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Aiming at the problems of large volume and instability in agricultural hole planting machinery that requires seedling cultivation, an adjustable spacing type hole planting machinery was studied and designed,in order to better avoid the limitation of low automation when there are many kinds of existing seedling-raising hole-sowing crops, and provide a small and convenient planting machinery and equipment for farmers. Firstly, the principle and structure of the machinery was introduced and it was included by a driving module, a drilling module, seedling storage and transportation module. The power and planting needs were met by the three modules of this machinery. Secondly, the motor parameters of the planting machinery were clarified and the functions such as normal travel, adjustment of planting row spacing, adjustment of tire spacing, and remote control were achieved by the control system. Finally, according to the above design requirements, an experimental prototype of seedling-raising hole-sowing machinery with adjustable spacing was made, and the function and performance of the prototype were tested, and the planting parameters of the experimental prototype were verified. The research results show that the hole planting machine is designed with a seedling cup storage plate and a transportation mechanism, which can be used to plant seedlings of crops that require the use of seedling cups for transplantation. The planting machine has adjustable planting spacing, which solves the adaptability problem of seedlings. At the same time, the seedling hole planting machine has solved the problems of adjustable spacing between planting lines, high human resource consumption, and low planting efficiency. In addition, the seedling hole planting machine has the advantages of a wide variety of planting types, which can better adapt to the diversified planting of the fields and help promote the diversified and distinctive development of agriculture. The planting machine has maximum planting depth of 110 mm, a maximum row spacing of 1 000 mm, full load speed of 39 km/ h, and maximum planting quantity of 1 500 plants per hour with dual drill bits. The planting machine reduces planting costs and improves planting efficiency. It provides reference and guidance for the development of modern agricultural mechanization. [ABSTRACT FROM AUTHOR]

This article presents the design and development of a manual groundnut planter, specifically tailored for smallholder farmers cultivating less than two hectares of land. The planter serves as an intermediate technology between hand tools and tractor-drawn multi-row planters, addressing the financial constraints faced by a significant portion of the farming population. The planter’s design focuses on minimizing drudgery by eliminating continuous bending and standing up, ultimately improving efficiency and reducing time wastage. Key considerations during the design phase include affordability, ease of construction using locally available materials, and low technological complexity, requiring minimal training for operation and maintenance. Operational functionality involves a single-row tiller drawn type planter, utilizing a feed-in disc roller principle. Seeds are poured into the hopper, picked up by the metering plate, and introduced into the chute. The furrow opener continuously opens the soil, and the seeds fall into the furrow, simultaneously closed by the leveller. The planter achieves a continuous planting at a 30 cm intra-row spacing. The article further details the description of the groundnut planter, highlighting its components such as the handle, seed hopper, furrow opener, seed discharge tube, main body (frame), and metering roller housing. The planter’s power is derived from the rotation of the wheel, and motion is transmitted through the shaft to the metering unit. The methodology is outlined, including a flowchart illustrating the design process and the use of AutoCAD software for the 2D design. Mechanical factors considered for the planter design include uniformity of seed depth placement, distribution along rows, transverse displacement, and soil cover. Design considerations prioritize the ease of fabrication, operator safety, simplicity for small-scale farmers, and the use of locally available materials. The viability and nature of the seed, including orientation and moisture content, are also taken into account. The article concludes with a discussion on the collection of required materials, including the seed box, seed metering disc, seed transmission hose, and main frame. The presented manual groundnut planter aims to enhance the planting process for smallholder farmers, offering an affordable and efficient solution to improve agricultural practices.

Modular protein engineering is a powerful approach for fabricating high-molecular-weight assemblies and biomaterials with nanoscale precision. Herein, we address the challenge of designing an extended nanoscale filamentous architecture inspired by the central rod domain of human dystrophin, which protects sarcolemma during muscle contraction and consists of spectrin repeats composed of three-helical bundles. A module of three tandem spectrin repeats was used as a rigid building block self-assembling via coiled-coil (CC) dimer-forming peptides. CC peptides were precisely integrated to maintain the spectrin α-helix continuity in an appropriate frame to form extended nanorods. An orthogonal set of customizable CC heterodimers was harnessed for modular rigid domain association, which could be additionally regulated by metal ions and chelators. We achieved a robust assembly of rigid rods several micrometers in length, determined by atomic force microscopy and negative stain transmission electron microscopy. Furthermore, these rigid rods can serve as a scaffold for the decoration of diverse proteins or biologically active peptides along their length with adjustable spacing up to tens of nanometers, as confirmed by the DNA-PAINT super-resolution microscopy. This demonstrates the potential of modular bottom-up protein engineering and tunable CCs for the fabrication of functionalized protein biomaterials.

