氮磷配施和化肥减施对小麦生长、养分利用及产量性状的影响OA

This study aimed to elucidate the effects of combined nitrogen and phosphorus and reduced fertilizer applications on the growth,nutrient utilization,and yield traits of wheat.The research was conducted through a hydroponic experiment and a field positioning experiment from 2019 to 2021,involving eight main wheat varieties cultivated in southern Shanxi.In the hydroponic experiment,four nitrogen and phosphorus treatments(N 0.2 mmol·L-1+P 0.1 mmol·L-1、N 0.2 mmol·L-1+P 2.5 mmol·L-1、N 4 mmol·L-1+P 0.1 mmol·L-1、N 4 mmol·L-1+P 2.5 mmol·L-1)were applied to preliminarily investigate and screen seedling traits of the different wheat varieties.In the field experiment,the effects of reduced fertilizer application on wheat growth and development,nutrient utilization,and yield were examined throughout different years using three treatments,i.e.,conventional fertilization(CF),reduced fertilizer application(FR),and no fertilizer application(CK).Results showed that under hydroponic conditions,the sample Pinyu 8161 had the lowest plant height,root length,plant dry weight,root dry weight,and root-to-shoot ratio among all wheat varieties in terms of the nitrogen and phosphorus levels.Under low phosphorus conditions,the dry weight increase of Liangxing 67 with normal nitrogen was only 17.07%,while the root dry weight decreased.Moreover,the root cap was relatively low under normal nitrogen and phosphorus conditions.In addition,under normal nitrogen and phosphorus conditions,the root cap was relatively low.Under field production conditions,the yields of Pinyu 8012 and Jimai 22 remained high when the fertilizer application reduced from 2019 to 2020(wet year),showing no significant difference in their yields.In contrast,under the same conditions,the yield of Hannong 1412 was the lowest(only 7 520.18 kg·hm-2)among all varieties.Compared to conventional fertilization,the yields were significantly lower in cultivars of Shannong 20,Zhongmai 4072,and Hannong 1412 with reduced fertilizer application.During the period from 2020 to 2021(dry year)when fertilizer was reduced,the yield of Jimai 22(6 191.53 kg·hm-2)was significantly higher than that of Pinyu 8012 and Shinong 086.Jimai 22 also had a high grain nitrogen accumulation(130.35 kg·hm-2)and phosphorus absorption efficiency(0.79 kg·kg-1).Reducing the application of chemical fertilizers in dry years led to early leaf senescence in the later stages of wheat growth,which significantly reduced the dry matter accumulation during maturation but impacted little on stem morphological characteristics.In summary,when 180.0 kg·hm-2 N,105.0 kg·hm-2 P2O5,and 34.5 kg·hm-2 K2O were applied during wheat growth in the wheat-corn rotation region of Jinnan,and N 60.0 kg·hm-2 N was applied during the jointing period,the yields of cultivars Pinyu 8012 and Jimai 22 were higher in the wet year.Jimai 22 also had the highest yield in the dry year,and reducing the chemical fertilizer improved the storage and re-transportation of dry matter in the nutrient organs of wheat before flowering,as well as the grain yield contribution rate and the thickness of the third internode.However,merely reducing continuous fertilizer application in dry years could lead to varying degrees of instability and unsustainability in wheat yield.Overall,the findings of this study provide more strategies for a stable and efficient cultivation in the wheat region of southern Shanxi.