采用常规施肥(CF)、指数施肥(EF)和2倍指数施肥(DEF)3种施肥处理,研究大田条件下不同施N肥处理对山桃稠李1年生播种苗生物量和养分(N,P,K)含量动态及养分承载的影响.结果表明:1)生长季结束后,EF和DEF处理单株生物量分别为37.00 g和35.60 g,比CF处理(27.10 g)分别增加36.5％和31.3％ (P ＜0.05)；2)苗木生长高峰期第9～11周,EF和DEF处理单株苗木N含量增量分别为0.28 mg和0.17 mg,均高于CF处理(0.03 mg)(P＜0.05)；3)EF和DEF处理均提高了播种苗体内N养分承载,生长季结束时,单株苗木N含量分别为0.69g和0.73 g,均显著高于CF处理(单株0.44 g)(P＜0.05)；4) EF,DEF处理促进了苗木对P,K吸收,生长季中P,K的吸收速率顺序均为DEF＞ EF＞ CF.生长季结束时,EF和DEF处理P质量分数较CF处理分别高28.4％和9.0％；2种指数施肥处理K质量分数较CF处理高12.5％和19.9％.采用指数施肥有效促进山桃稠李播种苗生长,可改善苗木营养状态,同时苗木造林成活率和生长效果较佳.%Biomass, nutrients (N, P, K) content dynamics and nutrient load of Padus maackii one-year-old bare-root seedlings were studied under conventional (CF) , exponential (EF) and doubled exponential fertilization (DEF) regimes. 1) At the end of the growing season, the biomass accumulation of seedlings was 37.00 g · stem-1 and 35. 60 g · stem -1 under EF and DEF treatment, respectively, and they were 36. 5% and 31.3% greater than that with CF treatment (P < 0. 05) ; 2) From the 9th to llth weeks, the fast-growing periods of seedlings, N content increment of seedlings was 0.28 mg · stem-1 and 0. 17 mg · stem-1 under EF and DEF treatment, respectively, and they were significantly higher than that with CF treatment (0.03 mg · stem-1) (P<0.05); 3) N load of seedlings under EF (0.69 g· stem -1) and DEF (0.73 g · stem-1) treatments were significantly greater than that with CF treatment (0.44 g · stem-1) (P<0.05); 4) N exponential fertilization (EF, DEF) improved P and K uptake by seedlings (DEF > EF > CF). At the end of the growing season, P mass fraction in seedlings was 28.4% and 9.0% greater under EF and DEF treatments than that with CF treatment (P <0.05) ; K mass fraction in seedlings was 12.5% and 19.9% higher under EF and DEF than that with CF treatment ( P < 0. 05 ). Exponential fertilization regimes effectively promoted biomass accumulation and improved nutrient loading in P. maackii seedlings. Outplanting , meanwhile, results so far indicate the seedlings with exponential fertilization had higher survival rate and better growth performance than CF seedlings when outplanted.
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