In order to eliminate the plug stem phenomenon and reduce the transmission power consumption of the self-developed integrated tobacco stalk pull-out crusher transmission mechanism when the culms are pulled out at high speed in the field, based on the analysis of the reasons of plug stem, a new rubber-type roller pair transmission mechanism with easy disassembly and adjustable spacing was designed. Through the force analysis, the mathematical model of the force, deformation and transmission power of the tobacco stalk during the extrusion and transportation phase was obtained, and the test platform of the tobacco stalk pull-out crusher transmission mechanism was built to carry out the orthogonal rotation combination test. The test results show that the optimal working parameter combination within the range of test factors is: the roller speed is 530 r/min, the II pair of roller spacing is 90 mm, the III pair of roller spacing is 30 mm, and the tobacco stalk feeding rate is 1.5 s/n. At this time, the plugging rate of stem is 2.22%, the transmission power consumption is 645 W, and the actual average leak stalk rate obtained by repeating 10 tests under this parameter is 3.33%, and the actual transmission power consumption is 684 W, the actual plugging rate of stem and transmission power are basically consistent with the optimized values, indicating that the improved design structure is reasonable, and the established regression model is basically reliable.

Rice production is distributed broadly in China. The rice growing environment conditions are different in different regions, so there is large difference in rice transplanting spacing. Even in the same growing area, the rice transplanting density and the planting spacing are different due to the difference of the transplanting rice species and the growing conditions. The wide-narrow row planting is beneficial to the field management, which can effectively use the field marginal effects, improve the performance of air and light, and enhance the plant photosynthesis. The microclimate in the field is changed to reduce the humidity between plants, and the pests and diseases of rice. Considering the diversity of rice species and the conditions of soil, water and fertilizer, the conventional transplanter which had fixed row spacing, including the constant row spacing transplanter and the wide-narrow row spacing transplanter, could not meet the rice spacing requirements and caused the low adaptability and the low efficiency. For overcoming above shortcomings together with considering the quality of mechanized transplanting and the agronomic requirements of rice, a spacing-adjustable wide-narrow row high speed rice transplanter, which could transplant the rice seedlings with wide row spacing of 300 mm and adjustable narrow row spacing in the range of 200-300 mm, was designed creatively by using the technology of multi-body dynamics, multidisciplinary design optimization, virtual prototyping and simulation. The force analysis of seeding box, supporting beam and screw shaft was carried out to achieve their reasonable structures. The transplanting spacing of this machine was adjustable according to the requirements of specific rice planting density. The machine could meet the agronomic requirements of rice planting spacing in the different regions, and achieved the full potential of individual strain and rice population and improved the adaptation scope and use efficiency. The rice tranplanter was developed based on the Kubota SPU68C high speed rice transplanter. The key structural parameters of the machine were determined according to the adjustable spacing performance requirements. A coaxial forward and reverse double-helix adjusting mechanism, an eccentric locking mechanism, a separable combination seeding box and other key parts were designed and manufactured. According to the agronomic requirements of mechanized transplanting technology for different rice species, the single cropping mid-season rice species Xinliangyou 98 and the double cropping late rice species Zhendao 18 were chosen as test materials, the field experiments were carried out with the prototype of spacing-adjustable wide-narrow row high speed rice transplanter, and the transplanting seedling quality and the machine performance were studied. Field test results showed that the machine performance was pretty good, the damaged rate of seedling was less than 2.5%, the leakage transplanting rate was less than 3%, the qualified rate of relative uniformity degree was more than 96%, the floating rate of seedling was less than 2.5%, the overturning rate of seedling was less than 2.5%, and the acceptance rate of planting depth was more than 92%, which met the Criteria of Rice Transplanter Technical Conditions (GB/T 20864-2007). The good actual yield results were also achieved with planting the single cropping mid-season rice species Xinliangyou 98 with wide row spacing of 300 mm and narrow row spacing of 250 mm, and the double cropping late rice species Zhendao 18 with wide row spacing of 300 mm and narrow row spacing of 200 mm. The effect of transplanting spacing on the yield of the double cropping late rice is larger than that on the single cropping mid-season rice. The machine has changed the conventional mechanical rice transplanting method. It meets the actual rice production requirements in different regions, effectively solves the problems of the transplanter with fixed spacing which is difficult to meet the diversity of rice species and growing environments, improves the adaptability and the efficiency of machine, and raises the productivity and the mechanization level of rice production. [ABSTRACT FROM AUTHOR]