental factors affecting residue incorporation performance were studied, i.e. six lengths of straw (30-150 mm), four heights of stubble (50-200 mm), and three rotary speeds (240-320 rpm). Chopped straw and stubble with certain sizes were prepared for the test, and measure the dispersion uniformity and burying rate of residue after rotary tillage. The results indicated that straw length, stubble height, and rotary speed all impact residue incorporation quality. The dispersion uniformity and burying rate of residue decreased with the increase of straw length and stubble height; Lower rotary speed parameter buried lesser residue and dispersed worse uniformity than higher one; It is suggested that farmers determine the straw length and stubble height at the stage of harvest according to the burying rate and dispersion uniformity of residue.

Agricultural production can achieve sustainability by appropriately applying agricultural mechanization, especially in developing countries where smallholding farmers lack sufficient agricultural machinery for their farming operations. This paper aimed to study the extent to which small-, medium-, and large-scale farms in the Delta of Egypt use agricultural mechanization in their wheat crop farming operations. K-means clustering was used to aggregate and analyze the scenarios implemented by farmers for wheat cultivation so as to suggest guidelines for each cluster of farmers on how to mechanize their indoor wheat agricultural operations to maximize production. The study is divided into two parts: Firstly, data were collected regarding the percentage of small, medium, and large farms; the cultivated area of wheat crops in small-, medium-, and large-scale farms; and the size of tractors, as an indicator of the mechanization available in the governorates of Egypt’s Delta. Secondly, data were collected through a questionnaire survey of 2652 smallholding farmers, 328 medium-holding farmers, and 354 large-holding farmers from Egypt’s Delta governorates. Based on the surveyed data, 14, 14, and 12 scenarios (indexes) were established for small-, medium-, and large-scale farms, respectively, related to various agricultural operations involved in wheat crop production. These scenarios were analyzed based on the centroids using K-means clustering. The identified scenarios were divided into three clusters for the three levels of farms. The data obtained showed the need for smallholding farmers to implement mechanization, which could be achieved through renting services. These findings, if implemented, would have huge social and economic effects on farmers’ lives, in addition to increasing production, saving time and effort, and reducing dependence on labor.

Field-based phenotyping (FBP) of crop root system architecture (RSA) provides a way to quantify the root growth and distribution in field with a smaller scale. Studies on a better understanding of the interrelations between field crop root physiological traits, root developmental phases and environmental changes are hindered due to deficiency of in situ root system architecture testing and quantitative methods for field crop. The present study aimed to propose a protocol for field-based wheat root system architecture with technical details of key operational procedures. Phenotyping of RSA traits from root spatial coordinate data acquisition and visualization software presented scaled illustrations of wheat RSA dynamics and root developmental phases which also revealed the root topological heterogeneities, either within a plant or among individuals. Percentage of horizontal and vertical soil coverage by root showed that root foraging capability along soil depth was better than within the horizontal dimension. In brief, our data indicated that FBP of wheat RSA could be achieved using the protocol of data-driven model-assisted phenotyping procedure. The proposed protocol was demonstrated useful for FBP of RSAs. It was proved effective to illustrate the topological structures of the wheat root system and to quantify RSA-derived parameters, this could be a useful tool for characterizing and analyzing the structural distortion, heterogeneous distribution and the soil space exploration characteristics of wheat root. Keywords: Field-based phenotyping (FPB), Data-driven model-assisted, Paddy-wheat root system architecture, FBP protocol

A method consisting of soil core with undisturbed sample of root architecture, digitizer and commercial software was developed to visualize wheat root system architecture (RSA) in a field experiment. At first, root-zone soil was excavated and wheat RSA was digitized in every 5-mm-thick soil layers. By then, the 3D root morphological data were re-integrated by Pro-E software, where 3D models of wheat RSAs could be reconstructed, scaled and calculated. Results revealed markedly distorted morphological structures of wheat axial roots in both curvature and helical morphology. Scaled RSA models also revealed severe restrictions on overall RSAs, illustrating the intense constraint of root topology by the heterogeneous environment. Time-series presentation of RSAs clearly displayed the fine structural details of root morphological dynamics, indicating that a high accuracy of data had been achieved for field crop physiology. Laminated digitization combined with Pro-E modelling was featured as a deterministic, data-driven and model-assisted procedure, which was particularly suitable for crop RSAs in field. Wheat RSA dynamics and temporal variations of 3D root topology illustration could be realized by undisturbed sampling, digitizing and modelling method for field-state crops with fine and fibrous root systems. It had potential to provide a means of illustrating the influence of anisotropy of the soil environment.

