Effect Of Different Cultivation Practices On Morphology And Physiology Of Roots And Yield Of Rice

Rice is an important food crop in China.With the development of society,the increase in population,the reduction in the area of arable land,and the increasing demand for grain yields are imminent.However,the increase in yield is often accompanied by an increase in the input of water and fertilizers,which leads to a low efficiency of water and fertilizer utilization.How to achieve high productivity and efficient collaborative development has always been a key problem for scholars to solve with.The roots of plants are important sites for the absorption,translocation and synthesis of substances.Its morphological and physiological characteristics are closely related to the construction of aboveground parts.In this study,the conventional Japonica rice Wuyunjing-24 and Yongyou-2640 were field-grown with 7 cutivation methods,no nitrogen fertilizer(ON),local conventional cultivation(control),densification and nitrogen reduction,precision irrigation,increased cake fertilizer,soil deep turning and manure application,were used to evaluate the effects of 7 cutivation methods on yield and its components,photosynthetic characteristics,nitrogen fertilizer absorption and utilization efficiency,and root morphology and physiology of rice.1.Growth and development characteristics and physiology of rice population qualityThe yields of nitrogen reduction and precision irrigation of Yongyou-2640,increase of cake fertilizer,soil deep turning,and manure treatment were respectively 10.69 t hm'2,11.9 t hm-2,12.69 t hm-2,and 13.63 t hm-2.11.18t hm-2,which is 11.2%-43.3%higher than the local production,and the output increase of Wuyunjing-24 is 8.67%-32.3%.Density and nitrogen reduction,precision irrigation,increased cake fertilizer,soil deep turning,and manure application significantly reduced the number of ineffective tillers compared with the control(local routine),the chlorophyll content and photosynthesis rate of flag leaf after flowering were both significantly increased.It shows that the comprehensively optimum cultivation management practice can improve the rice population quality,especially improved efficiency of absorption and utilization of water nutrients of rice and eventually increased the production.2.Nitrogen absorption and utilization efficiency of riceCompared with conventional cultivation in the local area,the absorption and utilization efficiency of nitrogen fertilizer respectively increased by 15.6%,23.48%,52.9%,30.3%and 46%under nitrogen reduction,precision irrigation,increased cake fertilizer,soil deep turning and manure application.The agronomic efficiency of nitrogen fertilizer increased by 50.9%,122.1%,152.3%,114.8%and 166.4%,respectively.What's more,the application of precise irrigation and increased cake fertilizer both significantly increased the amount and rate of nitrogen transferred in rice from heading to maturity.It suggested that ice yield and nutrient uptake and utilization efficiency can be significantly increased at the same time by the application of optimum cultivation techniques.3.Root morphology and physiologyThe root system is an important organ for nutrient absorption.Compared with conventional cultivation in the local area,the application of nitrogen reduction,precision irrigation,increased cake fertilizer,soil deep turning,and manure significantly enhanced the root morphology,which also significantly increased the root dry weight per unit area,root length per plant,and root diameter.Moreover,the physiological traits of the roots including the oxidative power of the roots per plant,the intensity of the root turbulence,the absorption surface area of the roots,were siginificantly improved.In addition to all the indicators above,the increased amounts of IAA,ABA and Z+ZR in the root system also indicated that the application of optimum cultivation practice can promote root growth and lay a important foundation for high yields.