Fig. 2

Variations in four indirect spectral vegetation indices, normalized difference vegetation index (NDVI), red edge normalized ratio (NR_{red edge}), green chlorophyll index (CI_green), red edge chlorophyll index (CI_{red edge}), and six water-sensitive spectral vegetation indices, water index (WI), moisture stress index (MSI), simple ratio water index (SRWI), normalized difference water index (NDWI), normalized difference water index centered at 1640 nm (NDWI₁₆₄₀), and normalized difference water index centered at 2130 nm (NDWI₂₁₃₀) under different water treatments during the growing season of 2013 for maize agroecosystem. Treatments 1–7 indicate seven different irrigation amounts, 120 + 80, 100 + 40, 80, 60, 40, 25, and 15 mm as well as a rainfed control plots with no irrigation (Control) and a rainfed field control (Field)