High-yielding agriculture in an intensive rice–wheat rotation system leads to plenty of residues left in the field after harvest, which is detrimental to seeding operation, seed germination, and early plant growth. Some residue thus needs to be incorporated into the soil. Providing the relationship between tillage operations and residue incorporation and establishing a mathematical model play important roles in residue management and the design of tillage machinery. In order to obtain detailed data on the interaction between residue incorporation and tillage operations, a multifunctional field-testing bench with precise parameter control was developed to assess residue incorporation characteristics of rotary tillage, and we investigated the effects of straw length, stubble height and rotary speed on residue incorporation. Three experimental factors affecting residue incorporation performance were studied, i.e., six lengths of straw (30–150 mm), four heights of stubble (50–200 mm), and three rotary speeds (240–320 rpm). Chopped straw and stubble with certain sizes were prepared for the test, and we measured the burying rate and distribution uniformity of residue after rotary tillage. The results indicated that straw length, stubble height, and rotary speed all impact residue incorporation quality. The burying rate and distribution uniformity of residue decreased with the increase in straw length and stubble height; a lower rotary speed parameter buried less residue and distributed it with worse uniformity than a higher one. It is suggested that farmers determine the straw length and stubble height at the stage of harvest according to the required burying rate and distribution uniformity of residue.

High-yielding agriculture leads to dense straw cover (mulching). Soil-engaging tools for conservation tillage in these scenarios demand enhanced tool performance, e.g., improved soil penetration, reduced force requirement, better straw cutting and minimised soil disturbance. These interdependent and yet conflicting performances could not be easily realised with traditional tillage tools. Instead, biomimetic tool design could provide a compromised solution. A biomimetic disc mimicking the mole-rat’s claw was fabricated and evaluated in comparison with traditional discs (i.e. a plain and a notched disc) in straw-mulched soil. Soil bin tests on the 3 discs were conducted at 3 tillage depths (i.e. 40, 70 and 100 mm). Results showed that the biomimetic disc achieved 21.4 % reduction in vertical resistance and 28.7 % reduction in draught forces, as compared with the notched disc (P

Predicting soil stress with analytical models requires proper selection of the models’ concentration factor. But due to the insufficient knowledge about the effects of soil conditions on stress transmission, little is known about how the concentration factor varies with soil states and loading conditions. Thus there is a need to supply specifically defined parameters with clearer physical meanings for soil stress transmission while easily being measured with simple laboratory setups. The function of the concentration factor was transformed and a dimensionless factor standing for soil-induced attenuation on the stress transmission between two points, ( σ 0 - σ z )/ σ 0 , was derived, which complement, σ z / σ 0 , is the soil stress transmission coefficient and is denoted as STC. Since soil stress transmission property is affected by soil states and loading conditions, a modified oedometer testing setup with a soil stress sensor was used to evaluate controlled soil properties on STCs. Totally 15 soil states were tested by controlling 5 soil water contents and 3 bulk densities. Correlation analysis were performed between measured STCs and soil state parameters, i.e. water content, bulk density and soil strength. The concentration factor was then back-calculated from the acquired STCs. The highly linear correlation between soil stress and applied surface stress indicates a stable STC for each particular soil state, suggesting that the theoretically derived STC could be used as a specific mechanical property to quantify soil stress transmission. In general, a high soil water content leads to an increased STC, meaning that wetter soils are more effective in transmitting the stress to deeper places. STC was also found both linearly decreased with dry bulk density and precompression stress. A higher soil strength imposes an improved shielding effect on soil stress transmission. The back-calculation of concentration factor from measured STCs illustrates that the proposed solution for soil stress transmission provides a means to define concentration factor for each soil state with measured result. Concentration factor varied from 2.64 to 12.39, being in agreement with the past reports. But the detail of how the concentration factor is affected by the changed states of soils is provided.

