**3.2 Soil**

The initial Villacañas test soil plot (**Table 3**) had a sandy loam texture [33], basic pH (8.6) and was somewhat saline. The contents of Cl<sup>−</sup> (42 mg kg−1), CEC (12.3 meq 100−1 g), Fe (2.72 mg kg−1), Zn (0.27 mg kg−1) and Cu (0.78 mg kg−1) were medium, while the levels of organic matter (1.69%) and total N (0.09%) were low [34]. Normal N release was indicated by the C:N ratio (11) [35]. Finally, the amounts of P (19 mg kg−1), total CO3 2− (30.5%), K (0.66 meq 100−1 g), Na (1.70 meq 100−1 g) and Mn (0.70 mg kg−1) were high [34].

Soil from the Quero test plot (**Table 3**) had higher pH (9.15) than the Villacañas one, but the difference lay in a very saline soil. The contents of Cl<sup>−</sup> (153 mg kg−1) and K (0.77 meq 100−1 g) were high. Na (3.80 meq 100−1 g) and Ca (87.14 meq 100−1 g) came in large amounts. Organic matter content (2.22%), total CO3 2− (15.63%), CEC (10 meq 100−1 g), Zn (0.38 mg kg−1), Cu (0.35 mg kg−1) and Mn (2.15 mg kg−1) were medium [34]. The C:N ratio indicated little N release [35].

The main difference between the original soils of both plots were salinity and SO4 2− content as the Quero plot soil was very saline (EC: 13.65 mmhos cm−1) and rich in gypsum (2,102 mg 100−1 g), unlike the Villacañas soil (EC: 0.52 mmhos cm−1 and 75 mg 100−1 g, respectively).

In the soils to which CF was applied significant differences were observed between Villacañas and Quero for all the analysed parameters (**Table 6**), except for Cu, Mn and CEC.

In the Quero plot soil (**Table 4**), the values of pH (9.14), EC (19.86 mmhos cm−1) and the C:N ratio (6.37), and the contents of Cl− (286 mg kg−1), SO4 2− (857 mg 100−1 g), organic matter (1.6%), N in all its forms (total-N: 0.15%; nitric-N: 25 mg kg−1; soil-N: 94 kg ha−1), Zn (0.33 mg kg−1), B (3.59 mg kg−1), K (1.89 meq 100−1 g), Na (6.8 meq 100−1) and Ca (100.12 meq 100−1 g) were significantly higher than in the Villacañas plot (pH:8.2; EC: 0.56 mmhos cm−1; C:N ratio: 4.4; Cl<sup>−</sup> : 19.33 mg kg−1), SO4 = : 64.3 mg 100−1 g; organic matter: 0.7%; total-N: 0.09%; nitric-N: 3.67 mg kg−1; soil-N: 14.3 kg ha−1; Zn: 0.19 mg kg−1; B: 0.12 mg kg−1; K: 0.53 meq 100−1 g; Na: 0.59 meq 100−1 g) and Ca: 25.25 meq 100−1 g). On the contrary in Villacañas, the percentages of total CO3 2−(29.45%), the K:Mg (0.56) and Ca:Mg (28.67) ratios, Fe (1.12 mg kg−1) and P (9.3 mg kg−1) contents were significantly higher than those obtained in Quero (CO3 2−: 14.19%; K:Mg and Ca:Mg ratios: 0.06 and 3.03, respectively; Fe: 0.31 mg kg−1 and P: < d.l: detection limit).

Regarding SS treatment, no significant differences were observed between Villacañas and Quero with respect to the content of organic matter, total N, total CO3 2−, Cu, Mn or CEC (**Table 6**).

The differences were significantly greater in Quero regarding pH value (9.01), EC (18.56 mmhos cm−1), Cl− (362.6 mg kg−1), SO4 = (860 mg 100−1 g), C:N ratio (6.7), nitric N (38 mg kg−1), soil N (142.6 kg ha−1), Zn (0.92 mg kg−1), B (5.8 mg kg−1), K (2.1 meq 100−1 g), Na (5.8 meq 100−1 g) and Ca (93.28 meq 100−1 g).

