Study On The Schedule And Water-Fertilizer Coupling Techniques Of The Cotton Under Mulched Drip Irrigation

According to technology application characteristic of cotton mulched drip irrigation in Sinkiang, experiments were conducted to test irrigation schedule of cotton under mulched drip irrigation and coupling effect of soil water and fertilizer on the base of results of water infiltration into soil. The results showed that: (l)Under condition of equal irrigation quantity, the width of horizontal wetted edge of the heavy loam is larger than the one of moderate loam, then the latter is larger than light loam., but the width of vertical one is opposite. When the flux of emitter is 4 liters per hour and total quantity is 41.5 liters, the width of wetted edge reach to 1.4 meters, which make layout of one dripline with four row crop possible. (2) Under condition of normal year, the cotton water consumption under mulched drip irrigation is about between 500 and 600 millimeters, during the seedling , booming-bolling and open boll is respective 2, 9 and 4mm/day. In total growth period total irrigation quantity is 3000-3300 m~3/ hm~2, irrigation times is about 10 times. Compared cotton under mulched drip irrigation with furrow irrigation, the lint output of drip irrigation increased by 24%, and saved water up to 61%. WUE is 0.63. kg/m~3. (3)In the whole growth time the better parameters of coupling soil water and fertilizer are that irrigation ration is 3000-3300 m~3/hm~2, fertilizing pure nitrogen 180~225 kg/hm~2, which fertilize 5% in seedling, 25-30% from boiling to booming, 60-65% from booming to open boll and 5% from open boll to mature.