| 【Objective】In the face of the current situation of excessive fertilizer application in farmland, the nitrogen application of maize needs to be further explored under the condition of drip irrigation and fertigation in Xinjiang. Use the function equation of fertilizer effect and the application of nitrogen diagnosis technology to the recommend fertilization of Maize, reduce nitrogen and increase ammonium to improve nitrogen nutrition status of drip irrigation corn, in order to save nitrogen and improve the utilization rate of nitrogen fertilizer, optimization of nitrogen fertilizer application in Maize under the condition of drip irrigation with water and nitrogen in arid area of Xinjiang. 【Method】In this study a two-year nitrogen test was set up:(1) five levels of nitrogen treatments(0, 225, 330, 435, 540 kg/hm2) in 2013 year.(2) Different Nitrogen and increase ammonium treatments(N0, N375,75%N375+CP, N375+CP) in 2014 year. Explore the response law of dry matter and nitrogen, construct nitrogen application model and optimize the application rate nitrogen fertilizer. 【Result】(1) Field experiment in 2013-2014 years showed that maize yield, dry matter production and nitrogen uptake were increased significantly with the increase of the amount of nitrogen fertilizer, but when nitrogen application amount is higher than 435 kg N/hm2 was decreased, the order was: N435 > N540 > N330 > N225 > N0. The order of different nitrogen and increas ammonium treatments was: N375+CP > N375 > 75%N375+CP > N0, but there was no significant difference between each treatments.(2) Appropriate increase of the amount of Nitrogen and Nitrogen combined application with Nitrapyrin can extend the dry matter vigorous growth period, the maximum accumulation rate of dry matter of the N435 and N375+CP treatment were higher than other treatments(807.0 kg/hm2·d and 785.9 kg/hm2·d respectively).(3)The Nmin content in 0 ~ 20 cm Topsoil were higher in the N540 and N375 + CP treatment, ammonium nitrate ratios were no significant difference between different levels of nitrogen treatments; the different nitrogen and increase ammonium treatments increased the content of ammonium nitrogen, inhibited the conversion of nitrate nitrogen and increased soil ammonium nitrate ratio.(4) According to a function between yield and Nitrogen availability Nitrogen Tianshan Mountains drip corn economically optimal yield 17049 kg/hm2 under the 402.5 kg/hm2. Ammonium nitrogen fertilizer and increasing treatment can significantly increase the number of corn grain, single panicle weight. N partial factor productivity and nitrogen use efficiency increased with nitrogen rate decreased nitrogen use efficiency performance N225(46.6%)> N330(45.8%)> N435(43.6%)> N540(34.6%). Drip N partial productivity of maize and nitrogen use efficiency are 75% N375 + CP treatment was the highest, respectively, compared with 330 ~ 435 kg/hm2 between the average of other treatments increased 31.4%, 27.9% and 5.8%, 6.4%. 【Conclusion】(1) With the increase of nitrogen fertilizer, drip Irrigated Maize Dry matter, nitrogen accumulation amount increased constantly, but more than 435 kg/hm2 becomes constant and decreasing trend. Urea fertilizer Nitrapyrin can improve maize dry matter and nitrogen accumulation, which N375+CP treatment showed the best.(2) Maize Leaf SPAD value, leaf nitrate content and nitrogen application rate showed very significant positive correlation(P < 0.05). Through the SPAD chlorophyll meter and nitrate reflex instrument can be on the drip irrigation of maize were fast nitrogen diagnosis. But in every stage of corn growth NO3- content and nitrogen application amount, yield equation were higher than those of the SPAD value. Nitrate quick test is determination of SPAD value of nitrogen abundance and deficiency response more sensitive, the stability of data.(3) Based on the nitrate reflex instrument to diagnose maize jointing stage, pumping silking stage and filling stage of NO3- critical diagnostic value, respectively 729.3 mg/L, 536 mg/L and 81.2 mg/L, the corresponding unit of NO3- content changes applied amount of nitrogen was 0.178 kg/hm2, 0.452 kg/hm2, 3.82 kg/hm2.(4) On the northern slope of Tianshan Mountains drip irrigated maize optimize the economic quantity of nitrogen fertilizer is of combined of 402.5 kg/hm2. Urea and Nitrapyrin drip application(75%N375+CP) can make the application amount of nitrogen reduced by 25% than conventional recommended amount(93.8 kg/hm2), reduction of nitrogen enhanced ammonium measures can significantly improve the drip irrigated maize nitrogen utilization efficiency, reducing nitrogen application amount did not result in Maize Production. |
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