| To face challenges such as a large population base,low grain yield and quality,and increasing greenhouse effect,it is a long-term research topic for scientists cultivating new varieties with high yield and good quality,and could make full use of nutrient resources,and environmentally friendly..Excessive fertilization has caused many environmental problems,such as reduced lodging resistance of rice,reduced rice quality,increased greenhouse gas emissions from fields and serious water eutrophication.Therefore,it is urgent to establish a green,efficient,and low-carbon system.The experimental site is located in the west plantation of Anhui Science and Technology University,Fengyang County,Chuzhou City,Anhui Province.We used the wild type(WT),OsNRT2.3b overexpression materials O8 and OsNRT2.3a RNAi silencing material osnrt2.3a as experimental materials.This experiment set up 6 fertilizer treatments: single application of high nitrogen fertilizer as N2(270kg/ha),single application of low nitrogen fertilizer as N1(90kg/ha),single application of high carbon fertilizer as C2(270kg/ha),single application of low carbon fertilizer as C1(90kg)/ha),high nitrogen fertilizer(270kg/ha)replaced with 20%carbon fertilizer as N2C2-20%,low nitrogen fertilizer(90kg/ha)replaced with 20%carbon fertilizer as N1C1-20%,each treatment has three replicates,a total of 18 test plots.The main results are as follows:1.Results of yield,total nitrogen content,and nitrogen use efficiency under different fertilization treatments: the yield and total nitrogen content of O8 were higher than WT under every fertilization conditions.Compared with single application of nitrogen fertilizer,single application of carbon fertilizer reduced the yield and total nitrogen content of O8,osnrt2.3a and WT.The yield and total nitrogen content of single application of nitrogen fertilizer(N2),single application of carbon fertilizer(C2),and 20% carbon fertilizer replacement(N2C2-20%)nitrogen fertilizer were higher than that of single application of nitrogen fertilizer(N1),single application of carbon fertilizer(C1),and 20% carbon fertilizer replacement of nitrogen fertilizer(N1C1-20%).2.Results of lodging characteristics under different fertilization treatments: Compared with WT,the plant height,center of gravity height,internode length,internode thickness,internode fresh weight,internode dry weight,internode dry mass per unit length,breaking force,and bending moment all increased under every fertilization conditions in O8,and decreased in osnrt2.3a;Compared with WT,the lignin content had no difference in O8 and under the condition of single application of high nitrogen(N2),and increased in other fertilization treatments,also the lignin content of osnrt2.3a had no difference under the conditions of single application of high nitrogen(N2)and 20% carbon fertilizer instead of low nitrogen(N1C1-20%),and decreased in other fertilization treatments.Moreover,O8,osnrt2.3a and WT had higher breaking force and lower lodging index under the condition of 20% carbon fertilizer instead of nitrogen fertilizer.The breaking force of O8,osnrt2.3a and WT showed a significant positive correlation with internode length,internode fresh weight,and center of gravity height,while showed a significant negative correlation with plant height,center of gravity height and lodging index.The breaking force of single application of nitrogen fertilizer(N2),single application of carbon fertilizer(C2),and 20%carbon fertilizer instead of nitrogen fertilizer(N2C2-20%)was lower than that of single application of nitrogen fertilizer(N1),single application of carbon fertilizer(C1)and20%carbon fertilizer replaces low nitrogen fertilizer(N1C1-20%).3.Results of rice quality under different fertilization treatments: under various fertilization treatment conditions,the appearance quality,nutrition and taste quality of O8 were overall higher than WT,and osnrt2.3a nutrition and taste quality were lower than WT.According to the high-quality rice standard of the People’s Republic of China,O8 was the national first-class high-quality rice,and osnrt2.3a was the national third-class high-quality rice.Compared with single application of nitrogen fertilizer,single application of carbon fertilizer improved the eating quality of O8,osnrt2.3a and WT,while 20% carbon fertilizer instead of nitrogen fertilizer did not influence the eating quality of O8,osnrt2.3a and WT compared with single application of nitrogen fertilizer.4.Results of greenhouse gas emissions under different fertilization treatments: the methane emissions of O8 were lower than WT each fertilization treatment except single carbon fertilizer application,and the emissions of nitrous oxide of O8 were lower than WT under all fertilization conditions.There were no significant difference between osnrt2.3a and WT emissions in general.Compared with single application of nitrogen fertilizer,single application of carbon fertilizer increased soil methane emissions of WT,and reduced nitrous oxide and carbon dioxide emissions of O8,osnrt2.3a,and WT;the soil carbon dioxide emissions didn’t have no significant reduce in replacing nitrogen fertilizer with 20%carbon fertilizer of O8,osnrt2.3a and WT,but significantly reducing the emissions of methane and nitrous oxide.At the same time,the methane,nitrous oxide,and carbon dioxide emissions in single application of nitrogen fertilizer(N2),single application of carbon fertilizer(C2),20% carbon fertilizer instead of nitrogen fertilizer(N2C2-20%)were all higher than those of nitrogen fertilizer alone(N1),carbon fertilizer alone(C1),and20% carbon fertilizer substitution low(N1C1-20%).In summary,OsNRT2.3b overexpression material O8 has the advantages of high yield,high total nitrogen content,strong lodging resistance,high rice quality,and low greenhouse gas emissions,while OsNRT2.3a RNAi silencing material osnrt2.3a has poor lodging resistance,the characteristics of low rice quality and high greenhouse gas emissions.In addition,the carbon fertilizer treatment improves the eating quality of rice and enhances the emission of greenhouse gases.The mixed application of carbon fertilizer and nitrogen fertilizer reduces the emission of methane and nitrous oxide. |
PDF Full Text Request