Determining the Optimum Inflow Rates for Micro-flood Irrigation on the Tukulu Soil

The performance of micro flood irrigation （MFI） under different inflow rates was evaluated on 90 m closed ended furrows in the South African Tukulu soil. A single irrigation was used to characterise the surface and subsurface soil water distribution from the 20, 40, 80 and 160 L/min inflow rates treatments. Neutron access tubes were installed to a depth of 1 m at every 10 m distance interval starting at 5 m from the furrow inlet. Soil water content measurements were taken using the WaterMan neutron water meter. The HYDRUS-2D software was also used to provide insight on irrigated furrows soil water content and subsurface water distribution. The 20 L/min produced a stream flow that could advance up to the 60 m furrow distance. The stream flow from the rest of the inflow rates were able to reach the furrow end with the 180 L/min recording the fastest advance time of 23 min. The 20 L/min and 40 L/min had recession period of less than 7 min while the 80 L/rain and 160 L/min lasted more than an hour. Distribution uniformity （DU） at longer furrow distances was the highest from the 80 L/min and 160 L/min with the 20 L/min and 40 L/min recorded similar performances at shorter distances. The 40 L/rain was one of the smaller inflow rates that recorded the highest DU of 0.96 for the generated average infiltrated depth of the 30 m long furrow and therefore should be adopted for furrow distances of less than 60 m on the Tukulu soil.     

Effect of Introduction of Irrigation on Technical Efficiency of Olive-Growing Farms in Tunisia

This paper investigates the effect of the introduction of an irrigation technique on the technical efficiency of olive production in a sample of olive-growing farms in Tunisia, estimating the Cobb-Douglas form of stochastic frontier production function. Results indicate that estimated technical efficiency scores vary, ranging from a minimum of 3.0% to a maximum of 91.2% with a mean value of 61.2%. This suggests that olive-growing farms in Tunisia can increase their production on average by 38.8% through more efficient use of technology and inputs. The introduction of irrigation increased productivity, however, the estimated technical efficiency of irrigated olive farms varies across farms and they are less efficient than non-irrigated farms. This finding suggests that the introduction of irrigation to non-irrigated farms has the potential to increase production levels, however, the current production of the irrigated farms is far from the ＂best practice frontier＂ that realizes maximum possible output. Accumulation of experience and knowledge by farm owners and selection of olive cultivar significantly contribute to improving technical efficiency.     

Analysis of Soil Water Dynamics in a Tropical Rain Forest Soil （Arinic lixisol）, Abeokuta,Nigeria

Soil water dynamics in the dominant lwo soil series （Arinic lixisol） were evaluated at the Federal University of Agriculture, Alabata, Abeokuta, Nigeria. Field capacity, infiltration and water retention characteristics were evaluated in situ for a period of 161 d in the dry season for two root zone depths. Results show that the Iwo soil series has a field capacity ranging from 2.6%-5.5% at 0-45 cm and 45-90 cm root zone depths, respectively. The soil is quick draining with high infiltration rate and very poor water retention capacity confirming that the soil will require a short irrigation interval of about 2-3 d since available water for plant growth in predominantly sandy soils ranges between 2%-8%. Based on the foregoing, sprinkler irrigation is best suited for the lwo soil series, it should, however, be noted that the water application rate must be less than the infiltration rate of the soil in order to prevent surface ponding and runoff. A multivariate model relating soil moisture content with soil moisture tension and soil temperature calibrated within the study had very low model accuracy of 56% and 45% for the two root zone depths, respectively, implying the need for further studies.     

