Owing to its unique features, biochar (BCH) is an excellent surrogate approach to improving the chemical properties of soil with undesirable characteristics. Under multiple abiotic stresses (ECe = 10.8 vs. 10.7 dS.m−1; CaCO3 = 19.1 vs. 18.8%; soil pH = 8.15 vs. 8.13) during two growing seasons (2020/2021 and 2021/2022), an experimental pot study was conducted to investigate the potential effects of palm tree frond BCH applied at three rates (0.0, 28.0, and 56.0 g.pot−1, labeled as BCH0, BCH1, and BCH2) and generated under three pyrolysis temperatures (350, 500, and 700 °C, labeled as PYT350, PYT500, and PYT700). The experiment was set up according to a randomized complete block design. The results indicated that both the PYT700 x BCH2 and PYT700 x BCH1 treatments had the highest impact on the soil chemical properties, soil nutrient status, and leaf nutrient contents, except for the soil pH, which was positively affected by PYT350 and BCH1 in both seasons, and the available potassium content (AKC) in the first season. Regarding the germination parameters, the data reveal that PYT350 x BCH2 and PYT700 x BCH2 were the superior treatments for the germination percentage (GP) and the mean germination time (MGT), while PYT500 x BCH2 led to noteworthy elevations of seed vigor (SV) in both seasons. The heat map illustrating the studied soil chemical properties fluctuates between positive and negative. In short, the application of BCH has profoundly desirable effects on the soil chemical properties depending on the PYTs and BCH addition rates.