# The Quantity and Composition of Leachate from Hop Plant Biomass during Composting Process
## 3 Results and Discussion
### The Impact of Composting Procedure on the Leachate Quantity and Composition during Composting
Our study revealed that biochar itself did not improve phosphorus leaching. In fact, the most phosphorus was lost in pile LES where biochar was used. According to [PERSON] et al. [33], nitrification occurred much faster during the summer season because of higher temperatures. However, on the other hand, a long duration of high temperatures in a compost pile can slow down the nitrification of compost [34]. To achieve complete nitrification, longer processing periods were required in winter. In Figure 5, we can see that nitrification in our study started at the end of November (time stamp 2), because NH\({}_{4}\) concentrations were either dropping or not rising much, while NO\({}_{3}\) concentrations were rising significantly. [PERSON] et al. [6] reported that the concentration of NO\({}_{3}\)-N in leachate in mature compost increased. Total N concentrations did not increase significantly, with the exception of pile ZUP, where higher total N concentrations could be attributed to a high NO\({}_{3}\) concentration. Time stamp 3 shows a considerable decrease in the total P concentration in leachate. [PERSON] et al. [6] also discovered that fresh compost leachate had higher P concentrations than mature compost leachate. The composting procedure with pH was s.s. (\(p\) = 0.00013); the lowest values were observed in LES pile (7.99), followed by ROZ (8.33) and ZUP (8.58) piles. The interaction between Time stamp and pH was s.s. with \(p\) = 0.0049. The pH values in Time stamps 1 and 2 were similar, with values of 8.39 and 8.57, respectively. The lowest pH was observed in Time stamp 3 (7.94). The interaction between Time stamp \(\times\) Procedure was insignificant. The interaction plot (Figure 5) shows that the lowest pH values in all three Time stamps were observed in the LES pile, followed by ROZ and ZUP piles. However, in Time stamp 3, the pH values in ROZ and ZUP piles were very similar, resulting in 8.13 and 8.2. Leachate produced using the Bokashi method is usually yellow or orange, acidic (pH 4.5-6.0), and contains effective microorganisms [31]. In our experiment, leachate from the pile using the Bokashi method (ROZ) was not acidic, but rather basic. All leachates in our study were slightly basic and their pH decreased significantly in Time stamp 3. The optimum pH for the nitrification process is within the range of 7.8-9.0 [35], suggesting that the pH in our study, which was within this range in Time stamps 1 and 2, causednitirification and higher NO\({}_{3}\) concentrations in leachate. The pH value dropped during nitrification [36], and our investigation confirmed this. In their research with compost mixes, [PERSON] et al. [6] discovered a similar pH range (8.2-8.7). The volatilization of ammonia (NH\({}_{3}\)) and nitrous oxide (N\({}_{2}\)O) can also result in nitrogen losses (N\({}_{2}\)O). NH\({}_{3}\) emissions are the most significant losses, and they are closely linked to the pH and the presence of volatile fatty acids. They occur during the intensive phase of degradation. The pH rise causes the transformation of NH\({}_{4}\)\({}^{+}\) into the volatile nitrogen NH\({}_{3}\) under ideal aeration conditions [9].