黄土高原山地苹果园土壤水分动态及蒸散研究

发布时间：2018-05-01 17:00

本文选题：黄土高原丘陵沟壑区 + 山地苹果园　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：本研究以陕北米脂山地红富士苹果园为研究对象,围绕蒸散过程,在定点监测的基础上,分析山地苹果园土壤水分动态、冠层截留特征、树干液流及其与气象因子的相关性,科学分析和研究苹果树蒸散耗水与需水规律,明确水分利用特征,为该地区苹果生产提供与降水条件相适应的水分管理依据,为苹果园地旱作技术发展、缓解土壤干化提供重要的科学依据,也对解决苹果生长所需的水分供需矛盾提供一定的指导意义与理论价值,使山地苹果产业实现生态、经济持续健康发展。主要研究结论如下:陕北山地苹果园时段干旱严重,春季土壤干旱程度取决于上年入冬前土壤贮水量高低;20、40、60 cm土层深处的水分表现为与降雨变化较一致的季节变化特征,但降雨对土壤水分的影响随土层加深减弱;苹果树生长季100 cm深处土壤含水量呈缓慢下降趋势,只有很大的连续降雨能使该层含水量提高;土壤剖面中200 cm以下土层土壤含水量保持相对稳定,降水很难入渗补充到200 cm土层。6年生山地苹果园土壤已经出现干化现象,且在90~300 cm存在明显的低湿层,土壤体积含水量常年处在12%以下。苹果树单株尺度范围内,土壤含水量表现为随着距树干距离的增加单调递增的趋势,且沿行向距树干不同距离位点的土壤含水量显著高于沿株向距树干等距离位点的含水量。采用地面覆盖措施,可以有效减少土壤水分蒸发,保持水土,增强蓄水保墒能力,提高果园土壤含水量,缓解生长季果树的水分供需矛盾。在0~60 cm土层,秸秆覆盖、起垄覆膜垄沟集雨和有机肥覆盖措施的土壤储水量分别比对照提高14.7%~16.9%、21.2%~22.5%和17.9%~20.9%;60~200 cm土层,秸秆覆盖、起垄覆膜垄沟集雨和有机肥覆盖措施的土壤储水量分别比对照提高8.9%~9.3%、13.6%~15.4%和10.3%~12.3%,建议陕北黄土峁状丘陵区山地雨养苹果园采用起垄覆膜垄沟集雨的旱作措施。林冠对果园降水再分配过程具有重要影响。降雨再分配过程中,穿透雨量最大,冠层截留量次之,树干茎流量最小,分别占总降水量的72.1%、24.4%、3.5%。不同降雨量级对林冠的降雨再分配有明显影响,随着降雨量级的增大,林内穿透雨量、穿透率、林冠截留量、树干茎流量均增大,但冠层截留率降低;在同一降雨量级中,苹果不同发育时期对降雨再分配作用的变化也有明显影响,穿透雨率随时间先降低再升高,冠层截留率随时间先升高再降低,在整个生长季内,穿透雨率与冠层截留率呈负相关关系。蒸腾速率的变化可以用苹果树干液流速率变化来表示。液流速率在晴天表现为单峰曲线,呈“几”字形分布,夜间保持在趋近于0的水平,在10:00-14:00达到峰值;阴雨天表现出明显的昼夜变化特征,但其日变化不规律,为较低水平的多峰曲线,峰值的出现时间不确定。太阳辐射、温度、风速、相对湿度和土壤含水量是影响果树液流速率的重要因子。在生育期内,苹果树的液流速率与太阳辐射、温度、风速、土壤含水量呈正相关,与相对湿度呈负相关。苹果生育期内蒸散量变化表现为先增大后减小的特征,蒸散贡献量由小到大依次为冠层截留,果树蒸腾和棵间土壤蒸发,且土壤蒸发量及果树蒸腾量在生育期内均出现先增大后减小的特征。试验果园不同发育时期的作物系数分别为萌芽、开花期0.26、新梢生长和幼果发育期0.35以及果实膨大期0.47。果园水量收支不平衡,大气降雨不能够满足果园的需水量。
[Abstract]:This study took the red Fuji apple orchard in the northern Shanxi mountain area as the research object. On the basis of the transpiration process, the soil moisture dynamics, canopy interception characteristics, the correlation between the stem liquid flow and the meteorological factors were analyzed on the basis of fixed monitoring, and the water consumption and water requirement of the apple tree were analyzed and studied, and the water use characteristics were clearly defined. It provides a basis for water management adapted to the conditions of precipitation in this area. It provides an important scientific basis for the development of dry farming technology in apple orchard and alleviating the dry soil. It also provides a certain guiding and theoretical value for solving the water supply and demand contradiction needed by apple growth, so that the ecological and economic sustainable health of the mountain apple industry is realized. The main conclusions are as follows: the drought in the apple orchard in the mountain area of Northern Shaanxi is severe, and the degree of soil drought in spring depends on the soil water storage before winter. The water performance in the depth of the 20,40,60 cm soil layer is the seasonal variation that is consistent with the change of rainfall, but the influence of rainfall on soil moisture is weakened with the soil layer; In the long season, the soil moisture content of the soil is slowly decreasing in 100 cm, and the water content of the layer can be increased only by the large continuous rainfall. The soil moisture in the soil layer below 200 cm in the soil section is relatively stable, and the precipitation is difficult to add to the 200 cm soil layer and the soil of the.6 year mountain apple orchard has been dry, and there is a obvious existence in 90~300 cm. In the low humid layer, the volume of soil water content is under 12%. The soil water content in the single plant of the apple tree is increasing