遮荫条件下水氮处理对小粒咖啡生长及光合特性的影响

发布时间：2018-01-18 10:35

本文关键词：遮荫条件下水氮处理对小粒咖啡生长及光合特性的影响　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：小粒咖啡是一种对生长环境要求较高的半荫蔽作物,喜阴凉、潮湿环境,过高的太阳辐射容易引起光抑制。作为云南省热带优势农产品,种植面积及产量占全国90%以上,小粒咖啡生产受到土壤干旱、营养不足及光照过度三重制约,产量和品质得不到保证。基于以上背景,本研究以小粒咖啡幼树为供试材料,采用两个完全组合试验:试验Ⅰ(盆栽试验)设3个施氮水平(无氮No为对照、中氮N1、高氮N2),3个遮荫水平(S0为无遮荫、S1为中度遮荫、S2为重度遮荫);试验Ⅱ(小区试验)设3个灌水水平(低水W0、中水W1、高水W2),3个遮荫水平(SC0为无荫蔽、SC1为中度荫蔽、SC2为重度荫蔽)。在不同遮荫条件下,通过设计不同施氮处理和不同灌水水平,来探寻不同遮荫条件下水氮处理对小粒咖啡生长和光合特性的影响。(1)增加施氮量能显著促进盆栽小粒咖啡幼树各形态指标的生长(株高、茎粗、叶片数、枝条数、冠幅及新枝长度),在相同氮肥处理下,株高及冠幅随着遮荫度的增加而增加。与N0S0处理相比,N2S2处理分别使株高增加31.88%,冠幅增加 29.08%。(2)增加施氮量使叶片叶绿素总量及类胡萝卜素显著增加。增加遮荫度使叶绿素总量及类胡萝卜素显著增加,S2处理能显著增加叶绿素总量。与N0S0相比,其余处理使叶绿素总量提高28.22%～597.71%。N2S2处理的叶绿素总量最大。(3)在相同施氮水平下,增加遮荫度分别提高叶片日均净光合速率、蒸腾速率、气孔导度及水分利用效率11.85%～25.84%、7.32%～18.76%、22.14%～50.38%、12.75%～21:22%。而在同一遮荫水平下,增加施氮量分别增加叶片日均净光合速率.和蒸腾速率1.4%～11.64%,6.79%～12.20%。考虑氮肥和遮荫的交互作用N2S2处理的日均Pn、Tr及WUE均达到最大,与NoSo相比,N2S2处理提高日均水分利用效率65.48%。通过对光响应的研究得出,氮肥的充足能使小粒咖啡叶片高效地利用弱光环境,并且土壤氮肥含量较高的条件下,遮荫处理显著提高小粒咖啡叶片利用弱光的能力。(4)在相同遮荫条件下,增加施氮量可提高小粒咖啡总干物质量25.45%～32.21%,根冠比先减小后增加,同一施氮水平下,小粒咖啡的总干物质量随着遮荫强度的加大呈现先增后减的趋势,根冠比则随之减小,S1处理的总干物质量最大,与S0处理相比提高22.22%,与NoSo处理相比,N2S1提高总干物质量76.87%。(5)在相同灌水水平下,在SC2处理下的净光合速率和气孔导度最大,与SC0处理相比,分别增加了 46.47%和9.54%。与W0SC0处理相比,W2SC2处理增加叶片水分利用效率61.56%。相同荫蔽栽培下,增加灌水量分别增加小粒咖啡株高、茎粗为5.42%～9.18%,15.01%～18.60%。相同灌水水平,适度增加荫蔽栽培密度可显著提高咖啡株高和茎粗,SC1处理的株高和茎粗均最大,而过度的荫蔽反而使株高增加不明显。其中W2SC1处理小粒咖啡的株高和茎粗均达到最大。考虑小粒咖啡幼树干物质累积最大选择最优光氮供给模式为N2S1处理;基于小粒咖啡光合特性及叶片水分利用效率两方面考虑,小粒咖啡幼树最优水光组合为W2SC2处理。
[Abstract]:Arabica coffee is a high requirement on the growth environment of semi shade crops, like a cool, humid environment, solar radiation is too high to cause photoinhibition. As the advantage of tropical agricultural products in Yunnan Province, the planting area and output accounted for more than 90%, small coffee production by soil drought, poor nutrition and light weight restriction over three, yield and quality can not be guaranteed. Based on the above background, in this study, Arabica coffee saplings as tested materials, using two complete combination test: Test 1 (pot experiment) with 3 nitrogen levels (no nitrogen nitrogen in No as control, N1, N2, 3 high nitrogen level (shade) S0 for S1 without shade, moderate shading, S2 severe shading); test II (cell test) with 3 levels of irrigation (low water W0, water W1, water W2), 3 shading levels (SC0 = no shade, SC1 moderate shade, SC2 is a heavy degree in different shade). Under the shade conditions, through the design of different Nitrogen treatments and different irrigation levels, to explore the different shading effects of nitrogen treatment on growth and photosynthetic characteristics of Arabica coffee water. (1) increase the application of nitrogen can significantly promote the morphological index of potted saplings of Arabica coffee growth (plant height, stem diameter, leaf number, branch number, width and length of shoots). In the same nitrogen treatment, plant height and crown width increases with the increase of shading degree. Compared with N0S0, N2S2 respectively. The plant height increased 