滴灌条件下重度盐碱地土壤水盐调控及植物生长研究

发布时间：2018-01-30 15:11

本文关键词： 滴灌盐碱地土壤基质势水盐调控植物生长　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：盐碱地属于重要的土地资源,治理改造及合理开发利用这些资源,促进盐碱地农业高效、可持续利用成为保障国家粮食安全和促进农业可持续发展的重要途径之一,对推动区域经济可持续发展、改善生态环境也具有重要意义。大同盆地盐碱地面积占山西省盐碱地总面积的70%,是我国土地盐碱化较严重的地区之一,盐碱化使得土壤条件更加恶化,生产水平低下,大大降低了土地的利用率,盐碱地改良对当地的生态和经济有重要意义。本论文通过在滴灌土壤水盐调控研究基础上,继续在山西省朔州市山阴县开展田间试验研究。通过种植耐盐碱植物披碱草,并以负压计控制土壤基质势指导灌溉,研究不同基质势(-15 kPa、-25 kPa和-35 kPa)对土壤水盐运移及披碱草生长的影响。在此基础上,在经过2年滴灌种植地块上种植高粱,研究自然条件下(不灌水)高粱生长和土壤水盐情况,研究结果表明:(1)土壤基质势的变化与灌水频率、降雨蒸发量、作物不同时期的生长需水大小紧密相关,-35 kPa处理下土壤含水率相对较低。滴灌对0~40cm范围的土层含水率、电导率和pH值产生了一定影响。随着控制基质势升高,灌水的影响越来越明显,含水率越高,pH值和电导率越低。3个处理的灌溉水量分别为3.640 m3(-15 kPa)3.399m3(-25 kPa)2.209m3(-35kPa),土壤湿润体的水平扩散半径大小排列顺是:-15 kPa-25 kPa-35 kPa。3个处理下的土壤剖面含水率分布均变化明显,土壤含水率整体提高6%,其中-15kPa处理下的土壤pH值和电导率下降最多,分别下降了7%和66%。(2)经过一个试验期灌溉淋洗,-15 k Pa、-25 kPa和-35 kPa处理下的土壤钠离子含量整体下降了87%、80%和73%,钾离子含量整体下降了77%、59%和41%。滴灌过程中有一部分碳酸根离子水解生成碳酸氢根离子,导致碳酸氢根离子含量阶段性增多,但随着灌水量的增加,四种离子所占比例越来越小,钾离子含量较低,溶脱率也低,钠离子比钾离子更容易被洗脱。(3)在披碱草收获时,3个处理的株高、盖度和生物量大小顺序表现-15kPa-25 kPa-35 kPa,所以不论从作物株高、盖度和生物量来看,3个土壤基质势的控制对其影响的优异程度均表现一致,即-15 kPa为最优。(4)在经过2015年的滴灌控制土壤基质势试验后,试验地土壤盐碱程度大有改善。土壤含水率增加了10.1%,土壤平均p H值和平均电导率值下降了0.85和151μS/cm。在2016年试播高粱试验结束时,土壤平均pH值和电导率值与2015年试验初期土壤p H值和电导率相比,分别下降了19.5%和42.6%,土壤盐碱情况改良效果明显。(5)在滴灌改良土壤上种植高粱结果表明,试播“晋杂”101号高粱的生长情况良好,在收获期平均株高达171.51 cm,平均穗重达99.7 g,平均产量为838.7 g/m2,无大片死亡干枯现象,收获时株高和产量均接近国内试验区平均水平,表现出较好的适应性和稳产性。
[Abstract]:Saline-alkali land is an important land resource, so it can promote the agricultural efficiency of saline-alkali land. Sustainable utilization is one of the important ways to guarantee the national food security and promote the sustainable development of agriculture, which can promote the sustainable development of regional economy. It is also of great significance to improve the ecological environment. The area of saline-alkali land in Datong Basin accounts for 70% of the total area of saline-alkali land in Shanxi Province. It is one of the more serious salinization areas in China, and the salinization makes the soil condition worse. The low level of production has greatly reduced the utilization rate of land. The improvement of saline-alkali land is of great significance to local ecology and economy. This paper is based on the study of soil water and salt regulation of drip irrigation. The field experiment was carried out in Shanyin County, Shuozhou City, Shanxi Province. By planting the saline-tolerant plant Ephedrine, and controlling the soil substrate potential under the guidance of irrigation with a negative pressure meter, the potential of different substrates was studied for -15 kPa. The effects of -25 kPa and -35 KPA on soil water and salt migration and the growth of Elaeagnus capsicum were studied. On the basis of this, sorghum was planted on the plot of drip irrigation for 2 years. The growth of sorghum and soil water and salt were studied under natural conditions. The results showed that the change of soil substrate potential, irrigation frequency and rainfall evaporation. The soil moisture content was relatively low under different crop growth stages under the treatment of -35 kPa. The soil moisture content of 0 ~ 40 cm soil layer was affected by drip irrigation. With the increase of substrate potential, the effect of irrigation is more and more obvious, and the water content is higher. The lower the pH value and the electrical conductivity were, the irrigation water of the three treatments was 3.640 m ~ 3 ~ (-1) -15 kPa)3.399m3(-25 KPA 2.209 m ~ (3) C ~ (-1) ~ (35) KPA, respectively. . The horizontal diffusion radius of soil wetted soil was arranged in the order of: -15 kPa-25 kPa-35 kPa.3. The distribution of soil moisture content in soil profile all changed obviously under the treatment of 1: -15 kPa-25 kPa-35 kPa.3. The soil moisture content was increased by 6%, and the soil pH value and electrical conductivity decreased the most under -15kPa treatment, which decreased by 7% and 66.5%, respectively) after an experimental period of irrigation leaching. The content of sodium and potassium decreased by 87% and 73% in soil treated with -15 kPa and -25 kPa and -35 kPa, respectively, and the content of potassium decreased by 77% as a whole. In the process of drip irrigation, some carbonate ions hydrolyzed to form bicarbonate ions, which led to the increase of bicarbonate ion content in phases, but with the increase of irrigation amount. The ratio of the four ions is smaller and smaller, the potassium ion content is lower, the dissolution rate is also low, the sodium ion is easier to be eluted than the potassium ion. The order of coverage and biomass was -15kPa-25 kPa-35 KPA, so no matter the plant height, coverage and biomass. The control of soil substrate potential showed the same excellent degree, that is, -15 kPa was the best. 4) after the experiment of soil substrate potential controlled by drip irrigation in 2015. The salinization degree of the soil in the experimental field was greatly improved, and the soil moisture content increased by 10.1%. The soil average pH value and average conductivity value decreased by 0.85 and 151 渭 S / cm. At the end of the sorghum trial in 2016. The average pH and conductivity of the soil decreased by 19.5% and 42.6%, respectively, compared with the initial soil pH and conductivity in 2015. The results of sorghum cultivation on drip irrigation soil showed that the growth of "Jinza" 101 sorghum was good. At harvest stage, the average plant was 171.51 cm, the average ear weight was 99.7 g, the average yield was 838.7 g / m ~ (2). At harvest time, plant height and yield were close to the average level of domestic experimental area, showing good adaptability and stable yield.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S156.4;S275.6

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