Effects of Chlorination on Soil Chemical Properties and Nitrogen Uptake for Tomato Drip Irrigated with Secondary Sewage Effluent

Chlorination is usually an economical method for treating clogging in drip emitters during sewage application. Appropriate assessment of the responses of soil and crop is essential for determining an optimal chlorination scheme. During 2008 to 2009, field experiments were conducted in a solar-heated greenhouse for tomato drip irrigated with secondary sewage effluent, to investigate the influences of chlorine injection intervals and levels on soil chemical properties and nitrogen uptake. Injection intervals ranging from two to eight weeks and injection concentrations ranging from 2 to 50 mg L-1 were used. A salinity factor and a nutrient factor were extracted from the pool of the nine soil chemical constituents using factor analysis method. The results demonstrated that chlorination practices increased the residual Cl in the soil, resulting in an increased salinity factor, especially for the frequent chlorination at a high injection concentration. Chlorination weakened the accumulation of nutrients factor in the upper soil layer. Nitrogen uptake of the tomato plants also was inhibited by the increased salinity in the upper soil layer caused by high chlorination levels. In order to reduce the unfavorable effect on soil chemical properties and nitrogen uptake, chlorination scheme with concentrations of lower than 20 mg L-1 was recommended.     

调亏灌溉对滴灌核桃树土壤温度及产量的影响

【目的】研究调亏灌溉对干旱区滴灌核桃树土壤温度的影响,分析最有利的灌水模式。【方法】研究3个不同灌水量(正常灌水ET_C、轻度缺水75% ET_C和中度缺水50% ET_C),7个处理不同程度水分亏缺对土壤温度、SPAD值、果实体积和产量的影响。【结果】调亏度越大,土壤温度越高,在调亏的生育期内有增温的效果。油脂转化期(Ⅴ)之前,随着土层深度的增加,土壤温度在降低,表现为5 cm>10 cm>20 cm>30 cm>40 cm。在油脂转化期(Ⅴ)和成熟期(Ⅵ)时,开花坐果期+果实膨大期(Ⅱ + Ⅲ)进行中度缺水土壤温度最高。开花坐果期(Ⅱ)调亏时,灌前与灌后的土壤温度差最小。调亏灌溉促进SPAD值的增加,在开花坐果期(Ⅱ)进行调亏果实体积最大。开花坐果期(Ⅱ)轻度缺水获得最高产量为4 150.70 kg/(hm²),水分利用效率(WUE)最高,达到9.25 kg/(hm²·mm)。【结论】结合土壤温度、果实体积、产量及WUE情况,开花坐果期(Ⅱ)轻度缺水是最有益处的处理。     

Positive Impact of Deficit Irrigation on Physiological Response and Fruit Yield in Citrus Orchards： Implications for Sustainable Water Savings

Different strategies of deficit irrigation based on water stress dynamics were applied in an 11-year old citrus trees （Citrus sinensis L. Osb. cv. Navelina） grafted on carrizo citrange （Citrus sinensis L. Osb.×Poncirus Trifoliata L. Osb.）. The trees were subjected to two irrigation treatments： （1） sustainable deficit irrigation （SDI） established with water supplied at 60% of the crop evapotranspiration （ETc） and （2） low frequency deficit irrigation （LFDI） irrigated according to the plant water status. In addition, a treatment irrigated at 100% of ETc was included as a control （C）. Midday stem-water potential （ψUstem）, stomatal conductance （gs）, and micrometric trunk diameter fluctuations were measured during the maximum evapotranspirative demand period to evaluate the plant-water status, and establish the main relationships among them. The seasonal pattern of the studied variables had a behavior consistent with the contributions made by the volumes of applied irrigation water. Especially significant close relationships of ψstem with gs, and with the maximum daily shrinkage （MDS） were found. The lowest ψstem and gs values were registered in the treatments with lowest irrigations levels （SDI and LFDI）, being the MDS was significative higher than in the C treatment. The LFDI showed an oscillating behavior in these parameters, which was on line with the supplied irrigation restrictions cycles. Thus, according to the results of the present experiment the physiological stress indexes based in MDS or ψstem allow establishing different irrigation restriction cycles, encouraging important water saving without significant impact on yield and the fruit quality parameters.     

