Impacts of deficit irrigation and organic amendments on soil microbial populations and yield of processing tomatoes

Altered precipitation patterns and increased water demands from urban, industrial, environmental needs often reduce the volume of irrigation available for agriculture. Strategies that inputs, e.g., deficit (DI), need further evaluation to determine potential impacts on yield soil microbial communities driving critical biogeochemical cycles. Whether organic amendments can stabilize DI effects remains unknown. Processing tomato beds were established in a full factorial experimental design soils unamended or amended with one-time application—four five years before sampling—of either biochar compost three regimes: (100 % plant demand), treatments at 75 50 irrigation. We profiled bacterial archaeal community compositions two growing seasons determined C N metabolic potentials biomass groups using high throughput sequencing 16S rRNA genes phospholipid fatty acid analysis. tested discrete interactive chemical biological properties, crop yield. had stronger composition than amendments. However, did not strongly affect total individual groups, but it productivity processing tomatoes. Although compositional shifts induced by DI, their recalcitrant still residual after incorporation. Furthermore, moisture correlated community's potentials, likely augmenting amendments' residence time soils. Our results provide insight into water-saving mechanisms could increase profit margins water-scarce without affecting populations support growth productivity.