华北平原春玉米滴灌均匀系数对土壤水氮时空分布的影响

【目的】研究滴灌均匀系数及土壤特性对土壤水氮时空分布的影响,定量评价现行标准的适宜性。【方法】试验在华北平原进行,供试作物为春玉米,滴灌均匀系数（CU）设置0.66（低）、0.81（中）和0.99（高）3个水平,灌水量设置灌溉需水量的50%（低）、75%（中）和100%（高）3个水平,监测不同生育阶段的土壤水分和硝态氮含量。【结果】土壤含水量均匀系数在生育期内大于0.85（2009年）和0.80（2010年）,低灌水均匀系数处理与中、高灌水均匀系数处理没有明显区别,远大于滴灌均匀系数（0.66）,初始含水量均匀系数的影响大于滴灌均匀系数,灌水量的影响较小。滴灌均匀系数对硝态氮均匀系数的影响不显著。【结论】在华北平原半湿润地区,滴灌均匀系数不是影响春玉米生育期内土壤水氮分布的主要因素,现行微灌均匀系数标准（CU≥0.80）可适当降低,以降低系统投资。     

插入式地下滴灌对土壤入渗和水盐分布的影响

【目的】研究插入式地下滴灌对盐碱土壤入渗与水盐分布的影响。【方法】采用室内土柱试验,以阿拉尔灌区春季返盐的盐碱土土壤为研究对象,比较分析不同滴头流量与滴头埋深,对土壤湿润峰运移和湿润体内部水分及盐分的影响规律。【结果】相同入渗时间和滴头流量条件下,地下滴灌比地表滴灌湿润峰深度、湿润面积、湿润体内土壤平均含水量和脱盐深度增加。与CK处理相比较,T₁处理土壤湿润峰深度和土壤湿润面积分别增加20.89%和18.01%;T₂处理土壤湿润峰深度和土壤湿润面积分别增加45.78%和19.06%。T₁和T₂处理土壤湿润体内含水量平均值分别增加2.48%和1.37%。土壤脱盐深度由10 cm增加至25 cm。增加滴头埋深和流量,能够增加土壤持水效率,T₁～T₄处理0～25 cm土层土壤持水效率分别为2.56%、3.82%、9.81%和13.35%。滴头流量较小,随滴头埋深增加,土壤盐分表聚。T₂处理0～5 cm土层深度土壤积盐率为67.98%。若增加...     

不同土壤湿度对膜下滴灌棉花根系生长和分布的影响

 【目的】精量制定膜下滴灌棉花的田间水分管理制度和揭示滴灌棉花的增产机理。【方法】以田间试验为基础,设置90%θf、75%θf和60%θf（θf田间持水量）3个土壤湿度处理,在棉花不同生育阶段采用双向切片法测定棉花根系和根冠比;用时域反射仪测定土壤水分;最终测棉花产量。【结果】3个土壤湿度所对应的棉花根系生长过程呈“S”形变化,但是,由于75%θf处理的棉田土壤含水量始终处于适宜范围内,全生育期棉花根系生长速度快及最终根重大;90%θf处理的土壤水分太充足,根系生长速度缓慢,其根区土壤中根重最小;60%θf处理的根重介于其它2处理的根重之间。3个处理的棉花根重垂直分布呈锥形负指数递减模式,且随土壤湿度提高,深层根重减小幅度大,根系变浅。0～30 cm土层中,75%θf处理的棉花根系所占总根重比例最高。水平方向上棉花根系主要分布在膜下窄行和宽行土壤中,膜外裸地中根重很小;各土壤湿度处理中,75%θf处理下膜下窄行或宽行的根重都比90%θf和60%θf处理的根重大。棉花根冠比随着土壤湿度的增加有减少的趋势。不同土壤湿度处理对棉花产量有不同的影响,75%θf处理下的产量最高。【结论】膜下滴灌条件下土壤水分持续维持较高水平,对棉花根系生长及产量有不利的影响。     

Effects of Soil Water Content on Cotton Root Growth and Distribution Under Mulched Drip Irrigation

