关键词: 黄土旱田, 轮作, 免耕, 秸秆覆盖, 杂草

Abstract: Using the data observed with ASD FieldSpec Pro FR spectroradiometer based on a trial with various levels of drought stress during different growth periods of maize in Jinzhou, Liaoning Province, the variation characteristics of maize canopy hyperspectral reflectance were investigated and inversion models on soil water content considering spectral parameters were established. The results showed that, after drought stress during the period from seven leaves to jointing, the spectral reflectance within spectral bands of 750 to 1400 nm, the amplitude and the area of red edge decreased and the time of their response to drought stress was shorter, and differed from those under wellwatered condition, while the reflectance within the spectral bands from 350 to 750 nm and from 1400 to 2300 nm demonstrated an increasing trend. As far as inversion methods, the inversion error of soil water content with regression method based on hyperspectral reflectance was smaller than that of first derivative spectra. Moreover, the inversion accuracy of soil water content at the 10 cm depth was higher than that at the depth of 30 cm.

Key words: dry land of loess region, rotation, no-tillage, stubble retention, weed.