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

The aggregate stability of the soil is subject to theinfluence of anthropogenic factors and is of great interest all overthe world. The research aimed to quantify the correlations betweensoil organic carbon, total nitrogen, total phosphorus, and totalpotassium, soil macropore parameters and water-stable aggregatesunder no-tillage and conventional tillage in Cambisol. The contentof water-stable aggregates and macroporosity tended to increasein the following order: conventional tillage (returned residues)< conventional tillage (removed residues) < no-tillage (removedresidues) < no-tillage (returned residues) in both fertilizations.The relationships between total nitrogen and various soil factorswere investigated: soil organic carbon (r = 0.65, p < 0.05), totalphosphorus (r = 0.65, p < 0.05), were statistically significant. Soilorganic carbon and total nitrogen were positively correlated withwater-stable aggregates (r = 0.81, p < 0.01 and r = 0.68, p < 0.05,respectively), whereas the relationship between total potassiumand water-stable aggregates was negative. The relationshipbetween total phosphorus and water-stable aggregates (r = 0.62,p < 0.05) was positive. The soil chemical properties, macroporesand water-stable aggregates that were averaged across theresidues and fertilizations were higher in no-tillage than in conventionaltillage. Soil organic carbon, total nitrogen and totalphosphorus all had a positive direct influence on the formation ofwater-stable aggregates under different tillage conditions. Sinceour results are largely based on correlations, the mechanismsof interaction between the soil chemical properties, water-stableaggregates and the formation of pores in the soil need to beexplored further in future investigations.