Study on a Bowl-based Mechanism for Transplanting Potted Strawberry Seedlings

To improve the efficiency of fetching and transplanting seedlings for the mechanization of strawberry planting,an integrated transplanting mechanism was designed with protruding,fetching and planting performance to achieve rapid fetching and pushing bowl movements.According to the working principle of the slewing mechanism,a kinematics model and the optimization goal were established,respectively.Based on visual auxiliary analysis software,optimal parameters were obtained.A three-dimensional model was established to obtain a simulation trajectory by means of a virtual simulation design analysis.Three-dimensional printing technology was used to manufacture the test prototype,and the actual working trajectories of the test prototype were extracted using high-speed photography technology,which verified the consistency of the actual trajectory with the theoretical and simulated trajectories.A prototype transplanting experiment was performed with the success rate of seedling extraction of 91.2%and excellent planting rate of 82.8%,which met the requirements for integrated strawberry harvesting,planting and transplanting.The experimental results verified the correctness and feasibility of the design of integrated transplanting mechanism.

Growth and yield of rice as affected by transplanting dates and seedlings per hill under high temperature of Dera Ismail Khan, Pakistan

Studies were initiated for two consecutive years to find out the effect of time of transplanting and seedlings hill?1 on the productivity of rice in Dera Ismail Khan district of North West Frontier Province (NWFP), Pakistan. The experiment was laid out in a randomized complete block design with split plot arrangements. Main plots consisted of four transplanting dates viz. 20th and 27th of June and 4th and 11th of July while sub-plots contained 1, 2, 3 or 4 seedlings hill?1. Among transplanting dates, June 20th planted crop gave highest paddy yield and net return with 1 seedling hill–1. It explains that the use of more seedlings hill?1 not only adds to cost but is also a mere wastage of natural resources. Based on research findings, we conclude that the use of 1 seedling hill?1 is most appropriate for timely sowing otherwise 4 seedlings hill–1 should be used to compensate for the yield gap in late transplanted rice.

Contrast Test Between Direct Seeding and Seedling Transplanting of Diwangcai

To improve the yield of Diwangcai and explore its best cultivation way,direct seeding and seedling transplanting of Diwangcai were contrasted. The results showed that cumulative annual yield of Diwangcai by seedling transplanting was 16% higher than that by direct seeding.

Overlapped Tray Seedling Raising Model for Mechanical Transplanting of Rice

With the development of China's social economy,transfer of rural labors,and rise of labor costs,the rice production technologies are changing from manual operation to mechanical operation.The core of mechanical rice production is mechanical planting,while the key to mechanical planting is the seedling raising.On the basis of analyzing and studying the problems and experience of traditional mechanical transplanting of rice,a new overlapped tray seedling raising model was introduced.Main features of this model: substrate seedling raising and overlapped seedling tray.The seedling trays for seeding line are overlapped,and the overlapped trays are moved into the seedling room with controlled temperature and humidity.The temperature of the seedling room is controlled at 30-32℃,and the humidity of the seedling room is controlled at above 90%.After about 48 h,when the seedling height reaches 0.5 cm,move the seedling trays to the nursery.This model consists of one seeding center( seedling raising center) and N nurseries,to realize 1 + N seedling raising for mechanical transplanting of rice.One seeding center can provide seedlings for several hundred to several thousand hectares of mechanical transplanting of rice,and provide a new model for social services.This model could improve the quality of seedlings,increase the seedling survival rate by about 20%,reduce the seedling raising costs by 15%-20%,reduce the seedling raising risks,and greatly increase the utilization rate of the site and equipment of seedling raising center.

