| Rice and wheat is the main rotation crop in the middle and lower reaches of the Yangtze River of China, nitrogen plays a important role on rice and wheat high-yield. However, unreasonable application of nitrogen fertilizer was lead to low crop nitrogen utilization. Most of the nitrogen losses to the environment, and leads to an increase of greenhouse gas emissions and water eutrophication. Our field experiment studied the effects of disposable simplified fertilization on physiological characteristics and nitrogen utilization of rice and wheat, provide technical guides for simplify fertilization application and improve nitrogen utilization on rice and wheat rotation crop.In this paper, there were 5 treatment in rice season:no fertilization (T1)?conventional fertilization (T2)?a blend with 20% of N from control-release urea and 80% from urea (T3)?a blend with 30% of N from control-release urea and 70% from urea (T4)?total N decreased by 15%, a blend with 30% of N from control-release urea and 70% from urea (T5),6 treatment in wheat season:no fertilization treatment (T1)?conventional treatment (T2)?a blend with 30% of N from control-release urea and 70% from urea (T3)?total N decreased by 15%, a blend with 30% of N from control-release urea and 70% from urea (T4).The main results were as follows:(1) in the rice season, T4 treatment perform the best effect on physiological characteristics in each growth stages, compared with the conventional fertilization treatment, rice yield increased by 4.66%, and agronomic nitrogen use efficiency, nitrogen fertilizer utilization rate, nitrogen partial productivity increased by40.18%,24.99%,22.09% respectively. (2) In wheat season, in T2 treatment, although wheat physiological characteristics were the worst in the early growth period than those in other treatment, but after topdressing there were no significant difference between them, and nitrogen utilization rate and the yield were the highest. T3 treatment was second only to T2 in the nitrogen utilization rate and yield. T3 treatment reduced the yield by 8.16% as compared with T2. Therefore, we suggested that the increased proportion of the water base coating controlled release fertilizer is better for nitrogen supply during the later growth stage of wheat season.(3) In our experiment, in-situ measurement of ammonia and nitrous oxide concentration in soil headspace using mid-infrared photoacoustic spectroscopy was applied in the field experiment, Compared with the traditional chamber detection method, our monitoring method of soil headspace has three advantages:First, there is no need any chemical reagent for collection gas sample, it can reduce the error caused by chemical experiments; Second, the experimental process is simple, direct scanning, do not require tedious chemical experiments; Third, our monitoring method of soil by headspace is in situ analysis method, which can better reflect the real situation, whereas, chamber methods change the inner temperature, humidity and air flow to some extent.In our study, we proved that the water-based coating controlled-release fertilizer has good effects on rice and wheat rotation system in the middle and lower reaches of the Yangtze River. The T4 treatment in rice season was superior to the conventional fertilization treatment in the nitrogen utilization rate and physiological characteristics; In order to meet the nitrogen supply during the later growth stage of wheat season, the proportion of water base coating controlled-release fertilizer should be increased. Thus, water-based coating controlled-release fertilizer has good application potential in field production. |
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