【作者】 张杰；

【导师】 贾志宽；

【作者基本信息】 西北农林科技大学 ， 植物资源学， 2010， 博士

【摘要】 为解决干旱半干旱地区覆盖普通地膜所造成的“白色污染”问题,本试验于2008年～2010年在陕西省合阳县甘井镇的试验基地进行,以普通地膜和无覆盖地膜为对照,选用生物降解地膜和液态地膜两种环保材料在同一气候条件下进行玉米的集雨保墒试验,研究了在环保型地膜覆盖条件下,玉米集雨种植田土壤的水、温、养分及土壤酶的变化和玉米生长的生理生态响应状况,研究结果如下:1环保地膜覆盖的土壤水温状况对环保型地膜覆盖的蓄水效果研究表明,覆盖生物降解地膜的蓄水效率明显高于液态地膜和对照,与普通地膜的蓄水效率相当,随时间的推移生物降解地膜的蓄水效率相比普通地膜有所降低,而液态地膜的蓄水效率与对照相似,明显低于普通地膜。环保型地膜处理生育期间的土壤贮水量动态分析表明,覆盖生物降解膜处理能明显提高0～60 cm、60～120 cm和120～200 cm土层的土壤贮水量,并与普通地膜无显著差异;液态地膜的土壤贮水量则显著低于普通地膜覆盖,与对照无明显差异。覆盖生物降解地膜与普通地膜一样可以明显增加玉米生育前期的土壤温度,尤其对5 cm和10 cm土层的土壤温度影响较大,但对15cm以下土层的增温作用不明显,而覆盖液态膜处理与对照相比对不同土层的增温效果均不明显。2环保地膜覆盖对土壤养分和酶的影响覆盖生物降解地膜、液态地膜和普通地膜处理与CK相比均能增加土壤耕层土壤全效养分的含量。同时由于覆膜处理的集水集肥效果,生育期覆盖处理耕层土壤的有机质,速效N、P、K含量均有明显增加,且覆盖生物降解膜和液态膜与普通地膜之间无显著差异。对0～100 cm土层的土壤速效养分分析发现,集雨覆盖主要增加了0～40cm土层的速效养分含量,对深层土壤养分没有明显的影响。在试验过程中,不同年份各处理的酶活性差异不尽一致,覆盖生物降解膜和液态膜处理的土壤蔗糖酶、脲酶和磷酸酶的活性与覆盖普通地膜处理之间没有显著差异,并均较对照有所提高,且各处理的酶活性随着土层的加深逐渐降低。通过对不同材料地膜覆盖的集雨种植能的农田养分利用效率分析表明,覆盖生物降解地膜和液态地膜处理的农田养分利用效率与普通地膜无明显差异,但三者较对照均有明显增加。其中覆盖生物降解膜、液态膜和普通地膜处理的土壤N素的利用效率(NUEN)较对照分别提高33.93%、12.60%和34.73%,土壤P素的利用效率(NUEP)分别提高59.15%、19.48%和67.47%,土壤K素的利用效率(NUEK)分别提高53.58%、10.96%和57.24%。3环保地膜覆盖对玉米光和特性的影响从玉米叶片叶绿素含量、光合速率、蒸腾速率、气孔导度、叶片水分瞬时利用效率及荧光参数等多项指标综合衡量,生育期覆盖生物降解地膜、液态地膜和普通地膜处理对玉米的光合作用均有促进作用,其中生物降解膜的促进作用与普通地膜一样均较明显,而液态膜的促进作用有限或不明显。4环保地膜覆盖对玉米生长发育的影响集雨种植条件下,环保地膜覆盖使玉米的生育进程有所提前,其中覆盖生物降解地膜和普通地膜对玉米生长发育的促进作用较为明显。试验表明,覆盖生物降解地膜、液态地膜和普通地膜的玉米平均最大株高分别比对照提高5.83%、2.08%和6.03%;生物量干重分别比对照提高了20.03%、3.63%和19.51%。分析表明,覆盖生物降解地膜处理的株高和生物量较对照有显著提高(P﹤0.05),并与普通地膜之间无显著差异,液态膜和CK之间无显著差异。对产量性状的分析表明,覆盖生物降解地膜的籽粒产量、千粒重、穗粒数和穗长均与普通地膜的差异不显著,且两者显著高于对照(P﹤0.05);覆盖液态地膜的产量性状显著低于普通地膜,并与对照无显著差异。在3年的试验中,覆盖生物降解地膜和普通地膜处理的玉米水分利用效率(WUE)分别比对照提高了19.36%和20.02%,而液态膜的效果不明显。由此可见,生物降解地膜和液态地膜与普通地膜相比,生物降解地膜的集雨保墒效果虽略低于普通地膜,但两者对玉米生长发育的促进作用没有明显差异,因此其可以替代普通地膜应用于农业生产,解决普通地膜带来的“白色污染”问题;而液态地膜的集雨保墒效果明显低于普通地膜,对玉米生长发育的促进作用也不稳定,需进一步研究验证。更多还原