Effects of soilless substrates on seedling quality and the growth of transplanted super japonica rice

This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings （HLMS） on seedling quality and field growth characteristics of transplanted super japonica rice. A widely grown conventional super japonica rice cultivar （Wuyunjing 23） was selected as the test material. The effect of HLMS on seedling quality, mechanical transplantation quality, field growth characteristics, yield, and benefit-cost ratio were compared with seedlings grown in organic substrates and traditional nutritive soil, whJch was selected as the control. Root number, root twJstJng power and root activity of seedlings cultivated by HLMS were decreased compared to that of the organic substrates andcontrol. However, seedling root length as well as aboveground growth were increased compared to the organic substrates and control seed- lings. In the HLMS, the content of gibberellin acid （GA3） decreased while abscisic acid （ABA） content increased compared to that of the organic substrates and control seedlings. During the early stages after transplanting, the re-greening of HLMS was delayed compared to that of the organic substrates and control seedlings. Nevertheless, there were no significant differences in tiller dynamics and crop yield among the HLMS, organic substrates and control treatments. The effects of HLMS on seedling production were similar to those of the organic substrates and traditional nutritive soil in the present study, suggesting that HLMS have the potential to replace traditional nutritive soil in seedling production without decreasing crop yield. Finally, it is important to reduce organic substrates and topsoil dependence during rice seedling production and worthwhile to consider HLMS popularization and its application on a larger scale.

Why high grain yield can be achieved in single seedling machine-transplanted hybrid rice under dense planting conditions?

This study was conducted to identify the factors associated with high grain yield in single seedling machine-transplanted hybrid rice under dense planting conditions. Field experiments were done in Yong＇an Town, Hunan Province, China in 2015 and 2016. Two hybrid rice cultivars were grown under single seedling machine transplanting （SMT） and conventional machine transplanting （CMT） at a high planting density in each year. Grain yield and yield attributes were compared between SMT and CMT. Averaged across cultivars and years, grain yield was 12％ higher under SMT than under CMT. Plant height, basal stem width, and shoot and root dry weights were higher in seedlings for SMT than those for CMT. SMT had less maximum tiller number per m2 and consequently less panicle number per m2 than did CMT. Branch number per panicle, especially the secondary branch number per panicle, and spikelet number per cm of panicle length were more under SMT than under CMT, which resulted in more spikelet number per panicle under SMT than under CMT. SMT had higher or equal spikelet filling percentage than did CMT. The difference in grain weight between SMT and CMT was relatively small and inconsistent cross years. SMT had higher or equal total biomass and harvest index than did CMT. Dry weight per stem under SMT was heavier than that under CMT. Larger leaf area per stem was partly responsible for the heavier dry weight per stem under SMT than under CMT. Our study suggests that improvement in seedling quality, panicle size, and dry weight per stem are critical to the high grain yield in single seedling machine-transplanted hybrid rice under dense planting conditions.

Organic Ginger (<i>Zingiber officinale</i>Rosc.) Development in a Short Temperate Growing Season: Effect of Seedling Transplant Type and Mycorrhiza Application

Global warming and consumer demand for medicinal plants present an opportunity to introduce ginger growth to the US Delmarva Peninsula. High tunnel and field studies were conducted to assess the development of organic ginger (Zingiber officinalis, Rosc) seedling transplants in mycorrhiza-amended soil. Transplant types were tissue culture derived with less than three tillers (TCS1), three or more tillers (TCS2), and nontissue culture derived (NTCS1). Transplants were grown with or without mycorrhiza (2.8 g per plant) in a split plot design with soil amendments as main plot and transplant type as subplot. Data were collected for air temperatures, plant height, tiller number, leaf chlorophyll index (LCI), rhizome fresh weight, plant biomass, rhizome nutrients, and levels of As and Pb. TCS2 transplants produced significantly higher, or trended to higher rhizome yield than transplants with less than three tillers, except for year two field study. The maximum rhizome fresh weight per plant was 648.3 g for TCS2 in high tunnel in year one. Generally, TCS2 had most tillers throughout the growing season ranging from 6.9 to 25.7 tillers per plant over three studies. Mycorrhiza had no effect on ginger height, tiller number, LCI or rhizome yield. Sustained high temperatures above 37°C, plus high light in the field caused dieback and stunted shoot growth in year two. There were no consistent effects of mycorrhiza or transplant type on rhizome nutrient content. Content of total Pb, As and other elements were at safe threshold levels for rhizome consumption. These results suggest that gingers grown from TCS2 transplants with at least three tillers yielded more rhizome than those grown from S1 transplants with fewer tillers. Introduction of ginger to a short season region such as the Delmarva may require consideration of environmental condition such as high temperature and light to which seedling transplants may be exposed in summer.