The relation between soil water content and the growth of cotton root was studied for the scheme of field water and cotton yield under mulched drip irrigation. Based on the field experiments, three treatments of soil water content were conducted with 90%, 75%θf, and 60%θf （θfis field water capacity）. Cotton roots and root-shoot ratio were studied with digging method, and the soil moisture was observed with TDR （time domain reflector）, and cotton yield was measured. The results indicated that the growth of cotton root accorded with Logistic growth curve in the three treatments, the cotton root grew quickly and its weight was very high under 75%θf because of the suitable soil water condition, while grew slowly and its weight was lower under 90%θf due to water moisture beyond the suitable condition, and the root weight was in between under 60%θf For the three water treatments, the cotton root weight decreased with soil depth, and decreased more significantly in deeper soil layer with the soil moisture increasing. And the ratio of cotton root weight in 0-30 cm soil layer to the total root weight was the highest under 75%θf. The cotton root system was distributed mainly in the soil of narrow row and wide row mulched with plastic film, and little in the soil outside plastic film. The weight of cotton root was the highest in the soil of narrow row or wide row mulched with plastic film under 75%θf. Root-shoot ratio decreased with the soil moisture increasing. The soil water content affected cotton yields, and cotton yield was the highest under 75%θf. The higher soil moisture level is unfavorable to the growth of cotton root system and yield of cotton under mulched drip irrigation.     

Wetting Patterns and Nitrate Distributions in Layered-Textural Soils Under Drip Irrigation

Laboratory experiments were conducted in different sequence and thickness of the soil layers to investigate the effects of layered-textural soils on wetting patterns and water and nitrate distributions from a surface point source under various combinations of application rate and applied volume. Three layered soils, including a sandy-over-sandy loam (SL), a sandy loam-over-sandy (LS), and a sandy loam-sandy-sandy loam (LSL), and two uniform soils (a uniform sandy loam and a uniform sandy soil) were tested. In the experiments, the application rate was varied from 0.69 to 3.86 L h-1 and the applied volume from 5.7 to 12.1 L. The experimental results demonstrated that the wetting patterns and water and nitrate distributions were greatly affected by the sequence and thickness of soil layers as well as the application rate and volume applied. An interface existing in the layered soils, whether a fine-over-coarse or a coarse-over-fine, had a common feature of limiting downward water movement and of increasing horizontal water movement. For the fine-over-coarse layered soils of LS and LSL, water and nitrate were uniformly distributed at a given depth in the top layer soil. For a coarse-over-fine layered soil of SL, however, water accumulated in the sublayer soil underneath the interface and a zone of lower nitrate concentration was observed. The effect of application rate on water distribution pattern was dependent upon soil layering. A minor influence of application rate on water distribution for the fine-over-coarse layered soils (LS and LSL) than for the uniform soils was found. To obtain a greater wetted depth through selecting the emitters having a smaller application rate, which is a common method in the system design for a uniform soil, may not be necessarily applied for the layered soils.Measurements of nitrate distribution showed that nitrate accumulated toward the boundary of the wetted volume for both the uniform and the layered soils. This suggests the importance of optimal management of drip fertigation because nitrate is susceptible to the movement out of the root zone by mismanagement of fertigation. The information obtained from this research is useful in the design, operation, and management of a drip fertigation system.     

膜下滴灌条件下棉田耕层土壤中盐分变化的影响因素研究

本研究运用SP-3型棉田信息采集与精量灌溉控制系统，对棉田耕层土壤电导率、土壤含水量、温度变化进行连续的动态监测。结果分析表明，土壤盐分变化范围在3．1～6．5g／kg，土壤含水量在15．13％～30．54％，温度在17．25-31．00℃，并且土壤盐分与土壤含水量之间呈极显著负相关（R=-0．836），与温度呈极显著正相关（R=0．729），说明土壤含水量和温度的变化极大程度地影响着土壤盐分的变化和积累。     

阿瓦提丰收灌区无排水条件下葡萄滴灌土壤水盐运移规律研究

以新疆阿瓦提县丰收灌区为例，对葡萄滴灌的土壤盐分运移进行了监测研究，结果表明：干旱区尤排水条什下，宽行葡萄实施滴灌灌溉，干排盐功能和压盐、抑盐作用明显。在土壤盐分含量较高的干旱区引用地面水实施滴灌，系统的设计必须考虑压盐、抑盐水量，同时采用高频滴灌制度，确保供水保证率，才能达到林果业可持续发展的目的。     

