Fig. 1. Grain yields and fertilizer rates. A and B, Box and whisker plots showing rice grain yield of blanket recommendations, basic calibration (NESL1) (A), and comprehensive calibration (NESL2) (B). The red line denotes the mean. Different lowercase letters near the red lines indicate significant difference in average yields at P < 0.05 by paired sample t-test. C-H, Recommended fertilizer rates by NESL1 (n = 71) and NESL2 (n = 26) for experimental sites: nitrogen (N) (C and D), phosphorus (P) (E and F), and potassium (K) (G and H). Red horizontal lines represent nutrient amounts supplied by the blanket recommendation.

Fig. 2. Plant uptake of nitrogen (N), phosphorus (P), and potassium (K). A-C, N uptake by rice plants: total N uptake (A), grain N uptake (B), and straw N uptake (C) under the blanket and basic calibration (NESL1) fertilizer management (n = 71). D-F, P uptake by rice plants: total P uptake (D), grain P uptake (E), and straw P uptake (F) under the blanket and NESL1 fertilizer management (n = 71). G-I, K uptake by rice plants: total K uptake (G), grain K uptake (H), and straw K uptake (I) under the blanket and NESL1 fertilizer management (n = 71). The box’s bottom line indicates the 25th percentile, the middle line represents the median, and the top line signifies the 75th percentile. The red line denotes the mean, while the whiskers represent the minimum value and the upper end represents the maximum value. Different lowercase letters near red lines indicate significant differences in average yields at P < 0.05 by paired sample t-test.