Untitled Document

Abstract

Phosphorus (P) is one of the mineral nutrients that exhibit a high propensity for fixation in soil. Interplanting herbage is considered as a mode to produce green orchards that can effectively improve soil quality and ecological function. To assess the impacts of intercropping herbage on the morphological characteristics and availability of P in the acidic soil of mango ( Mangifera indica L .) orchards, three kinds of soil (clean tillage [CK], intercropping Stylosanthes guianensis [SC], and intercropping Cynodon dactylon (L.) Pers. [CC]) were collected from a tropical mango orchard during a 4-year field study. This study determined the morphological characteristics of P in the water-stable aggregates and bulk soil, analysed the bacterial-fungal community structure and diversity, and evaluated the correlation between the environmental factors, P fractions, and microbial communities. This study showed that interplanting S. guianensis and C. dactylon enhanced the availability of soil P by increasing the organic P, and partial inorganic P (Al-P and Fe-P) in the 0.25–2 mm aggregate compared with the CK. In addition, interplanting herbage also altered the structure and diversity of soil bacterial-fungal community. A Mantel analysis revealed that the structure of the bacterial community had a greater influence on the P fractions compared to bacterial α-diversity. The fungal community had minimal impact on the P fractions. Interestingly, the Nitrospira, Candidatus-Udaeobacter, Pseudolabrys, MND1, Tepidisphaera, Aquicella, unclassified-Vicinamibacterales, ADurb.Bin063‒1, Humicola, and Purpureocillium contribute to the availability of soil P. In conclusion, interplanting herbage favors the activation of soil P in the acidic soil of mango orchards.