No-tillage effects on grain yield and nitrogen requirements in hybrid rice transplanted with single seedlings: Results of a long-term experiment

This study was conducted to determine whether,and if so how,the grain yield and nitrogen(N) requirements of hybrid rice transplanted as single seedlings are affected by no-tillage(NT) practices.A fixed field experiment was done at the Experimental Farm of Hunan Agricultural University in Changsha,Hunan Province,China,from 2004 to 2014.Grain yield and yield attributes(panicle number per m2,spikelet number per panicle,spikelet filling percentage,grain weight,total biomass,and harvest index) were evaluated as well as the N-use characteristics(total N uptake,internal N-use efficiency,and N requirements) of hybrid rice transplanted as single seedlings comparing NT with conventional tillage(CT).A significant finding was that there were no significant differences in grain yield,yield attributes,and N-use characteristics between CT and NT.Averaged across the 11 years,grain yield and N requirements were 9.51 t ha^(-1) and 20.2 kg t^(-1) under CT and 9.33 t ha^(-1) and 20.0 kg t^(-1) under NT,respectively.There were significant yearly variations in grain yield,yield attributes,and N-use characteristics observed under both CT and NT.The yearly variation in grain yield was related to simultaneous changes in spikelet number per panicle,grain weight,total biomass,and harvest index.Also,it was found that grain yield was positively correlated with internal N-use efficiency but negatively correlated with N requirements.It is concluded that grain yield and N requirements in hybrid rice when transplanted as single seedlings are not affected adversely by NT.The results of this study suggest that(1) compatible relationships among yield attributes can be established in hybrid rice that is transplanted as single seedlings,and(2) higher grain yield and higher N-use efficiency can be concurrently achieved in hybrid rice transplanted as single seedlings.

Effect of Transplantation in Different Seedling Age on Growth and Yield of Spring Maize in Shanxi Early Mature Area

In order to explore a new mulch-free maize planting mode and the best seedling age for maize transplantation in Shanxi early mature area,a field experiment was carried out using completely randomized block design. Taking mulch based direct sowing as the control group,effects of transplantation in different seedling age on maize growing process,plant height,yield and composition factors of maize were analyzed.Results indicate that growing process of maize seedlings transplanted in different seedling age is slightly slower than the control group. Transplantation has the effect of reducing plant height. Although the yield of transplanted maize in different seedling age is lower than the control group. Besides,with the growth of seedling age of transplantation,the gap is widening. However,it is expected to realize mulch-free maize planting by transplantation in Shanxi early mature area. The yield of maize transplanted in two-leaf seedling age is not significantly different from the control group,and the yield is only 9% lower than the mulch-based direct sowing( CK). In conclusion,two-leaf period is the best seedling transplantation age for maize in Shanxi early mature area in this experiment condition.

A Study of the Factors that Affect Safe Full Heading of Machine-transplanted Rice Seedlings in the Temperate and Cool Rice-growing Areas

This paper studies the factors that affect the safe full heading of machine-transplanted rice seedlings in the temperate and cool ricegrowing areas,and explores the influence of machine-transplanted rice seedling varieties,seedling age,nitrogen fertilizer application rate and management on the safe full heading of machine-transplanted rice seedlings. Results show that for the mechanized production in the temperate and cool rice-growing areas,we should select the mid-early maturity cold-resistant varieties with growth period of not exceeding 180 d,control the seedling age to be 30- 35 d and total amount of pure nitrogen to be not more than 300 kg / ha,and moderately reduce the nitrogen fertilizer postponing ratio. Under this condition,we can achieve safe full heading of machine-transplanted rice seedlings and ensure the yield.

