Study On Drip Irrigation Technique Of Mulching Apple Orchard

Based on the principle water balance, the drip irrigation technique such as irrigation quota, irrigation position, irrigation crucial stage, irrigation frequency, irrigation planned depth of wetted soil, percentage of wetted soil, irrigation way, and hair canal distribution, were studied by means of field and pit experimentation under the grass mulch, plastic film mulch and clean tillage conditions, respectively. The study was conducted on Beizhuang Experiment Station of Shangxiao Country in Qingyang city, and the results were as follows:1.The water requirement for Fuji apple tree during the whole growing period were 433.5 mm～478.5mm, but the effective rainfall at the same period in the experimental area were 355.6 mm～449.6mm, which was only account for 82%～94% of water requirement. Even taken the mulching measurement, the water consumption reduced not more than 9.39% for the grass mulch, and 5.85% for the plastic film mulch compared to clean tillage. Therefore, irrigation play an very important role in the improving fruit quality and increasing fruit production in the Qingyang city.2. According to the regulation of water requirement and growth and development, the optimum drip irrigation time were pre- germination, new shoot growing stage, fruit swelling stage, and pre-period of freezing weather. The drip irrigation quota was 1030m~3/hm~2 at the normal year (50%). The drip irrigation quota was increased 10%-20% and optimum drip irrigation time was also increased to 4-5 times (2times at fruit swelling stage) at the slightly dry year(75%). The drip irrigation quota was increased 15%-30% and optimum drip irrigation time was also increased to 5-6 times (2 times at new shoot growing stage, 2 times at fruit swelling stage) at the seriously dry year(95%). The drip irrigation quota can reduced 5%-10% for grass mulch or plastic film mulch compared to clean tillage.3.The main roots of Fuji apple tree were distributed 10cm-50cm below surface and 1/3-2/3 of crown radial from stem on horizontal directions. While the drip water reached 30 liters, the soil-wetting dimension meet the needs of main roots distribution. So the optimum drip irrigation norm per times was30 liters or 240 m~3/hm~2.4.Due to the main effective roots of Fuji apple tree were situated at 1/3-2/3 of crown radial from stem on horizontal directions, and distributed as a cirque, the drip irrigation tube-lateral line should layout on the cirque surface and forming a "S" type, which can be easily carry out, for the drip tube were moveable on the land.5.The water productivity of Fuji apple tree was affected by fruit production, and was increased with the production increasing. The treatment of mulch with plastic film was best, and its water productivity was 5.4 kg/m3, economic effect of irrigation was 6.39 yuan/m3. Next was grass mulch, and clean tillage among three treatments.6.Semi-fixed drip irrigation is very useful in the orchards, for the lateral line can movable easily. At the same time, the irrigation way can induce the tree's roots expand to outside, which can increase drought resistant of the fruit tree's.