【作者】 于稀水；

【导师】 廖允成；

【作者基本信息】 西北农林科技大学 ， 作物栽培学与耕作学， 2014， 博士

【摘要】 如何合理科学、安全、高效的进行节水灌溉一直是旱区利用微咸水进行农田灌溉所关注的核心问题。西北地区水资源匮乏、生态环境日趋恶化,要实现该区农业可持续发展,必须提高水资源的利用效率,走节水型的发展之路。发展节水灌溉农业是目前西北地区从根本上摆脱水危机,确保农业可持续发展的必经之路。本研究在分析国内外微咸水灌溉及长期滴灌研究的基础上,开展了不同节水灌溉模式对玉米生长的影响以及相关节水技术的分析研究。主要结论如下:(1)分析微咸水灌溉和土壤初始含盐量对玉米出苗率和出苗时间的影响,结果表明,当灌溉水矿化度大于3.0 g/L时,可显著降低玉米出苗率,并延迟玉米出苗时间;土壤初始盐分含量过高不利于玉米出苗,但当灌溉水中的盐分和土壤中的盐分的含量相当时,灌溉水矿化度对玉米出苗率和出苗时间的影响大于土壤初始含盐量。当灌溉用水的矿化度和土壤初始含盐量增大时,玉米株高呈现逐渐降低趋势;与未灌溉处理比较,在玉米生长的穗期和籽粒成熟期进行微咸水灌溉可有效提高玉米产量,但玉米千粒重及总产量均随着灌水矿化度的增加而降低;灌溉水矿化度对玉米干物质累积的抑制作用亦显著大于土壤初始含盐量。(2)不同矿化度微咸水灌溉后,土壤含盐量显著高于灌溉前,且随着灌溉用水矿化度的增加,土壤含盐量显著增加;采用3.0 g/L微咸水进行灌溉时,灌溉前后上壤含盐量的变化趋势与淡水处理一致,但变化幅度大于淡水处理。3年的灌溉试验表明,采用3.0 g/L微咸水进行灌溉后,0～40 cm上体无显著积盐现象,0～120 cm土体的平均上壤含盐量在年内和年际间亦能保持平衡。而采用4.0 g/L微咸水进行灌溉后,土体在灌溉第3年发生次生盐碱化,0～120 cm 上体的平均土壤含盐量逐年增大,上体处于积盐状态,但主根层的土壤含盐量增大到一定程度后,便不再增大,该层成为盐分的传导区。对微咸水灌溉后0～120 cm 上体土壤盐分绝对盈亏量进行分析表明,由灌溉水带入土壤中的盐分并非全部累积在0～120 cm 上层,其中一部分被作物吸收,另外,还有相当数量的盐分由灌溉水或降雨淋洗至120 cm以下上层。整个研究期间,0～120 cm上体盐分盈亏量随着灌溉水矿化度的增大而减小,即灌溉水矿化度越大,被淋洗及吸收的盐分的量越大。(3)分析不同滴灌处理条件下玉米地土壤水分及盐分动态变化,结果显示,滴灌条件下,高灌水量处理玉米耗水量最大,其次为中灌水量和低灌水量处理。3种灌溉量对玉米千粒重和产量影响显著,且低灌水量处理玉米千粒重和产量显著低于高灌溉量和中灌溉量处理。整个生育期内,不同灌水量下玉米蒸腾速率变化规律基本一致,均表现为苗期至抽穗期,随前玉米生长时间的延长,其蒸腾速率逐渐增高;抽穗期-灌浆期,各处理的蒸腾速率达到最大值;抽穗-灌浆后至收获期,玉米蒸腾速率缓慢降低;整个生育期内,高灌水量处理蒸腾速率最大,低灌溉水量处理最小,中灌溉水量处理居于两者之间。拔节期前,地面蒸发是常规滴灌处理玉米水分散失的主要途径,0～20 cm 土壤含水量显著低于20～40 cm和40～60 cm。地面不进行覆膜时,大量水分通过蒸发作用散失,土壤含水量呈持续降低的趋势。灌浆期和成熟期上壤含水量有所增加,土壤水库得以补偿。基于废旧塑料水瓶的低成本滴灌系统试验结果表明,当滴孔孔径为1.0～2.5 mm时,可以用于高孔隙率或渗透速率的上壤,如沙质土壤;孔径为3.0～6.0 mm时则适用于渗透性较好的土壤;当孔径大于6.0 mm时滴灌效果不明显。本研究采用的简易滴灌系统利于环境保护,成本较低,可在贫困国家推广使用。更多还原

