番茄根系层分布与土壤水分变化区域间的关系研究

发布时间：2018-01-26 11:51

本文关键词： 番茄根系长度土壤含水率根系层　出处：《中国科学院研究生院（教育部水土保持与生态环境研究中心）》2015年硕士论文　论文类型：学位论文

【摘要】：番茄是高耗水蔬菜作物,所以水分是制约番茄生长发育的重要因素之一。在常规种植模式下(这里指土壤栽培),土壤含水分的高低直接影响番茄地上植株部分的生长发育、地下根系的分布和番茄的果实生长,水分的亏缺不仅会使番茄品质降低,而且对番茄的产量也有较大的影响。由于温室的特殊性,番茄生长所需水分全面依赖于灌溉补充,因此精准的水分补充是保准番茄正常生长发育的关键措施。为了及时获取番茄根系层区域土壤水分状况,为精准灌溉提供可靠依据,本研究在温室环境和膜下滴灌条件下,通过对不同生育期的不同阶段番茄的根系进行采挖冲洗,测定根系参数。并采用TRIME水分传感器定时测定番茄根系层不同空间位置土壤含水率,根系层土壤含水率测点分布设计为距植株5cm、15cm、25cm水平距离处和5cm、10cm、20cm、30cm、40cm、50cm深度土层,测定频率为每天一次,灌水后加测一次,所测数据采用Excel分析处理,并用Sigmaplot作图。对番茄不同生育期不同阶段的根系生长情况与根系层区域的土壤含水率变化情况进行了研究分析,得出了以下主要结论:1)番茄的种植方式为育苗移栽定植,其定植缓苗后至开花之间的苗期时间相对较短,苗期根系生长及分布区域很小,主要集中分布在距植株水平距离5cm,地面以下10cm以内的土层,根长度也以10cm以内居多,且具有典型的双子叶植物所具有直根系特点,主根较为粗壮,强势发育,侧根较为细弱。苗期土壤含水率的主要变化区域与根系层分布较为一致,土壤水分的变化幅度也与根系的分布密度较为一致,变化幅度随距植株水平距离的增加而递减,苗期土壤含水率最小值出现在距植株5 cm,地表以下5-10 cm土层,这与根系在土层分布及根系长度吻合。2)开花结果期根系继续生长发育,根系长度增加,根系分布区域扩大,主要集中分布在距植株5cm的0-20cm土层,根系长度集中为5-15cm。开花结果期用距植株5 cm处0-30 cm土层含水率变化值计算的蒸腾量与用彭曼公式计算的腾发量具有较好的一致性,该区域土壤含水率能较好的代表开花结果期番茄整个根系层土壤含水率。3)盛果期番茄根系进一步生长,根系长度集中分布在5-15cm范围,盛果期距地表0-30cm,距番茄植株15cm的区域根系层土壤水分变化明显,在此区域内总体表现为随土层深度增加,土壤含水率减小,土壤含水率变化幅度减小。地表以下15cm-25cm,距植株水平距离0-10cm范围内最易出现土壤水分低值。随着时间的推移,土壤水分低值区向外逐渐扩展。4)在温室覆膜滴灌条件下土壤为砂壤土时,综合番茄不同生长阶段根系的伸长生长及根系层土壤含水率的变化规律,苗期探头埋设5cm深左右、开花结果期及盛果期探头埋设10cm左右所测得的番茄根系层土壤含水率最具代表性,可用于指导温室智能控制灌溉。
[Abstract]:Tomato is a water-consuming vegetable crop, so moisture is one of the important factors restricting the growth and development of tomato. The soil moisture content directly affects the growth and development of the above ground part of tomato, the distribution of underground roots and the growth of tomato fruit, and the water deficit will not only reduce the quality of tomato. Because of the particularity of greenhouse, the water needed for tomato growth depends on irrigation supplement. Therefore accurate water supplementation is the key measure to maintain the normal growth and development of tomato. In order to obtain the soil moisture status of tomato root layer in time and provide reliable basis for precision irrigation. In this study, the roots of tomato at different growth stages were harvested and washed under greenhouse environment and drip irrigation under film. The soil moisture content of tomato root layer at different spatial positions was measured by TRIME water sensor. The distribution of soil moisture content in root layer was designed to be 5 cm ~ (-1) ~ (15 cm) from the plant. At the horizontal distance of 25 cm and 5 cm ~ (10) cm ~ (10) ~ (20) cm ~ (10) ~ (30) cm ~ (10) ~ (30) ~ (30) cm ~ (10) ~ (10) cm ~ (10) ~ (30) cm ~ (10) ~ (30). The measured data were analyzed and processed by Excel. The root growth and soil moisture content of tomato at different growth stages and different growth stages were studied and analyzed by Sigmaplot. The main conclusions are as follows: 1) Tomato is planted by transplanting and transplanting, and the seedling period from slow planting to flowering is relatively short, and the root growth and distribution area is very small at seedling stage. It was mainly distributed in the soil layer less than 10 cm below the ground level, and the root length was more than 10 cm. The root length of dicotyledonous plant had the characteristics of straight root system in typical dicotyledonous plants. The main soil moisture content in seedling stage is consistent with the distribution of root layer, and the variation range of soil water content is consistent with the distribution density of root system. The range of variation decreased with the increase of horizontal distance from the plant. The minimum value of soil moisture content at seedling stage was 5 cm from the plant and 5-10 cm below the surface. This is consistent with root distribution in soil layer and root length. 2) during flowering and fruiting period, root system continued to grow and develop, root length increased and root distribution area expanded. It was mainly distributed in 0-20cm soil layer 5 cm away from the plant. The root length was 5-15 cm. The transpiration calculated from 0-30 cm soil layer in flowering and fruiting stage was in good agreement with that calculated by Pengmang formula. Soil moisture content in this area can better represent the soil moisture content of the whole root layer of tomato in flowering and fruiting stage. 3) the root system of tomato growing further in the period of full fruit, and the root length is concentrated in the range of 5-15 cm. The soil moisture of root layer in the region from 0-30 cm to the surface and 15 cm from tomato plants changed obviously in the fruiting period, and the soil moisture content decreased with the increase of soil depth in this region. The variation range of soil moisture content was decreased. The range of soil moisture content was 15cm-25cm below the ground surface, and it was most likely to occur in the range of 0-10cm from the horizontal distance from the plant to the soil moisture content. When the soil was sandy loam under the condition of plastic film mulching drip irrigation in greenhouse, the growth of tomato root system and the variation of soil moisture content of root layer in different growth stages were synthesized. The soil moisture content of tomato root layer measured by the probe at seedling stage was about 5 cm deep, and that at flowering and fruiting stage was about 10 cm, which could be used to guide intelligent irrigation in greenhouse.
【学位授予单位】：中国科学院研究生院（教育部水土保持与生态环境研究中心）
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152.7;S641.2

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