Screening Of Rice Dry Direct Seeding And Greenhouse Gas Emission Reduction In Northern China

As a rice producing country,China's rice development is crucial in China's agriculture.With the development of China's social science and technology,the rural labor force is lost,and water shortages limit the development of rice.As a kind of water-saving and simple cultivation method for rice,rice derect seeding has become a development trend.At present,the varieties used for derect seeding research in China are all transplanted used.The transplanted varieties are difficult to meet the requirements of derect seeding,and the cold damage in the north occurs frequently.It is also required to screen the derect seeding varieties suitable for the north.At the same time,global climate change has received much attention in recent years,mainly caused by greenhouse gas(CO2,CH4,N2O)emissions,while traditional transplanted rice fields are considered to be the main source of greenhouse gas emissions in rice fields.Dry derect seeding can effectively reduce rice field greenhouses.In this study,13 kinds of northern japonica rice varieties,such as TJ7,TJ11 and TJ14,were used as experimental materials,and the varieties suitable for dry-field cultivation in northeast rice region were selected and the derect seeding was explored.The law of greenhouse gas emission reduction,in order to achieve the purpose of drought and live reduction.The main findings are as follows:(1)The emergence rate of TJ7 and TJ11 was higher at 10 °C,and the emergence rate of JJ809 was higher at 12 °C.The emergence rate of the three varieties was higher under 5 cm deep sowing.The hypocotyl elongation is sufficient to meet the requirements of low-temperature emergence and deep-emergence emergence in the early stage of derect seeding.The mesocotyl elongation indicates that the top soil has strong seedling emergence ability.(2)Under the direct seeding cultivation,JJ511 has good yield and various indexes,and has strong resistance to drought and weeds.It is suitable for direct dry cultivation innorthern China;TJ16,BJ1,BJ3 yield and various indicators are better,but lack of research on drought and weed stress resistance,which can be supplemented by future research.(3)In this study,compared with transplanting,dry derect seeding can significantly reduce greenhouse gas emissions,and GWP(comprehensive warming potential value)is significantly reduced by about 60%-70%;under the same water and fertilizer management,different varieties under dry and direct cultivation There is no difference between greenhouse gas emissions and GWP.