不同水肥处理对刺槐苗期生长和营养积累的影响OA

[Objective]This study explores the effects of different water and fertilizer management measures on the growth and nutrient accumulation of Robinia pseudoacacia seedlings,to provide a basis for the selection of the best water and fertilizer management strategies for promoting the growth of R.pseudoacacia seedlings.[Method]In this study,first-year R.pseudoacacia seedlings were used as the ex-perimental subjects,and a two-factor randomized block design was adopted,with fertilization levels and wa-ter levels as variables.Fertilization ratios of nitrogen,phosphorus,and potassium(N∶P∶K)were set at 1.2∶0.7∶2 for the emergence stage,1∶0.9∶2 for the seedling stage,and 0.9∶2.2∶1 for the rapid growth stage.Four fertilization gradients were established:extremely low fertilization(F1),low fertiliza-tion(F2),medium fertilization(F3),and high fertilization(F4).Water availability was controlled based on field capacity(FC)with two gradients:80%FC(mild drought,W1)and 100%FC(normal moisture,W2).Samples were collected at the end of the emergence stage(April 16,2024),the seedling stage(May 25,2024),and the rapid growth stage(August 8,2024).Growth indices,photosynthetic pigment content,and leaf nutrient element content of R.pseudoacacia seedlings under different treatments at each growth stage were analyzed.[Result]At the end of the rapid growth stage,R.pseudoacacia seedlings exhibited the optimal ground diameter under the W2F3 treatment,with significant differences compared to other treatments.As fertilization levels increased,seedlings under W1 and W2 both showed a clear changing trend in seedling ground diameter and height:an initial increase followed by a decline.The highest fresh and dry biomass per seedling were observed under the W1F3 treatment.The height/diameter ratio,shoot/root ratio,and Dickson quality index reached their optimal levels under the W2F1,W1F2,and W2F2 treat-ments,respectively.The highest chlorophyll a and b contents were observed under the W2F1 treatment,while carotenoid content peaked under the W2F3 treatment.The leaf nitrogen(N)and phosphorus(P)contents,as well as the nitrogen accumulation rate,reached their maximum values under the W2F3 treat-ment,whereas the highest potassium(K)content and its accumulation rate were observed under the W2F1 treatment.Grey relational analysis indicated that the correlation coefficients for W1F3 and W2F3 treat-ments were 0.86 and 0.84,respectively,suggesting that these two treatments had the highest efficiency.[Conclusion]Rational water and fertilizer management practices can significantly promote the growth and nutrient accumulation of R.pseudoacacia seedlings.The optimal water and fertilizer management scheme for the seedling stage is determined to be the W2F3 treatment,which involves providing sufficient water and applying specific amounts of fertilizers at different growth stages.During the emergence stage,0.014 g of urea,0.005 g of diammonium phosphate,and 0.012 g of potassium sulfate should be applied per seed-ling.In the seedling stage,the application rates should be increased to 0.180 g,0.090 g,and 0.198 g per seedling,respectively.During the rapid growth stage,the application rates further increase to 0.226 g,0.552 g,and 0.251 g per seedling,respectively.