| Abstract： |
Against the background of the COVID-20 pandemic and various armed conflicts, the world is experiencing an unprecedented food crisis. The reclamation of abandoned cropland with food production potential may increase the global food supply in a short period mm to 1 mm) of purple mudstone from Penglai Group (J(3)p) were selected as the test material. Two nitrogen fertilizers, i.e., urea (U) and ammonium bicarbonate (AB), and four application levels (0, 280, 560, and 840 N kg & BULL;ha(-1)) with 18 replications were designed in an incubation experiment. The weathering indices and bacterial community structure of the purple mudstone particles were investigated after 120 days of incubation. ResultsThe results showed that the weathering indices of purple mudstone particles in the AB treatment were higher than that in the U treatment at the same fertilization levels and a reducing trend was observed with increasing nitrogen fertilizer levels under the same nitrogen fertilizer application types. The diversities of the bacterial community were extremely significantly altered by nitrogen fertilizer application (p < 0.01). The effect of the nitrogen fertilizer application level on the beta diversity of the bacterial community (R-2 = 0.34) was greater than that of the nitrogen fertilizer application type (R-2 = 0.20). Through stepwise regression analysis, the positive effects of nitrification of Nitrobacter (Nitrolancea) (R-2 = 0.36), the Phosphorous-dissolving bacteria (Massilia) (R-2 = 0.12), and N-NO3- (R-2 = 0.35) on the weathering indices of J(3)p purple mudstone particles could be observed. Structural equation modelling indicated that nitrogen fertilizer application level affects the abundance of the dominant species at the genus level (Nitrolancea and Massilia), and key environmental factor (N-NO3-), which in turn accelerated the weathering indices (59%). Discussion and ConclusionOur findings imply that the enhancements of nitrification of Nitrobacter (Nitrolancea) and of phosphorus solubilization of Phosphorous-dissolving bacteria (Massilia) by nitrogen fertilization are the key factors affectJ䨀㵡$萘⊕難ဓweatheriF䘀㵭$ရ还ᖎes of J(3)p purple mudstone particles. :㨀㵑$ |
