## 2 Materials and Methods
### Fertilizers  
In total, five kitchen waste streams were investigated in a glasshouse experiment and compared with the commercially available mineral and organic NP fertilizer. Table 1 shows the basic characteristics of the materials used. The first step towards preparing the final fertilizer was to prepare the substrate mixture (model waste) for its production. The mixture consisted of 100 g of each of the following ingredients: apple, lemon, roll, butter, sour cream, milk, cottage cheese, yogurt, eggs, meat with bones, sausage, fish meat, potatoes, banana, tomato, lettuce, fruit juice, and bun and 200 g of each flowers and paper. Then, the ingredients were pre-cut with a knife and then ground twice in a meat mincer in order to obtain a homogenous paste. For a given mixture, total solids (TS%, % fresh mass) and volatile solids (VSS%, %TS) were determined which were 54% and 90%, respectively. Before planting, soil samples were analyzed for pH and electrical conductivity (EC) (1:5 H\({}_{2}\)O), along with total soil nitrogen, phosphorus (both Olsen and total), and potassium (both Olsen and total). After the final harvest, samples were again tested for pH, EC, and total nitrogen [43]. Phosphorus concentration in liquid samples (soil extracts) was measured using a portable spectrophotometer DR3900 (Hach GmbH, Dusseldorf, Germany) with Hach Method 8048, including a mineralization step. Prior to analysis, soil-water samples were filtered through a paper filter followed by a 0.45 \(\upmu\)m syringe filter. Total K was measured on solid, ground samples using Energy Dispersive X-Ray Fluorescence EDX 7000 spectrometer (Shimadzu Scientific Instruments Inc., Columbia, MD, USA). Available phosphorus using the Olsen method (P-Olsen) was determined by phosphorus extraction \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Material** & **Symbol** & **TS** & **VS** & **N-Total** & **P-Olsen** & **P-Total** & **K-Olsen** & **K-Total** \\ \hline Unit & & \% & \% & & & g/kg & & \\ \hline Soil & - & 88.77 & 6.08 & 1.32 & 0.0190 & 0.186 & 0.0649 & 0.610 \\ S1 Kitchen waste \(1\times\) dose & KW 1 EM & 95 & 91.42 & 33.82 & 0.0486 & 1.511 & 5.715 & 8.482 \\ SZ Kitchen waste decayed, & DKW 2 EM & 95 & 89.30 & 30.04 & NA & NA & NA & NA \\
2 \(\times\) dose EM-incubated & & DKW 1 EM ST & 95 & 89.30 & 32.18 & NA & NA & NA & NA \\ S3 Kitchen waste decayed, & DKW ST & 95 & 92.37 & 36.11 & & & & \\ decayed, sterilized & DKW ST-dig & 95 & 89.53 & 42.67 & NA & NA & NA & NA \\ Organic cow & & CMG & 100 & NA & 30.00 & & & \\ manure, granulated & Mineral fertilizer & MF & 100 & 0 & 190 & NA & NA & NA & NA \\ FLOROVIT NP. & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Basic characteristics of soil and fertilizer materials applied. using 4.2% NaHCO aqueous solution with the addition of 0.05% polyacrylamide solution adjusted with 50% sodium hydroxide to pH 8.5. Commercially available fertilizers were used as a reference material, mineral FLOROVIT NP 'fast growth' with additional S and Fe contents and an organic one--granulated cow manure (REF CM). Although the intention is to compare organic fertilizers to organic reference fertilizer (cow manure), the mineral fertilizer was used as an additional reference. No treatment (control) without any fertilizer materials was added for comparison as well. Then, model wastes were placed in 5 jars for which different pre-treatments were implemented like microorganism addition, decaying, sterilization, and fermentation (Table 2). In the first scenario, the model wastes were inoculated with EMs after being placed in the jar. Commercially available (mainly anaerobic) effective microorganisms (Greenland Technologia EM Ltd., Janowiec, Poland) were used. Inoculation with a single dose was achieved by dispersing 1 mL of the bacterial product (EM) in 250 mL of deionized water, and mixed with 1 kg of substrate. In the second scenario, however, the waste was left for 12 days; during this time the wastes decayed, then the solution with a double dose of EM was added.