Fig. 1: Effects of warming and management on soil microclimate and crop yields.
From: Conservation agriculture improves soil health and sustains crop yields after long-term warming
a Experimental settings for treatments. b, c Effects of warming and management on soil temperature and moisture over eight years was estimated by linear mixed model with sampling time as random factors. Statistical significance is based on Wald type II χ² tests (n = 8 independent soil samples per treatment). All reported P values result from two-sided statistical tests. Boxplots display the mean (horizontal line), the 25th and 75th percentiles (colored box), the minimum and maximum (whiskers). d Average winter wheat yields. Boxplots display the mean (horizontal line), the 25th and 75th percentiles (colored box), the minimum and maximum (whiskers). The winter wheat yield data were analyzed based on eight sampling years (n = 24 independent soil samples per treatment). Statistical analysis was performed using a linear mixed model with sampling time as random factors. Statistical significance is based on Wald type II χ² tests. All reported P values result from two-sided statistical tests. Asterisks indicate significant differences in the warming effect of the individual management system as compared with their matched ambient condition. e Shift in the effect size of warming on crop yields over time for conservation and conventional agriculture, respectively. A linear regression model with two-sided test was used for the statistical analysis, and adjusted R-squared was used. Relationships are denoted with solid lines and fit statistics (R2 and P values) for each management practice. The solid line represents the significant linear regression (P < 0.05), and the gray shading indicates the 95% confidence intervals. All reported P values result from two-sided statistical tests where *P < 0.05, **P < 0.01, and ***P < 0.001. Conserv-Amb, conservation agriculture without warming; Conserv-Warm, conservation agriculture with warming; Conven-Amb, conventional agriculture without warming; Conven-Warm, conventional agriculture with warming. Source data are provided as a Source Data file.
