【作者】 孙一；

【导师】 马履一；

【作者基本信息】 北京林业大学 ， 森林培育， 2013， 硕士

【摘要】 精准施肥技术是107杨苗木高效培育的关键之一。本研究通过砂培盆栽指数供氮试验结合大田施肥试验的方法,对不同处理条件下107杨扦插苗形态指标(苗高、地径)、生物量、苗体氮含量、苗木光合参数等方面开展了研究,揭示了欧美107杨扦插苗年生长规律和需氮规律,提出了较为合理的施肥时间和施肥量。具体研究结果主要如下：(1)107杨扦插苗苗高、地径生长规律表现为“慢-快-慢”的节奏。苗木成活期为4月,幼苗期为5月初-6月底,此两阶段苗木生长缓慢；速生期为7月初-8月底,硬化期为9月初-10月底。(2)盆栽砂培指数施肥条件下,随供氮水平升高,107杨扦插苗木高茎生长、生物量积累以及苗木光合参数等指标不同程度升高,但当供氮过量(10g/株·年)时,苗木各项生长指标不升反降。通过比较发现,N2处理(6gN/株·年)107杨扦插苗生长表现在各个处理中为最佳,在生长季末该处理单株苗木苗高172.38cm,地径13.64mm,生物量94.783g(3)田间试验的结果与砂培试验具有较好的一致性：N2(6gN/株·年)107杨苗木形态指标、生物量和苗体N含量等生长指标与N1(15gN/株·年)无显著差异(P>0.05)。从节约用肥角度出发,培育1年生107杨优质苗木的供氮量为6gN/株·年。苗木合理施肥期为幼苗期6月、速生期7月、8月,速生期8月是最需要施肥的阶段。施肥应该在苗木生长高峰来临前的15天内进行施肥,即在6月中旬施肥为宜。更多还原

【Abstract】 Rational fertilization techniques is one of the key factors that can be used to promote the quality of Populusxeuramericana cv.’74/76’seedlings. Pot exponential fertilization experiments under sand culture combined with field fertilization experiments were conducted in this paper. We analysed the morphologic parameters (height and ground diameter), biomass, nitrogen concentration and photosynthesis parameters of Populus×euramericana cv.’74/76’seedlings at various experimental treatments, and besides, revealed its annual growth rule and nitrogen-fertilizer requirement feature. On this basis, we calculated the reasonable fertilization time and fertilizer amount. The main results were showed as follows:(1) The height and ground diameter growth principle of Populusxeuramericana cv.’74/76’seedlings was characteristic by rhythm of slow-fast-slow. The growth period in one year of Populusxeuramericana cv.’74/76’seedlings was divided into four phases, which were survive time (April), seedling stage (May to June), fast-growing stage (July to August) and hardening stage (September to October), respectively.(2) Under the condition of exponential fertilization of pot stand culture, different degree of increase were observed in height, diameter growth, biomass accumulation and seedling photosynthetic parameters when nitrogen supply level increased from0.0to6g-seedling-1year-1.However, when the nitrogen supply exceed10mg-seedling-lyear-1, the plants’morphologic parameters, biomass (gseedling-1), photosynthesis parameters declined, compared with N2level (6g-seedling-1-year-1). It was detected that the seedlings under N2treatments had the optimal growth status within all the four experimental treatments, with172.38cm height,13.64mm ground diameter, and94.783g biomass gain in the end of year.(3) The results of sand culture and Held fertilization experiments were in accord with each other. No significant differences were recorded between treatment1(15gseedling-lyear-1) and treatment2(6gseedling-l·year-1)(P>0.05).For the purpose of fertilization economization,6gN-seedling-l year-I can be applied for the cultivation of one-year old Populusxeuramericana cv.’74/76’seedlings. Reasonable fertilization period was June in seedling stage, July and August in fast-growing stage, and the fast-growing period (August) was the key phase for nitrogen supply, fertilization should be implemented within15days before seedling growth peak. Fertilization should be implemented in the middle of June.更多还原