monotonically with the increase of distance from the tree trunk, and the soil water content along the distance to the tree trunk is significantly higher than the water content along the distance to the tree trunk. The soil water evaporation, soil water conservation, water conservation, water conservation, water content of orchard soil and the water supply and demand in the growing Ji Guoshu soil can be effectively reduced, and the water supply and demand in the growing Ji Guoshu cm soil layer, straw mulching, ridge furrow furrow collecting and organic manure cover are improved by 14.7%~16.9%, 21.2%~22.5% and 17.9%~, respectively. 20.9%, the soil water storage of 60~200 cm soil layer, straw mulching, ridge furrow furrow collecting and organic manure covering measures increased 8.9%~9.3%, 13.6%~15.4% and 10.3%~12.3% respectively. It is suggested that the rain raising in the hilly hilly hilly area of Northern Shaanxi uses ridge furrow furrow collecting and rain collecting measures. It has important influence. In the process of rainfall redistribution, the penetration of rainfall is the most, the canopy interception is the second, the stem stem flow is minimum, which accounts for 72.1%, 24.4% of the total precipitation, and the different rainfall magnitude of 3.5%. has obvious influence on the rainfall redistribution of the canopy. With the increase of rainfall, the penetration of rain, penetration, canopy interception and stem flow are all Increase, but the canopy interception rate decreased; in the same rainfall magnitude, the different development period of Apple also had a significant influence on the change of rainfall redistribution. The penetration rate was first reduced and then increased with time. The canopy interception rate increased first and then decreased. In the whole growing season, the transpiration rate was negatively correlated with the canopy interception rate. The change can be expressed as the change of the flow rate of the apple tree sap flow. The liquid flow rate shows a single peak curve in a sunny day, showing a "few" shape distribution, keeping at the level of near to 0 at night, reaching the peak in 10:00-14:00, and showing obvious diurnal changes in the cloudy and rainy days, but its daily variation is irregular, which is a lower horizontal multi peak curve and peak value. The time is uncertain. Solar radiation, temperature, wind speed, relative humidity and soil water content are important factors affecting the liquid flow rate of fruit trees. In the growth period, the liquid flow rate of the apple tree is positively correlated with the solar radiation, temperature, wind speed, soil moisture content and relative humidity. The change of the evapotranspiration in the growth period of apple is first increased. After decreasing, the contribution of evapotranspiration from small to large was canopy interception, fruit tree transpiration and soil evaporation, and soil evaporation and fruit tree transpiration were first increased and then decreased in the growth period. The crop coefficient of the experimental orchard at different developmental stages was respectively germination, flowering period 0.26, new shoot growth and young fruit development period 0.35. And the water balance of 0.47. orchard during fruit enlargement is not balanced. Atmospheric rainfall can not meet the water requirement of orchard.

【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S661.1;S152.7

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