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Introduction: Previous studies have proven that different tillage measures have significant different effects on soil structure, hydrology properties and soil erosion. However, few studies have clarified the dynamic changes in soil aggregate stability and infiltration properties during crop growth under four tillage measures. Methods: Four field plots (150 m x 15 m) managed by four tillage methods including wide ridge tillage (DT), no-tillage (NT), contour ridge tillage (CT) and traditional tillage (CK) were built in 2021 to evaluate their effects on dynamic changes of soil structure and water conductivity during crop growth. Soybean was the seasonal crop. Soil bulk density, soil porosity, soil aggregate stability and soil infiltration characteristics were measured to assess dynamic changes in soil aggregate stability and infiltration from June to October 2022. Results: The results showed that NT significantly increased soil bulk density by up to 21.62% compared with CK, while DT did not show significantly increase in soil bulk density. DT, NT and CT could greatly increase the capillary porosity and proportion of capillary porosity to total porosity. DT and NT also improved the stability of soil water-stable aggregates by 3.37% and 10.6%. In terms of soil infiltration properties, all three tillage methods increased the initial, stable and average infiltration rates by 8.4%-52.94%, of which the DT and NT showed the greatest improvement. The soil infiltration process of four tillage measures could be better fitted by Horton model than Kostiakov and Philip models. Soil saturated hydraulic conductivity (SHC) of CK exhibited a significant negative correlation with soil bulk density and capillary porosity, and showed a positive correlation with total porosity and geometric average diameter of water-stable aggregate (GMD), whereas the other three treatments only displayed a significant correlation with the stability of soil water-stable aggregate. Conclusion: The results suggest that DT, NT and CT have potential to improve soil structure and infiltration capacity compared with CK, and contribute to preventing and controlling soil erosion in sloping farmland of Northeast China. [ABSTRACT FROM AUTHOR]

The application of organic materials contributes to the sustainable development of agriculture. Increased manure inputs have a fundamental effect on the composition and dynamics of soil organic carbon (SOC). In this study, we conducted a 10-year field experiment in Changchun, Jilin, Northeast China, to investigate the effects of manure addition on soil organic carbon components and soil microorganisms. Specifically, we established four treatments: (i) chemical fertilizer or no addition of manure (CK), (ii) pig manure with chemical fertilizer (ZF), (iii) cow manure with chemical fertilizer (NF), and (iv) chicken manure with chemical fertilizer (JF). The results showed that the JF treatment significantly increased the soil organic carbon (SOC), dissolved organic carbon (DOC), and readily oxidized organic carbon (ROC) content by 20.36%, 105.9%, and 61.32%, respectively, relative to CK. The microbial biomass carbon (MBC) content in JF, ZF, and NF treatments were significantly higher than that of CK, which increased by 107.24%, 116.45%, and 96.71%, respectively. The particulate organic carbon (POC) content in NF and JF treatments differed significantly, increasing by 25.61% and 19.01%, respectively, relative to CK. Redundancy analysis showed that continuous manure application had a positive effect on soil microbial community diversity and abundance, which was favorable for the accumulation of soil carbon. We also found that soil fungi were more sensitive than bacteria to changes in soil carbon composition following manure application. In conclusion, adding different organic materials can better support biodiversity conservation and realize ecosystem services of surface carbon storage and soil conservation. Our results reveal the importance of microbial fixation in soil carbon dynamics according to the different distribution of active organic carbon pools, which will help enhance our understanding of the carbon cycle. [ABSTRACT FROM AUTHOR]

The application of agricultural wastes to the soil does not only improve soil fertility but also helps in the recycling of agricultural waste resources. However, the effects of agricultural organic materials on soil physicochemical properties in primary saline and alkaline lands unsatisfactory. In this study, the effects of different organic materials on the physicochemical properties of primary saline-alkali soil were studied in the west of Jilin province for two consecutive years. The organic materials included: grass (FG), sheep manure (SM), coarse corn straw (CS), and granular corn straw (GS). Soil pH, EC, total salt content, CEC, exchangeable sodium, ESP, organic matter, field capacity, water immersed bulk density, sedimentation coefficient, hardness and the morphological characteristics of soil aggregates were measured by conventional methods. CEC, SOM, and the physical properties varied significantly among the different treatments, whereas pH, EC, total salt content and exchangeable sodium did not. Moreover, the morphology of the organic materials significantly affected pH, EC1 : 5, total salt content, SOM and physical properties of the soil however, it did not affect the CEC, exchangeable sodium and ESP. Comparing granular corn straw with coarse corn straw, granular corn straw increased the SOM and field capacity by 48.5 and 17.0% respectively and decreased the pH, EC1 : 5, total salt content, water immersed bulk density, sedimentation coefficient and soil hardness by 2.6, 2.4, 3.7, 11.3, 6.2 and 7.7% respectively. In conclusion, the application of organic materials effectively improved the physical and chemical properties in the saline-alkali soil however did not cause a complete change in the saline-alkaline nature of the soil. The morphology of the organic materials also significantly affected soil properties, with granular corn straw having a better effect than the other treatments. [ABSTRACT FROM AUTHOR]