关键词: 地理信息系统, 水稻, 产量, 施氮量, 吉林省

Abstract: 【Objective】The differences of nitrogen fertilizer effect in rice planting regions were studied to strengthen precision nitrogen management, to increase crop yield and fertilizer use efficiency, and to reduce nitrogen emission from farmland.【Method】Rice yield and effect of applied nitrogen fertilizer in different rice planting regions in Jilin Province were studied to explore the differences of nitrogen effect and emission reduction potential in different regions with no nitrogen fertilizer treatment (N₀P₂K₂) as the control, three levels of nitrogen fertilizer application treatments including (0.5N₂P₂K₂), (N₂P₂K₂), (1.5N₂P₂K₂) were designed in “soil testing and formulated fertilization” field experiment carried out in 2005-2013 in Jilin Province. 【Result】The results showed that rice yields in different regions in Jilin Province were variant significantly, the highest was in the western region, and the lowest was in the eastern region. The yield in western region averaged 7.6 t·hm^-2 with no nitrogen fertilizer application, yield differences of which reached 2.1 t·hm^-2 and 2.2 t·hm^-2 on an average, respectively, compared to that in the central and eastern regions. With nitrogen fertilizer application, minimum increasing yield rate in the central and eastern regions was 29.8% (the maximum was 59.5%), which was significantly higher than 12.6% in the western region (the maximum was 29.4%). Agronomic utilization ratios of nitrogen fertilizer in the central and eastern region were 12.2-19.7 kg·kg^-1 and 12.5-19.5 kg·kg^-1, far higher than 8.8-13.1 kg·kg^-1 in the western region. Function relation between the nitrogen fertilizer rate and net income was established by maximum economic income(MRTN) method to calculate the best nitrogen application rate. The optimal nitrogen rate in the western region, central region and eastern region was 114.9, 128.9, and 134.1 kg·hm^-2, respectively, which reduced by 25.6, 18.3, and 5.3 kg·hm^-2, respectively, compared with the recommended fertilizer rate. With no significant differences in rice yield, nitrogen fertilizer rate decreased in three regions, especially in western and central regions. By calculating nitrogen reduction cost and yield income, economic benefit was increased in all regions, especially in the western region. Yearly nitrogen input reduction in western, central and eastern regions in Jilin Province was 4 378, 7 064 and 604 t respectively; nitrogen emission reduction was 98.2, 158.6, and 13.6 t, respectively, by optimal fertilizer amount input with no obvious yield differences. 【Conclusion】Measures should be made to control the nitrogen fertilization rate in western region; total emission reduction potentials in central region is the largest because of the planting areas; fertilizer application rate in the eastern region is moderate presently, rice yield can be improved by cooperating with other management measures to reduce the limitation of natural factors.

Key words: geographic information system(GIS), rice, yield, nitrogen fertilizer rate, Jilin Province