【作者】 孟秦倩；

【导师】 蔡焕杰；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2011， 博士

【摘要】 相对于传统农业,黄土高原山地苹果园改变了土壤水分的供需规律,加剧了黄土高原土壤干层的发展,苹果园土壤水分供需矛盾突出。黄土高原山地苹果园土壤水分消耗规律及果树生长响应的研究,对准确认知苹果树蒸腾耗水规律,进行苹果园用水科学管理十分重要,并可用于苹果园非充分灌溉制度的优化。论文以延安地区山地苹果园为研究对象,根据2003年至2008年田间定位试验,研究苹果树蒸腾耗水和果实发育规律,对其进行定量模拟。取得了以下主要结论:(1)降水的分布不均是制约山地苹果高产稳产的关键性因素,根据山地苹果树生长所需水量,采用适宜度模糊分析方法,分析了延安各县苹果树生长对降水的适应性。延安各县降水效能指数由0.42增加到0.60,黄陵县降水效能指数最大,子长、安塞、志丹和吴旗最小,黄龙、洛川、富县和甘泉降水效能指数的平均值大于0.5。(2)黄土高原山地苹果园土壤水分在不同坡向、不同坡位、不同树龄、不同栽植密度及不同降水水平年间均存在较大差异,土壤水分有效水利用系数随土层深度增加而减小。0-2.0 m土层供水量在不同坡向差异很大,阳坡0-2.0 m土层供水量占总耗水量的97%,阴坡仅占67%。苹果园深层土壤水分变化可用隔室模型进行描述。(3)综合考虑果树根系分布和不同土层土壤水分含量,定量评价了土壤水分含量对苹果树生长的适宜性。理论土壤水分最大利用深度的范围为3.0-5.17 m;试验确定不同坡向果园土壤水分最大利用深度分别为:阳坡3.0 m,阴坡可达4.5 m,半阴坡、半阳坡和峁顶分别为3.5 m、4.0 m和4.0 m;(4)实测山地苹果园多年平均耗水量为675.5 mm,苹果园耗水集中在5~8月,占全年耗水的64.0%。苹果树蒸腾变化可分为初始生育期缓慢增加阶段,快速发育期迅速增加阶段,发育中期高耗水阶段,成熟期蒸腾回落阶段以及休眠期低耗水阶段。苹果树在不同生育期的作物系数分别为:初始生长期,作物系数由0.33增至0.45;快速发育期由0.45增至1.0;发育中期为1.0;成熟期由1.0减为0.33;整个越冬期为0.33。果树蒸腾耗水与土壤水分生态位密切相关,土壤水分生态位较高时,果树蒸腾耗水不受土壤水分胁迫,接近充分供水条件下的果树蒸腾耗水,土壤水分修正系数近似为1;随着土壤水分生态位降低,果树蒸腾耗水受到抑制,土壤水分修正系数降低。(5)Richards模型可较好描述苹果果实增长过程,土壤水分充足条件下,苹果果径变化呈现“S”型曲线,纵径较横径生长较为缓慢。幼果期,苹果生长较快,60天左右进入果实膨大期,苹果生长速度达到最大,75天后苹果进入缓慢生长阶段。果径增长的关键时间为5月下旬至7月中旬,果重增长关键时段为6月下旬至8月中旬。关键期苹果园水分供应直接影响着苹果的生长。不受土壤水分胁迫时,果实膨大期苹果纵径月增长幅度达26.08 mm,横径月增幅32.05 mm。土壤水分生态位低于0.79时,受土壤水分胁迫的影响,苹果膨大速率受到抑制。(6)根据水文典型年分析,丰水年需在5月进行补充灌溉,灌水定额75 mm;平水年需在5月和7月进行灌溉2次,灌溉定额150 mm;枯水年需在6月、9月和11月均需进行补充灌溉,以保证果树高产稳产,灌水定额采用75 mm,灌溉定额225 mm。更多还原

【Abstract】 Comparing to traditional agriculture, the relation of soil moisture supply-demand of traditional agricultural is changed. This situation aggravates the trend of soil dry layer and worsens the contradiction of the apple orchard moisture supply-demand. The research on apple orchard soil moisture consumption pattern is important for conducting scientific management. It can be used to simulate and forecast the orchard production and optimize the orchard insufficient irrigation system.This paper research the law of apple tree transpiration water consumption and fruit development and carries on the quantitative simulation according to field test data of the soil moisture content from 2003 to 2008 in hilly orchard in Yanan region. The main conclusions as followings:(1) The key factor restraining the high production and stable of apple is rainfall. The thesis analyzes the apple growth adaptability in different counties in Yanan and studies the efficient exponential of rainfall in different counties by using the method of fuzzy analysis. The average efficient index enlarged form 0.42 to 0.60. The maximum come up in Huangling county and the minimum is in Zichang county, Ansai, Zhidan and Wuqi county. The average value exceeds 0.5 in Huanglong, Luochuan, Fuxian and Ganquan county.(2) The soil moisture of slope orchard is quite different in different slopes, different slope positions, different tree-age, different planting density and different precipitation level year. The utilization of the soil moisture is changed with the soil depth during the growth period. The efficient utilization coefficient of the effective water increases with the soil depth decreases. The soil water between 0-2.0m is different in different slope direction. It accounts for 97% of total soil water consumption in sunny slope and only 67% in shady slope. The three forms of the Compartment Model can describe the change of soil moisture in different season.(3) The thesis evaluates the suitability of fruit tree under the soil moisture content quantity according to the root distribution and soil moisture content of different layer. The thesis ascertains the maximum utilization depth of the soil moisture is 3.0-5.17m. It is 3.0m only in the sunny slope, 4.5m in the shady slope, semi-sunny and semi-shady slope is 3.5m and 4.0m, the replat top is 4.5m.(4) The average water consumption is 675.5 mm in slope orchards. The water consumption mainly concentrates in 5 ~ 8 months, which account for the 64%. The variation of transpiration can be divided into the slow increase of initial growth period, quick increase of quick growth period, high water consumption in middle growth stage, transpiration decrease in mature stage and the low water consumption in dormant. The crop coefficients of apple tree in different growth stages are as following: it is from 0.33 to 0.45 in initial growth period, from 0.45 to 1.0 in rapid growth period, 1.0 in the middle growth period, until after the mature, crop coefficients by 1.0, form 1.0 to 0.33 in the mature stage. It is 0.33 in the whole over-wintering stage. The transpiration water consumption is not affected when the niche is high, the amount of which close to the amount of sufficient water supply, the moisture coefficient approximate 1. The moisture coefficient will degrade ass the soil moisture niche lower because of water stress.(5) The Richards model can better describe the growth of apple with time changes. The growth process of fruit diameter is significantly "S" curve on condition that the soil moisture is sufficient. The growth of vertical diameter is slower than the transverse diameter. The fruit grows quickly in young fruit stage and then is the fruit expending period in 60 days which is the greatest growth rate, finally is the slow growth stage in 75 days later. The key stage of the fruit diameter increase is the late of March to mid-July; the key stage of the fresh fruit weight added is late of June to mid-August. Water stress restrains the apple’s growth. The growth of the vertical diameter can reach 26.08mm and the transverse diameter reaches 32.05mm within one mouth without water stress. The growth of fruit will be restrained when the soil moisture niche is under 0.79 because of the water stress.(6) it should be replenished 75mm in wet year during May and 150.0mm in medium year during MAY and July twice and 225mm in dry year during June September and November respectively according to the typical year of hydrological.更多还原