长期施肥对水稻光合特性及水分利用效率的影响

Effects of long-term fertilization on rice photosynthetic traits and water use efficiency.

在实施了27年的长期田间定位试验区,研究了长期不同施肥对红壤区水稻光合特性及水分利用效率的影响。结果表明:在不施肥(CK)、无机肥(N、NP、NPK)、有机肥(猪粪+紫云英绿肥,M)和无机肥与有机肥配施(NPKM)处理中,长期施用肥料,特别是有机肥与无机肥配施提高水稻各生育期剑叶叶绿素含量、净光合作用速率、气孔导度、蒸腾速率、水分利用效率和水稻产量,降低水稻剑叶胞间CO2浓度;水稻剑叶叶绿素含量、净光合作用速率、气孔导度、蒸腾速率随发育阶段演进而减小,孕穗期>齐穗期>乳熟期,而胞间CO2浓度相反;水分利用效率以齐穗期为最大;水稻发育阶段叶绿素含量、净光合速率和水稻产量之间均呈显著正相关;长期施用肥料,特别是有机肥与无机肥配施更有利于红壤区水稻的生长发育、产量和水分利用效率的提高。

A field experiment has being conducted for 27 years in Jinxian County, Institute of Red Soil in Jiangxi Province （116°20′24″ E, 28°15′30″ N） to study the effects of fertilization on the rice photosynthetic traits and water use efficiency. Four treatments were installed, i. e. , no fertilization （CK）, chemical fertilization （N, NP, NPK）, organic fertilization （M）, and chemical and organic fertilization（NPKM）. Long-term fertilization, especially treatment NPKM, increased the flag leaf chlorophyll content, net photosynthetic rate, stomatal conductance, transpiration rate, and water use efficiency of rice at its all growth stages and the rice yield, and decreased the flag leaf intercellular CO2 concentration. With the growth of rice, the chlorophyll content, net photosynthetic rate, stomatal conductance, and transpiration rate decreased, but the intercellular CO2 concentration increased. The water use efficiency was the greatest at full-heading stage. There were significant positive correlations between the chlorophyll content and net photosynthetic rate at various growth stages and the rice yield. Long-term fertilization, especially the combined chemical and organic fertilization, was favorable to the rice growth and development, water use efficiency, and yield production in red soil region.