中国棉花遥感估产最佳时相的选择

The Effect of Different Stocking Rate on Greenhouse Gases N 2O and CH 4 Fluxes from Grazing Grassland Ecosystem

兼顾棉花遥感识别和单产遥感估算的要求，综合考虑多种因素，分析了棉花遥感估产最佳时相的选择依据和方法，并在选择全国各地棉花遥感估产最佳时相的基础上，作出了最佳时相分区图，供棉花估产者参考。

Using the closed chamber technique,the in situ measurements of N 2O(N 2O-N) and CH 4(CH 4-C) fluxes from temperate semi-arid grazing grassland ecosystem was firstly conducted in the Inner Mongolia.The range of N 2O fluxes from low stocking rate medium stocking rate,top stocking rate,and nonstocking rate grasslands were 1.64～9.69、0.07～18.05、1.22～11.17 and -0.42～10.47μg·m -2 ·h -1 ,respectively.Their annual average N 2O fluxes were 0 31、0 45、0 42 and 0.31 kg·hm -2 ·a -1 . The range of CH 4 fluxes were -54 58～5 27、 -36 39～-6 44、-43 17～-19 06 and -47 76～-16 99μg·m -2 ·h -1 .Their annual average CH 4 fluxes were -1.88、-1.89、-2.03 and -2.05 kg·hm -2 ·a -1 .