**163**

pH EC Cl− SO4

Total CO3

Organic matter

Total -N

Nitric-N

Soil-N Ass. P Ass.Fe Ass.Zn Ass.Cu Ass.Mn

Ass.B

CEC Ass.K Ass.Na Ass.Ca

meq 100−1 g meq 100−1 g meq 100−1 g

0.0001\*

25.25 a

100.12 b

0.0001\*

26.03 a

93.28 b

0.0000\*

24.8 a

100.05 b

0.0062\*

0.59 a

6.8 b

0.0166\*

0.65 a

5.8 b

0.0019\*

0.67 a

7.17 b

0.0048\*

0.53 a

1.89 b

0.0023\*

0.54 a

2.1 b

0.0005\*

0.47 a

2.06 b

(%)

% mg kg−1 kg ha−1 (\*\*)

mg kg−1 mg kg−1 mg kg−1 mg kg−1 mg kg−1 mg kg−1 meq 100−1 g

0.4398

14.15 a

12.27 a

0.3994

12.9 a

15.2 a

0.1286

13.8 a

15.1 a

0.0004\*

0.12 a

3.59 b

0.0458\*

0.1 a

5.8 b

0.0055\*

0.2 a

4.5 b

0.4285

4.9 a

3.5 a

0.0717

7.3 a

3.8 a

0.0181\*

8.7 b

3.9 a

0.0948

0.51 a

0.38 a

0.1265

0.62 a

0.47 a

0.4762

0.57 a

0.49 a

0.0087\*

0.19 a

0.33 b

0.0681

0.38 a

0.92 b

0.2264

0.68 a

0.93 a

0.0183\*

1.12 a

0.31 b

0.1177

2.24 a

0.5 a

0.0005\*

2.31 b

0.4 a

0.0030\*

9.3 b

<d.l

0.0016\*

12.7 b

<d.l

0.0061\*

17.7 b

<d.l

0.0021\*

14.3 a

94.0 b

0.0018\*

30.6 a

142.6 b

0.0003\*

24.3 a

152.6 b

0.0020\*

3.67 a

25.0 b

0.0016\*

8.0 a

38 b

0.0003\*

6.3 a

40.6 b

0.0011\*

0.09 a

0.15 b

0.1757

0.13 a

0.16 a

0.0035 a

0.103 a

0.200 b

0.0102\*

0.7 a

1.6 b

0.1797

0.99 a

1.86 a

0.053

0.8 a

2.25 a

=

=

mmhos

0.0157\*

0.56 a

19.86 b

0.0132\*

0.36 a

18.56 b

0.0027\*

0.47 a

18.38 b

cm−1

mg kg−1 mg 100−1 g

%

0.0442\*

29.45 b

14.19 a

0.1287

39.98 a

15.18 a

0.0386\*

32.8 b

13.34 a

0.0000\*

64.3 a

857 b

0.0000\*

46 a

860 b

0.0000\*

42.3 a

860 b

0.0106\*

19.33 a

286 b

0.0082\*

19.33 a

362.6 b

0.0006\*

20.6 a

327.3 b

**CF**

**P-value**

0.0133\*

8.2 a

9.14 b

0.0238\*

8.4 0a

9.01 b

0.0011\*

8.4 a

9.01 b

**V**

**Q**

**P-value**

**V**

**Q**

**P-value**

**V**

**Q**

**SS**

**CS**

*Sewage Sludge to Fertilise Durum Wheat: Effects on Crop and Soil*

*DOI: http://dx.doi.org/10.5772/intechopen.95896*


#### *Sewage Sludge to Fertilise Durum Wheat: Effects on Crop and Soil DOI: http://dx.doi.org/10.5772/intechopen.95896*

*Humic Substances*

The maximum yield was obtained in the Quero plot (3,423 kg ha−1) with the minimum one in Villacañas (2,884 kg ha−1), both cases with CS (**Table 5**). It was, therefore, clear that soil type strongly influenced crop response to the application of the same product. In Villacañas, the highest yield was obtained with SS (3,371 kg ha−1) and the lowest with compost (2,884 kg ha−1). On the contrary, CS treatment gave the highest yield in the Quero plot (3,423 kg ha−1), where the lowest

The initial Villacañas test soil plot (**Table 3**) had a sandy loam texture [33],