Design and Experimental Research on Seedling Pick-Up Mechanism of Planetary Gear Train with Combined Non-circular Gear Transmission

Currently, transplanting mechanisms for dryland plug seedlings in China are mainly semiautomatic and have low efficiency. The rotary seedling pick-up mechanism with a planetary gear train for non-uniform intermittent transmission, and a concave and convex locking arc device, has a large rigid impact. To solve these problems, according to the design requirements for a dryland plug seedling transplanting mechanism, a rotary seedling pick-up mechanism of a planetary gear train with combined non-circular gear transmission of incomplete eccentric circular and noncircular gears was proposed. This has the characteristics of two-times greater fluctuation of the transmission ratio in a cycle, and can achieve a non-uniform continuous drive. Through analysis of the working principle of the seedling pick-up mechanism, its kinematics model was established. The human–computer interaction optimization method and self-developed computer-aided analysis and optimization software were used to obtain a set of parameters that satisfy the operation requirements of the seedling pick-up mechanism. According to the optimized parameters, the structure of the seedling pick-up mechanism was designed, a virtual prototype of the mechanism was created, and a physical prototype was manufactured. A virtual motion simulation of the mechanism was performed, high-speed photographic kinematics tests were conducted, and the kinematic properties of the physical prototype were investigated, whereby the correctness of the theoretical model and the optimized design of the mechanism were verified. Further, laboratory seedling pick-up tests were conducted. The success ratio of seedling pick-up was 93.8% when the seedling pick-up efficiency of the mechanism was 60 plants per minute per row, indicating that the mechanism has a high efficiency and success ratio for seedling pick-up and can be applied to a dryland plug seedling transplanter.

Effects of uniconazole rate on agronomic traits and physiological indexes of rapeseed blanket seedling

Mechanized transplanting of rapeseed(Brassica napus L.)blanket seedling is an innovative cultivation technology.Cultivating high quality blanket seedling to ensure high survival rate of seedling after transplanting is the key of the technology.The effects of different uniconazole rates of 0,0.5,1.0,1.5 and 2.0 mg/tray,spraying at one leaf and one heart stage,on selected agronomic traits,physiological indexes and survival rate of two rapeseed cultivars(‘Qinyou 100 and’Yangyou 90)were investigated in 2018 and 2019.Our results showed that the plant height decreased significantly with the increase of uniconazole rate.However,the collar diameter increased significantly with the increase of uniconazole rate up to 1.5 mg/tray,and the leaf area,dry weights of root and shoot increased with increased uniconazole rate up to 1.0 mg/tray.The root to shoot ratios,N concentrations of root and shoot with the uniconazole rates of 1.0 and 1.5 mg/tray were higher than those with other treatments.As uniconazole rate increasing,gibberellin(GA)and auxin(IAA)concentrations of root and shoot decreased,while abscisic acid(ABA)concentrations increased,and cytokinin(CTK)concentrations topped at uniconazole rate of 1.0 mg/tray and decreased thereafter.The seedling survival rates with 1.0 and 1.5 mg/tray were greatly higher than those in other treatments.Regression analysis suggested plant survival rate was positively related to CTK concentrations and negatively to GA concentrations of root and shoot.To achieve high survival rate after mechanized transplanting,our study revealed that the uniconazole applied at a rate of 1.0 mg/tray was recommended as the best,followed by 1.5 mg/tray.The findings would help to enhance qualities of rapeseed blanket seedling and to promote popularization of mechanized transplanting of rapeseed production.

Early Forage Biomass and Sward Structures of Native Warm-Season Grasses Established at Different Seedling Densities

