Crop Residue (tons ha⁻¹)

Humic Acid (kg ha⁻¹)

Mean

1

1.5

2

2.5

5 Mungbean

1.6

1.8

2.1

2.8

2.1 a

10 Wheat Straw

1.1

1.3

1.6

2.0

1.5 c

2.5  mungbean + 5 wheat straw

1.3

1.4

1.8

2.2

1.7 b

Mean

1.3 d

1.5 c

1.8 b

2.3 a

Control

0.5 b

Rest of treatments

1.7 a