Meta-analysis data quantifying nitrous oxides emissions from Chinese vegetable production.

This paper describes data of nitrous oxides (N2O) emissions from open-field and greenhouse systems in Chinese vegetable production. The data also describes the potential soil and management factors to identify the effective measures to mitigate N2O emissions. The data were collected from 21 peer-reviewed papers, covering 153 N2O emission field measurements as affected by fertilizer nitrogen (N) management. This data were subjected to meta-analysis for a comprehensive assessment on N2O emission and applied N based emission factor in Chinese vegetable production.

Specifications Table

Value of the data

Data cover 153 field measurements of N2O emission from 21 experiments.

Data are suitable for meta-analysis.

Data can be used to quantify N2O emissions and emission factors (EFs) from Chinese vegetable production in open-field and greenhouse systems.

Data can be used to identify effects of fertilizer N managements (rate and type) and soil properties (Soil organic matter, total N content, etc.) on N2O emissions and EFs.

Data

Data were extracted from peer-reviewed journal papers published until 2017 January. Totally 153 field measurements of N2O emission from 21 experiments were included in a meta-analysis. Detailed data are listed in supplementary material, giving the following information: year, location, vegetable species, cultivation type, formulation of synthetic and manure N fertilizer, N fertilizer rate, cumulative N2O emission over the growing season, EFs, the response ratio (RR), yield, soil organic matter content, soil total N content, irrigation, rainfall, duration of experimental period, gas sampling method, literature reference.

Experimental design, materials, and methods

Design, materials, and methods

Databases including ISI-Web of Science (Thomson Reuters, New York, NY, USA), Google Scholar (Google Inc., Mountain View, CA, USA), and the China Knowledge Resource Integrated database (CNKI) were used to search for studies enrolled in the meta-analysis. The Keyword search included ‘nitrous oxide’, ‘N2O’, ‘nitrogen’, and ‘vegetable’, which were adopted to identify all relevant literatures on N2O emissions from vegetable production. Data in only graphical form were digitized using GetData v.2.22 software [2].

To minimize bias, the following criteria were used to select studies for meta-analysis: (i) N2O emissions were measured during the entire growing seasons of vegetable crops in open-field or greenhouse systems, and the vegetables were grown in the field rather than in soil columns or pots; (ii) N2O emissions were reported for experiments that included treatments both with and without N fertilizer application, to calculate the EFs; (iii) N fertilizer sources were synthetic fertilizer or manure (e.g. pig, cattle, poultry manures, plant residues, compost etc), but the synthetic fertilizer could only include conventional commercial N fertilizer (e.g., urea, thiamine, compounds), i.e., could not include slow-/controlled-release or stabilized fertilizers.; (iv) N2O emissions were measured with manually operated chambers, automatic chambers, or towers.

Meta-analysis

An unweighted pair-wise meta-analysis were conducted on N2O emission and EFs. The effect size for each control-treatment pair was estimated using the response ratio [RR=ln(N2Otreatment/N2Ocontrol), where N2Otreatment and N2Ocontrol were means of N2O emissions (kg N2O-N ha−1) for the fertilized treatment and for the unfertilized control in each field observation, respectively [3]. Data of RR, N2O emission and EFs were subjected to Kolmogorov–Smirnov test for determination of normal distribution [4]. Response ratio followed normal distribution, suggesting the capacity of using meta-analysis for examination of fertilizer N effects on N2O emissions. Data of N2O emission and EFs followed non-normal distribution and were therefore subjected to nonparametric test for further analysis.

Subject area	Agriculture
More specific subject area	Agricultural environmental pollution
Type of data	Table
How data was acquired	Data was acquired from the published articles
Data format	Raw, analyzed
Experimental factors	The criteria used for screening previous publications were described in Wang et al.[1].
Experimental features	Data were subjected to meta-analysis to quantify nitrous oxides (N2O) emissions in Chinese vegetable production and identify the effective fertilizer management practices to reduce emissions.
Data source location	China
Data accessibility	Data are within this article
Related research article	Wang et al.[1]