Impact of intercropping on the coupling between soil microbial community structure, activity, and nutrient-use efficiencies

Abstract

Sugarcane-soybean intercropping has been widely used to control disease and improve nutrition in the field. However, the response of the soil microbial community diversity and structure to intercropping is not well understood. Since microbial diversity corresponds to soil quality and plant health, a pot experiment was conducted with sugarcane intercropped with soybean. Rhizosphere soil was collected 40 days after sowing, and MiSeq sequencing was utilized to analyze the soil microbial community diversity and composition. Soil columns were used to assess the influence of intercropping on soil microbial activity (soil respiration and carbon-use efficiency: nitrogen-use efficiency ratio). PICRUSt and FUNGuild analysis were conducted to predict microbial functional profiling. Our results showed that intercropping decreased pH by approximately 8.9% and enhanced the soil organic carbon, dissolved organic carbon, and available nitrogen (N) by 5.5%, 13.4%, and 10.0%, respectively. These changes in physicochemical properties corresponded to increased microbial diversity and shifts in soil microbial communities. Microbial community correlated significantly (p < 0.05) with soil respiration rates and nutrient use efficiency. Furthermore, intercropping influenced microbial functions, such as carbon fixation pathways in prokaryotes, citrate cycle (TCA cycle) of bacteria and wood saprotrophs of fungi. These overrepresented functions might accelerate nutrient conversion and control phytopathogens in soil.

Assessment of Diazotrophic Proteobacteria in Sugarcane Rhizosphere When Intercropped With Legumes (Peanut and Soybean) in the Field

“…In the present study, we used the nifH gene database pipeline TaxADivA, which is specially designed by Gaby et al (2018) to analyze the nifH gene community. The outcome of the present study is also consistent with several researchers who verified that grass-legume intercropping enhanced the microbial diversity of soil ( Li et al, 2013 , 2016c ; Lian et al, 2019 ). However, a dramatic change in the Shannon index, and beta diversity NMDS plot, also reflecting on the nutritional depletion of soil under the elongation and maturation stages.…”

Cassava/peanut intercropping improves soil quality via rhizospheric microbes increased available nitrogen contents

“…Eggplant/garlic relay intercropping system increased available N contents from 61.95 mg kg − 1 to 76.30 mg kg − 1 [47]. In sugarcane-soybean intercropping system, available N increased by 10% [29]. The increase of available N was related to the urease activities, which was the only significant change in IC and IP comparing with that in MC and MP ( Table 2).…”

“…For instance, molecular mechanisms of microbial disease control in intercropping were related to signals triggered by neighboring plants [28]. Sugarcanesoybean intercropping increased microbial diversity [29]. Microbiome-dependent immunity was related to soil organic matter content [30].…”

Intercropping Alters the Soil Microbial Diversity and Community to Facilitate Nitrogen Assimilation: A Potential Mechanism for Increasing Proso Millet Grain Yield

“…In cereal-legume intercropping systems, N fixation by microorganisms associated with legumes increases the availability of N for plants, with soil N uptake by intercropped cereal greatly inducing N fixation by the root nodules in the legume rhizosphere, which stimulates N utilization by coordinating interspecific interactions (Latati et al, 2016). This practical technique influences N transformation processes by regulating microbial activities, diversities and community compositions (Lian et al, 2019;Vidal et al, 2019). Actinobacteria and Proteobacteria, two common and ubiquitous bacterial groups, are markedly affected by intercropping systems due to their biology and habitats (Stach and Bull, 2005;Gong et al, 2019b).…”