Chin J Plant Ecol ›› 2006, Vol. 30 ›› Issue (2): 261-267.DOI: 10.17521/cjpe.2006.0035

• Original article • Previous Articles     Next Articles

QUANTITATIVE RELATIONSHIPS BETWEEN CANOPY SPECTRAL REFLECTANCE AND LEAF STOMATAL CONDUCTANCE IN RICE

TIAN Yong_Chao, ZHU Yan, YAO Xia, ZHOU Chang_Jun, CAO Wei_Xing*()   

  1. Hi-Tech Key Laboratory of Information Agriculture, Jiangsu Province, Nanjing Agricultural University, Nanjing 210095, China
  • Accepted:2005-02-23 Published:2006-03-30
  • Contact: CAO Wei_Xing

Abstract:

This investigation was conducted to determine the quantitative relationship between leaf stomatal conductance and canopy spectral reflectance of rice crops under different water and nitrogen regimes. Results showed that leaf stomatal conductance on main stem leaves under different water treatments decreased in the following order throughout the growth cycle: GsL1 > GsL2 > GsL3 > GsL4. The leaf stomatal conductance in the high nitrogen treatment was higher than in the low nitrogen treatment when the soil water content was above W3. Below W3, there were no significant differences in leaf stomatal conductance between the high and low nitrogen treatments. It also was found that the correlation between the ratio index R(1 650, 760) and stomatal conductance averaged over different layer leaves was the following: GsL1 > GsL12 > GsL123 > GsL1234 > GsL2 > GsL3 > GsL4 (GsL1, GsL2, GsL3, GsL4, GsL12, GsL123 and GsL1234 denoted the first, second, third, fourth leaf and two leaves, three leaves, four leaves from top). The best relationship was between canopy stomatal conductance (the product of GsL1 and LAI) and R(1 650, 760). The ratio index R(1 650, 760) showed a power relationship with both stomatal conductance of L1 and canopy leaf stomatal conductance with an RMSE of 0.05 and 0.24, respectively. It was concluded that the ratio index R can be used to monitor leaf stomatal conductance during different growth stages of rice.

Key words: Rice, Stomatal conductance, Reflectance spectra, Vegetation index, Monitoring