Design of continuous ditching and fixed distance apple planting machine for high density dwarfing orchard

Abstract: Aiming at the present situation of high labor intensity and low precision of plant spacing control in fruit tree planting, the agricultural machinery agronomic integration technology based on standardized cultivation mode was studied in this paper, and an apple planting machine for high density dwarfing orchard was designed, the key technical problems in mechanized planting of fruit seedlings, such as continuous wide and deep furrow opening, vertical planting of fruit seedlings and precise control of plant spacing, were solved. The apple planting machine for high density dwarfing orchard was powered by a tractor above 58 kW and used a rear three-point suspension operation mode. The structure mainly composed of continuous ditching device, clamping and conveying device, fixed-distance planting device, overburden pressing device and other auxiliary devices. The ditching device was powered by power-output shaft to drive opener ditching continuously. V-type double-disc opener was used, ditching blade was installed on ditch cutter supported by inclined bearings. Soil retaining plate was installed at the rear of the opener, front and side plates were used with the opener to ensure the grooving structure was stable. Bottom plate was used together with grid bar to assist positioning. By manually placing the seedlings and placing the rotes on the bottom plate, the tree trunk was placed obliquely on the grid bar lying on the conveying channel for initial positioning. After the sensor of the fixed-distance planting device installed at the rear of the frame detected the position information of the planted seedlings, the cylinder action of the clamping conveyor was started by controlling the switch. the positioning bar was opened, and the seedlings entered the clamping state, and then the seedlings were transmitted backward by the carrying belt. The carrying belt was powered by the ground wheel with the same rate, therefore, the speed of the carrying belt was the same as the machine working speed, and the seedlings were placed in the planting ditch statically with a zero speed relative to the ground, then the scraper-type cover pushed back the soil and the compaction wheel pressed the soil compactly, at the same time it pushed forward the seedlings to complete the upright planting. The fixed-distance sensor detected the seedlings just planted, the process was repeated, ensuring the distance between the adjacent 2 seedlings was equal, continuous ditching, vertical planting, backfilling and repressing were realized in one-time. By adjusting the height of the bottom plate (from 0 to 20 cm), the angle and depth for initial inclined positioning could be changed, so that the machine could work in different soils and for different varieties. The ditching depth of the machine was adjustable from 0 to 40 cm, the ditching width was 30~37 cm, and the working speed was 0.8-1.5 km/h. The results of field experiment showed that the average qualification rate for planting depth was 91.43%, the average planting qualification rate was 93.79%, and the variation coefficient of plant spacing was about 5.03%, average planting efficiency was about 720 plants per hour, which was 36 times more efficient than manual planting, the machine worked stably and the planting effect met the mechanized production requirements of modern standard orchard.