干旱区滴灌棉田冻融季土壤水热盐分布规律研究

[目的]研究滴灌棉田冻融期及其前后水热盐分布规律.[方法]实验以野外实测和室内试验数据为基础,分析水热盐在干旱区滴灌棉田冻融季土壤各层中分布特征.[结果]表层土壤11月下旬开始冻结,到翌年2月上旬达到最大冻结深度,4月上旬土壤完全融通,冻融期5 cm深处土壤温度变幅为19.95℃,170 cm深处变幅为10.25℃;0～60 cm土层2009年11月29日～2010年2月11日含水量和含盐量冻结过程中都呈上升趋势,2010年2月11日～4月21日为融化期,土壤垂直含水量和含盐量分布表现出复杂的变化方式,60～200 cm土壤水盐垂直分布变化不大;土壤水分与盐分时间变异特征表现为:冻融期土壤表层变异性大于底层,0～80cm水分变异程度大于盐分,80～200 cm水盐变异系数差异不大,变异性低.[结论]为冻融季土壤水热盐分布进一步研究提供参考,对盐渍土的改良、农业灌溉等相关问题的研究有一定参考价值.     

土壤含水率和盐分对土壤电导率的影响

基于电流－电压四端法的“polar-dipole array”形式,以壤土作为研究对象,对土壤含水率和土壤盐分与土壤电导率之间的相互关系进行了试验研究,结果表明,在土壤盐分和含水率2个相关因素中,土盐分对土壤电导率的影响较土壤含水率要大得多。     

滴灌土壤湿润范围的研究及应用

本文为滴灌土壤水分湿润土体的定量描述和计算,给出了计算公式和有关数值,并举例说明其在滴灌规划设计中的应用     

Soil Water Distribution and Irrigation Uniformity Under Alternative Furrow Irrigation

Field experiments were conducted to investigate the spatial-temporal distribution and the uni-formity of soil water under alternative furrow irrigation in spring maize field in Gansu Province. Resultsshowed that during the crop growing season, alternative drying and wetting furrows could incur crops to en-dure a water stress, thus the adsorptive ability of root system could be enhanced. As there was no zero fluxplane between irrigated furrows and non-irrigated furrows under alternative furrow irrigation, lateral infiltra-tion of water was obviously increased, thus decreasing the deep percolation. Compared with the conventionalirrigation, although the water consumption in alternative furrow irrigation was reduced, the uniformity of soilwater was not obviously affected.     

交替隔沟灌溉土壤水分时空分布与灌水均匀性研究

 以春玉米为试验材料 ,在甘肃河西民勤沙漠绿洲区进行大田试验 ,研究控制性交替隔沟灌溉水分的时空分布特性和灌水均匀性。试验结果表明 ,在玉米生长期内 ,对灌水沟进行交替干燥和湿润 ,可以使作物根系经受一定程度的干旱锻炼 ,提高根系的吸收补偿效应 ;交替隔沟灌溉中 ,由于在灌水沟和非灌水沟之间没有形成零通量面 ,其水分的侧向入渗明显增强 ,从而可减少土壤水分发生深层渗漏的机率 ;同常规灌溉相比 ,虽然交替灌溉的用水量有所减少 ,但其灌水均匀性与常规灌溉没有显著差异     

论新疆膜下滴灌棉花土壤水分布

新疆棉花的膜下滴灌技术从开始试验到实地应用的全过程经历着实地的研究验证、全面的推广应用、大面积的膜下滴灌棉花种植全过程。     

盐角草对滴灌条件下积盐范围内盐分的影响

[目的]确定湿润峰、积盐范围及盐角草吸盐能力,控制积盐范围内盐分。[方法]以pH 7.9的水作为灌溉水源,在不同土壤初始含水率、土壤容重及滴头流量的条件下研究土壤湿润体的变化过程。[结果]盐角草吸走部分Na＋、Cl-抑制盐分,积盐范围内土深20cm处的总含盐量降低了0.12 g/kg。[结论]该研究可以为有效地控制滴灌条件下湿润锋边缘积累盐分提供依据。     

Effects of Irrigation Water Quality and Drip Tape Arrangement on Soil Salinity,Soil Moisture Distribution,and Cotton Yield (Gossypium hirsutum L.) Under Mulched Drip Irrigation in Xinjiang,China

More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irrigation, the mechanism of soil moisture and salinity distribution and transport should be well understood for developing optimum management strategies. In this paper, field experiments were carried out at Junggar Basin, China, to study the effects of drip irrigation water quality and drip tape arrangement on distribution of soil salinity and soil moisture. Six treatments were designed, including two drip tape arrangement modes and three irrigation water concentration levels (0.24, 4.68, and 7.42 dS m-1). Results showed that, soil moisture content (SMC) directly beneath the drip tape in all treatments kept a relatively high value about 18% before boll opening stage; the SMC in the narrow strip in single tape arrangement (Ms) plot was obviously lower than that in the double tapes arrangement (Md) plot, indicating that less sufficient water was supplied under the same condition of irrigation depth, but there was no significant reduction in yield. Mulching had not significant influence on salt accumulation but the drip tape arrangement, under the same condition of irrigation water depth and quality, compared with Md, Ms reduced salt accumulation in root zone and brought about relatively high cotton yield.     

