丘陵山地甘薯膜上仿形扦插移栽机研制

针对北方丘陵山地甘薯膜上移栽机械缺乏这一产业难题,该研究基于甘薯覆膜栽培“浅栽、多埋节”农艺需求,以理论扦插角度、栽植深度、膜下薯苗长度、穴口长度的最优综合得分为目标,对薯苗栽植单元取植动作时空配合参数和工作参数进行分析,并设计了丘陵山地仿形扦插甘薯移栽机,进行了室内外试验。室内取苗试验结果表明,在40～50 r/min植苗速度下,栽植单元对黄淮海地区常用薯苗品种取苗效果较好,取苗率在99%以上,满足田间作业需求。以作业速度、薯苗基部形态、薯苗伸出夹苗刷长度为影响因素,以膜下薯苗长度、栽深合格率和漏苗率为考核指标,进行田间移栽正交试验。结果表明,影响薯苗栽植指标综合评分的主次因素为薯苗伸出夹苗刷长度、薯苗基部特征、作业速度,最优参数组合为作业速度0.5 km/h、薯苗基部形态优、薯苗伸出长度60 mm。验证试验结果表明,最优参数组合下,平均薯苗扦插深度为73.6 mm,膜下薯苗平均长度为205.4 mm,平均穴口长度为76.5 mm,薯苗栽植后与地面平均夹角为53.8°,扦插株距变异系数为8.9%,栽深合格率为93.7%,漏苗率为3.5%,扦插效果良好,满足北方膜上船底形插的农艺需求。...

Development of the profiling up-film transplanter for sweet potato in hilly and mountainous region

Sweet potato is one of the most favorite crops that is widely cultivated from the tropical to temperate regions. There is an ever-increasing need to produce more sweet potatoes on the existing arable land under the challenges of labor scarcity and population growth. However, it is still lacking the optimal machinery to transplant the spring sweet potato seedlings on mulched ridge planting system, especially in the hilly and mountainous region of northern China. In this study, a profiling transplanter was designed for the "shallow planting and multiple buried joints" of sweet potato seedlings, according to the agronomic requirements of "shallow cultivation and multiple burying nodes". The boat-bottom planting placement of mulch raised the beds'' cultivation system of sweet potatoes. The space-time coordination and working parameters of the transplanting unit were optimized to consider the transplanting angle, transplanting depth, seedling length under the film and hole length. Indoor and outdoor tests were also carried out to verify the model. The indoor seedling-taking tests showed that the planting unit posed the super seedling taking effect on the five sweet potato varieties, which were widely planted in Huang-Huai-Hai area. More narrowly, the seedling picking success rates of the planting unit were more than 99% under the rotating speeds of 40-50 r/min, which fully met the needs of field operation. Furthermore, the orthogonal experiment of field transplanting was carried out in the field, in which the influencing factors were taken as the operation speed, the shape of sweet potato seedlings base, the length of seedlings extending out of the brush, and the average number of buried nodes, the qualified rate of transplanting depth, and the missing rate determined as the evaluation indexes. The field experiment showed that the influence factor on the average number of buried nodes was ranked in the descending order of the length of seedlings extending out of the brush, the operation speed, and the shape of the sweet potato seedlings base. By contrast, the influence factor on the qualified rate of transplanting depth was the length of seedlings extending out of the brush, the shape of the sweet potato seedlings base, and the operation speed. The influencing factors on the missing seedling rate were the operation speed, the shape of sweet potato seedlings base, and the length of seedlings extending out of the brush. The operating parameters were optimized using fuzzy evaluation and range analysis. As such, each factor on the comprehensive score of field experiment performances was ranked in the descending order of the length of seedlings extending out of the brush, the shape of the sweet potato seedlings base, and operation speed. The optimal combination of parameters was as follows: the operation speed of 0.5 km/h, the most upright sweet potato seedlings base, and the extension length of sweet potato seedlings of 60 mm. Finally, the transplanting efficacy of the sweet potato seedlings profiling transplanter was evaluated under the optimal operation parameters in the hilly and mountainous regions. The results showed that the average transplanting depth, the transplanted seedling length under the film, the hole length, and the transplanting angle were 73.6, 205.4, 76.5 mm and 53.8°, respectively. Meanwhile, the transplanting space variation coefficient, the qualified rate of planting depth, and the rate of missing seedlings were 8.9%, 93.7%, and 3.5%, respectively. The performance fully met the agronomic requirements of "shallow cultivation and multiple burying nodes" for the boat-bottom planting placement and the regulations of transplanting quality on dry land transplanting equipment. This finding is of considerable importance to developing the transplanting machine for planting spring sweet potato seedlings on mulched ridge planting systems in the hilly and mountainous regions of northern China, as well as for sustainable development of the sweet potato industry.