Abstract:In order to avoid the obstacles of soil continuous cropping,it is necessary to mix the soil in the tree holes with the bacterial fertilizer to improve the survival rate of fruit trees.Aiming at the problems of poor quality of mixed fertilizer,separation of operation flow and high labor intensity in the process of fruit tree planting, an integrated fruit tree planting machine was developed.The key components were designed according to the requirements of planting agratics.The backfilling device of pit mixing fertilizer realized simultaneous excavation and fertilizer mixing,vertical pit feeding,fertilizer metering and discharge,and in-situ backfilling and watering.The length of each connecting rod of the lifting device was determined according to the in-situ operating distance.The plant operation control system developed realized automatic plant operation,and real-time adjustment of pit feeding amount based on PWM control according to the operation load characterized by oil pressure monitoring.Against the blending problem of less bacterial manure and more soil,the discrete element simulation was used to simulate mixing process of soil in the mixing chamber at different rotational speeds and mixing time, net-poles through the analysis of the relative standard deviation method in different depths,and soil mixture mixing evenness variation coefficient,and the best theory mixing operation parameters were got as follows:the speed was 250r/min,and the mixing time was 14s. The results of field validation test showed that the total time of single planting of the prototype was less than 3min,the variation coefficient of mixing uniformity of the upper,middle and lower layers of the tree hole was not more than 16%,operating depth was adjustable from 0mm to 400mm,and diameter was 500mm,all indexes of the prototype met the agronomic requirements of fruit tree planting.