Fruit Yield and Quality,and Irrigation Water Use Efifciency of Summer Squash Drip-Irrigated with Different Irrigation Quantities in a Semi-Arid Agricultural Area

Fruit yield, yield components, fruit mineral content, total phenolic content, antioxidant activity and irrigation water use efifciency （IWUE） of summer squash responses to different irrigation quantities were evaluated with a ifeld study. Irrigations were done when the total evaporated water from a Class A pan was about 30 mm. Different irrigation quantities were adjusted using three different plant-pan coefifcients （Kcp, 100% （Kcp1）, 85% （Kcp2） and 70% （Kcp3））. Results indicated that lower irrigation quantities provided statistically lower yield and yield components. The highest seasonal fruit yield （80.0 t ha-1） was determined in the Kcp1 treatment, which applied the highest volume of irrigation water （452.9 mm）. The highest early fruit yield, average fruit weight and fruit diameter, length and number per plant were also determined in the Kcp1 treatment, with values of 7.25 t ha-1, 264.1 g, 5.49 cm, 19.95 cm and 10.92, respectively. Although the IWUE value was the highest in the Kcp1 treatment （176.6 kg ha-1 mm-1）, it was statistically similar to the value for Kcp3 treatment （157.1 kg ha-1 mm-1）. Total phenolic content and antioxidant activity of fruits was higher in the Kcp1 （44.27 μg gallic acid equivalents （GAE） mg-1 fresh sample） and in the Kcp2 （84.75%） treatments, respectively. Major （Na, N, P, K, Ca, Mg and S） and trace （Fe, Cu, Mn, Zn and B） mineral contents of squash fruits were the highest in the Kcp2 treatment, with the exception of P, Ca and Cu. Mineral contents and total phenolic content were signiifcantly affected by irrigation quantities, but antioxidant activity was not affected. It can be concluded that the Kcp1 treatment was the most suitable for achieving higher yield and IWUE. However, the Kcp2 treatment will be the most suitable due to the high fruit quality and relatively high yield in water shortage conditions.     

不同水分处理方式对玉米生长发育及产量的影响

为制定玉米节水高效灌溉制度,推动节水农业的发展,采用试验测桶研究了黔中地区玉米产量与水分的关系。结果表明,玉米生育期内平均水分利用效率为1.32 kg/m3,产量和灌溉水量之间的函数式y=-0.000 3x2+3.794x-2 792.7,产量与耗水量之间的函数关系式y=-0.000 6x2+7.215 4x-13 286;水分亏缺的敏感指数以抽穗-灌浆期最高,为0.178,其次是拔节-抽穗期,为0.164。     

滴灌模式对苹果光合特性、产量及灌溉水利用的影响

【目的】 探明黄土区苹果优质高效生产的滴灌模式。【方法】 该研究以8年生寒富苹果树为研究对象,试验设3种滴灌方式：分根交替滴灌（ADI）、单管滴灌（UDI）和双管滴灌（BDI）,及3个灌水梯度：高水（W1）、中水（W2）和低水（W3）,采用正交试验设计,共9个处理。研究滴灌方式与灌水处理对苹果冠层、光合、外观品质、产量及灌水利用效率的影响。【结果】 与W1相比,减少灌水量显著减少叶面积指数、叶倾角和丛生指数（P<0.05）。与单管滴灌相比,分根交替处理显著增加叶面积指数（P<0.05）,显著降低叶倾角与丛生指数（P<0.05）。在果实膨大期（DAF=80 d）,ADI-W2处理的净光合速率、羧化效率和叶片瞬时水分利用效率达到最大值。苹果叶片11：00的净光合速率、蒸腾速率、气孔导度和羧化效率随开花后天数（DAF）增加呈先增加后减小的趋势。各水分处理下苹果叶片净光合速率日变化呈“M”型规律,ADI处理净光合速率“午休”现象不明显,各处理的叶片瞬时水分利用效率(除ADI-W2外）处理峰值均出现在上午10：00,ADI-W2处理推迟了峰值的时间,其叶片瞬时水分利用效率的日均值为各处理的最大值（3.22 μmol·mmol^-1）。ADI与W2组合能够提高产量,在两年内,ADI-W2处理的苹果硬度（9.09 kg·cm^-2）、果形指数（0.88）、大果率（63.46%）、单果重（224.12 g）和产量（33 010.15 kg·hm^-2）均最大,ADI与W3组合能够提高灌溉水利用效率,ADI-W3处理灌溉水利用效率（36.21 kg·m^-3）最高。【结论】 运用综合评分法得到ADI-W2处理为最优组合,因此黄土区苹果节水增产应采用中水量分根交替滴灌的方式。     

