Installation System Research Used For Tree Deep Planting In Arid Area

Desertification is the one of serious problems to human being's alive. Most country paid a lot of attention to combat the desertification. China is one of the deserted countries on all over the world. The deserted land was up to 27.32% of total China's cultivated land. Afforestation and recover vegetation on the deserted is most efficiency and practical method to combat the desertification. An investigation on tree deep planting in arid area showed that planted trees have had almost 100% survival rate when planting depth under 1.4m and 78% survival rate when planting depth in 70cm to 80cm. Tree deep planting is a remarkable technology and effective method to increase the tree planting survival rate and keep rate. Two equipments for tree deep planting were designed and manufactured in order to increase tree planting efficiency and decrease cost. One of them is the deep planting earth auger that powered with mini agricultural tractor. The machine was totally hydraulic driving, operating and controlling. It is easy to couple with tractor and simple operating. The efficiency of tree planting is 60 to 120 per hour according to different soil hardness. The deep planting earth auger will have a bright future to be distributed to arid area. Medium Depth Planter is another machine for tree deep planting. A crawl tractor with power of 50 to 60 kW towed the machine. It could plant 1000 to 1500 trees per hour. It is an effective tree planting equipment. Limited by tractor's power, the maximum depth of tree planting is 80 cm in Keerqing sand area. The relations of resistant torque with the parameters of spiral auger's structure and movement have been find out by theoretical research and analyzing in this thesis. It supplies a theoretical basis for spiral auger design. A test for deep planting earth auger reveal out the relationship between auger's rotation speed, feeding speed with its drilling resistant torque in three typical tree planting land of moving dune, sand soil and road side in the area of Keerqing. It will have minimum drilling resistance torque and efficiency tree planting when the auger bit with 300 to 400 rpm rotation speed and 0.047m/s feeding speed. The test also shows that torque has not big change by using difference augers'tip and different angle of soil cutting blade on the end of auger's spiral wing. The maximum drilling torque was less than 90Nm in all tests using the auger bits with diameter of 90mm, spiral wing throw of 75mm and hole length of 1.7m. The results of the tests supply reliable data for similar kind of machine design, power unit select and hydraulic components choosing. The test of traction resistance for Medium Depth Planter reveals almost a line relation between its tow resistance and depth of soil loose. The machine traction resistance would be 0.79 times its working depth and plus rolling resistance. The maximum working depth would be 80cm underground if DHF tractor with 50 to 60kW as power to tow the machine. The results of the test would be theoretical basis to design same machine and furrowed tree planter. The theoretical and test research of tree planting equipment used in arid area give out theoretical and reliable basis for afterwards machine design and manufacture. The developed two tree deep planting machines are suited local conditions and have been distributed in that area. The machines will act the role to speed up combat desertification by their tree planting efficiency.