*2.3.1 Soil*

Initially a soil sample from each study plot (Villacañas and Quero) was collected at 10 different random points in an "S" pattern at a depth of 0–35 cm with a hand auger. The analysed parameters were EC, Cl<sup>−</sup> , SO4 2−, organic matter, N, C:N ratio, P, CO3 2−, K:Mg ratio, Ca:Mg ratio, Fe, Zn, Cu, Mn, B, cation exchange capacity (CEC), K, Na and Ca (**Table 3**). One month after harvesting, a 0–35 cm-deep soil sample was collected from 10 random points of each replicate. Therefore, nine soil samples per treatment (CF, SS and CS) from each test plot (Villacañas and Quero) were collected and analysed. The assessed parameters are presented in **Table 3**.


*\*\*N-soil was calculated according to the equation N-soil = (N-nitric x 50)/(10 x density), where N-nitric is expressed as mg kg−1 and density is 1.*

**159**

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

Each soil sample was air-dried, sieved to <2 mm and analysed by the following techniques: texture by the Bouyoucos hydrometer method; pH by the potentiometric method (saturated soil paste 1:2,5); electrical conductivity; N by the Kjeldahl procedure; extractable P. Soil samples were prepared for the analysis with acid digestion to determine Ca, Mg, Na and K (atomic emission); Fe, Zn, Cu, and Mn by

The preharvested random (215 post-sowing days) bunches of plants were cut far away from the bottom, close to soil, at the center of the subplot (replicate) to prevent board effects. Compared to soil sampling, nine sets of collected plants were used (1 sample x 3 treatments x 3 replicates) per treatment. Yield information (kg ha−1) was recorded. Finally, in the laboratory, 25 plants from each set sample were chosen to estimate spike weight, and length, number, and total weight of

The experimental design involved three treatments (CF, SS and CS) and nine replicates per plot. The data about spike weight (g), spike length (cm), number of grains per spike and total weight of the set of grains of that spike (g) were subjected to statistical processing by an analysis of variance. This was done to determine the factor or factors, and the possible interactions between them, which could affect

All the statistical calculations were performed with Statgraphic Centurion XV. The ANOVA table decomposes the variability of the studied parameters (spike length, spike weight, number of grains per spike, total weight of grains per spike and yield) in contributions due to several factors. In the analysis, the sum of the type III squares was chosen. Thus, the contribution of each factor was measured by eliminating the effects of the other factors. P-values proved the statistical significance of all the factors, and those less than 0.05 indicated that these factors had a statistically significant effect on each parameter at the 95%

**Table 4** displays the effect of the factors plot (Villacañas or Quero), treatment (SS, CS and CF) and plot-treatment interaction on the studied parameters. Spike length, spike weight, and number of grains per spike were significantly influenced by the plot where the crop was grown (Villacañas or Quero), and by treatment (CF, SS or CS). This did not occur with weight of grains per spike and, consequently, with yield. The plot-treatment interaction was not significant in

A simple factorial ANOVA based on the treatment received (**Table 5**) showed that the type of treatment in Villacañas affected all the studied parameters, except

In Quero, only spike length and spike weight were influenced by treatment. No significant differences were observed in either number of grains per spike or weight

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

atomic absorption spectroscopy.

*2.3.2 Crop*

grains per spike.

confidence level.

**3. Results**

**3.1 Crop**

any case.

for spike weight.

of grains or yield.

**2.4 Statistical procedure**

any differences observed among the treatments.

#### **Table 3.**

*Characterization of Villacañas and Quero initial soil plots. Ass: assimilable. CEC: Cationic Exchange Capacity.*

Each soil sample was air-dried, sieved to <2 mm and analysed by the following techniques: texture by the Bouyoucos hydrometer method; pH by the potentiometric method (saturated soil paste 1:2,5); electrical conductivity; N by the Kjeldahl procedure; extractable P. Soil samples were prepared for the analysis with acid digestion to determine Ca, Mg, Na and K (atomic emission); Fe, Zn, Cu, and Mn by atomic absorption spectroscopy.

### *2.3.2 Crop*

*Humic Substances*

**2.3 Sampling and measurement**

auger. The analysed parameters were EC, Cl<sup>−</sup>

matter.

*2.3.1 Soil*

CO3

SO4

Total CO3

details from the label are: P2O5 (soluble in neutral ammonium citrate and water), 14.50%; P2O5 (soluble in water), 11.50%; K2O (soluble in water), 8.00%; Organic C, 12.50%; Humic acids, 1.00%; Cu, 208 mg kg−1 dry matter; Zn, 559 mg kg−1 dry

Initially a soil sample from each study plot (Villacañas and Quero) was collected at 10 different random points in an "S" pattern at a depth of 0–35 cm with a hand

2−, K:Mg ratio, Ca:Mg ratio, Fe, Zn, Cu, Mn, B, cation exchange capacity (CEC), K, Na and Ca (**Table 3**). One month after harvesting, a 0–35 cm-deep soil sample was collected from 10 random points of each replicate. Therefore, nine soil samples per treatment (CF, SS and CS) from each test plot (Villacañas and Quero) were collected and analysed. The assessed parameters are presented in **Table 3**.

**Parameter Units Villacañas Quero** pH 8.60 9.15 EC mmhos cm−1 0.52 13.65 Cl− mg kg−1 42 153

<sup>=</sup> mg 100−1 g 75 2102

Org. matter (%) 1.69 2.22 Total -N % 0.09 0.10 Nitric-N mg kg−1 5.0 19 Soil-N kg ha−1\*\* 19.23 73 Ass. P mg kg−1 19 9 Ass. Fe mg kg−1 2.72 0.35 Ass. Zn mg kg−1 0.27 0.38 Ass. Cu mg kg−1 0.78 0.35 Ass. Mn mg kg−1 8.70 2.15 Ass. B mg kg−1 0.61 2.45 Ass. K meq 100−1 g 0.66 0.77 Ass. Na meq 100−1 g 1.70 3.80 Ass. Ca meq 100−1 g 20,31 87.14 CEC meq 100−1 g 12.3 10 C:N ratio 11 13 K:Mg ratio 0.60 0.04 Ca:Mg ratio 18.5 4.9 *\*\*N-soil was calculated according to the equation N-soil = (N-nitric x 50)/(10 x density), where N-nitric is expressed* 

*Characterization of Villacañas and Quero initial soil plots. Ass: assimilable. CEC: Cationic Exchange* 

<sup>=</sup> % 30,5 15.60

, SO4

2−, organic matter, N, C:N ratio, P,

**158**

**Table 3.**

*Capacity.*

*as mg kg−1 and density is 1.*

The preharvested random (215 post-sowing days) bunches of plants were cut far away from the bottom, close to soil, at the center of the subplot (replicate) to prevent board effects. Compared to soil sampling, nine sets of collected plants were used (1 sample x 3 treatments x 3 replicates) per treatment. Yield information (kg ha−1) was recorded. Finally, in the laboratory, 25 plants from each set sample were chosen to estimate spike weight, and length, number, and total weight of grains per spike.
