【作者】 李静；

【导师】 张富仓；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2015， 硕士

【摘要】 本试验于2013年8~11月在西北农林科技大学旱区农业水土工程教育部重点实验室日光温室中进行,针对西北半干旱地区温室蔬菜灌水施肥不合理等问题。利用温室小区试验,以‘博耐9-1’黄瓜为试材,设置3个灌水水平:低水W1(60%ET0)、中水W2(80%ET0)和高水W3(100%ET0);和4个施氮水平:无氮N0(0 kg/hm2)、低氮N1(180 kg/hm2)、中氮N2(360 kg/hm2)和高氮N3(540 kg/hm2),共12个处理。通过研究不同水氮供应对温室黄瓜生长、产量、品质、水氮利用及土壤环境的影响,以期科学地对水肥进行调控,为实际生产提供参考依据。论文取得了如下研究结论:(1)除茎粗外,灌水量与施氮量对黄瓜株高、叶面积指数、干物质量都有显著影响。灌水量与黄瓜株高、叶面积指数有显著正相关作用,而施氮量对黄瓜生长指标的影响则因施氮量的不同表现出不同变化趋势。其株高、叶面积指数随施氮量的增加表现为先增大后降低,并在中氮处理中获得最大值。干物质量变化趋势略有不同,表现为在低水水平下,干物质量在中氮处理中获得最大值,而在高氮水平下略有下降,且中氮与高氮之间差异不显著,其余灌水水平下则随着施氮量的增加表现为不同程度的增加。(2)灌水量和施氮量对小区产量及产量构成因素有极显著性影响,产量随施氮量的增加而增加,当施氮量增加到中氮水平时,继续增加施氮量,其增产效果在不同灌水水平下表现为不同趋势,即在低水、中水水平下,施氮量增加至中氮平后继续增加时,产量之间无显著性差异;而在高水处理下,高氮比中氮水平增产8.4%,差异显著。黄瓜瓜条数和单果重的变化规律和产量类似,且瓜条数与产量、单果重与产量之间的拟合关系均呈现线性拟合关系,R2分别为0.989和0.934。通过产量与生长指标间的通径分析可知,干物质量和叶面积指数对黄瓜产量的增加具有重要作用,可分别作为黄瓜高产的第一指标和第二指标。(3)灌水量对黄瓜可溶性固形物、可溶性糖及硝酸盐含量有显著负相关作用,Vc含量则随着灌水量的增大表现为先增大后降低的趋势,而可溶性蛋白含量则在不同灌水量及施氮条件下表现为不同的变化趋势。果实中的可溶性固形物及硝酸盐含量随施氮量的增加显著增加,可溶性糖与Vc含量则随施氮量的增加变现为先增大后降低的趋势。采用主成分分析法对黄瓜品质及营养产出进行综合评价,采取低水中氮(60%ET0、360kg/hm2 N)的水氮供应模式可以获得黄瓜最优品质,若综合考虑产量及品质,采取中水中氮(80%ET0、360 kg/hm2 N)的水氮供应模式可达到农业生产中较为高产质优的目的。(4)黄瓜叶绿素含量随着生育期的推进呈现先增加后降低的趋势,在盛果期取得最大值。在开花坐果期、盛果期及末果期,低水、中水灌水条件下,适量施氮对提高叶片叶绿素含量有促进作用,过量施氮则会抑制叶绿素的合成。而在高水处理下,水氮之间的耦合作用更有利于叶绿素合成对水分及养分的需求,呈现正相关关系。净光合速率日变化在各水氮供应条件下呈现单峰曲线,不施氮肥或严重亏水均会显著影响作物的净光合速率,而适量的节水节肥不仅能节约农业成本,且相比于充分灌水施肥,作物也能达到较好的净光合速率。(5)施氮量、灌水量对黄瓜IWUE及WUE均有显著影响,水氮交互作用对黄瓜WUE也有显著影响,而水氮交互作用对IWUE无显著影响。施氮量相同时,WUE随灌水量不同表现为中水>低水>高水;在低水、中水处理时,WUE随着施氮量增加表现为先增大后降低的趋势,而对于高水处理,WUE随着施氮量的增加显著增加。IWUE随着施氮量的增加而增加,而随着灌水量的增加逐渐下降。在各灌水条件下,NUE、UPE及PFP均随着施氮量的增加而减少,且在低水水分条件下,增加施氮量对NUE和UPE均有明显抑制作用,而在中水、高水水分条件下,当施氮量达到中氮条件时,继续增加施氮量,NUE没有明显变化,适当减少施氮量可显著提高PFP。对于同一施氮水平,UPE均随着灌水量的增加显著提高。(6)氮素在植株体各器官中的累积量随生育期的推进,总体增长趋势呈现“S”型,并在盛果期累积量最大。在不同生育期,黄瓜各器官中氮累积量均表现为叶>茎>根,到达盛果期后,氮素在果实中的吸收量达到最大,且植株氮吸收量随灌水量和施肥量的增加而增大。土壤中的硝态氮含量也随生育期的推进不断累积,并不断往下迁移。灌水量及施氮量对土壤硝态氮分布有重要影响,且施氮量是影响土壤硝态氮累积的关键因素,随灌水量的增加表层土壤中硝态氮含量呈逐渐降低的趋势,而随施氮量的增加则逐渐增大,且施氮量越高,淋洗现象越明显,并在湿润体横向边缘产生累积。更多还原

