**3.4 Effect of fertilizers on yields of crop growth**

As shown in **Table 4** presents the stem height, leaf area of radish. Overall, the treatment of fertilizers was highest than control (soil only).

In the treatment of compost, the highest rate of 0.3% with 4.46 and 0.98 cm on stem height and leaf area, respectively. While for treatment of struvite-K the


#### **Table 3.**

*Characteristics of soil cation exchange capacity.*


**Table 4.** *Radish (*Raphanus sativus L.*).*

#### *Crystallization and Applications*

highest rate of 0.3% with 6.36 and 1.31 cm on stem height and leaf area, respectively. For images of radish on pot treatment as shown in **Figure 5**. Both of fertilizers were given benefits effect on yields of radish and positive correlation with soil CEC. If we comparison, the struvite-K was given more benefits effect which cause the struvite-K is higher contains of macro content such as magnesium, potassium and phosphate as nutrient sources on crop growth. Furthermore, **Table 5** presents the stem height and leaf area of komatsuna. The same dosage treatment with radish between 0.1% and 0.3%. Overall, the supplying of fertilizers was given benefits effect on yields of komatsuna. However, the more benefits in the treatment of

#### **Figure 5.**

*Images of radish on pot treatment; (C) 100% (control), (A1) 0.1% of compost, (A2) 0.3% of compost, (B1) 0.1% of struvite-K and (B2) 0.3% of struvite-K.*


#### **Table 5.**

*Komatsuna (Japanese mustard plant).*

#### **Figure 6.**

*Images of komatsuna on pot treatment, (C) 100% (control), (A1) 0.1% of compost, (A2) 0.3% of compost, (B1) 0.1% of struvite-K and (B2) 0.3% of struvite-K.*

*Simultaneously Recovery of Phosphorus and Potassium Using Bubble Column Reactor… DOI: http://dx.doi.org/10.5772/intechopen.100103*

struvite-K on dosage of 0.3% with 5.24 and 1.27 cm, on stem length and leaf wide, respectively. This might be indicated that struvite-K is more slow-release than compost and higher macro nutrient supplied on soil which needed on crop. Slow-release fertilizer which releases nutrients slowly over a long release time. Furthermore, it can reduce the number fertilization times and amount of fertilizer applied, which have good impact on fertilizer use efficiency [32–35]. Images of komatsuna on pot treatment as shown in **Figure 6**.