(12.3 meq 100−1 g), Fe (2.72 mg kg−1), Zn (0.27 mg kg−1) and Cu (0.78 mg kg−1) were medium, while the levels of organic matter (1.69%) and total N (0.09%) were low [34]. Normal N release was indicated by the C:N ratio (11) [35]. Finally, the

Soil from the Quero test plot (**Table 3**) had higher pH (9.15) than the Villacañas one, but the difference lay in a very saline soil. The contents of Cl<sup>−</sup> (153 mg kg−1) and K (0.77 meq 100−1 g) were high. Na (3.80 meq 100−1 g) and Ca (87.14 meq 100−1 g) came in large amounts. Organic matter content (2.22%), total

2− (15.63%), CEC (10 meq 100−1 g), Zn (0.38 mg kg−1), Cu (0.35 mg kg−1) and Mn (2.15 mg kg−1) were medium [34]. The C:N ratio indicated little N

The main difference between the original soils of both plots were salinity and

2− content as the Quero plot soil was very saline (EC: 13.65 mmhos cm−1) and rich in gypsum (2,102 mg 100−1 g), unlike the Villacañas soil (EC: 0.52 mmhos cm−1

In the Quero plot soil (**Table 4**), the values of pH (9.14), EC (19.86 mmhos cm−1)

In the soils to which CF was applied significant differences were observed between Villacañas and Quero for all the analysed parameters (**Table 6**), except for

100−1 g), organic matter (1.6%), N in all its forms (total-N: 0.15%; nitric-N: 25 mg kg−1; soil-N: 94 kg ha−1), Zn (0.33 mg kg−1), B (3.59 mg kg−1), K (1.89 meq 100−1 g), Na (6.8 meq 100−1) and Ca (100.12 meq 100−1 g) were significantly higher than in the Villacañas plot (pH:8.2; EC: 0.56 mmhos cm−1; C:N ratio: 4.4;

nitric-N: 3.67 mg kg−1; soil-N: 14.3 kg ha−1; Zn: 0.19 mg kg−1; B: 0.12 mg kg−1; K: 0.53 meq 100−1 g; Na: 0.59 meq 100−1 g) and Ca: 25.25 meq 100−1 g). On the contrary

(28.67) ratios, Fe (1.12 mg kg−1) and P (9.3 mg kg−1) contents were significantly

Regarding SS treatment, no significant differences were observed between Villacañas and Quero with respect to the content of organic matter, total N, total

(362.6 mg kg−1), SO4

The differences were significantly greater in Quero regarding pH value

ratio (6.7), nitric N (38 mg kg−1), soil N (142.6 kg ha−1), Zn (0.92 mg kg−1), B (5.8 mg kg−1), K (2.1 meq 100−1 g), Na (5.8 meq 100−1 g) and Ca (93.28 meq 100−1 g).

and 3.03, respectively; Fe: 0.31 mg kg−1 and P: < d.l: detection limit).

(42 mg kg−1), CEC

2− (857 mg

2− (30.5%), K (0.66 meq 100−1 g), Na (1.70 meq

(286 mg kg−1), SO4

2−(29.45%), the K:Mg (0.56) and Ca:Mg

2−: 14.19%; K:Mg and Ca:Mg ratios: 0.06

(860 mg 100−1 g), C:N

=

: 64.3 mg 100−1 g; organic matter: 0.7%; total-N: 0.09%;

yield was accomplished with CF treatment (3,056 kg ha−1).

basic pH (8.6) and was somewhat saline. The contents of Cl<sup>−</sup>

amounts of P (19 mg kg−1), total CO3

and 75 mg 100−1 g, respectively).

100−1 g) and Mn (0.70 mg kg−1) were high [34].

and the C:N ratio (6.37), and the contents of Cl−

=

in Villacañas, the percentages of total CO3

higher than those obtained in Quero (CO3

2−, Cu, Mn or CEC (**Table 6**).

(9.01), EC (18.56 mmhos cm−1), Cl−

*3.1.5 Yield*

**3.2 Soil**

CO3

SO4

Cl<sup>−</sup>

release [35].

Cu, Mn and CEC.

: 19.33 mg kg−1), SO4

**162**

CO3