Parameters for Use of BEWAB＋ Programme to Schedule Irrigation of Pea （Pisum sativum L,）

A large portion of irrigation farmers make use of subjective （intuition） irrigation scheduling methods as supposed to objective or scientific irrigation scheduling methods, which need to be changed. The BEsproeiingsWAterbestuursprogram （BEWAB＋） irrigation scheduling programme is based on the water balance equation and needs： （1） a crop production function; （2） a relative consumptive water demand curve and （3） an allowable depletion subroutine. The objective of this paper was to describe research aimed at obtaining information on （1） and （2） for pea and also to describe the effect of water application on yield and water use of pea. BEWAB＋ uses this information to estimate the daily irrigation water requirements for a particular soil-crop-atmosphere system under irrigation. A field experiment, based on published line-source irrigation methodology, was conducted on a 3 m deep loamy fine sand Bainsvlei or Ustic Quartzipsamment soil near Bloemfontein （26°08′S; 29°01′E） in South Africa. Results showed that there is a linear relationship of the form Ys = 8.07ET - 249 （r2 = 0.91）, where Ys is the seed yield of pea （kg/ha） and ET is evapotranspiration for the growing season （mm）. The relative consumptive water demand curve is represented by the following third order polynomial function that describes the relationship between time and relative ET for a pea growing season of 120 days： ETrelx = 0.09419646 - 0.01302413x ＋ 0.00059008x2 - 0.00000371x3. ETrelz denotes relative ET and x denotes time in days. A workable balance between practical problem solving and advanced irrigation science has been established with BEWAB＋. Pre-plant irrigation schedules can be made for semi-arid areas with the BEWAB＋ programme using easily obtainable inputs, like target yield, soil depth and soil particle size distribution information.     

亏缺灌溉对机采棉水分利用及产量形成的影响

【目的】 研究膜下滴灌条件下,亏缺灌溉对新疆机采棉产量及水分利用效率的影响。【方法】 在新疆典型机采棉地区,设置5个灌溉量分别为225 mm(Ir₁)、285 mm(Ir₂)、345 mm(Ir₃)、405 mm(Ir₄)和465 mm(Ir₅)。分析亏缺灌溉对棉田耗水特性、干物质积累与分配及棉花产量的影响。【结果】 随着灌溉定额的增加,棉田耗水量呈现递增趋势,提高了棉花生育后期的耗水模系数,使得干物质积累速度较快,快速积累期较长。随着灌溉定额增加,棉铃干物质分配量呈先增加后降低的趋势,Ir₃分配量最大为64.7～82.2 g/株,茎叶占比随着灌溉定额的增加而显著增加,而棉铃占比则显著降低;在棉花产量及水分利用效率方面,单株结铃数、单铃重,随着灌溉定额的增加而显著增加,籽棉产量提高,其中Ir₅处理的皮棉产量比Ir₄仅高了3.80%;随灌溉定额的增加水分利用效率显著降低,其中Ir₁较Ir₂～Ir₅分别高20.59%、34.59%、48.68%和57.93%。【结论】 适当的进行亏缺灌溉,有利于干物质积累量向生殖器官的转移,单株结铃数和单铃重显著提高。在棉花生育期实际的耗水量的基础上,降低12%的灌溉定额,不会显著降低棉花产量,能够获得较高的水分利用效率。     

