**Table 6.**

**165**

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

(2.24 mg kg−1) and P (12.7 mg kg−1) content were significantly higher.

(17.7 mg kg−1) and Mn (8.7 mg kg−1) contents were significantly higher.

In Villacañas, only the values of the K:Mg (0.63) and Ca:Mg (33.03) ratios and Fe

4

Thus, we described the results according to the applied treatment by comparing the test plots, but by also comparing to the initial soil, how the application of SS, CS

Changes noted in the Villacañas soil after harvest in relation to the initial situa

of the trial are also shown. Regarding the initial soil, no representative changes were

Large differences were found in the initial soil for certain parameters. This was

Conversely, the total N and soil N contents in the plots fertilised with SS and CS

Finally, when comparing treatments, significant differences in the Villacañas plot soil were observed for the total N percentage and assimilable P content. In both cases when SS and CS were applied, the content of these parameters significantly

In general, compared to the Villacañas plot, more changes took place in the

compared to the initial soil, no representative changes were seen in pH, total CO

observed. A slight decrease in organic matter content was found in the subplots

N, Mn, B, K, Na, Ca and the CEC all increased compared to the original soil. Soil N,

Finally, when comparing treatments, significant differences were found in the Quero plot soil for the percentage of total N (increased with CS), and for nitric N, N

Soil is where the root system of plants develops, and it provides them with anchorage, water and nutrients. It is also a non-renewable resource on a human time scale that can be lost through erosion or degraded by contamination. Thus, conser

ing salts [9]. Applying organic amendments, including sewage sludge, has been widely reported to remediate saline soils and to alleviate salinity and sodicity stress in crops [36, 37]. Our study showed that this did not happen in Villacañas, which

One of the main problems that affects soil productivity is a rising EC by increas

Large differences appeared in the initial soil for most parameters. A generalised

2− and assimilable P contents, and in the C:N and Ca:Mg ratios, was

−

Quero soil as regards the initial situation after the trial (see **Tables 3** and

On the contrary for any of the three treatments, EC, Cl

Fe, Zn and Cu in soil also increased, but only with SS and CS.

3

with SS and CS, and in assimilable P and Mn in the soils fertilised with CF.

3

2−(860 mg 100−1 g), total N (0.2%),

**6**. The differences among treatments at the end

2−, the K:Mg ratio, assimilable Fe content,

−

4

2− (32.8%), Fe (2.31 mg kg−1), P

, organic matter, B, K, Na and

2− content of the plots treated

content, total N, nitric


**6**). Thus,

3 2−



Finally, after applying CS, there were no significant differences between Villacañas and Quero for organic matter content, C:N ratio, Zn, Cu and CEC. The differences in Quero were significantly bigger for pH value (9.01), EC

soil N (152.6 kg ha−1), B (4.5 mg kg−1), K, Na and Ca. In Villacañas, only the values

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

(18.32 mmhos cm−1), Cl- (327.3 mg kg−1), SO

and CF affected Villacañas and Quero soils.

Cu, Mn (in SS or CS treatment), CEC and Ca.

the case of the generalised drop in the contents of Cl

the C:N ratio. A reduction was also recorded in the SO

tion when comparing **Tables 3** and

increased, as did Zn content.

decrease in SO

**4. Discussion**

observed in pH, EC, nitric N, total CO

increased compared to the control (CF).

or the K:Mg ratio after the applications.

in soil and Zn (increased with SS and CS).

vation and improvement should be made priorities.

4

treated with CF and SS.

of K: Mg (0.48) and Ca:Mg (25.3) ratios, total CO

*Comparison of the study plot soils (V: Villacañas; Q: Quero) for each fertiliser treatment. Ass.: assimilable. Distinct letters mean groups with significant differences at P < 0.05 between plots for the same treatment according to the LSD test.*
