Table 2 Biochar mean total macro-element concentrations (± standard error of the mean) based on pyrolysis type, feedstock source, and pyrolysis temperature, on a dry weight basis

60.6 ± 0.47

3.37 ± 0.08

19.1 ± 0.38

1.63 ± 0.06

0.85 ± 0.09a

14.2 ± 0.72

46.8 ± 4.69a

44.3 ± 4.01a

43.5 ± 12.1a

60.8 ± 0.34

3.36 ± 0.09

18.4 ± 0.29

1.63 ± 0.04

0.55 ± 0.04b

12.0 ± 0.56

22.8 ± 1.33b

29.1 ± 1.68b

5.73 ± 0.30b

70.5 ± 0.39a

3.38 ± 0.08b

17.7 ± 0.35bc

0.95 ± 0.03d

0.44 ± 0.07b

4.00 ± 0.46d

19.3 ± 2.62c

26.3 ± 2.60b

5.18 ± 0.84b

61.4 ± 0.41c

3.28 ± 0.10b

18.1 ± 0.38b

1.54 ± 0.06c

0.39 ± 0.06b

8.00 ± 0.97c

40.9 ± 3.62b

20.7 ± 2.16b

6.06 ± 0.76b

63.6 ± 0.72b

5.11 ± 0.50a

20.9 ± 0.74a

1.80 ± 0.14b

0.51 ± 0.21b

20.1 ± 6.08b

59.1 ± 12.2a

45.9 ± 12.0a

34.3 ± 12.7b

41.6 ± 0.68d

2.73 ± 0.10c

16.5 ± 0.70c

2.42 ± 0.06a

0.89 ± 0.06a

25.7 ± 1.44a

25.3 ± 1.79c

52.7 ± 3.64a

57.8 ± 20.5a

54.1 ± 0.59e

5.62 ± 0.25a

30.6 ± 0.60a

1.70 ± 0.10ab

0.43 ± 0.06

9.03 ± 1.32b

26.7 ± 5.24

25.0 ± 4.67bc

5.41 ± 0.88ab

58.0 ± 0.58d

4.70 ± 0.24b

23.6 ± 0.50b

1.81 ± 0.09a

0.44 ± 0.07

9.60 ± 1.56b

23.8 ± 4.04

23.0 ± 4.03c

43.0 ± 22.1a

62.3 ± 0.59bc

3.78 ± 0.19c

18.1 ± 0.41c

1.61 ± 0.08b

0.54 ± 0.08

10.1 ± 1.40b

32.7 ± 3.93

34.7 ± 4.80bc

9.61 ± 3.44ab

62.5 ± 0.59bc

2.83 ± 0.09d

14.2 ± 0.40d

1.34 ± 0.04c

0.54 ± 0.09

11.8 ± 1.36b

32.6 ± 3.93

28.6 ± 2.84c

24.3 ± 9.22b

65.8 ± 0.87a

2.31 ± 0.11e

12.7 ± 0.52e

1.32 ± 0.07c

0.60 ± 0.10

12.6 ± 2.29b

26.8 ± 4.93

36.0 ± 5.25abc

9.87 ± 3.51ab

64.7 ± 1.30ab

1.77 ± 0.12ef

13.0 ± 0.90de

1.26 ± 0.07c

0.63 ± 0.14

18.8 ± 2.49a

34.1 ± 8.68

43.0 ± 6.42ab

10.1 ± 4.25ab

61.0 ± 1.82c

1.45 ± 0.12f

9.51 ± 1.00f

1.51 ± 0.26abc

0.36 ± 0.07

14.5 ± 3.68ab

34.5 ± 6.21

54.1 ± 11.8a

12.7 ± 3.50ab