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To improve the efficiency of mechanization in transplanting vegetable seedlings and achieve the automation of vegetable transplanter in dry land, an automatic vegetable pot seedling transplanter for dry land was developed. This transplanter is mainly composed of 2 rotating seedling picking-up mechanisms of planetary gear train with ellipse gears and incomplete non-circular gears, a horizontal and longitudinal intermittent seedling sending device, 2 eccentric disc dibble-type planting apparatuses, and a power transmission system. Two rotating seedling picking-up devices and 2 eccentric disc dibble-type planting apparatuses were symmetrically arranged along the longitudinal surface center of the machine, constituting 2 sets of automatic seedling picking-up and planting systems. The seedlings were provided automatically from 2 standard seedling pots with 128 holes using the horizontal and longitudinal intermittent seedling sending device. The engine drive shaft could transfer power to the principal axis of the apparatus through chain drive to enable the rotating and planting of the apparatus. Meanwhile, the principal axis of the apparatus could transfer the power to the rotating seedling picking-up mechanisms of planetary gear train with ellipse gears and incomplete non-circular gear and intermittent seedling sending device. Subsequently the intermittent seedling sending device could move horizontally and longitudinally to send the seedling pots to the target place, where the seedling picking-up mechanism took the seedlings from the pot to the eccentric disc dibble-type planting apparatus. To test the performance of this automatic vegetable pot seedling transplanter for dry land, the experiments were conducted in the test field where the soil condition met the mechanical industry standard in People's Republic of China Dry Land Planting Machinery (JB/T 10291-2013). The tomato seedlings (ZheZa 809) used in this experiment were cultivated in the standard seedling pots with 128 holes and transplanted at the age of 35 days with an average height of 150 mm. The seedling sending, picking-up, delivering and planting were all carried out at a constant transplanting frequency by adjusting the speed of the input belt pulley of the walking gear-box. The seedling transplanting efficiency was tested at the low speeds of 45, 60, 75 and 84 plants/min, respectively, as well as at the high speed of 96 plants /min. The coefficient of variation for planting spacing, missing transplanting rate, qualified rate of planting depth and qualified rate of transplanting were determined according to the mechanical industry standard Dry Land Planting Machinery (JB/T10291-2013). The seedling-standing ratio was calculated based on the Technical Specifications of Quality Evaluation for Rape Transplanter (NY/T 1924-2010) according to the standards for agriculture industry in People's Republic of China. The results showed that the coefficient of variation for planting spacing and the missing transplanting rate increased slightly at the range of 6.6%-8.9% and 1.7%-2.8% accordingly when increasing the planting frequency from 45 to 96 plants/min. However, the qualified rate of planting depth, the qualified rate of planting perpendicularity and the qualified rate of transplanting decreased slightly in the range of 97.5%-98.9%, 96.7%-97.8%, and 91.1%-94.7% with the increasing of planting frequency. The coefficient of variation for planting spacing, the missing transplanting rate, the qualified rate of planting depth and the qualified rate of planting all met the requirements of the machinery industry standards (JB/T 10291-2013), and the qualified rate of planting perpendicularity was also within the specified value in the standards for agriculture industry (NY/T 1924-2010). The automatic seedling-sending device, the seedling picking-up device and the planting apparatus of the automatic transplanter coordinated well with each other to complete the process for sending seedlings, picking up seedlings, delivering seedling, planting and soil covering automatically. [ABSTRACT FROM AUTHOR]

The seeds cannot fully sprout owing to the seed quality and environmental differences. So it is difficult to provide seedling pots without empty seedling holes for automatic transplanting. In order to reduce the number of seedling shortage and the manual labor intensity of seedling supplement, and to improve transplanting quality, a method for supplementing seedlings in cotyledon phase was presented in the paper. According to the delicate seedling, undeveloped root system and the unconsolidated substrate in pot, a new type of end-effector for supplementing pot-seedling in cotyledon phase with 4 seedling shovels was designed. The 4 angular seedling shovels were synchronously driven up and down by stepper motor moving the X-shaped press rod. They can shape enveloping surface when they are inserted into the lower limit position of the whole pot and surrounded the seedlings from the 4 sides of seedling substrates during seedling. And then the pot seedling was taken out from seedling hole and transplanted to the target hole. The seedling supplementing was finished while the pot seedling was left in the target pot hole and the seedling spades lifted it up along the inclined guide. The 3 factor and 3 level orthogonal tests were conducted respectively with the Zheza809 tomato pot seedlings in cotyledon phase with the seedling age of 16, 21 and 26 d cultivated in standard seedling tray with 72 holes. In the test, the velocities of inserting and taking out of matrix for the shovels were measured by speedtro-50 laser velometer, and the average velocities were 29.85 and 31.12 m/s respectively. The mixture ratio of peat, vermiculite and perlite in nursery matrix, the moisture content of the substrate and the seedling age were chosen as factors. The matrix net rate, which is the percentage of the weight of pot seedling taken out from the pot holes by the end-effector in the total mass of the pot seedling in the pot hole, was set as index. The results indicate that the net rate of taking out the free substrate without seedlings or the pot seedlings in cotyledon phase is affected significantly by the pot seedling age and the mixture ratio of peat, vermiculite and perlite in nursery matrix. The net rate increases with the seedling age, which reaches the highest value at the end of cotyledon phase and the mixture ratio of peat, vermiculite and perlite in nursery matrix of 2:2:1. The effect of matrix water content from 67.1% to 79.2% on the net rate is not significant, while the net rate keeps a high value owing to good cohesive force and plasticity of the substrate when the moisture content of the substrate is 74.1%. When the growth age is 26 d, the mixture ratio of peat, vermiculite and perlite in nursery matrix is 2:2:1 and the moisture content of the substrate is 74.1%, the average net rate reaches the maximum of 89.5% and the shape and volume of the seedling pot keep complete. To further verify the optimal combination obtained by the test, the experiments of seedling taking out and supplementing were carried out with tomato pot seedlings with the age of 26 d, the mixture ratio of peat, vermiculite and perlite in nursery matrix of 2:2:1 and suitable substrate moisture content. The results show that the success rates for the free substrate without seedlings and pot seedlings are both 100%, which can take out the pot seedlings in cotyledon phase with crisp plant and loose matrix as a whole and fill them into target hole on the seedling pot completely. [ABSTRACT FROM AUTHOR]