Maize straw biochar improved soil nitrogen, but no effect on phosphorus in desert under mulched drip irrigation

Field experiments were conducted at the edge of the Horqin Desert to study the impact of biochar on peanut nutrient accumulation and soil nitrogen and phosphorus in a desert soil. The study utilized a split-plot design with drip irrigation (D) (CK) and mulched drip irrigation (M) as the main plot factors. The sub-plots received three maize straw biochar application rates: B0 (0 t/ha), B1 (24 t/ha), and B2 (48 t/ha). In 2020 and 2021, the podnitrogen accumulation(NA) of MB1 was 52.3 and 32.6% higher than MB0 at the pod-filling stage, respectively. In 2020, the phosphorus accumulation of MB0 and MB1 was 107.37 and 50.79% higher than MB2 at the pod filling stage, respectively. The correlation coefficient between soil total N and protein was 0.73, and that between soil pH and peanut oil was 0.83. Compared with MB2 and DB0, MB1 increased yield by 62.5 and 38.3%, respectively. Biochar combined with M increased the nitrate-Ncontent of soil, so that it could be fixed in the root area. Nevertheless, this intervention exhibited no discernible impact on the content of soil available phosphorus, and most of the soil phosphorus is concentrated in soil 40–60 cm. In conclusion, applying biochar (B1) to a peanut cultivation system in a semi-arid windy desert area increased peanut NA, and improved soil properties related to peanut yield and quality, but no effect on soil phosphorus.