Table 2 Balanced distribution of NIR spectra used for each rice genotype across nitrogen treatments. The table outlines the allocation of spectra for each PCA-LDA model (Model 1, model 2, and model 3), ensuring equal representation across training (TR, n = 90), cross-validation (CV, n = 30), and test (TE, n = 60) sets. Spectra were evenly distributed among three individual plants (P1, P2, and P3) within each dataset split, maintaining a balanced representation across nitrogen treatments.

From: Improving nitrogen use efficiency in rice by estimating leaf nitrogen content with near-infrared spectroscopy and chemometric modeling

Day

Model

Process

Plant

Nitrogen treatment

0%

25%

50%

75%

100%

Total spectra

1

1

TR (n=90)

P1

9

9

9

9

9

45

P2

9

9

9

9

9

45

P3

0

0

0

0

0

0

CV (n=30)

P1

3

3

3

3

3

15

P2

3

3

3

3

3

15

P3

0

0

0

0

0

0

TE (n=60)

P1

0

0

0

0

0

0

P2

0

0

0

0

0

0

P3

12

12

12

12

12

60

2

TR (n=90)

P1

9

9

9

9

9

45

P2

0

0

0

0

0

0

P3

9

9

9

9

9

45

CV (n=30)

P1

3

3

3

3

3

15

P2

0

0

0

0

0

0

P3

3

3

3

3

3

15

TE (n=60)

P1

0

0

0

0

0

0

P2

12

12

12

12

12

60

P3

0

0

0

0

0

0

3

TR (n=90)

P1

0

0

0

0

0

0

P2

9

9

9

9

9

45

P3

9

9

9

9

9

45

CV (n=30)

P1

0

0

0

0

0

0

P2

3

3

3

3

3

15

P3

3

3

3

3

3

15

TE (n=60)

P1

12

12

12

12

12

60

P2

0

0

0

0

0

0

P3

0

0

0

0

0

0

2

1

TR (n=90)

P1

9

9

9

9

9

45

P2

9

9

9

9

9

45

P3

0

0

0

0

0

0

CV (n=30)

P1

3

3

3

3

3

15

P2

3

3

3

3

3

15

P3

0

0

0

0

0

0

TE (n=60)

P1

0

0

0

0

0

0

P2

0

0

0

0

0

0

P3

12

12

12

12

12

60

2

TR (n=90)

P1

9

9

9

9

9

45

P2

0

0

0

0

0

0

P3

9

9

9

9

9

45

CV (n=30)

P1

3

3

3

3

3

15

P2

0

0

0

0

0

0

P3

3

3

3

3

3

15

TE (n=60)

P1

0

0

0

0

0

0

P2

12

12

12

12

12

60

P3

0

0

0

0

0

0

3

TR (n=90)

P1

0

0

0

0

0

0

P2

9

9

9

9

9

45

P3

9

9

9

9

9

45

CV (n=30)

P1

0

0

0

0

0

0

P2

3

3

3

3

3

15

P3

3

3

3

3

3

15

TE (n=60)

P1

12

12

12

12

12

60

P2

0

0

0

0

0

0

P3

0

0

0

0

0

0

3

1

TR (n=90)

P1

9

9

9

9

9

45

P2

9

9

9

9

9

45

P3

0

0

0

0

0

0

CV (n=30)

P1

3

3

3

3

3

15

P2

3

3

3

3

3

15

P3

0

0

0

0

0

0

TE (n=60)

P1

0

0

0

0

0

0

P2

0

0

0

0

0

0

P3

12

12

12

12

12

60

2

TR (n=90)

P1

9

9

9

9

9

45

P2

0

0

0

0

0

0

P3

9

9

9

9

9

45

CV (n=30)

P1

3

3

3

3

3

15

P2

0

0

0

0

0

0

P3

3

3

3

3

3

15

TE (n=60)

P1

0

0

0

0

0

0

P2

12

12

12

12

12

60

P3

0

0

0

0

0

0

3

TR (n=90)

P1

0

0

0

0

0

0

P2

9

9

9

9

9

45

P3

9

9

9

9

9

45

CV (n=30)

P1

0

0

0

0

0

0

P2

3

3

3

3

3

15

P3

3

3

3

3

3

15

TE (n=60)

P1

12

12

12

12

12

60

P2

0

0

0

0

0

0

P3

0

0

0

0

0

0