咸水滴灌条件下土壤盐分运动规律

选择新疆尉犁县土壤含盐量较高的当年造林地,利用咸水进行滴灌,比较研究了4个月间不同灌溉量的土壤盐分变化,并对一个灌溉周期内灌溉前及灌溉后168 h时段,距滴头不同距离的土壤剖面盐分运移规律进行观测.结果表明:咸水滴灌,地表积盐现象明显,在0～10 cm土壤湿润区内部可形成一个低盐区,适宜林木根系发育;灌溉周期相同,单次灌量越大,盐分会被淋洗的更远,滴头附近积盐程度越轻;在一个灌溉周期内,盐分先向下和向内移动,后向表层和外侧移动.     

滴灌条件下不同盐生植物对盐渍化土壤的脱盐效果研究

[目的]研究滴灌条件下种植盐生植物对盐渍化土壤的脱盐效果.[方法]在滴灌条件下种植盐生植物海蓬子和盐地碱蓬.[结果]盐生植物对耕作层土壤特别是0 ～ 20 cm土壤盐分影响显著,可有效降低土壤总盐含量以及盐分离子Na+、Cl-和K+浓度,但对土壤pH值影响不明显.种植盐地碱蓬的土壤总盐量下降幅度要高于海蓬子;种植盐地碱蓬土壤Na+、K+的含量下降较明显,而种植海蓬子土壤的Cl-含量明显降低.[结论]滴灌抑盐+生物脱盐模式在改良盐渍化土壤中效果明显,盐地碱蓬可作为较理想的脱盐植物,对于盐渍化土壤的开发利用具有一定的指导意义.     

新疆棉田地下滴灌土壤水盐运移变化规律的研究

为探讨新疆棉田地下滴灌方式地下滴灌下土壤水盐运移的规律,在棉花不同生育期运用烘干法和电导法,从水平方向和垂直方向测定棉田距离滴灌带不同距离的土壤含水量和土壤盐分,结果表明地下滴灌条件下棉花整个生育期土壤含水量的运移规律为:0~35 cm各土层苗期与蕾期较低,盛花期较高,吐絮期又较低,35~55 cm各土层在苗期与蕾期较低,花铃期至吐絮期均较高;土壤盐分含量的变化与土壤含水量的变化刚好相反。     

南疆小麦冬灌水量对土壤水库和分蘖成活情况的影响

由于南疆水资源时空分布不平衡,春旱成为困扰小麦持续高产的问题。从土壤水、灌溉水综合调控的角度,研究了小麦冬灌水量对土壤水库和小麦分蘖过冬存活的影响。结果显示:(1)小麦冬灌时不同的灌水量会形成差别很大的越冬土壤水库,常规灌水量下麦田越冬土壤水库较灌水前减小;(2)土壤水库大小对小麦分蘖越冬成活数量有影响,随着土壤水库增大单位基本苗发育成活的分蘖数提高;(3)综合考虑土壤水库大小、小麦越冬分蘖成活情况和土壤水渗漏等因素,初步确定和田地区沙性土壤小麦冬灌水量以116 m3/667 m2为宜。     

滴灌棉田非生育期春灌温度和灌水量对土壤盐分的影响

【目的】分析非生育期春灌温度和灌水量对土壤盐分的影响,为灌区提供较为合理的非生育期灌水方案。【方法】制定6种棉田灌水方案,开展田间试验,检测不同方案下的土壤盐分含量,分析非生育期春灌的灌水量和温度对土壤盐分的影响。【结果】在设置的三个灌水量2 250、1 800和1 350 m³/hm²方案中,2 250 m³/hm²为较优灌水量;地温5℃,气温12℃时灌水的脱盐效果比地温10℃,气温17℃时灌水的效果要好。【结论】灌水量越多,土壤洗盐效果越好;在相同灌水量下,温度对土壤脱盐效果影响极大;由于试验区蒸发强烈,导致土壤返盐速率很快,春灌时间不宜过早。