Effects of transplanted seedling density and species on sward structure of native warm-season grass (NWSG) stands were compared in a randomized complete block design. About 6-week-old NWSG (big bluestem (BB, Andropogon gerardii Vitman), eastern gamagrass (GG, Tripsacum dactyloides L.), indiangrass [IG, Sorghastrum nutans (L.) Nash] and switchgrass (SG, Panicum virgatum) seedlings were transplanted in 45-cm wide rows on clean-tilled seedbeds. Within-row spacing was 30, 25, or, 20 cm giving 10, 12, and 15 plants m-2 as low, medium, and high seedling density, respectively. During establishment, the stands were allowed uninterrupted first year growth without fertilizers or irrigation but when necessary, tall-growing broadleaf weeds were mechanically removed. In the following spring, all dead standing biomass was mowed down to allow emerging tillers access to sunlight. During the second year after planting, early-spring basal diameters, row-length intercepted by the NWSG crowns, mid-summer sward heights, and percentage bare ground were determined. From the second June after planting, and for two consecutive years, plots were harvested twice year-1 to assess forage biomass. Data showed that, unlike species, seedling density had no effect on the assessed parameters. Cumulative forage biomass, in kg DM ha-1, was the least for GG (4901) at low and the most (18,245) for SG at high seedling density during the second year. Corresponding values for the third year were 4500 and 7799 kg DM ha-1. Basal diameters ranged from 18 cm (BB) to 24 cm (IG) while percent row intercepts were from 6 (GG) to 46 (IG) with sward heights measuring 41 cm (IG) to 54 cm (GG). In each stand, percent ground cover by the NWSGs, and at every seedling density, averaged 60.5. Transplanting at ≥10 plant m-2 resulted in harvest-ready stands by the second year of establishment. And while close spacing favored the NWSGs against weeds, data showed that an initial plant density of >10 plants m-2 may not result in increased forage production worthy the additional establishment cost. Data on response to fertility management and forage quality attributes are necessary for more reliable practical recommendations.

Rice Transplanting Mechanization in Bangladesh: Way to Make It Sustainable

“Rice transplanter” has brought a radical change in the method of rice seedlings transplanting in Bangladesh. The machine is gaining popularity with the increase of labor crisis during the peak period of transplanting, reduction time of in-between crops, rapid urbanization and industrialization, and changing socio-economic status of the farmers. Alternatively, the traditional way of rice transplanting is labor-intensive and involves high drudgery. Mechanical rice transplanter is cost-effective and operation-friendly. It is suitable to plant young seedlings maintaining plant to plant and line to line distance which plays an important role in increasing yield. Moreover, it is easy to take care of the crops planted in rows. It helps in maintaining soil physical properties and is considered to be better from a crop management and productivity point of view. In malignancy of having an edge over the traditional broadcasting, the adoption rate of mechanical transplanters is low due to high primary investment, lack of knowledge in growing mat type nursery, lack of repair and maintenance facility to the end-users, and unavailability of spare parts. Imparting these, available supply, entrepreneurship development, and encouraging custom hire services may be some of the practical results for adding the rice area under mechanical transplanting. This review summarizes the problems and prospects associated with seedling rice transplanting, technological gaps in the adoption of mechanical transplanters in a sustainable manner, and future ways to make transplanters more user-friendly and cost-effective.

Design and experiment of the side insertion horizontal transplanting device for sweet potato(Ipomoea batatas Lam.)seedlings on mulch film

Side insertion horizontal transplanting sweet potato seedlings on mulch film is one kind of new planter pattern,which keeps the soil warm and moist restraining the infestation of pests and weeds,realizing dense transplanting and ensuring uniformity of sweet potato sizes.Therefore,a side insertion horizontal transplanting device for sweet potato seedlings on mulch film was designed,including the details and parameters of the reciprocating mechanism and the seedling clamping mechanism.Both the two mechanisms and the whole device were simulated and the test bench was built for field experiments to detect if this device can meet the agronomic requirements.The simulation results show that the designed device is in accordance with the agronomic requirements of horizontal transplanting,transplanting depth and transplanting length,and is potential for achieving rational close planting.The lateral length of the designed transplanting device is extended at about 90 mm compared with previous machine,which will promote the number of soil nodules of sweet potato seedlings and the growth of production enormously.The horizontal velocity of the transplanting claw is−17 mm/s when picking the seedling,the horizontal velocity of the transplanting claw 645 mm/s and the vertical velocity 83 mm/s when releasing the seedling.These data could ensure the accuracy requirements of horizontal transplanting trajectory.The field experiment results show the expulsion rate of sweet potato seedlings at 1.38%,the qualified rate of transplanting length and depth at 94.17%and 95.11%respectively,the average length and width of the mulch film breaking hole at 44.67 mm and 43.00 mm in several.The postures of the actual transplanted seedlings are consistent with the simulation results,meeting the requirements of horizontal transplanting with less damage to the mulch film.The designed transplanting device lays a foundation for the development of sweet potato seedlings side transplanting machine.