设施栽培下不同灌溉处理对‘希姆劳特’植株生长及果实的影响

【目的】在水资源短缺问题日趋凸显及设施栽培不断发展的背景下,研究设施栽培条件下水资源的有效利用具有重要的实际意义。研究旨在通过测定、分析不同灌溉处理对鲜食葡萄植株生长及果实品质和产量的综合影响,以期筛选出最优的灌溉模式,为实际生产应用提供理论支撑。【方法】在设施栽培条件下,以鲜食葡萄品种‘希姆劳特’为试材,在葡萄生育期内,分别采用充分灌溉、部分根区干燥、生长前期及生长后期水分亏缺4种不同的灌溉处理对试验植株进行灌溉处理。在果实成熟期,通过分析不同灌溉处理对葡萄植株的副梢发生数量、叶片面积、茎粗、节间距、夏剪重量、粒径大小、穗长、穗重、粒重,果实还原糖、总酸、可溶性固形物、Vc、外观内质评分,叶片初始量子效率、光补偿点、光饱和点、暗呼吸速率、最大净光合速率、水分利用效率,叶水势和果实产量的影响,综合评定获得最优灌溉方式。【结果】与充分灌溉相比,部分根区干燥、前期水分亏缺、后期水分亏缺这3种水分亏缺方式均能降低葡萄植株的副梢发生数量、叶片面积、茎粗、节间距和夏剪重量,也能减少果粒的横径、纵径和粒重以及果穗的穗长和穗重,但提高了果实的还原糖、可溶性固形物和Vc;3种水分亏缺方式对果实的外观内质评分的影响有所差异,部分根区干燥和后期干旱均能显著提高评分,而前期干旱的评分则略低于充分灌溉;不同的水分亏缺方式都降低了葡萄叶片的净光合速率、气孔导度、蒸腾速率,但提高了胞间CO2浓度和水分利用效率;不同形式水分亏缺的条件下,葡萄叶片的初始量子效率、光补偿点和暗呼吸速率均高于充分灌溉,而最大净光合速率则低于充分灌溉;不同形式水分亏缺处理下的叶水势均低于充分灌溉;部分根区干燥和转色前水分亏缺处理均能显著地降低产量,而转色后进行水分亏缺的处理植株产量降低不显著。【结论】水分亏缺可以作为可调节植株营养与生殖生长、促进果实品质和水分利用效率提高的手段,从而提高经济效益和生态效益。葡萄果实转色后水分亏缺的调亏灌溉方式在降低植株长势的同时又能稳定产量,并提高品质和水分利用效率,较其他灌溉方式效果好。     

河套灌区小麦套种向日葵高产节水灌溉制度

针对河套灌区水资源日益紧缺及生产中浪费严重的状况,以当前主要种植模式小麦套种向日葵为对象,以节水和高产为目标,研究不同灌溉时期及灌溉量对小麦套种向日葵经济产量、经济效益及水分利用效率的影响。结果表明,小麦套种向日葵模式下,随着灌水量增加,套种小麦和向日葵及套种作物全生育期总耗水量显著增加,水分利用效率(WUE)却明显下降。套种小麦和向日葵及套种总产量、经济效益均以全生育期浇3水以上处理较高,且处理间产量差异不显著。综合分析得出,河套灌区小麦套种向日葵节水与高产相统一的耗水量为5 000~6 000m3/hm2,全生育期灌3水是小麦套种向日葵实现高产的最佳节水灌溉模式,即小麦拔节期、抽穗期、向日葵开花期灌水3次,每次灌水定额900 m3/hm2,可实现套种小麦经济产量7 000kg/hm2、套种向日葵经济产量2 800kg/hm2以上,全生育期水分利用效率1.0kg/m3以上的目标。     

基于彭曼公式的膜下滴灌棉田灌水量研究

[目的]探讨基于彭曼公式,膜下滴灌棉田不同灌溉量对棉花生长的影响.[方法]基于彭曼公式,设计一定梯度的灌溉处理,结合气象数据和土壤墒情,进行小区试验,分析干物质积累、水分消耗的变化规律,研究干物质积累、产量与耗水量的关系.[结果]棉花各生育时期干物质积累趋势符合“S”型变化规律;基于彭曼公式推荐灌溉量下的土壤储水量基本上处于棉花各个生育期需水的适宜状态,在未对棉花生长造成胁迫的前提下,对土壤水分利用充分,起到了节水的作用;棉田日蒸散量在整个生育时期呈现“低-高-低”的趋势;从干物质日积累和日耗水量拟合结果来看,其2=0.857 8,说明两者之间具有显著的相关性;建立了籽棉产量与灌溉置的回归模型:Y=-0.010 8 x2+ 7.9069 X-1 029.9 R2=0.926 2).[结论]以彭曼公式为理论指导膜下滴灌棉花的灌溉量,基本符合棉花各个生育时期的需水规律.     

