CAJ | 학술논문

为探明甘薯收获期藤蔓茎秆机械特性，以便提高甘薯藤蔓机械粉碎还田作业质量，该文农机农艺结合，以江苏南京地区鲜食紫甘薯宁紫1号、宁紫2号为试验对象，应用电子万能试验机、甘薯藤蔓粉碎还田试验机等仪器设备，研究了收获期甘薯藤蔓茎秆含水率和剪切强度的变化，揭示了茎秆含水率、剪切强度和机械碎蔓作业质量的内在关系，获得了含水率在86.92%～70.08%时，2个紫甘薯品种藤蔓茎秆剪切力与含水率之间变化的二次函数回归方程；明确了经验收获期开始时藤蔓茎秆含水率分别为81.5%和78.1%、剪切力分别为90.1和94.8 N；从提高机械作业质量角度出发，提出了收获期内最宜机械碎蔓作业时间约为6～8 d。研究结果为新型甘薯藤蔓粉碎还田机转速、切刀线速度等参数设计提供了直接依据，并为适宜的甘薯收获期选择和适宜机械作业的栽培农艺研究提供了参考。
위탐명감서수획기등만경간궤계특성，이편제고감서등만궤계분쇄환전작업질량，해문농궤농예결합，이강소남경지구선식자감서저자1호、저자2호위시험대상，응용전자만능시험궤、감서등만분쇄환전시험궤등의기설비，연구료수획기감서등만경간함수솔화전절강도적변화，게시료경간함수솔、전절강도화궤계쇄만작업질량적내재관계，획득료함수솔재86.92%～70.08%시，2개자감서품충등만경간전절력여함수솔지간변화적이차함수회귀방정；명학료경험수획기개시시등만경간함수솔분별위81.5%화78.1%、전절력분별위90.1화94.8 N；종제고궤계작업질량각도출발，제출료수획기내최의궤계쇄만작업시간약위6～8 d。연구결과위신형감서등만분쇄환전궤전속、절도선속도등삼수설계제공료직접의거，병위괄의적감서수획기선택화괄의궤계작업적재배농예연구제공료삼고。
Sweet potato is a crop which is drought-resistant, tolerant of poor soil, and owns increasingly enormous potential. It is an important foodstuff, a raw material for starch industry, a kind of health food to prevent cancer and a new raw material for energy as well. The sweet potato planting area in China per year on average is usually 3 667 000 hectares, accounting for 45% of the world's planting area. As sweet potato vines are very long and broomy, the vines must be cleaned up before sweet potatoes are harvested, otherwise are unable to be harvested. Vine crushing and returning machine is usually the dominant form adopted to clean sweet potato vines internationally, but the problems existed in this type of machine were obvious such as low smashing proportion and more stubble residue on the top ridge. New problems have been brought by long stubble such as blocking, larger load and worse smooth working property. Aiming at these problems, the machinery and agronomy should be combined, in order to prove mechanical properties of sweet potato vine and stalk during harvest and working quality of sweet potato vine crushing and returning testing machine. In this paper, the types of fresh purple sweet potato Ningzi 1 and Ningzi 2 in Nanjing, Jiangsu Province were regarded as the tested subject, the electronic universal testing machine, electric drying oven with forced convection, and sweet potato vine crushing and returning testing machine etc. were applied, and the change of moisture percentage and shear strength of sweet potato stalk during harvest were studied. The results showed that at the beginning of experience harvest period, when the percentage of moisture were 81.5% and 78.1%, the shear force were 90.1 and 94.8 N, respectively, during 18 testing days the moisture percentage of sweet potato stalk reduced by 14.8% and 13.97%, respectively, but the shear force of stalk increased by 36.3 and 37.5 N respectively, which showed that the moisture percentage of sweet potato stalk was lower and the shear force was larger as the growth time of plants went on. The internal relations between mechanical crushing quality and percentage of moisture, shear strength were revealed: during the testing period of 18 days, the qualified rates of vine’s crushing length for sweet potato type Ningzi 1 and Ningzi 2 dropped by 6.3% and 6.7% respectively, stubble length on top ridge increased by 3.6 and 4.4 cm respectively, which showed that with the increasing of the growth period and the rising of stalk’s shear force, the working quality of sweet potato vine crushing and returning machine declined. The quadratic function regression equations on the change between shearing force and moisture percentage of the two types of fresh purple sweet potatoes’ stalk were obtained with Matlab when the percentage of moisture was 86.92%-70.08%, and the fitting coefficient of determinationR2 both reached above 0.99. From the point of increasing the quality of mechanical smashing and mechanical work, it was put forward that the most suitable time of mechanical crushing for the two kinds of purple sweet potatoes during harvest was about 6-8 days, which was a relatively short time. The results offer the direct basis for parameter design of new sweet potato vine crushing and returning testing machine such as machine speed, cutter linear velocity, and also provide the important reference for the selection of suitable harvest period and cultivation agronomic research that fits for machinery operations.