Biocrusts as a nature-based strategy (NbS) improve soil carbon and nitrogen stocks and maize productivity in semiarid environment

Biological soil crust (BSC) as a nature-based strategy has a great potential to restore soil and water in arid and semi-arid natural ecosystems. Yet, little is known about its effects on soil fertility and productivity as affected by the BSC inoculation in agroecosystems. We hypothesis that BSC inoculation can improve soil quality, while increasing crop productivity and economic benefits in semiarid rainfed region. To address this issue, we carried out field experiment using forage maize (Zea mays L.) from 2018 to 2019, with four treatments as follows: 1) conventional flat planting (control, CK), 2) flat planting with the inoculation of BSC (BSC), 3) ridge-furrow planting (RF), and 4) sectional ridge-furrow planting (SRF). The results showed that BSC inoculation significantly enhanced maize shoot and root biomass by 53–63 % and 30–67 % accordingly (P < 0.05), compared with CK in two growing seasons.Also, BSC treatment slightly increased soil water content and soil temperature, while significantly decreasing soil pH and soil bulk density, relative to CK, RF and SRF (P < 0.05). Compared with CK, the BSC inoculation markedly improved soil microbial biomass carbon by 54 % and nitrogen by 52%, soil organic carbon by 21 %, and total nitrogen by 30% respectively (P < 0.05) Critically, the contents of above four parameters were 42 %, 32 %, 19 % and 32 % greater in BSC than RF and SRF, respectively (P < 0.05). Simultaneously, the BSC significantly decreased soil C/N ratio by 7 %, while SRF and RF slightly decreased C/N ratio by 0.2 % and 2 % only, in comparison with CK. Interestingly, soil C&N mineralization efficiency were significantly greater in the BSC treatment than CK, RF and SRF (P < 0.05). In addition, the economic benefit under BSC was the highest relative to other three planting systems In conclusion, BSC can be used as a nature-based strategy (NbS) to improve soil properties, promote microbial C&N uptake and utilization via enhancing C&N mineralization and lowering C-N ratio. In conclusion, BSC can act as a green solution to achieve high productivity and promote soil fertility in semiarid agricultural ecosystem.