不同灌溉方法对保护地土壤磷·钾的影响

研究了连续7年以不同灌溉方法进行灌溉的保护地土壤磷、钾含量及其剖面分布,结果表明:3种灌溉方法下土壤全磷含量随土层深度的增加而递减,10～20 cm层全磷含量达到最大值;速效磷含量总体变化趋势与全磷相似。不同灌溉方法下土壤全钾含量19.013～19.990 g/kg,底层全钾含量明显高于表层;3种灌溉方法下土壤速效钾含量随土层深度增加均呈倒置的“S”形分布,0～20 cm层速效钾含量最高。     

灌水量对限根栽培‘阳光玫瑰’葡萄果实发育与香气物质积累的影响

【目的】通过分析不同灌水量处理对葡萄果实品质指标、香气组分积累、香气物质合成相关基因表达影响的差异，确定灌水模式与鲜食葡萄感官品质形成间的关系，为限根栽培葡萄最佳灌水量的确定提供参考。【方法】以鲜食葡萄‘阳光玫瑰’为试材，设置对照组CK、轻度水分亏缺组（DI-1）、重度水分亏缺组（DI-2），系统比较不同灌水量对葡萄果实外观形态指标、色泽指标、香气组分、萜烯合成相关基因表达水平等的影响。【结果】灌水量影响葡萄果粒的形态与质地特征，采收期时葡萄果粒的纵径并未受到灌水量的显著影响，而亏缺灌溉组果粒的横径、单粒重显著降低（P<0.05）。葡萄果肉的硬度也受到亏缺灌溉的影响而下降，特别是DI-2组，葡萄果肉硬度明显低于其他处理组。亏缺灌溉组DI-1、DI-2的葡萄果实中葡萄糖含量显著高于对照处理，重度亏缺组DI-2果糖含量显著高于其他处理，而轻度的亏缺灌溉（DI-1）并未对葡萄果实的可溶性固形物、可滴定酸含量产生显著影响。亏缺灌溉处理下葡萄果皮中叶绿素、类胡萝卜素含量均出现降低，DI-2组果皮中叶绿素与类胡萝卜素含量的比值最低。灌水量影响到葡萄果实中香气组分的积累，对于萜烯类物质，轻度亏...     

滴灌冬小麦不同滴灌量土壤水分时空分布及冠层特征响应

【目的】研究滴灌冬小麦不同滴灌量土壤水分时空分布及冠层特征响应,为北疆滴灌小麦灌溉制度、滴灌参考指标提供科学理论依据。【方法】采用大田试验,设不同滴灌量处理,研究滴灌后土壤含水量时空扩散特征,离滴灌带不同距离麦行土壤含水量在不同生育期动态变化特征及冬小麦冠层特征响应。【结果】在不同时段0～20 cm表土层土壤水分变化最为剧烈,且随滴灌量的增加而趋于缓和;滴灌方式20～80 cm土层为主要储水层;滴灌量为2 475 m³/hm²滴灌后远离滴灌带麦行土壤水分补充极少,该趋势在表土层更加明显;通过增加滴灌量使水分更早向远管麦行扩散;滴灌量低于3 750 m³/hm²进入扬花期后0～60 cm土层土壤含水量低于15.0%,滴灌量低于3 150 m³/hm²进入灌浆期后0～60 cm土层土壤含水量接近10%,不利于籽粒灌浆和产量形成;总叶面积指数近管麦行较远管麦行高水处理增加9.50%,中水处理增加7.40%,低水处理增加5.72%;不同处理冬小麦倒三节茎粗近管麦行＞远管麦行位置,高水近管麦行为0.210 cm,低水远管麦行为0.182 cm。【结论】北疆冬麦区随滴灌量降低土壤水分明显下降,影响了小麦叶面积、株高、穗长、茎粗等个体生长发育;冬小麦返青后滴灌量3 750 m³/hm²缩小近管麦行、远管麦行位置土壤水分差异,减少远离滴管带麦行土壤水分亏缺对小麦生长发育的影响;滴灌量低于3 150 m³/hm²北疆冬小麦种植区扬花期后0～60 cm土层会出现水分亏缺,显著影响小麦籽粒灌浆和产量形成。     