Using organic fertilizer or soil amendment such as humic substances is an important component for sustainable agriculture. The objective of this study was to determine the effects of different factions of humic acids (HAs) on corn seedling growth and nutrient uptake. The experiment was carried out with both an agar culture in root boxes and a hydroponic culture to which 400 mg/L of different factions of humus acids, mixed HAs, and raw Leonardite were added. The experiments were repeated twice with three replications for each treatment. The results showed that applications of HAs significantly improved the leaf and root growth of corn seedlings compared with the control (no HA addition). In the agar culture, seedlings treated with HAs with relatively low molecular weights had more leaves and twice long of roots compared to control and other treatments. In the hydroponic culture, the mixture of three factions was the best treatment for both shoot and root growth of seedlings.

Understanding chemistry and the effects of humic substances on plant growth is important for using organic fertilizer or soil amendment for sustainable snap bean production. The objective of this study was to characterize different fractions of humic acid (HA) derived from Leonardite and evaluate their effects on seedling growth and nutrient uptake of snap bean (Phaseolus vulgaris L.). HAs extracted from Leonardite were separated based on molecular weights into three fractions (HS1, HS2, HS3) plus sediment (SED). With direct polarization combined with spectral editing techniques, functional groups of HAs were quantified and the results indicated that HAs with low molecular weights had more O-alkyl and carboxyl C groups than those with large molecular sizes. A plant growth experiment was conducted as a randomized split-plot design with three replications and repeated for three plantings. The results show that addition of HAs was beneficial to leaf and root growth of snap bean compared with the cont...

A minimum amount of straw is still needed to protect soil from wind and water erosion. To better understand the soil protection effect of straw, the relation of wheat straw displacement and its burial status with plowing speed, tillage depth and the attachment of trash-board was studied. Three controlling factors were evaluated in a field tillage testing, i.e., two types of plow (with and without trash-board), three lengths of straw (100 mm, 150 mm, and 250 mm), and various straw conditions. Straw pieces with specific lengths were prepared before the experiment and used as point tracers to measure the soil and straw displacement. The results indicated that the soil and straw displacements were significantly different but that the two were interrelated. As the length of straw increased, the soil displacement decreased due to the forward and lateral displacements; the straw displacement was always significantly larger than soil displacement, independent of the straw mixtures. Attachment of a trash-board reduced the soil displacement, but had no apparent effect on the straw displacement. Longer straws were less effective to be incorporated into the soil than the shorter ones, and the presence of a trash-board led to higher straw burial performance. The results also indicated that low tillage speed resulted in larger soil fragments and straw displacement with more straw buried. Moreover, longer straw was less effectively buried than shorter straw at the same speed. However, straws neighboring the shear were more extensively displaced than those nearby the share bottom.

An important aspect of below-ground crop physiology is its root foraging performance, which is inherently related to root system architecture (RSA). A 2-yr field experiment was conducted and the field-state wheat RSA was phenotyped for root foraging trait (RFT). Four RSA-derived traits, i.e. Root horizontal angle (RHA), axial root expansion volume (AREV), RSA convex hull volume (CHV) and effective volume per unit root length (EVURL), were analyzed for RFTs in response to environment × management interactions. Results showed a dynamical RHA process but without statistical difference both within crop seasons and tillage treatments. AREV increased with root developmental stages, revealing an overall better root performance in the first year. However, tillage treatments did not induce observed difference within both crop seasons. CHV varied drastically from year to year and between tillage treatments, correlating well to the root length, but not with RHA. EVURL was both sensitive to tillage treatments and crop seasons, being a potential indicator for RFT. Above all, tillage effect on RFT was statistically far less than that induced by crop seasons. Pro/E assisted modeling can be used as an effective means for phenotyping integrated, RSA-derived, RFTs for root foraging response to induced environment × management interactions.

Draught requirement is an important parameter for tillage tool performances. This study investigated the influence of trash board on the performance of moldboard plough and the system optimization. Draught and vertical forces acting on the plough were measured with and without a trash board under two straw conditions, i.e. with only stubbles and with dense straw cover. Field soil moisture content was kept at 30%. The study also used the finite element method (FEM) to simulate stress distribution on the plough. Results showed that draught significantly increased without trash board under dense straw cover as compared with only stubbles. The trash board attachment reduced draught significantly. Similar trend was also true for vertical force. FEM results were found to be compatible with the experiment. The simulated maximum equivalent stress acting on the mouldboard plough was 279.43 MPa, while the material’s yield stress was 250 MPa. Attaching trash board with the moldboard plough is important where straw cover was dense.

