Soil bacterial communities interact with silicon fraction transformation and promote rice yield after long-term straw return

Abstract

Returning crop straw into the soil is an important practice to balance biogenic and bioavailable silicon (Si) pool in paddy, which is crucial for the healthy growth of rice. However, owing to little knowledge about soil microbial communities responsible for straw degradation, how straw return affects Si bioavailability, its uptake, and rice yield remains elusive. Herein, we investigate the change of soil Si fractions and microbial community in a 39-year-old paddy field amended by a long-term straw return. Results show that rice straw return significantly increased soil bioavailable Si and rice yield from 29.9% to 61.6% and from 14.5% to 23.6%, respectively, when compared to NPK fertilization alone. Straw return significantly altered soil microbial community abundance. Acidobacteria was positively and significantly related to amorphous Si, while Rokubacteria at phylum level, Deltaproteobacteria, and Holophagae at class level was negatively and significantly related to organic matter adsorbed and Fe/Mn-oxide-combined Si in soils. Redundancy analysis of their correlations further demonstrated that Si status significantly explained 12% of soil bacterial community variation. These findings suggest that soil bacteria community and diversity interact with Si mobility by altering its transformation, thus resulting in the balance of various nutrient sources to drive biological Si cycle in agroecosystem.

Silicon fertilizer mediated structural variation and niche differentiation in the rhizosphere and endosphere bacterial microbiome and metabolites of sugarcane

“…Therefore, our findings could broaden our understanding of how Si influences soil fertility and productivity, as well as microbial and metabolisms communities in different soil and sugarcane compartments. Here, we observed that the application of Si not only improved sugarcane agronomic parameters, but also promoted its yield, which is consistent with previous findings, where Si application enhanced the yield and quality of rice (Song et al, 2021) and sugarcane (Meyer and Keeping, 2000). It was also observed that Si amended soil remarkably enhanced soil nutrient status, especially Si, AP, and AK, which is in agreement with the finding documented by Zhang et al (2021b) and Matychenkov and Ammosova (1996).…”

Soil Microbial Indicators within Rotations and Tillage Systems

“…While Xiao et al [72] found that Luteimonas (G) was positively correlated with soybean and alfalfa (Medicago sativa L.) biomass. Relatively little information exists for the Holophagae (C) Subgroup 7 (O), except that RAs were found to be positively correlated with a legume treatment compared to grass [73], with pH [74], and negatively correlated to SOM [75]. Acidobacteria (P) and many of their subgroup RAs were negatively correlated to nutrient levels and associated with C degradation [76].…”

The role of silicon in the supply of terrestrial ecosystem services

“…Si addition may simply consist of keeping organic residues that are rich in Si in the field, as was done in traditional agriculture for centuries but has been largely abandoned in recent decades in "conventional" practices where removal of residues is common. Song et al (2021) studied a 39-year-old paddy field amended by a long-term straw return. They showed that the bioavailable Si and rice yield significantly increased when compared to NPK fertilization alone by 29.9 % to 61.6 % and 14.5 % to 23.6 %, respectively.…”