## 2 The Materials and Methods  
### Site and Experimental Design  
A long-term small-area field experiment with MBM applied to maize was conducted at the Agricultural Experiment Station in Tomaszkowo, Poland (53\({}^{\circ}\)71\({}^{\prime}\) N, 20\({}^{\circ}\) 43\({}^{\prime}\) E) in 2014-2017. The experiment had a randomized block design with four replications. The soil was classified as Haplic Luvisol Loamic (HLL) [34]. The soil contained 10.1 g kg\({}^{-1}\) organic matter, 0.55 g kg\({}^{-1}\) total N, 0.33 g kg\({}^{-1}\) P, 1.33 g kg\({}^{-1}\) K, and soil pH in 1M KCl was 4.89.  
Maize was sown in experimental plots with an area of 15 m\({}^{2}\) (3.00 m \(\times\) 5 m) and a harvested area of 11.25 m\({}^{2}\) each (2.25 m \(\times\) 5 m), with 0.75 m inter-row spacing and a plant density of 8 plants m\({}^{-2}\). Maize was grown in a four-year monoculture, and winter trticale was sown in 2013 as the preceding crop. Winter trticale was harvested on 15 August 2013, and the field was plowed. In each year of the study, shallow tillage treatments were applied before spring sowing to incorporate mineral fertilizers and MBM into the soil. After maize harvest, the plots were tilled with a disc cultivator, narrowed, and deep plowed before the winter in all experimental years. The plots were sown with MAS 15P maize (FAO 200 maturity group; supplied by Maisadour (Haut-Mauco, France)). The yield performance of this early, single-cross hybrid cultivar was estimated at 102% relative to the reference. Weeds were controlled with Lumax 537.5 SE herbicide at 4.0 L ha\({}^{-1}\) (active ingredients: mesotrione 37.5 g dm\({}^{-3}\), s-metolachlor--312.5 g dm\({}^{-3}\), terbuthylazine--187.5 g dm\({}^{-3}\)). Seeds were dressed with Mesurol 537.5 SE (methocarb--500 g dm\({}^{-3}\)) at 1 L per 100 kg of seeds to control pathogens. Chemical pesticides were not applied.  
Maize was fertilized with MBM supplied by an animal by-products disposal plant (SARIA Poland Ltd., Dlugi Borek, Poland). Meat and bone meal was applied at increasing rates of 1.0, 2.0, and 3.0 t ha\({}^{-1}\) (Table 1). The chemical composition of MBM (90% dry matter content) was as follows: 66.9 g C kg\({}^{-1}\); 6.10 g N kg\({}^{-1}\); 3.10 g P kg\({}^{-1}\); 0.40 g K kg\({}^{-1}\); 8.85 g Ca kg\({}^{-1}\); 0.30 g Mg kg\({}^{-1}\); 8.0 mg Cu g\({}^{-1}\), 1189 mg Fe g\({}^{-1}\); 86.5 mg Zn g\({}^{-1}\), and 29.0 mg Mn g\({}^{-1}\). Meat and bone meal was applied before sowing. Two control treatments were established (without fertilization and with mineral NPK fertilization). In the NPK treatment, mineral fertilizers containing nitrogen (urea, 46% N), phosphorus (triple superphosphate, 40.0% P), and potassium (potash salt, 49.8% K) were incorporated into the soil.  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Treatments** & **C\({}_{\text{organic}}\)** & **N** & **P** & \multicolumn{2}{c}{**K**} \\  & & & **MBM * ** & **K\({}_{\text{mineral}}\)** \\ \hline Without fertilization & 0.0 & - & - & - & - \\ Mineral fertilization & 0.0 & 133.0 & 79.6 & - & 83.1 \\ MBM * 1.0 t ha\({}^{-1}\) & 666.9 & 61.0 & 31.1 & 4.0 & 79.1 \\ MBM 2.0 t ha\({}^{-1}\) & 1333.8 & 122.0 & 62.2 & 8.0 & 75.1 \\ MBM 3.0 t ha\({}^{-1}\) & 2000.7 & 183.0 & 93.3 & 12.0 & 71.1 \\ \hline \end{tabular}
\end{table}
Table 1: The amount of organic matter (C\({}_{\text{organic}}\)) and macronutrients introduced to soil with fertilizers (mean of 2014–2017, kg ha\({}^{-1}\)).