Multifunctional soil health assessment of long-term manure application to ferric acrisol

Soil health refers to the capacity of soil to sustain ecosystem functions and provide a favourable environment for soil organisms and plants. However, it is challenging to quantitatively determine soil health by assessing its ecosystem functions. Here, we constructed a multifunctional soil health assessment method based on five soil functions including plant productivity (PP), water regulation (WR), nutrient cycling (NC), carbon storage (CS), and biodiversity preservation (BP), with soil acidification rate and soil erodibility factor as restrictive indicators. The entropy weight coefficient method was used to calculate the indicator weights, and the minimum data set (MDS) was established using random forest modelling. The impact of organic manure treatments on the five soil functions and the soil health index (SHI) was calculated using a long-term fertilization experiment. Our results showed that manure application significantly promoted the five soil functions and SHI, and the SHI was significantly positively correlated with soil fertility index (SFI) and soil quality index (SQI). Random forest modelling showed that the five soil functions contributed similar proportions to the variation in SHI. SHI based on the total data set and minimum data set was positively associated with maize characteristics, including root weight, shoot weight, and grain yield. In conclusion, the multifunctional soil health assessment method is crucial for elucidating the relationships of management practices with soil health and crop yield, enabling the achievement of healthy management and sustainable development for ferric acrisol farmland.