One of China's most pressing environmental problems is acid rain. The types of acid rain have undergone a transformation, evolving from a previous dominance of sulfuric acid rain (SAR) to a more varied form encompassing mixed acid rain (MAR) and nitric acid rain (NAR) in recent years. Roots, a source of soil organic carbon, participate in the construction of soil aggregates, thereby playing a critical role. In forest ecosystems, the shifting patterns of acid rain and the effect of root removal on the content of soil organic carbon remain poorly understood. Over three years, this study analyzed the changes in soil organic carbon, physical properties, aggregate size and mean weight diameter (MWD) in Cunninghamia lanceolata (CP) and Michelia macclurei (MP) plantations subjected to root removal and simulated acid rain with varying SO42-/NO3- ratios (41, 11, and 14). Removing roots from *C. lanceolata* and *M. macclurei* resulted in a striking 167% and 215% reduction in soil organic carbon, along with a 135% and 200% decrease in soil recalcitrant carbon, respectively, as indicated by the results. Significant root removal resulted in a marked reduction of MWD and the proportion and organic carbon content of soil macroaggregates in *M. macclurei*, but not in *C. lanceolata*. oncology access Soil organic carbon pools and soil aggregate structures were not impacted by acid rain. Forest root systems were found to significantly contribute to the stabilization of soil organic carbon, and the extent of this contribution varied according to the specific forest type, according to our results. In the short term, the stabilization of soil organic carbon is resistant to the differing chemistries of acid rain.
The decomposition of soil organic matter and the creation of humus are concentrated within soil aggregate structures. Soil fertility assessment can be aided by examining the characteristics of aggregate compositions based on their particle sizes. In moso bamboo forests, we assessed how the frequency of fertilization and reclamation (management intensity) influenced soil aggregates. We examined three groups: mid-intensity management (T1, every 4 years), high-intensity management (T2, every 2 years), and a control group representing extensive management (CK). Soil organic carbon (SOC), total nitrogen (TN), and available phosphorus (AP) distribution within the 0-10, 10-20, and 20-30 cm soil layers of moso bamboo forests was established after the separation of water-stable soil aggregates using a combined dry and wet sieving method. dermatologic immune-related adverse event Soil aggregate composition and stability, alongside SOC, TN, and AP distribution within moso bamboo forests, exhibited significant responsiveness to management intensities, as demonstrated by the findings. While CK served as a control, treatments T1 and T2 demonstrated opposing effects on soil macroaggregate characteristics at varying depths. In the 0-10 cm soil layer, a reduction in macroaggregate proportion and stability was seen, but this trend reversed in the 20-30 cm layer, where an increase was observed. Subsequently, both treatments resulted in a decrease in the content of organic carbon within macroaggregates, as well as a reduction in organic carbon, total nitrogen (TN), and available phosphorus (AP) levels within the microaggregates. Intensified management strategies, as indicated by the findings, proved ineffective in fostering the formation of macroaggregates in the 0-10 cm soil layer, thus impeding carbon sequestration within these aggregates. The accumulation of organic carbon in soil aggregates, along with nitrogen and phosphorus in microaggregates, was positively impacted by reduced human activity. https://www.selleckchem.com/products/jbj-09-063-hydrochloride.html The mass fraction of macroaggregates and the organic carbon content found within them exhibited a significant and positive correlation with aggregate stability, providing the most influential explanation for the differences in stability. Ultimately, the organic carbon content of the macroaggregates, along with the structure of the macroaggregates, played a critical role in the creation and stability of the aggregate. Decreasing disturbances positively influenced the buildup of macroaggregates in topsoil, leading to the sequestration of organic carbon by these macroaggregates, and the sequestration of TN and AP by microaggregates, thereby contributing to improved soil quality and sustainable management in moso bamboo forests, in relation to aggregate stability.