31.88%, crown diameter increased 29.08%. (2) nitrogen increased the contents of chlorophyll and carotenoids increased significantly. The degree of shading increased the total chlorophyll and carotenoid significantly increase, S2 treatment could significantly increase the chlorophyll content. Compared with N0S0, the rest of the total chlorophyll content increased by 28.22% ~ 597.71%.N2S2 and the chlorophyll content of the treatment. The maximum (3) at the same nitrogen level, increase the degree of shading increased leaf Slice of average net photosynthetic rate, transpiration rate, stomatal conductance and water use efficiency of 11.85% ~ 25.84%, 7.32% ~ 18.76%, 22.14% ~ 50.38%, 12.75% ~ 21:22%. and in the same shade level, increasing the amount of nitrogen fertilizer increased leaf average net photosynthetic rate and transpiration rate. 1.4% ~ 11.64%, 6.79% ~ 12.20%. the interaction of nitrogen fertilizer and shading treatment N2S2 daily Pn, Tr and WUE were the highest, compared with NoSo, N2S2 treatment to improve the utilization efficiency of 65.48%. results from the response to light of daily water, adequate nitrogen can make efficient use of Arabica coffee leaves in low light environment, and the soil nitrogen content was higher under the condition of ability shading treatments significantly increased leaf of Arabica coffee using weak light. (4) under the same shading conditions, increasing the amount of nitrogen fertilizer can increase the total dry mass of Arabica coffee from 25.45% to 32.21%, increase root shoot ratio decreased, the same nitrogen Level, total dry mass of Arabica coffee with the increase of shading intensity decreased after increasing, root shoot ratio decreased with S1 total dry weight, compared with the S0 treatment increased 22.22%, compared with NoSo, N2S1 increased the total dry weight of 76.87%. (5) in the same irrigation level under the net photosynthesis under SC2 photosynthesis and stomatal conductance were maximum, compared with the SC0 treatment, increased by 46.47% compared with 9.54%. and W0SC0 treatment, W2SC2 treatment increased leaf water use efficiency of 61.56%. are the same shade cultivation, increasing irrigation were increased coffee plant height, stem diameter was 5.42% ~ 9.18%. 15.01% ~ 18.60%. the same irrigation level, a modest increase in planting density shade coffee can significantly improve the plant height and stem diameter, SC1 height and stem diameter were the largest, and excessive shade but increased the plant height was not obvious. The W2SC1 processing of Arabica coffee Plant height and stem diameter reached the maximum. Considering the accumulation of dry matter and nitrogen supply maximum selection of optimal optical mode for N2S1 processing of Arabica coffee trees; consider the Arabica coffee on Photosynthetic Characteristics and leaf water use efficiency of two aspects based on the optimal combination of Arabica coffee trees Shuiguang W2SC2.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S571.2

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