DOI: 10.5061/dryad.t76hdr8dv
title: Data from: Soil functions are amplified along increasing planting densities via nutrient trade-off driven by rhizobacteria in drought-prone environment

description: It is unclear how plant growth-promoting rhizobacteria (PGPR) affect soil
 multifunctionality (SMF) and production function (SPF) along planting
 densities. To address this issue, Bacillus licheniformis (PGPR) was
 inoculated in maize fields with five planting densities (D1–D5 from low to
 high) in the drought-prone region of the Yunnan Plateau, southwest China,
 from 2022 to 2023. Data indicated that under non-inoculation (CK), SMF
 tended to increase from D1 to D4 (p&lt;0.05) and then stabilize in D5
 across two growing seasons. Yet, SPF was observed to elevate steadily with
 increasing densities. PGPR inoculation significantly improved SMF (0.129)
 and SPF (0.508) under increasing planting densities. Meanwhile, soil
 carbon and phosphorus cycling indices significantly improved by 0.272 and
 0.069 (p&lt;0.05), respectively, whereas no significant change was
 observed in the nitrogen cycling index (p&gt;0.05), relative to CK.
 Increased carbon cycling index was significantly associated with improved
 soil soluble organic carbon (2.26%) concentration, and enhanced
 carbon-related extracellular enzyme activities (9.57%). Similarly,
 phosphorus-related extracellular enzyme activity significantly increased
 by 10.51% (p&lt;0.05). Interestingly, no significant changes were
 observed in the levels of soil total nitrogen, ammonium nitrate,n and
 nitrate nitrogen, and the activities of nitrogen-related enzymes across
 planting densities. The above-mentioned phenomenon can be mechanistically
 explained by the variations in rhizosphere microbiomes, and the
 accelerated carbon exchanges with nitrogen/phosphorus, which amplified SMF
 for higher SPF by reshaping the nutrient trade-off in the
 plant-soil-microbe system through PGPR-enhanced microbial activity.
description: # Data from: Soil functions are amplified along increasing planting
 densities via nutrient trade-off driven by rhizobacteria in drought-prone
 environment Dataset DOI:
 [10.5061/dryad.t76hdr8dv](https://doi.org/10.5061/dryad.t76hdr8dv) ##
 Description of the data and file structure During harvest in both maize
 growing seasons, destructive sampling was performed in every plot, and
 three soil cores per plot were pooled to create a composite sample. For
 the first set, rhizosphere soil adhering to fresh maize roots at a depth
 of approximately 20 cm was gently brushed off with sterile fine nylon
 brushes and tweezers. All samples were immediately placed in a portable
 low-temperature freezer and subsequently transferred to a laboratory
 freezer for storage. Soil bacterial community samples were preserved at
 –80 °C for two weeks. In parallel, samples for the determination of soil
 microbial biomass carbon and nitrogen and enzyme activities were stored at
 –20 °C for one week to ensure sample stability (Ren et al., 2021). A
 second set, representing bulk soil, was collected with a 5 cm diameter
 auger at the same depth between plants in each plot. After passage through
 a 2 mm sieve, the bulk soil was air-dried for subsequent determination of
 physicochemical properties. #### Files and variables File: DATA.csv *
 Year: Year of cultivation - Number: Sample index * Inoculation PGPR: Plant
 Growth-Promoting Rhizobacteria (*Bacillus licheniformis*) inoculation
 treatment, non-inoculated (CK), inoculated (PGPR) - Planting
 densities: Maize planting densities were D1 (40,950 plants·ha⁻¹), D2
 (50,505 plants·ha⁻¹), D3 (58,275 plants·ha⁻¹), D4 (65,880 plants·ha⁻¹),
 and D5 (75,765 plants·ha⁻¹) * pH: Soil pH - SWS: Soil water storage (mm) *
 SOC: Soil organic carbon (g·kg⁻¹) - DOC: Dissolved organic carbon
 (mg·kg⁻¹) * TN: Total soil nitrogen (g·kg⁻¹) - NO₃⁻-N: Nitrate nitrogen
 (mg·kg⁻¹) * NH₄⁺-N: Ammonium nitrogen (mg·kg⁻¹) - AP: Available phosphorus
 (mg·kg⁻¹) * MBC: Soil microbial biomass carbon (mg·kg⁻¹) - MBN: Soil
 microbial biomass nitrogen (mg·kg⁻¹) * BG: β-1,4-glucosidase
 (nmol·g⁻¹·h⁻¹) - CB: Cellulase (nmol·g⁻¹·h⁻¹) * LAP: Leucine
 aminopeptidase (nmol·g⁻¹·h⁻¹) - NAG:
 β-1,4-N-acetylglucosaminidase (nmol·g⁻¹·h⁻¹) * PHOS: Acid
 phosphatase (nmol·g⁻¹·h⁻¹) - Plant Biomass: aboveground + belowground
 maize biomass (t·ha⁻¹) * Yield: Maize yield (kg·ha⁻¹)