蓄水坑灌坑深及灌水对矮砧苹果幼树生长影响研究

发布时间：2018-04-16 11:29

  本文选题：蓄水坑灌 + 坑深　； 参考：《太原理工大学》2017年硕士论文

【摘要】：我国北方山丘区是苹果种植的主要地区,果园规模日益扩大,与此同时,水资源短缺是果农面临的主要难题,粗放的灌溉方式也大大阻碍了苹果的优质、高产。蓄水坑灌法在黄土高原具有极大的发展潜力,可有效解决土壤干旱及水土流失等问题。本文对3a龄矮砧红富士苹果幼树进行田间试验,探究蓄水坑灌条件下适宜幼树生长的合理坑深和灌水上下限,分析了幼树的根系、形态、生理指标与不同坑深和灌水上下限之间的响应关系,并建立了果树各形态指标的Logistic生长模型,讨论了坑深和灌水对模型方程中各参数的影响情况,最后利用主成分分析法对各处理的优劣进行综合评价,并进一步制定基于幼树生长的合理坑深和灌水上下限评价指标。本文得出的主要结论如下:1、蓄水坑灌条件下各处理土壤水分变化规律的研究(1)蓄水坑灌处理土壤含水率在垂向上呈现先增大后减小的趋势。蓄水坑灌各处理的土壤含水率高值区,随坑深的增大而明显下移,随灌水上下限的增大而范围变广。土壤含水率极大值出现的土层深度为对应坑深的二倍。坑深影响土壤水分分布,灌水上下限影响土壤含水率大小,二者共同影响土壤含水率的变化情况。(2)蓄水坑灌条件下计划湿润土层内平均含水率降幅随坑深及灌水上下的增大而减小,地面灌溉处理的降幅最大。2、蓄水坑灌条件下各处理根系生长的变化规律的研究幼树的根长密度、总根量随生育期推进,呈先增大后减小的变化规律。根长密度与总根量均在灌水上下限为60%θ_田-90%θ_田时优于其他两种灌水处理(50%θ_田-80%θ_田,70%θ_田-100%θ_田);坑深40cm的根系分布情况与土壤水分分布的匹配程度比坑深60cm更高,同时比坑深20cm的处理更能诱导根系深扎,减小地表干旱对果树的影响,促进培育坑旱品种。3、蓄水坑灌条件下各处理幼树形态、生理指标变化规律的研究(1)幼树新梢和树干直径生长在全生育期均呈现为“S”型。新梢累计增长量在坑深40cm、灌水上下限60%θ_田-90%θ_田时最优;树干直径累计增长量随坑深增大而减小,随灌水上下限增大而增大,树干生长对灌水的变化更为敏感。Logistic生长模型能较准确地模拟苹果幼树的新梢累计增长量和树干直径累计增长量的月变化过程,模型的拟合程度高。(2)叶水势与土壤水分含量密切相关,地面灌溉叶水势低于各蓄水坑灌处理。蓄水坑灌条件下,叶水势随坑深和灌水上下限的增大而增大;叶水势日变幅在坑深40cm、灌水上下限70%θ_田-100%θ_田时最小。4、蓄水坑灌条件下各处理光合特性指标变化规律的研究(1)幼树的光合特性指标受太阳辐射强度、降雨、气温等外界影响的差异较明显,整体上蓄水坑灌优于地面灌溉。光合有效辐射在坑深60cm、灌水上下限70%θ_田-100%θ_田时最强;气孔导度和胞间CO_2浓度在灌水上下限60%θ_田-90%θ_田处理时明显优于其他两种灌水处理,且随坑深增大而增大;叶片蒸腾速率和净光合速率在灌水上下限70%θ_田-100%θ_田时达到最大。(2)全生育期幼树叶片水分利用效率呈现先减小再增大的规律。叶片水分利用效率随坑深及灌水上下限的增大而减小。全生育期幼树叶片光能利用效率呈现为先逐渐增大,后迅速减小,再逐渐增大的趋势。叶片光能利用效率随坑深加深而减小,随着灌水上下限升高而增大。整体上,蓄水坑灌处理的叶片水分利用效率和光能利用效率均高于地面灌溉处理。结合前文理论分析,利用主成分分析法得出,在北方典型的壤土质地土壤及大陆性半干旱气候条件下,适宜三年生矮砧密植红富士幼树生长的蓄水坑灌法处理为坑深40cm、灌水上下限为60%θ_田-90%θ_田的组合。
[Abstract]:North area is the main area of Apple Planting Orchard, the increasing size, at the same time, the shortage of water resources is the main problem faced by farmers, extensive irrigation has greatly hindered the apple quality, high yield. Irrigation has great development potential in the loess plateau water storage pit, which can effectively solve the problems of drought and soil the loss of 3A. The old dwarfing red Fuji apple trees for field experiment on the condition of water storage pit irrigation for reasonable sapling growth and deep pit irrigation limits, analysis of young root morphology, physiological response relationship between the lower limit refers to the standard and different pit depth and the irrigation, and the establishment of a growth model Logistic all the morphological indexes of fruit trees, discusses the influence of the pit depth and the irrigation of the model parameters in the equation, then the principal component analysis method on the merits of each treatment of comprehensive evaluation, and a Step reasonable sapling growth pit depth and the irrigation limit based on the evaluation. The main conclusions of this paper are as follows: 1. Study on the condition of water storage pit irrigation the variation in soil moisture (1) irrigation soil moisture content was first increased and then decreased in the vertical direction of soil water storage pit pit. With the processing rate, with the depth increased significantly with increasing irrigation lower down, and wider range of soil moisture content. The maximum depth is two times the corresponding deep pit. The pit depth influence the distribution of soil moisture, irrigation on soil moisture influence size limit of two. Influence of change of soil water content. (2) the plan of water storage pit irrigation increased soil moist in the average moisture content drop with pit depth and irrigation on the ground and decrease of maximum.2 drop irrigation treatment, the condition of water storage pit irrigation 鏍圭郴鐢熼暱鐨勫彉鍖栬�勫緥鐨勭爺绌跺辜鏍戠殑鏍归暱瀵嗗海�

本文编号：1758715