# Modeling the Impact of Atmospheric Warming on Staple Crop Growth in China in the 1960s and 2000s
## 3 Results
### Temperature Change Effects on Crop Productivity in Key Growth Periods
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Crop**} & \multirow{2}{*}{**DVI**} & \multicolumn{2}{c}{**GPP a**} & \multicolumn{2}{c}{**RA a**} & \multicolumn{2}{c}{**AGB a**} & \multicolumn{2}{c}{**Number of**} & \multirow{2}{*}{\begin{tabular}{c} **Tmean c** \\ **(\(\mathbf{gC}\) m\({}^{-2}\))** \\ \end{tabular} } \\  & & **(\(\mathbf{gC}\) m\({}^{-2}\))** & & **(\(\mathbf{gC}\) m\({}^{-2}\))** & & **(\(\mathbf{gC}\) m\({}^{-2}\))** & & **(\(\mathbf{gC}\) m\({}^{-2}\))** & \\  & & **1960s** & **2000s** & **1960s** & **2000s** & **1960s** & **2000s** & **1960s** & **2000s** \\ \hline \multirow{4}{*}{\begin{tabular}{c} Rice \\ (Changshu) \\ \end{tabular} } & 40 days before & 762 & 745 & 422 & 422 & 317 & 305 & 333 & 280 & 28.4 & 28.6 \\  & heading–heading & (47.0\%) & (44.4\%) & (47.5\%) & (45.5\%) & (45.8\%) & (42.6\%) & \\  & heading–maturity & 666 & 735 & 383 & 420 & 283 & 315 & 139 & 162 & 20.7 & 21.6 \\  & (41.1\%) & (43.8\%) & (43.1\%) & (45.2\%) & (40.9\%) & (44.0\%) & & & & & \\ \hline \multirow{4}{*}{\begin{tabular}{c} Single rice \\ (Sanjiang) \\ \end{tabular} } & 40 days before & 560 & 588 & 271 & 282 & 265 & 282 & 74 & 76 & 21.1 & 21.8 \\  & heading–heading & (51.5\%) & (50.8\%) & (50.4\%) & (50.0\%) & (51.2\%) & (50.5\%) & & & & \\  & heading–maturity & 404 & 421 & 210 & 217 & 194 & 204 & & & & \\  & heading–maturity & (37.2\%) & (36.4\%) & (39.0\%) & (38.5\%) & (37.6\%) & (36.6\%) & & & & \\ \hline \multirow{4}{*}{\begin{tabular}{c} Early rice \\ (Taoyuan) \\ \end{tabular} } & 40 days before & 398 & 423 & 166 & 175 & 210 & 225 & 168 & 198 & 23.2 & 24.2 \\  & heading–heading & (54.9\%) & (55.3\%) & (54.7\%) & (54.2\%) & (53.6\%) & & & & & \\ \cline{1-1}  & heading–maturity & 309 & 317 & 131 & 139 & 178 & 178 & & & & & \\ \cline{1-1}  & (42.6\%) & (41.5\%) & (43.1\%) & (43.1\%) & (43.3\%) & (42.5\%) & & & & & \\ \hline \multirow{4}{*}{\begin{tabular}{c} Late rice \\ (Taoyuan) \\ \end{tabular} } & 40 days before & 584 & 565 & 267 & 262 & 294 & 281 & 239 & 28.0 & 28.1 \\  & heading–heading & (58.0\%) & (54.9\%) & (59.8\%) & (57.0\%) & (55.0\%) & (51.6\%) & & & & \\ \cline{1-1}  & heading–maturity & 362 & 404 & 157 & 175 & 205 & 229 & 111 & 156 & 22.0 & 23.3 \\ \cline{1-1}  & heading–maturity & (36.0\%) & (39.2\%) & (35.2\%) & (38.2\%) & (38.4\%) & (41.9\%) & & & & \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} Winter wheat \\ (Fengqiu) \\ \end{tabular} } & 40 days before & 339 & 503 & 111 & 160 & 211 & 317 & 124 & 190 & 11.2 & 13.4 \\  & heading–heading & (54.2\%) & (51.4\%) & (42.3\%) & (42.2\%) & (61.8\%) & (58.2\%) & & & & \\ \cline{1-1}  & heading–maturity & 136 & 184 & 82 & 104 & 54 & 80 & & & & \\ \cline{1-1}  & heading–maturity & (21.8\%) & (18.8\%) & (31.1\%) & (27.5\%) & (15.9\%) & (14.7\%) & & & & \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Winter wheat \\ (Changshu) \\ \end{tabular} } & 40 days before & 351 & 531 & 115 & 176 & 217 & 324 & 90 & 162 & 10.8 & 13.0 \\ \cline{1-1}  & heading–heading & (45.6\%) & (46.5\%) & (37.3\%) & (39.1\%) & (51.1\%) & (52.2\%) & & & & \\ \cline{1-1}  & heading–maturity & 209 & 271 & 108 & 143 & 101 & 128 & & & & \\ \cline{1-1}  & heading–maturity & (27.2\%) & (23.7\%) & (35.0\%) & (32.0\%) & (23.8\%) & (20.5\%) & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Photosynthetic production and temperature changes in different growth periods for the 1960s and 2000s. Figure 4 shows the correlation between the change in the number of optimum temperature days and the AGB of different crops in the two key growth stages for rice, wheat and maize in the 1960s and 2000s. Changes in the number of optimum temperature days and AGB refer to differences in the number of optimum temperature days and in AGB in Table 4 between the 2000s and 1960s. Relative to the 1960s, the increase in the number of optimum temperature days in the 2000s not only improved crop productivity but also led to a significantly nonlinear positive correlation between crop AGB and the number of optimum temperature days (Figure 4).