【Abstract】 Aimed on the“White Pollution”caused by the universal utilization of normal mulching films in arid and semi-arid areas, the degradable mulching films and liquid mulching films were chosen to research the soil moisture, soil temperature, soil nutrients, the change of soil enzymes as well as the ecological and physiological response of corn planted under the coverage of those environmental friendly mulching films from the year 2008 to 2010. A series of experiments were carried out in the experiment base located in Ganjing town, Heyang county, Shannxi province with the comparison of normal mulching films and bare land. The results were concluded as follows:1 influence on the soil moisture and temperatureThe rainwater harvesting efficiency of normal mulching film (PM) and degradable film (SM) were better than liquid film (YM) and the contrast (CK), and compared with normal mulching film, the rainwater harvesting efficiency of degradable film decreased a little compared with normal mulching film (PM) while that of liquid films decreased evidently as the experiment went on. The dynamic analysis of soil water storage treated with environmental friendly mulching films during growth period indicated that the water storage in the 0～200 cm soil increased evidently under the degradable film (SM), which had the same effect with normal mulching film (PM); The soil water storage treated by liquid film (YM) was apparently less than normal mulching film (PM), and showed no significant difference with bare land(CK). As for the soil temperature, normal mulching film (PM) and degradable film (SM) had the same promotion effect, especially for the 0～10 cm soil, while the promotion effect on soil temperature of liquid film (YM) was not so significant compared with the bare land(CK).2 influence on soil nutrients and enzymesThe experiment showed that all the rain harvesting materials could increase the soil nutrients and had the same promotion effect compared to each other. The nutrients analysis of 0～100cm soil founded that rain harvesting coverage effectively increased the nutrients of 0～20cm soil other than the deeper ones, which indicated that rain harvesting coverage would not cause a leakage of soil nutrient and had no bad influence on crop’s nutrient absorption.The activity of soil enzymes was very sensitive to environment changes in this experiment, the activity of invertase, urease and phosphatase under the treatment of degradable film (SM) and liquid film (YM) compared with the CK, while showed no difference with the normal mulching film (PM), and all the enzyme activities decreased along with the depth of soil. The analysis of nutrient using efficiency indicated that the degradable film (SM), liquid film (YM) and normal film (PM) had the same promotion effect compared to CK, of which the nitrogen using efficiency (NUEN) respectively increased by 33.93%, 12.60% and 34.73%, the phosphorous using efficiency (NUEP) respectively increased by 59.15%, 19.48% and 67.47%, and the potassium using efficiency (NUEK) respectively increased by 53.58%, 10.96% and 57.24%.3 influence on corn photosynthetic characteristicsFrom the measurement results of leaf chlorophyll content, photosynthetic rate, transpiration rate, stomata conductance, leaf WUE and fluorescence parameters, the conclusion could be drawn as the degradable film (SM) and normal film (PM) had the same promotion effect on corn photosynthetic characteristics compared to CK, while the liquid film (YM) showed no significant promotion effect.4 influence on corn growthAll the rainwater harvesting materials could accelerate the growth of corn, of which the normal mulching film and degradable film had much more obvious effects. compared with CK, the average height of corn increased by 5.83%, 2.08% and 6.03% covered respectively by degradable film, liquid film and normal mulching film while the increase of dry biomass increased were 20.03%, 3.63% and 19.51%. The height and biomass of corn covered by normal mulching film and degradable film had a significant difference(P﹤0.05)with CK, but there were no obvious difference between liquid film and CK. The analysis of yield characteristic indicated that the seed yields, 1000-grain weight, grain number per spike and spike length of corn covered by normal mulching film and degradable film had great significance(P﹤0.05)with CK, but the influence of liquid film were not significant. The variance analysis of water use efficiency (WUE) showed that in the 3 years experiment, the WUE of corn covered by degradable film and normal mulching film increased by 19.06% and 20.02%, but the influence of liquid film was not significant.As a conclusion, compared with normal film, the degradable film had the same promotion effect on corn growth and soil water harvesting, which means that it can replace the normal film so as to resolve the“white pollution”problems. The applicability of liquid film needs more research because lower water harvesting effect and unstable promotion effect on corn growth.更多还原