长期施肥处理对双季晚稻叶绿素荧光特征及籽粒产量的影响

研究施肥模式对水稻叶绿素含量及荧光参数的调节作用,对提高水稻光能利用效率及籽粒产量具有重要意义。本研究以水稻品种赣929为试验材料,比较长期定位施磷钾肥(PK)、施氮磷钾肥(NPK)、等养分条件下70%氮磷钾肥配合施用30%有机肥(70F+30M)、50%氮磷钾肥配合施用50%有机肥(50F+50M)、30%氮磷钾肥配合施用70%有机肥(30F+70M)条件下水稻叶绿素荧光参数和产量变化特征。结果表明,水稻旗叶叶绿素含量从齐穗期到成熟期呈下降趋势,且表现为30F+70M50F+50M70F+30MNPKPK。水稻叶绿素荧光参数Fv/Fm随水稻生育期的推进呈降低趋势,其中PK处理Fv/Fm值最低,而施氮处理比不施氮处理Fv/Fm值增加了2.85%～4.18%。叶绿素荧光参数qL、ΦPSII在NPK处理中表现为齐穗期较高, 20 d之后显著降低;在50F+50M、30F+70M处理中表现为齐穗期较低, 20 d以后显著增加;在PK处理、70F+30M处理中一直处于较高水平。NPQ变化趋势与qL基本相反。ETR-PAR光响应曲线拟合结果表明, 70F+30M处理ETRmax、?和Ek值在齐穗期和20 d后值均最高。综合看来,等养分条件下配施30%有机肥具有最优的叶绿素荧光指标组合及籽粒产量;而配施超过50%有机肥由于前期热耗散增大使得用于光合作用的光能份额减少,而施用氮磷钾肥处理则由于后期的衰老使得光能利用效率下降。

Influence of long-term fertilizer application on chlorophyll fluorescence characteristics and grain yield of double cropping late rice

The regulating effect of different fertilization modes on the chlorophyll content and fluorescence parameters of rice is of great significance for the improvement of light use efficiency and grain yield of rice. In this research, the characteristics of variation of chlorophyll fluorescence parameters and yield in rice under long-term located fertilization with the treatments of phosphate and potash fertilizer (PK), nitrogen, phosphate and potash fertilizer (NPK), 70% NPK fertilizer mixed with 30% organic manure (70F+30M), 50% NPK fertilizer mixed with 50% organic manure (50F+50M) and 30% NPK fertilizer mixed with 70% organic manure (30F+70M) under the same nutrient conditions were studied. There was a downtrend in the chlorophyll content in flag leaves of rice from the full heading time to the maturation period; showing an order of 30F+70M > 50F+50M > 70F+30M > NPK > PK. In the proceeded of growth, the chlorophyll fluorescence parameter F_v/F_m decreased with the lowest in PK treatment; which was 2.85-4.18 higher in nitrogen fertilizer treatment than in the treatment without nitrogen fertilizer. Under NPK treatment, chlorophyll fluorescence parameters q_L and Φ_PSII were higher at the full heading stage and significantly lower after 20 d; under the treatments of 50F+50M and 30F+70M, however, they were lower at the full heading stage but increased significantly after 20 d; under PK treatment and 70F+30M treatment, they remained at a higher level. The variation tendency of NPQ was basically contrary to that of q_L. According to fitting results of ETR-PAR light response curve, the values of ETR_max, α, and E_k peaked under 70F+30M treatment both at the full heading stage and after 20 d. In general, under the same nutrient conditions, mixed application with 30% organic manure achieved the best combination of chlorophyll fluorescence parameters and highest grain yield; if the proportion of organic manure exceeded 50%, on the other hand, the light energy for photosynthesis would be reduced due to increased early-stage heat dissipation. In addition, the application of NPK fertilizer would lead to declining light use efficiency due to later aging.