| We intercalate 5 treatments of N dosage which is 0,90,180,270,360 kg/hm2,to obsere the crop's growth and the accumulated material of these treatments in the drip irrigation cotton field,and establish the recommendatory-decision system tried.The result shows that the treatment 270 kg/hm2 is the best and we got the return model of the seed cotton yield(y) and the nitrogen fertilizer dosage(x),which is y=3271.82+14.46x-0.0312x2(R=0.9604*). |