关键词: 固定道, 水氮互作, 根系, 春小麦, 籽粒产量

Abstract: Soil respiration is one of the important biochemical processes related to the mineralization and decomposition of soil organic matter (SOM) and the release of inorganic nutrients. In this study, an incubation experiment was conducted to study the mineralization potential of SOM in the re-vegetation area with an age sequence in Shapotou region of Ningxia. After 103 days of incubation, the released soil CO₂-C was in the age sequence of 55 years > 47 years > 30 years > 24 years > 21 years > mobile dune. Meanwhile, the released CO₂-C decreased along the soil profile 0-5 cm, 5-10 cm, and 10-20 cm in re-vegetation area, but increased along the soil profile in moving sand dune. There existed significant differences (P<0.05) in the soil carbon mineralization potential, total nitrogen, organic carbon, and electrical conductivity among the age sequence. All the variables increased with age sequence but decreased with soil depth. Correlation analysis showed that the soil carbon mineralization potential was significantly correlated to the soil organic carbon, total nitrogen, C/N ratio, soil temperature, soil water, pH, and electrical conductivity (P<0.01), and all the soil variables were significantly correlated each other (P<0.01). The soil nutrient contents increased obviously with age sequence, and the improvement of soil nutrient status was in accordance with the enhancement of soil carbon mineralization potential. It was suggested that the establishment of artificial vegetation promoted the activities of soil microbes, which was implied by the soil respiration, whereas the vegetation recovery and litter accumulation mitigated soil wind erosion, increased SOM input, and contributed to C sequestration.

Key words: permanent raised bed, spring wheat, root, grain yield., irrigation and nitrogen application