Design of potato casingsoil planter in all-in-one machine combined with fertilizing, sowing, ridging, complete film mulching and planting line covering

Abstract: Whole plastic mulching and furrow planting has been widely adopted as a drought resistant cultivation model of potato in the arid areas on the Loess Plateau of Northwest China in recent years. Research has shown that the technique increases the production by more than 20% compared with the open field cultivation. However, due to the lack of matching planting machine, the sectional operation is currently adopted, with film mulching and artificially dropping seeds. The mode is labor-consuming and has poor-quality work, which urgently calls for mechanized combined operation. Since the 1950s, potato production equipment has begun to develop in the direction of automation in many developed countries in Europe and America, potato planting machine has changed from the elementary semi-mechanization to the senior automation, and meanwhile great achievements have been made in technical level and basic theory research. After 1980s, potato planter has rapidly progressed in China. More than a dozen scientific research institutes or production units began to develop and produce potato seeder, and with the passage of time, the technology is maturing. Whole plastic mulching and furrow planting requires that adjacent film edge butts and the ridge as well as furrow should be completely covered with plastic film. The existing mulch film planting technology basically takes the way shoveling soil from membrane side. There is a bare strip between the films so as to shovel soil and to operate potato planter. It does not meet the requirement of whole plastic mulching and furrow planting. In order to solve the problems of releasing seedlings and dibbling artificially in potato mulching film cultivation, the growth-promoting mechanism of covering soil on plastic film is applied to potato high-yielding cultivation techniques of whole plastic-film mulching, and a potato planter combined with fertilizing, sowing, ridging, complete film mulching, planting line covering is designed. Aiming at the matching problem of widths that the width of the tractor is larger than the width of the planter, a hydraulic offset suspension device is designed. To solve the problems of wind damage, cavity dislocation and seedlings burnt caused by not having enough volume of covering soil, the device is designed which is suitable for whole plastic-film mulching machine, namely spanning type device of covering soil on plastic film. In view of the problem of poor seeding stability of traditional chain metering device, the seed metering system is optimized and improved. Sharp wing furrower is designed to make the soil strip and the seedlings belt aligned both up and down. A soil-crushing and reshaping device is designed to ensure the shape of ridges. A punch is designed to drill the holes for water seepage on the film surface of the ditch bottom and to effectively make use of the rainfall collected by rainwater collecting surface. The key components of the prototype are analyzed to determine the structure and working parameters of hydraulic offset suspension device, spanning type device of covering soil on plastic film, seed metering system, and soil-crushing and reshaping device. The working mechanisms of the key components are clarified too. Field experiments show that, the qualified rate of sowing depth under the mulching film is 86%, the qualified index of seed potato spacing is 89%, the reseeding and miss-seeding index are 5% and 4% respectively, the qualified rates of soil width and soil depth covered on planting line are 92% and 94% respectively, the qualified rate of adjacent row spacing is 86%, the mechanical damage degree of day lighting surface of plastic film is 48.1 mm/m2, and the spacing qualification rate of water-leaking hole is 96%. Field performance test indices have reached the requirements of the national and industry standards; moreover, the results meet the design requirements, and the machine can realize integrated operation of fertilization, sowing, ridging, whole film mulching and covering soil on planting line.