农业工程学报2019，Vol.35Issue(19)：29-36,8.DOI:10.11975/j.issn.1002-6819.2019.19.004
蚯蚓仿生注液沃土装置设计与试验
Development of device for bionic sub-soil liquid fertilizer
摘要
Abstract
The conservation tillage and liquid fertilization can enhance the productivity of farmland. However, soil adhesion occurs on the surfaces of soil-tillage implements during liquid fertilizer applications. Soil adhesion phenomenon can increase energy consumption and decreases fertilizer application quality. The working procedure of liquid fertilizer application by sub-soil liquid fertilizer involves soil compression and shearing, hence, the shape and surface features of the sub-soil liquid fertilizer could significantly affect the perfor-mance of soil penetrating, in turn, affect the quality of liquid fertilizer application. Improving the shape design of soil engaging tool is one of the effective methods for reducing operating resistance and increasing working quality. Therefore, a sub-soil liquid fertilizer with novel geometries and surface features should be investigated, and attempts should be made to improve operating efficiency of liquid fer-tilizer application. Biologically inspired engineering is the application of biological methods found in nature to the study and design of engineering systems. When pressed with an engineering problem in agriculture, engineers could find wisdom and inspirations from the natural world. Through learning from the natural world, it is found that the interactions of living organisms with natural surroundings have led to the evolution of biological systems and environmental adaptabilities. Among the living organisms, earthworms have long been acknowledged to largely contribute to the aggregate stability of soils varying in texture, carbonate, and concentration of organic matter by burrowing, foraging, and casting on the soil surface and within the soil. Besides, earthworms can comfortably move in moist or adhesive soil, it＇s worth noting that soil particles seldom sticking to bodies. One of the soil fertilization mechanisms for earthworms is that the earthworm swallowed soil and excreted particle casts while burrowing in soil. In this process, the earthworm mucus plays criti-cal roles in adhesion reducing, soil fertilizing and so on. Inspired by this special behavior of earth worm, bionic engineering approach was used and novel method for improving soil fertility were provided in this study. The profile curves of earthworm head and body sur-face were extracted and fitted using image processing technology. Geometric structure surface of sub-soil liquid fertilizer injection de-vice was designed based on the contour curve equations. The sub-soil liquid injection fertilizer devices (3 injection holes and 6 injection holes) which matched with the bionic subsoiler, were designed. Ultra-high molecular weight polyethylene (UHMWPE) was chosen as the material for manufacture this device. The significant influence of factors for investigation was the liquid injection, the number of holes, the materials and the surface structure for drag resistance, and the surface structure, the number of holes, the materials and the liq-uid injection for soil adhesion. The prototype performances were tested by using soil bin test system. The performance parameters of holes, liquid injection, material and geometrical structure surface were taken into account to present the effects on drag-reducing and an-ti-soil adhesion in tests. The results showed that the significant influences of the performance parameters for drag resistance were as liq-uid injection> hole number> material> surface structure. The significant influences of the performance parameters for soil adhesion were surface structure > hole number > material > liquid injection. The optimal level of each parameter was the liquid injection, six holes, UHMWPE material and geometrical structural surface. The optimized prototype was selected from eight types of sub-soil liquid fertilizer injection devices, which was UHMWPE in material, with geometry structure surface and six liquid injection holes. In the same experiment conditions, the mean value of the drag resistance of the selected bionic prototype was 283.48 N, the mean weight of soil ad-hesion was 10.93 g, which was lower than that of other prototypes. This study provided technical references for the mechanization of sub-soil fertilizing engineering.关键词
仿生/设计/几何结构表面/脱附减阻/注液沃土/蚯蚓Key words
bionics/design/geometric structured surface/drag-reducing/sub-soil liquid fertilizer injection/earthworm分类
通用工业技术引用本文复制引用
张东光,左国标,佟金,张智泓..蚯蚓仿生注液沃土装置设计与试验[J].农业工程学报,2019,35(19):29-36,8.基金项目
国家自然科学基金青年基金项目(51805356, 51605210) （51805356, 51605210）
山西省自然科学基金(201701D12111209) （201701D12111209）
土壤环境与养分资源山西省重点实验室开放基金(2016003) （2016003）