【Abstract】 How to utilize saline water reasonably,scientificly,efficiently and safely has always been a core problem in farmland irrigation.In northwest,because of lack of water resources and ecological environment getting worse,we must increase the water-use efficiency,go the way of the development of water-saving.Develop water-saving irrigation agriculture is now fundamentally get rid of the water crisis in northwest China,to ensure agricultural sustainable development path.Based on the relative research about saline water irrigation and drip irrigation both at home and abroad,this paper studied on the effect of the saline water on typical crops growth,as well as related water saving method.The main results are as follows:(1)Through study the effect of mineralization salinity water irrigation and soil salt content on corn emergence rate and emergence time,we found that when the mineralization of water over 3.0 g/L,which can inhibition com emergence rate and delay time of maize emergence;Initial soil salt content too high was bad for maize emergence,but when the salinity of irrigation water and the salt content of soil was about the same,the effect of irrigation water salinity on corn seedling emergence rate and emergence time significantly greater than the initial soil salt content;When the irrigation water salinity and initial soil salinity increased,maize plant height showed a reduce trend gradually;At maize spike and mature periods,mineralization water irrigation can improve the com yield effectively,but corn kernels and the total output decreased with the increased of water salinity;The inhibitory effect of irrigation water salinity on maize dry matter accumulation was significantly greater than the initial soil salt content(2)After different mineralization salinity water irrigation,soil salinity was significantly higher than before irrigation,With the increased of irrigation water salinity,soil salt content increased significantly;When use 3.0 g/L mineralization salinity water irrigation,the change trend of soil salt content was the same as fresh water treatment before or after irrigation,but amplitude of variation more than fresh water.Three years of irrigation experiments showed that using 3.0 g/L of mineralization salinity water irrigation,0 to 40 cm soil had no significant phenomenon of salt deposition,the average salt content in 0 to 120 cm soil layer maintain a balance in a year or in interannual.With 4.0 g/L mineralization salinity water irrigation,soil secondary sanitization occurred in the third year after irrigation,the average soil salt content in 0-120 cm soil layer increased year by year,the soil in a salt deposition state,but when the soil salt content increased to a certain degree in taproot layer,it no longer increase,the layer became the salt conduction zone Based on the study on the soil salt contents of 0-120 cm in the soil profile after salinity water irrigation,the results showed not all the salt will concentrate between the soil profile of 0-120 cm,of which some will absorbed by the plant,furthermore,most part will be leached by irrigation water or the rainfall.During the whole period,the salt content in the soil profile of 01-20 cm decreased with salinity increasing.Moreover,the higher the salinity,the more the salt will be leached and absorbed.(3)Based the experimental study on evaporation rate in corn field,the irrigation water amount of all the growth periods have similar effect on the evaporation rate in the corn field.The main results are as follows:the consumption of water is the largest with the largest water irrigation amount;however,the consumption will decrease with the irrigation amount.All the irrigation water amount treatment have great effect on the thousand-grain weight and productivity,moreover,the effect became much more obvious when the irrigation water amount is very low.Evaporation is the main way that the water was lost during the shooting periods of the com and soil water in the surface is obvious lower than that of any other profile(20-40 cm and 40-60 cm).So if the membrane tectonic was not conducted in the corn field,the water will lost a lot through evaporation and the soil water content decrease.The soil water content increased during the and grout filling and maturity period which will be help with the soil water reserve.The experimental studied on cheap dripping system with the waste plastic bottle were studied and the main results showed as follows.When the orifice diameter was between 1.0-2.5 mm,the simple drip irrigation system could be used in the soil with large porosity,such as sandy soil;while when the orifice diameter was between 3.0-6.0 mm,the simple drip irrigation system could be used in the soil with good percolation;however,when Orifice sizes is above 6.0 mm,the simple system were found to be unsuitable.The report recommended that the system should be popularized among rural farmers who should be motivated with incentives that may be commensurate to their waste disposal service.更多还原