Soil failure patterns play an important role in obtaining a better understanding of the mechanical behavior of soils. Despite the large number of studies over the past few decades, a better understanding of soil failure patterns and its relation to soil and tool parameters for particular soils such as dry land and paddy has not been developed. This study investigated soil failure patterns and related draft at sticky, plastic and liquid consistency limits and the sticky point of dry land and paddy soils. A soil cutting test rig was developed to perform soil cutting at three consistency limits (sticky limit, plastic limit and liquid limit) and the sticky point of soil, three rake angles (15°, 30° and 45°), and three operating depths (30 mm, 50 mm and 70 mm). A flat triangular shaped tool operating at a constant speed of 10 mm s−1 was used in all experiments. Soil failure patterns were observed and recorded using a digital camera, and draft per unit displacement was measured by load cells attached to the soil bin. A direct relationship between soil failure patterns or draft and the consistency limits of soil was found. Brittle failure was obtained at the sticky limit, chip forming failure was observed at 15° rake angle and 30 mm depth, and bending failure with little strains of elements at 30° and 45° rake angles and 50 mm and 70 mm depths at plastic limit, while flow failure was linked to the liquid limit of the soil. At the sticky point, flow failure was observed at an operating depth of 30 mm and 15° rake angle, while flow with considerable bending and no strains of elements occurred at 50 mm and 70 mm operating depths and 30° and 45° rake angles. However, bending was more prominent at 70 mm depth and 45° rake angle. The draft at the sticky limit, plastic limit and sticky point was cyclic in nature, whereas at the liquid limit it was comparatively diverse and fading. The highest draft was found at the plastic limit, and the lowest at the liquid limit. Since the soil failure patterns may change with moisture content, soil type and particle size distribution within the same textural class, consistency limits can provide clearer and more accurate definitions of soil failure patterns than moisture content levels alone.

We investigated a method to quantify field-state wheat RSA in a phenotyping way, depicting the 3D topology of wheat RSA in 14d periods. The phenotyping procedure, proposed for understanding the spatio-temporal variations of root-soil interaction and the RSA dynamics in the field, is realized with a set of indices of mm scale precision, illustrating the gradients of both wheat root angle and elongation rate along soil depth, as well as the foraging potential along the side directions. The 70d was identified as the shifting point distinguishing the linear root length elongation from power-law development. Root vertical angle in the 40 mm surface soil layer was the largest, but steadily decreased along the soil depth. After 98d, larger root vertical angle appeared in the deep soil layers. PAC revealed a stable root foraging potential in the 0–70d period, which increased rapidly afterwards (70–112d). Root foraging potential, explained by MaxW/MaxD ratio, revealed an enhanced gravitropism in 14d period. No-till post-paddy wheat RLD decreased exponentially in both depth and circular directions, with 90% roots concentrated within the top 20 cm soil layer. RER along soil depth was either positive or negative, depending on specific soil layers and the sampling time.

A laboratory rig was developed for a scale- and energy-controlled tender soil fragmentation test, which required multiple impacts and step-by-step decomposition of the soil structure on a macroscale. Soil sample size classes were scaled down by a factor of two, giving ranges of 128, 64, 32, 16, 8, 4, 2, 1, and 0.5 mm, respectively. These size classes were also used as control scales for respective fragmentation stages. Fragmentation tests were conducted to illustrate the possible influences from shape effects, falling weights, displacements, and fragmentation stages, and to investigate the relations among specific fragmentation energy, number of strokes per fragmentation stage, and fragmentation fractal dimension. Specific fragmentation energy was influenced by both the size and the shape of the soil samples. The cylindrical- and ball-shaped soil samples behaved similarly. Thus ball samples were used for a benchmarking test on soil structural stabilities. Subsequent fragmentation on 60- and 80-g ball samples with changed displacements from 5 to 45 cm yielded a decreased number of strokes from around 150 to 10. Whereas, their respective fragmentation fractal dimensions varied insignificantly, ranging from 1.52 to 1.64 for samples of 60-g mass and 1.55 to 1.72 for 80 g, values much smaller than previously reported. Fragmentation fractal dimension appeared to be a nominal index for remolded soils under laboratory impacting actions. There was a slight increase in specific fragmentation energy as the number of impacts increased. But this increase was aggravated for a single or only few impacts. Thus 20 to 40 strokes was the appropriate stroke number to finish one fragmentation stage. A five-stage fragmentation on a sample in the 32- to 64-mm size range yielded fragmentation fractal dimensions of 1.29, 1.52, 1.45 and 1.61, for the first four stages, respectively, whereas their specific fragmentation energies increased linearly.

