水肥管理对机收再生稻产量形成、再生芽生长及氮素吸收利用的影响OA

Breeding rolling-resistant rice varieties and optimizing water and fertilizer management are important approaches to mitigating the mechanical rolling damage during the harvest of the main season and increasing the yield of ratooning rice.To investigate the effects of water and fertilizer management on the yield formation,regeneration bud growth,and nitrogen(N)uptake and utilization of ratooning rice,a field experiment was conducted with Liangyou 6326(with high rolling resistance)and Taoyouxiangzhan(with low rolling resistance)as materials.The experiment set up two water treatments,namely light soil drying(to start water drainage and soil drying 24 days after full heading in the main season)and heavy soil drying(to start water drainage and soil drying 18 days after full heading in the main season).The experiment also set up three N fertilizer treatments,namely no N application(CK,N0),one-time N application as the seedling-promoting fertilizer(pure N was applied at 75.0 kg/hm2 1 day after the harvest of the main season,N1),and split N application as the seedling-promoting fertilizer(pure N was applied at 37.5 kg/hm2 1 day and 20 days after the harvest of the main season,respectively,N2).After the harvest of the main season,all rice stubbles was rolled by the tracks of a harvester to conduct the field experiment.The results were summarized as follows.(1)Compared with that of Taoyouxiangzhan,the average yield of Liangyou 6326 in the ratooning season increased by 6.2%,which was mainly due to the increases in the number of effective panicles per unit area,number of total grains per panicle,1 000-grain weight,and aboveground biomass at the maturity stage of the lower nodes.(2)Compared with the light soil drying treatment,the heavy soil drying treatment increased the average yield of the two varieties in the ratooning season by 14.4%,which was attributed to the simultaneous increases in the number of effective panicles per unit area and aboveground biomass at the maturity stage of the upper and lower nodes.(3)Compared with N0,N1 and N2 treatments increased the average yields of the two varieties in the ratooning season by 18.1%and 36.7%,respectively,which was mainly because the seedling-promoting fertilizer increased the number of effective panicles per unit area and aboveground biomass at the maturity stage of the upper and lower nodes,as well as the number of total grains per panicle of the lower nodes.(4)Liangyou 6326 achieved the highest yield of 6.19 t/hm2 under the combination conditions of heavy soil drying and split N application as the seedling-promoting fertilizer.In summary,the selection of rolling-resistant varieties,heavy soil drying at the filling stage in the main season,and split N application as the seedling-promoting fertilizer in the ratooning season can promote the regeneration bud growth,dry matter accumulation,and nitrogen uptake and utilization of ratooning rice under mechanical harvesting,thereby increasing the yield in the ratooning season.