氮铁配施对苹果砧木品种M9T337幼苗生长及氮素利用的影响OA

To clarify the synergistic regulation mechanism of combined application of nitrogen and iron on the growth and nitrogen utilization of apple seedlings,and to provide a theoretical basis for reducing fertilizer application and increasing efficiency,this study took apple rootstock cultivar'M9T337'seedlings as test materials,adopted a two-factor experimental design,and set two nitrogen levels and two iron levels to explore the effects of different combined application of nitrogen and iron on the growth,physiological characteristics and nitrogen fertilizer use efficiency of seedlings.The results showed that there was a significant interaction between nitrogen and iron supply.Under the same nitrogen level,high iron treatment significantly promoted the plant height,stem diameter,plant dry weight,leaf number,leaf area and root growth of seedlings,and the combination of high nitrogen and high iron achieved the best effect;high iron treatment increased leaf chlorophyll content,net photosynthetic rate,nitrate reductase(NR)activity and nitrite reductase(NiR)activity,and significantly improved plant nitrogen accumulation and nitrogen fertilizer use efficiency.In conclusion,appropriate iron fertilizer can effectively promote the growth of apple seedlings and improve nitrogen fertilizer use efficiency by synergistically enhancing photosynthetic capacity and nitrogen metabolism efficiency.The implementation of combined application of nitrogen and iron has good application potential in production.