A laboratory test following a field experiment was conducted to investigate the performance of stress wavelets as a tool for soil structure quantification. Based on the test, comprehensive calculations of indices were performed, including per fragment surface contacting energy, fragment fractal dimensions and specific fragmentation energies. Fragment fractal dimensions were 2.46 for autumn-tilled soil and 1.86 for spring-tilled, showing the improvement of soil structure from winter process, mainly from statistical point. Specific fragmentation energy ranged from 78.72 to 1135.44 J/kg, depending both on the way of field treatment and initial size ranges of soil been fragmented. Compared with these, stress wavelets analysis was capable of distinguishing, specifically from mechanical points, differences between autumn-tilled and spring-tilled soils. Results shown that fractal dimensions provided information on soil fragment size distributions, bearing no significance on soil mechanical properties. Stress wavelets, on the other hand, permitted calculations of specific fragmentation energy and per fragment surface contacting energy, which had a uniquely straight-forward connection with soil mechanical properties. The low per fragment contacting energies possessed by autumn-tilled soil, as compared with spring-tilled soil, indicated that winter process reduced soil contacting energies significantly. But a negative value of per fragment contacting energy for autumn-tilled soil was un-interpretable. The combination of stress wavelets and fractals may serve as a fundamental quantitative index for modeling soil structures in its thorough dimensions. The difference between autumn-tilled and spring-tilled soils also indicated that tillage alone should not be taken as a sole way for the improvement of soil qualities.

Stress wavelet properties are inherently involved in the process of the drop-shatter method of assessment on soil structural characteristics. The analogies between wavelet analysis and the drop-shatter process are based on two factors: scale and resolution. By carefully following the requirements of wavelet analysis, a standard procedure of soil fragmentation and sieving is described. Following this procedure, a set of equations can be derived from which surface contacting energy between soil aggregates of a specific scale can be calculated. The resultant values in fact mirror the multi-resolutions of wavelets. Natural soil clods as well as artificial structured soil cores were used for fragmentation. Though the experiment can do well on natural soil clods, and it is precise enough in predicting structural state of a sub-dimensional clods of 8 mm, its use on artificial soil cores produced a set of data that was quite chaotic. The unique behavior experienced in the process of fragmentation of artificial soil structure indicates that there is no distinct stage between mother soil clods (cores) and its constituent primary particles. Such a state should result from an excessively large impact energy (too low a resolution in the wavelet analysis) for each drop stroke impact. With an ultimate goal for soil process simulation, the construction of the experiment for artificial structured soil core preparation brings the traditional methods of sample preparation a step forward further by creating an environment much nearer to the field conditions experienced in natural soils. Still, extensive refinements are needed, especially for the mode of water application, cycle and intensity of management.

Social and economic development in Jiangsu of China requires increased energy supplies. The total energy used was 81.0 MTce in 1995 and about 80% of it is coal. The energy demand per 10 000 yuan GNP was 2.45 Tce. Jiangsu has become one of the most severely polluted provinces in China and should well consider the pollution caused by energy using. Low polluted energy supplies as a strategy are discussed.

A route detecting algorithm was proposed for the cucumber picking robot navigation in greenhouse environment. Possible navigation route was determined from the additive value of the column scanning results. Color difference between cucumber plants and the mid row soil was analyzed through combining the RGB elements segregations with extra-green (ExG) value and extra-red (ExR) value. The obtained gray image was segmented with OTSU threshold method, which made the gray-color abruptly changed pixels along the two sides of the central line identified. Mean value of these selected pixels in each line was calculated to provide the discrete points along the navigation route. Finally least square method was used to fit these discrete points to provide the navigation lines, from which, the route for current navigation scheme can be determined. The proposed algorithm was applied to multiple images for its high speed and anti-noise verification.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.