【Abstract】 This experiment carried in greenhouse of Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education in Northwest A&F University from August to November in 2013, and in view of the questions of irrigation and nitrogen unreasonable in the vegetable greenhouse for semiarid northwest area. Choosing ‘Bonai 9-1’ as the test cultivar, the greenhouse plot experiment was subjected to three irrigation water levels [W1(60% ET0), W2(80% ET0) and W3(100% ET0)] in interaction with four nitrogen fertilization levels [N0(0 kg/hm2), N1(180 kg / hm2), N2(360 kg/hm2), N3(540 kg/hm2)], and there were 12 treatments in total. The effect of different water and nitrogen supply on cucumber growth, yield, quality, water and nitrogen use and soil environment were investigated, in order to regulate water and fertilizer scientifically and provide scientific reference for actual production. The results showed that:(1)In addition to stem diameter, irrigation and nitrogen application influenced cucumber plant height, leaf area index, and dry weight significantly. Irrigation had a significant positive correlation effects on plant height and leaf area index, whereas the impact of nitrogen fertilizer on cucumber growth showed different trends due to the different nitrogen levels. The impact of nitrogen fertilizer on Plant height and leaf area index showed an increasing trend and then decreasing, reaching the maximum at N2 treatment. Dry weight was slightly different, which showed under W1 level, reaching the maximum at N2 treatment, decreasing slightly at N3 treatment afterwards, and there were no significant difference at the N2 and N3 treatment. The remaining irrigation levels showed varying degrees of increase with the increasing of nitrogen fertilizer.(2) Irrigation and nitrogen application influenced yield and yield components significantly, cucumber yield increased with the increasing of nitrogen rate. When the nitrogen rate increased to N2 level, and continued to increase, the effect of yield showed different trends under different irrigation levels. In other words, there was no significant difference between yield when nitrogen rate increased to N2 levels and continued to increase under W1 and W2 level, while difference was significant between N2 and N3 treatment and N3 improved yield by 8.4% than N2 under W3 level. Changes of fruit number and average fruit weight were similar to cucumber yield, and the fitting relationship of fruit number and yield, average fruit weight and yield all showed a linear relationship, R2 were 0.989 and 0.934 respectively. Via the path analysis between yield and growth index, it showed that dry weight and leaf area index had the important effects on cucumber yield improvement, which can be used for the first and second index of high yield.(3)Irrigation amount was significantly negatively correlated with cucumber soluble solids, soluble sugar and nitrate contents. Along with the increasing of irrigation levels, Vc content showed an increasing trend and then decreasing, while the soluble protein content showed different trends under different irrigation and nitrogen conditions. Soluble solids and nitrate content in the fruit were significantly increased with increase of nitrogen, but soluble sugar and Vc content showed an increasing trend and then decreasing. According to the comprehensive evaluation of the cucumber quality and nutrition output with principal component analysis, W1N2(60%ET0、360 kg/hm2 N) obtained the best quality, and W2N2(80%ET0、360 kg/hm2 N) gained the maximum nutrition output of cucumber, which can be used as a suitable choice to obtain high yield and quality in agricultural production.(4)Chlorophyll content of cucumber showed an increasing trend and then decreasing with the growth progress, and obtained maximum at full bearing period. In fruit setting stage, full bearing period and telophase of fruiting, appropriate amount of nitrogen had a role in promoting chlorophyll content increasing, whereas excessive nitrogen application restrained chlorophyll synthesis under W1 and W2 levels. However, the coupling effect between water and nitrogen was more conducive to chlorophyll synthesis for the demand for water and nutrients, showing a positive correlation under W3 level. The diurnal variation of Pn of cucumber appeared a single peak curve in the condition of water and nitrogen supply. No nitrogen or severe water deficit would significantly affect Pn, and appropriate amount of water and fertilizer conservation could not only save costs, but also achieved better Pn comparing to full irrigation and fertilizer application.(5)Irrigation and nitrogen fertilization influenced cucumber IWUE and WUE significantly, and water and nitrogen interactions also had a significant effect on WUE, but the interaction of water and nitrogen had no significant effect on IWUE. With different irrigation levels, WUE expressed as W2>W1>W3 under the same N application. Under W1 and W2 treatment, WUE showed an increasing trend and then decreasing with the increase of nitrogen rate, while for W3 treatment, WUE was significantly increased with the increase of nitrogen rate. IWUE also increased with the increase of nitrogen rate, but decreased with the increasing irrigation amount. NUE, UPE and PFP all decreased with the increase of nitrogen rate under different irrigation conditions, and NUE and UPE were significantly inhibited with the nitrogen rate increasing. Under W2 and W3 levels, When the nitrogen rate reached N2 treatment, continuing to increase nitrogen rate, NUE did not change significantly. Reducing nitrogen rate appropriately could significantly increase PFP. For the same nitrogen rate, UPE increased significantly with the increasing irrigation amount.(6)Nitrogen accumulation in various organs of cucumber appeared "S" type with the growth progress, and obtained maximum cumulated amount at full bearing period. At different growth stages, nitrogen accumulation in different organs of cucumber showed the situation of leaf> stem> root, and nitrogen uptake in fruit reached the maximum at harvest period, and plant nitrogen uptake increased with the increasing Irrigation amount and nitrogen rate. The nitrate nitrogen content in the soil continued to accumulate with the growth progress, and migrated downward continuously. Irrigation and nitrogen amount had important impact on soil nitrate nitrogen distribution, and nitrogen rate was a key factor in soil nitrate nitrogen accumulation. Nitrate nitrogen content in surface soil gradually decreased with the increasing irrigation amount, whereas gradually increased with the nitrogen rate increasing. The higher nitrogen rate was more likely to result in nitrate nitrogen leaching, and generate accumulation at the lateral boundary of the wetted volume.更多还原