Intercropping herbage promoted the availability of soil phosphorus and improved the bacterial genus structure and the abundance of key bacterial taxa in the acidic soil of mango (Mangifera indica L.) orchards

Abstract

This study aims to understand the characteristics and distribution patterns of soil phosphorus (P) forms in the tropical high‐P orchards under cover cropping and to explore the biotic and abiotic factors driving the changes in P forms. The study collected three kinds of soil (clean tillage [CK, control], Stylosanthes guianensis cover [SC, legume], and Cynodon dactylon (L.) Pers. cover [CC, grass]) from a mango orchard and determined P forms in the water‐stable aggregates and bulk soil, analyzed the environmental factors and the structure of the bacterial‐fungal community. Compared to CK, SC and CC have a significant positive influence on the forms and distribution of soil P, increase the content of organic P (Org‐P) and certain inorganic P forms (Al‐P and Fe‐P), and enhance the content of P within macroaggregates (>0.25 mm), thereby maintaining total P (TP) and Olsen‐P in the top 30 cm of soil, particularly for the SC treatment. SC and CC also improved acid phosphatase (ACP), and water‐stable aggregates while decreasing bulk density (BD) and exchangeable aluminium (Ale) in the topsoil (0–15 cm). Redundant and Pearson analysis revealed these factors significantly affected soil P availability. Moreover, SC and CC increased the relative abundance of Nitrospira, Candidatus‐Udaeobacter, Pseudolabrys, and ADurb.Bin063–1 in the topsoil (0–15 cm), and decreased the relative abundance of Occallatibacter. Redundant and Pearson analysis indicated that these bacterial communities are likely associated with the availability of P. Overall, cover cropping promoted the transformation and distribution of P forms by altering the physical, chemical, and biological environment of the soil, which was beneficial for the sustainable P management in tropical high‐P soils. This research offers practical insights into the use of cover crops as a tool for enhancing soil health and sustainable P management in tropical high‐P orchards.