不同粮食作物光能利用效率研究

Radiation use efficiency of different grain crops in Northeast China

作物产量高低主要取决于作物的光能利用效率,明确不同作物光合、光截获能力与光能利用效率的差异性,对提高作物资源利用效率和种植结构调整有重要意义。该研究以吉林省梨树县玉米、春小麦、大豆、谷子和马铃薯5种主要粮食作物为研究对象,通过2 a田间试验,分析研究了不同作物不同生育阶段的光合特性、光截获能力和光能利用效率。结果表明:玉米和谷子在营养及生殖生长阶段的最大净光合速率均不低于28.34μmol/(m^2·s),高于其他作物,且光合作用适宜光强范围较其他作物更宽。对比作物光合有效辐射截获能力可知,玉米、大豆和谷子的光截获能力明显优于其他作物,但基于光截获能力分析需适当减小种植密度,避免种植密度过大影响作物中下部叶片发育;马铃薯和小麦则可在充分考虑水分、肥料等限制条件后适当增加种植密度来提升作物群体光截获能力;作物上部最大光截获由营养生长阶段向生殖生长阶段的过渡时期最高,对作物光能利用率的提高有重要影响。马铃薯、玉米及谷子的全生长季光能利用率显著高于小麦和大豆;马铃薯、玉米及谷子在营养生长到生殖生长过渡时期的光能利用率较其他生育期高。仅考虑产量最高,吉林梨树县优先种植玉米、马铃薯和谷子。

Grain productivity mainly depends on the radiation use efficiency(RUE)of crops.The RUE can be defined as the relationship between the accumulation of biomass related to the light intercepted by the crop.It is necessary to clarify the relationship between crop photosynthesis,light interception ability,and RUE,in order to improve the utilization efficiency of crop resource,further to adjust planting structure.Additionally,the Northeast China,as an important major grain producing area,is playing a critical role in national food security.Taking maize,spring wheat,soybean,millet,and potato in Lishu county of Jilin province in Northeast China as research materials,2 a field experiments were conducted to investigate the photosynthetic characteristics,light interception,and RUE of five main crops in different growing periods.The crops were first planted in the traditional way,where the cultivation and management were commonly used in the local area.A LI-6400 XT portable photosynthesis and fluorescence system was used to measure the diurnal changes of net photosynthetic rate in the vegetative and reproductive growth stages.The light response curve was fitted to obtain the main parameters of light response.A linear light quantum analyzer was selected to measure the light interception of different parts in the key growth period.The light interception and bioaccumulation were used to calculate the utilization efficiency of light energy in different growth periods,whereas,the photosynthetic ally active effective radiation and bioaccumulation were used to calculate that in the whole growing season.The results showed that the maximum net photosynthetic rates of maize and millet were higher than 28μmol/(m^2·s)at the vegetative and reproductive growth stages,indicating significantly higher than those of soybean,spring wheat,and potato.The diurnal variation curve of net photosynthetic rate for soybean and potato showed a single peak curve,where the peak appeared in the morning.Maize and millet showed a high light saturation point,and a low light compensation point of each crop leaf,where the suitable range of light intensity for photosynthesis was higher than that of other crops.Maize and millet also obviously dominated in the net photosynthetic rate curve and main light response parameters of various crops in the vegetative and reproductive growth stages.The light interception ability of maize,soybean and millet was significantly better than that of other crops,but the planting density can be appropriately reduced to avoid the influence on the development of middle and lower leaves of crops.Nevertheless,the increase of planting density can contribute to improve the light interception ability in the population of potato and wheat.In the transition period from vegetative to reproductive growth stage,the maximum light interception was found in the upper part of crops,indicating an important impact on the improvement of crops RUE.The RUE of potato,maize and millet in the whole growing season was significantly higher than that of wheat and soybean,whereas,that in the transition period from vegetative to reproductive growth was higher than that in other growth periods.Therefore,it is recommended that potato,maize,and millet can be planted preferentially on the adjustment of planting structure using RUE and yield.The finding can provide valuable information to formulate more reasonable and effective planting structure,according to resource utilization efficiency in the future.