Selection Of Direct Seeding Rice Varieties In Cold Regions And Comparison Of Yield And Quality With Conventional Planting Methods

Direct seeded rice is a light and simple cultivation method with less labor and high benefit.Heilongjiang province is one of the main rice planting areas in China.The development of direct seeding rice in Heilongjiang Province has broad application prospect.However,there are limited varieties of rice currently used for direct seeding.Using existing rice varieties to select suitable varieties for direct seeding will be helpful for the popularization of direct seeding rice cultivation.To select cold rice varieties suitable for water direct seeding at the lower limit of the first temperate zone and the upper limit of the second temperate zone in Heilongjiang Province.In this study,with conventional transplanter as the control,the groups were arranged randomly,29rice varieties were used as experimental materials for water direct seeding cultivation.And the suitable water direct seeding varieties were selected as materials,the yield,quality and economic benefit were compared with conventional transplanting cultivation.This can provide theoretical and technical support for the application and popularization of water direct seeding cultivation in cold areas.The main results were as follows:1.The coefficient of variation of ARI?Adaptation of rice direct sowing on paddy soil slurry response index?of panicle length,single panicle weight,primary branches,secondary branches,panicles,grain number,biomass,harvest index,theoretical yield,head rice rate,chalkiness degree,chalkiness rate,amylose content of 29 cultivars direct sowing on paddy soil slurry in two years were higher and were more sensitive to the rice direct sowing on paddy soil slurry.The coefficient of variation of ARI of seed setting rate,thousand-grain weight,milled rice rate,brown rice rate,grain length of milled rice,grain width of milled rice,ratio of length and width of milled rice and protein content were smaller and were blunt to the rice direct sowing on paddy soil slurry.During the two years,the rice cultivars with adaptation of rice direct sowing on paddy soil slurry coefficient,adaptation of rice direct sowing on paddy soil slurry index,comprehensive adaptability?D?showed moderate or high adaptation andtheoretical yield greater than 7.5 t/hm²and rice taste value greater than 74 were Longjing 20 and Longjing 58.2.The characteristics of panicle of Longjing 20 and Longjing 58 under direct sowing on paddy soil slurry showed a decreasing trend compared with conventional rice transplanting.In the past two years,the theoretical yield of Longjing 20 under direct sowing on paddy soil slurry was 7.85%lower than that of conventional rice transplanting.The theoretical yield of Longjing58 under direct sowing on paddy soil slurry was 6.96%lower than that of conventional rice transplanting.The grain length of milled rice and grain width of milled rice under direct sowing on paddy soil slurry were smaller than conventional rice transplanting.Chalkiness degree and chalkiness rate of rice direct sowing on paddy soil slurry were mostly higher than those of conventional rice transplanting.The brown rice rate,protein content and rice taste value of rice direct sowing on paddy soil slurry showed a decreasing trend compared with conventional rice transplanting.The interannual variation of milled rice rate,head rice rate and amylose content of rice direct sowing on paddy soil slurry were large.3.The input-output ratio of rice direct sowing on paddy soil slurry was 3 times of that of conventional transplanting,while the cost was only 76.4%of that of conventional transplanting.The cost of rice direct sowing on paddy soil slurry was 30.0%lower than that of conventional transplanting.The cost was reduced by 4260 yuan·hm^-2,and the net benefit was increased by3936.0 yuan·hm^-2.In conclusion,Longjing 20 and Longjing 58 were selected to be suitable for direct sowing on paddy soil slurry,which could effectively reduce the cost of rice production and improve the economic efficiency.