Analysis On The Formation Of Gap In Yield And Resource Utilization Efficiency Of Japonica Rice In Liaoning Province

Rice is the main food crop for half of the world’s population,making an important contribution to solving the problem of food and clothing.China has a vast territory,and regional differences in light,temperature and soil have a huge impact on rice production.In recent years,the research and application of high yield cultivation mode of rice has improved the yield of rice.Scholars all over the world have focused their attention on"gap-narrowing and yield-increasing",which has been studied more in large spatiotemporal domains than in small regional levels.Otherwise,in China,much more interest is paid attention on efficiency increasing while stabilizing high yield of rice.In order to clarify the reasons for the differences in yield and resource utilization efficiency of japonica rice,this experiment was carried out in the Liaohe Delta of Panjin,the southeast coastal area of Donggang and the mountainous rice area in the east of Huanren in Liaoning Province.The main local varieties Yanfeng 47,Danjing20 and Jiyang 100 were selected as experimental materials,and the control variety Shendao 505was set up to carry out field tests in each test site from 2018 to 2020.Four cultivation modes were designed:basic yield level(BY),farmer yield level(FY),high and efficient yield level(HH)and super high yield level(SH).This experiment systematically studied rice yield and yield components,dry matter accumulation,yield gap and contribution rate,and canopy morphology of population.The main results were as follows:1.Yield and yield components:The interannual yield was affected by the accumulated temperature of the growing season,which was the highest in 2019 and the lowest in 2018;the yield of Panjin was the highest,followed by Donggang,Huanren,and the yield among treatments increased with the optimization of cultivation pattern,and the difference between treatments was significant.The yield difference between treatments increased in high-yield years.The inter-regional output of Panjin is the highest,followed by Donggang,followed by Huanren.In 2019,Yanfeng 47 reached 12.83 t/hm~2 in SH.The high yield of super-high-yield model benefited from the number of effective panicles per unit area,total spikelets,aboveground dry matter quality and higher population growth rate,but had nothing to do with harvest index and 1000-grain weight.2.Dry matter accumulation:To further improve the yield of japonica rice in Liaoning area,it is necessary to increase the material production capacity of rice at each growth stage,especially before full heading stage,which will be beneficial to the rapid establishment of rice population in the early stage.improve the utilization efficiency of temperature and light energy in rice population.Compared with FY,the dry matter of SH and HH increased by 4.0%and26.9%after anthesis.The synergistic improvement of the transport capacity of stems,leaves,sheaths,and other organs during grain filling is one of the main technical ways to reduce the yield of japonica rice in Liaoning province.3.Yield potential and yield gap:the potential production of light and temperature is affected by the total solar radiation and total accumulated temperature in the growing season,which is the spatial distribution of high in the west and low in the east.The growing season in Panjin area is longer,the average temperature in the growing season is higher,the total solar radiation intercepted by crops is large,the heat resources are abundant,the light energy utilization efficiency of rice population is high,and the yield potential is significantly higher than that of Donggang and Huanren.The experimental study on the commonness of four different yield levels showed that there was a decreasing relationship in the yield gap among different cultivation patterns.Compared with Ysh-Yhh,the yield-increasing and shrinking effect of Yhh-Yfy was obvious.The selection of suitable rice cultivation mode can make rational use of light and temperature resources,increase yield,and improve efficiency.4.Population characteristics and resource use efficiency:the super-high-yield cultivation model rice population LAI is suitable,the canopy extinction coefficient is low,the functional leaf SPAD and population LAI are higher and the duration is higher at filling stage,and the nitrogen use efficiency of rice is improved cooperatively.These characteristics are important factors for high light energy use efficiency and dry matter accumulation in super-high-yield population.A good population structure is the physiological basis of high yield of japonica rice,and the utilization efficiency of heat,light energy and light and temperature resources will also be improved in the process of yield improvement.Therefore,the appropriate increase of crop leaf area index and net photosynthetic rate and the coordinated increase of maximum leaf area duration is an important way to reduce the difference of japonica rice in Liaoning province.