Objective: This paper focuses on exploring the effect of two chlorinated pyridine nitrification inhibitors under drip irrigation on soil nitrogen transformation and the yield of cotton. Method: A field experiment was conducted on nitrification inhibitor in cotton drip irrigation in the Agricultural Center. Result: The two types of tested nitrification inhibitor showed significant inhibitory effect on nitrification six days after they are applied with water drops, the content of soil NH 4+-N increased 3.82%-211.25%, NO 3--N decreased 56.2%-77.12%, the rate of apparent nitrification decreased 2.66%-52.83% compared with control treatment, the nitrogen validity increased by 1.54-4.15 percent, the increase of seed cotton yield per hectare is 202.5-247.5 kg, which showed 3.43%-4.3% increase rate, the newly increased economic benefit is 1 059-1 306.5 RMB. Conclusion: Under drip irrigation, the nitrification inhibitors apply with water drops, which is easy to operate and can effectively improve the N nutrition level of the cotton plants, therefore, the yield increase is significant.
