DOI: 10.5061/dryad.931zcrjgz
title: Large-scale homogenization of soil bacterial communities in response to agricultural practices in paddy fields, China

description: This dataset contains data from 257 sites in four typical rice-growing
 regions across a 4,000-km transect in China, including geographic location
 data and environment factors data. The study was conducted across a
 4,000-km transect of China’s rice-growing areas, from Heilong Jiang
 province to Yunnan province (100°55′ E to 134°08′° E, 22°46′ N to 48°02′
 N, Table S1). Four typical rice-growing regions were selected along this
 transect: Sanjiang Plain (modern mechanical farming), Taihu Plain
 (mechanical plus minor manual farming), Lianghu Plain (manual plus minor
 mechanical farming), and Hani Terrace (traditional manual farming). Field
 sampling was conducted during July and August in 2014 and 2015. Soil
 samples were collected from 178 flooded paddy fields and 79 surrounding
 non-paddy areas across four typical rice-growing regions of China. At each
 site, one homogenized sample was obtained, which was then separated into
 two parts. One part, which was obtained for DNA extraction, was placed
 into a sterile plastic tube then immediately placed in liquid nitrogen for
 short-term transportation. After shipping to the laboratory, these tubes
 were stored at −80 °C. The second part of the soil sample was placed into
 a plastic bag and stored at 4.0 °C for determining the soil
 physicochemical properties. Main results of the experiments are that: (1)
 Distance–decay patterns of bacterial communities in paddy fields revealed
 reduced β-diversity compared to surrounding natural habitats. (2) Modern
 rice farming practices (plowing with machines) caused stronger
 homogenization of soil bacterial communities than traditional farming
 (plowing by hand). Among the four paddy regions, plowing by hand retained
 the highest soil bacterial β-diversity. (3) Moreover, a significant
 inverse correlation was observed between bacterial β-diversity and the
 agricultural mechanization level. (4) Among multiple environmental
 factors, dramatic spatial homogenization of soil physicochemical
 properties, particularly soil nutrient contents, and reduced dispersal
 limitation caused by modern farming activities both strongly predict a
 reduction of bacterial β-diversity in modern paddy fields.
description: Across a 4000 km transect of China, we collected a total of 257
 samples from four typical rice-growing regions. These regions follow a
 rice cultivation management gradient from modern mechanical to traditional
 manual practices. We examined distance decay patterns of soil bacterial
 communities regionally and continentally. With more than 50 environmental
 factors determined, we then used multiple statistical tools to unveil
 mechanisms underlying such patterns.
description: <strong>Sample ID and geographic location.xlsx</strong> The longitude (long) and latitude (lat) coordinates for a total of 257 soil samples taken across four rice-growing regions, China.    <strong>Studied environmental factors.xlsx</strong> All studied environmental variables and their measured/determined values, including 19 climate variables, 26 plant-soil variables, and 9 landscape/topography variables. Long: longitude Lat: latitude AMT: Annual mean temperature MDR: Mean diurnal range ISO: Isothermal sex TSEA: Temperature Seasonality MAXTWM: Max Temperature of Warmest Month MINTCM: Min Temperature of Coldest Month TRANGE: Temperature Annual Range TWETQ: Mean Temperature of Wettest Quarter TDQ: Mean Temperature of Driest Quarter TWARQ: Mean Temperature of Warmest Quarter TCQ: Mean Temperature of Coldest Quarter AP: Annual Precipitation PWETM: Precipitation of Wettest Month PDM: Precipitation of Driest Month PSEA: Precipitation Seasonality PWETQ: Precipitation of Wettest Quarter PDQ: Precipitation of Driest Quarter PWARQ: Precipitation of Warmest Quarter PCQ: Precipitation of Coldest Quarter TC: Total carbon TN: Total nitrogen TP: Total phosphorus Olsen-P: Olsen-phosphorus C_N: Ratio of carbon and nitrogen C_P: Ratio of carbon and phosphorus N_P: Ratio of nitrogen and phosphorus TK: Total potassium Ca: Total calcium Mg: Total magnesium S: Sulfur Fe: Iron Mn: Manganese K<sup>+</sup>: exchangeable potassium Ca<sup>2+</sup>: exchangeable calcium Mg<sup>2+</sup>: exchangeable magnesium