Changes in soil macropores: Superposition of the roles of organic nutrient amendments and the greenhouse pattern in vegetable plantations

Abstract

Organic farming can potentially mitigate soil compaction, which commonly occurs in vegetable plantations, particularly in greenhouses when compared with open-air systems. Although several studies have addressed the effect of planting patterns on soil pore characteristics, few studies have focused on changes in pore attributes under organic fertilization. We used adjacent fields during green manure planting as a control to compare the differences in soil physicochemical and macropore parameters between 14-year-old greenhouse plots and open-air plots under organic fertilization. Pearson's correlation analysis was performed to analyse the drivers of soil macropore characteristics in vegetable plantations in Jiangsu Province, China. A significant increase in connectivity, fractal dimensions and total macroporosity and a decrease in bulk density after 14 years of organic farming, particularly in the surface layer in the greenhouse, were observed. However, the difference in pores in the plough pan layer was not significant between the treatments. The volume of small pores (50-500 μm) and medium pores (500-1,000 μm) increased significantly (p < 0.05) in both the greenhouse and open-air systems, showing significantly positive relationships with soil organic matter (SOM) and total nitrogen (TN) content. Large pores (>1,000 μm) showed a clear decrease, especially in open-air fields, possibly due to the disappearance of the original straw residues in the surface layer. Small and medium pores in the plough layer increased in greenhouse fields, whereas the opposite occurred in open-air fields. Overall, compared with open-air systems, long-term organic greenhouse patterns had a significantly positive effect on soil pore attributes. K E Y W O R D S different planting patterns, long-term organic fertilization, macropore characteristics, X-ray computed tomography

Global gross nitrification rates are dominantly driven by soil carbon‐to‐nitrogen stoichiometry and total nitrogen

“…Therefore, the implication of this study is that addition of organic amendments with high C:N will reduce GN via improving soil microbial NO 3 − assimilation (Cheng et al, 2017), and thus reduce the risk of N leaching and runoff from soil (Zhang, Zhu, et al, 2013). However, it should not be neglected that application of organic amendments, a common practice to lessen soil compaction, would reduce soil bulk density (Xu et al, 2019), thereby stimulating gross N mineralization (Elrys et al, 2021) and ultimately increase GN.…”

Sustainable soil use and management: An interdisciplinary and systematic approach

“…In comparison with open-air systems, the use of organic fertilizers for indoor greenhouse soils may have a greater positive influence on soil functionality due to its effect on porosity and pore connectivity (Xu et al, 2019). It should be noted that organic fertilizers may not increase crops yields to the levels achievable with inorganic fertilizers.…”

Long-term contrasting tillage in Cambisol: effect on water-stable aggregates, macropore network and soil chemical properties

“…Different types of macropores have various functions which are related in different ways to the physical (Singh et al, 2021) and chemical properties of the soil. Xu et al (2019) found that soil organic matter increased the total soil porosity, and the volume of both the small and medium size pores. Hu et al (2016) wrote that the variability in the transfer of soluble substances affects soil voids and cracks between the soil aggregates, which increases the volume of soil porosity.…”