温室辣椒自动补苗机构控制系统设计与试验

针对辣椒培育过程中会出现一定量劣苗影响穴盘苗一致性,且目前移栽机械自动化程度低、移栽效果不理想的问题,依照农艺要求规范设计了机-电-气一体的自动补苗机构控制系统。阐述了自动补苗机构工作原理和系统结构,结合传感器和执行器布局和剔补苗运行机制设计了补苗机构控制系统软件和硬件。参照移栽手工作要求,设计气路系统并进行相关计算。对45天辣椒幼苗进行移栽补苗试验,以水平移动速率、取苗深度、含水率为试验因子,剔苗成功率、移栽成功率为衡量指标,设计三因素三水平正交试验,结果表明:水平移栽速率对剔苗成功率和移栽成功率影响较小,移栽手运行平稳,剔苗成功率平均值为94%,移栽成功率为91.1%,表明自动补苗机构性能可靠。

辣椒漂盘苗机械化移栽适应性研究

为了探索辣椒漂盘苗对机械化移栽的适应性,以贵州某辣椒基地所育适栽期辣椒漂盘苗和2ZB-2旱地吊杯鸭嘴式移栽机为测试对象,完成了辣椒苗形态特征参数测量、落苗基质损失及田间机械栽植的试验研究。结果表明:从辣椒苗的苗高、叶面展幅、基质情况来看,所育漂盘苗基质饱满,且适于膜上移栽常用的鸭嘴式栽植器;漂盘苗基质含水率在56.4%~63.5%时,利于机械移栽的基质保持;田间机械移栽的栽植深度合格率、漏栽率、伤苗率分别为76.7%、2.4%、3.2%,满足指标要求;直立度合格率为88.7%,低于93%的指标下限。总体来说,辣椒漂盘苗与移栽机适应性较好,基本能达到贵州辣椒机械化栽植作业要求。

番茄钵苗移栽探出式取钵机构设计与试验

为了降低番茄钵苗移栽过程取钵机构对秧苗钵土根系的损伤,同时避免机械式钵苗移栽机构设计特殊取苗轨迹与姿态的优化难题,提出了一种可与系列移栽机构配合使用的番茄钵苗探出式取钵机构,实现取苗各关键位置机构秧针以固定角度完成探出入钵、移动送苗及收回推秧工序。根据钵苗移栽取钵过程分析与设计要求,建立了探出式取钵机构力学分析模型,并获得影响秧针扎入钵土时驱动杆受最小驱动力的因素。基于Matlab App Designer平台开发了取钵机构计算机辅助分析设计软件,获得满足番茄钵苗移栽要求的取钵机构设计参数集。采用三因素五水平二次回归正交旋转中心组合试验方法,以驱动杆斜杆夹角、钵体含水率、入钵深度为试验因素,以钵体完整率和取苗成功率为评价指标,试制样机并搭建台架实施参数组合优化及验证试验,结果表明:探出式取钵机构可有效地配合取苗机构完成各项性能工作要求,在参数组合为驱动斜杆间夹角112°、钵体含水率57.5%、入钵深度28.4 mm时作业效果最佳,钵体完整率为96.44%,取苗成功率为97.06%,满足钵苗移栽作业性能。

钵苗移栽机取苗装置的设计与试验

设计了一种钵苗移栽机取苗装置,并对夹苗和松苗两种状态下的末端执行器进行运动仿真,从而选择合适行程的气缸或推杆作为原动件。选用凸轮机构用于顶苗,根据凸轮各阶段工作规律设计出合理的轮廓线,利用仿真验证出满足设计要求。试验结果表明:设计的取苗装置未取出率平均值为8.22%,取苗成功率平均值为91.78%,达到了设计目标。