Appreciating the different sap flow rates of spring maize within typical mollisol landscapes, and recognizing the primary factors affecting them, is significant for assessing water consumption through transpiration and adjusting agricultural water management strategies. The filling-maturity stage of spring maize sap flow was continuously monitored in this study using wrapped sap flow sensors and TDR probes, while also recording soil water content and temperature data from the topsoil. We investigated the impact of environmental factors on the sap flow rate of spring maize across different time intervals, using data collected from a nearby automatic weather station. Fluctuation in sap flow rate was pronounced in spring maize growing in typical mollisol areas, with high daytime values and low nighttime values. The highest instantaneous rate of sap flow, 1399 gh-1, occurred during daylight hours, while nighttime sap flow was considerably weaker. Cloudy and rainy days saw a considerable decrease in the starting time, closing time, and peak values of spring maize sap flow, as opposed to sunny days. Hourly measurements of sap flow rate demonstrated a strong correlation with the variables of solar radiation, saturated vapor pressure deficit (VPD), relative humidity, air temperature, and wind speed. Only solar radiation, vapor pressure deficit, and relative humidity demonstrated a substantial daily correlation with sap flow rate, each correlation coefficient surpassing 0.7 in absolute value. The high soil water content observed during the study period yielded an insignificant correlation between sap flow rates and the soil water content and temperature of the 0-20 cm soil layer, with absolute correlation coefficients remaining below 0.1. In this region, solar radiation, VPD, and relative humidity were the primary factors influencing sap flow rate, even without water stress, consistently across both hourly and daily time scales.
For the sustainable exploitation of black soils, understanding the consequences of different tillage practices on the functional abundance and diversity of microorganisms involved in the nitrogen (N), phosphorus (P), and sulfur (S) cycles is essential. An 8-year field experiment in Changchun, Jilin Province, provided data on the abundance and composition of N, P, and S cycling microorganisms, along with their driving factors, in black soil at various depths under both no-till and conventional tillage practices. The investigation of NT versus CT treatments revealed a substantial augmentation of soil water content (WC) and microbial biomass carbon (MBC) at the 0-20 cm depth in the NT treated soil. NT displayed a marked increase in functional and coding genes related to nitrogen, phosphorus, and sulfur cycling when compared to CT, including nosZ (N2O reductase), ureC (organic nitrogen ammoniation), nifH (nitrogenase), phnK and phoD (organic phosphorus mineralization), ppqC (pyrroloquinoline quinone synthase), ppX (exopolyphosphate esterase), and soxY and yedZ (sulfur oxidation) genes. Analysis of variance partitioning and redundancy analysis highlighted soil fundamental characteristics as the primary drivers influencing the microbial community composition within nitrogen, phosphorus, and sulfur cycling functions. The total interpretation rate amounted to 281%. Crucially, microbial biomass carbon (MBC) and water content (WC) were found to be the dominant factors shaping the functional capacity of soil microorganisms participating in nitrogen, phosphorus, and sulfur cycles. Ultimately, prolonged no-till farming practices have the potential to augment the diversity of functional genes present in soil microorganisms, contingent upon modifications to the soil's environment. Molecular biological examination indicated that no-till farming methods prove unsuccessful in boosting soil health and sustaining green agricultural production.
In the Mollisols of Northeast China, at a long-term maize conservation tillage station (established in 2007), a field experiment was set up to analyze the influence of varying stover mulch amounts with no-till practices on soil microbial communities and residue characteristics. The treatments included no stover mulch (NT0), one-third stover mulch (NT1/3), two-thirds stover mulch (NT2/3), full stover mulch (NT3/3), and a conventional tillage control (CT). Across different soil strata (0-5 cm, 5-10 cm, and 10-20 cm), we investigated the correlations between phospholipid fatty acid, amino sugar biomarkers, and soil physicochemical properties. Compared to CT, the no-tillage method, lacking stover mulch (NT0), showed no changes in soil organic carbon (SOC), total nitrogen (TN), dissolved organic carbon and nitrogen (DOC, DON), water content, the microbial community, or their byproducts. The consequences of no-tillage and stover mulch techniques were primarily observed in the topsoil layer. In comparison to the control (CT), NT1/3, NT2/3, and NT3/3 demonstrated significant increases in soil organic carbon (SOC) content—272%, 341%, and 356%, respectively. NT2/3 and NT3/3 treatments also exhibited substantial increases in phospholipid fatty acid content (392% and 650%, respectively). Correspondingly, NT3/3 treatment led to a 472% rise in microbial residue-amino sugar content within the 0-5 cm soil layer compared to the control. Stover mulch application levels and no-till practices influenced soil properties and microbial diversity in ways that decreased significantly with soil depth, practically eliminating differences within the 5-20 centimeter stratum. Influencing both the microbial community's make-up and the accumulation of microbial residue were SOC, TN, DOC, DON, and the proportion of water. Microbial residue, especially fungal residue, correlated positively with the overall amount of microbial biomass. Summarizing the results, all stover mulch applications promoted a buildup of soil organic carbon to varying degrees.