膜下滴灌不同灌溉定额对土壤水盐分布和春玉米产量的影响

【目的】研究膜下滴灌条件下,不同灌溉定额对土壤水盐时空分布特征、春玉米产量和水分利用效率的影响。【方法】在石羊河流域中游,通过2014-2015两年的灌溉试验,对春玉米生育期设置不同灌溉定额（4 800、4 200和3 600 m³·hm^-2）,测定0-100 cm土层内,土壤水盐时空分布特征,春玉米播种前和收获后土壤全盐量在年内和年际间的变化,春玉米产量及其构成要素。【结果】随灌水定额的增加,0-60 cm土层土壤含水率增加明显,当灌水定额从420 m³·hm^-2增加到480 m³·hm^-2时,春玉米吐丝扬花期0-60 cm土层平均含水率可保持在24.52%以上。在作物需水关键期,当灌水定额为480 m³·hm^-2时,能明显增加深层土壤的蓄水量。当灌溉定额低于360 m³·hm^-2时,灌水量严重不足,土壤水分亏缺明显。在非灌溉期,土壤盐分随水分蒸发在表层耕作土壤中积聚。垂直方向上,在0-40 cm土层发生积盐现象,80-100 cm土层发生脱盐现象。在灌溉期,在垂直方向上,随着灌溉定额的增加,土壤淋洗深度呈增加的趋势。不同灌溉定额条件下,0-20 cm土层土壤发生脱盐现象,40-100 cm土层发生积盐现象。但0-100 cm土层内,土壤全盐量盈亏量总体基本平衡。在水平方向上,土壤盐分以滴头为中心向滴灌带两侧运移,滴头间土壤水分的交汇作用将原耕层的部分盐分迁移到滴灌带的湿润锋边缘处。各处理土壤含盐量均表现为滴灌带间较滴头间增加明显。不同灌溉定额对春玉米穗长、穗行数、行粒数影响不显著,对穗粗、秃尖长、百粒重影响显著。降低灌溉定额可增加春玉米的穗粗和百粒重,但对作物增产无显著作用。【结论】膜下滴灌条件下,春玉米耗水量受灌水量影响,适度水分亏缺能提高水分利用效率（WUE）,但使春玉米产量降低4.45%-20.99%。春玉米全生育期灌水10次,灌水定额为420 m³·hm^-2,灌溉定额为4 200 m³·hm^-2的灌溉制度节水、压盐、增产效益最优。     

密度和灌溉定额对76 cm等行距棉田土壤硝态氮分布和氮素利用的影响

【目的】研究76 cm等行距机采棉种植模式下,土壤硝态氮分布和氮素利用对密度和灌溉定额调控的响应机制,为优化76 cm等行距机采棉栽培模式提供理论依据。【方法】在大田试验基础上,设置3个种植密度(低密度M₁,13.5×10⁴株/hm²;中密度M₂,18×10⁴株/hm²;高密度M₃,22.5×10⁴株/hm²)和灌溉定额[重度亏缺W₁(50%ET_C),3 150 m³/hm²;轻度亏缺W₂(75%ET_C),4 050 m³/hm²;充分灌溉W₃(100%ET_C),4 980 m³/hm²]。研究其对76 cm等行距机采棉田土壤无机氮...     

山东省蔬菜产地灌溉水重金属环境质量分析与评价

[目的]评价山东省蔬菜基地灌溉水重金属环境质量.[方法]对山东省主要蔬菜产地的灌溉水进行了重金属Hg、Cd、As、六价Cr、Pb、Cu和Zn含量的抽样调查分析,并采用单项质量指数与综合质量指数相结合的方法对重金属的环境质量状况进行了评价.[结果]寿光、莱阳、金乡和章丘4个蔬菜产地灌溉水中各重金属的平均含量均远低于《食用农产品产地环境质量评价标准》(HJ332-2006)规定的限值,未发现重金属含量超标现象;4地灌溉水重金属的单项质量指数均小于0.5,综合质量指数分别为0.3178、0.3204、0.2326和0.2607,灌溉水环境质量均为1级.[结论]4个蔬菜产地的灌溉水环境质量属于清洁水平,适宜作为无公害蔬菜的灌溉用水. Abstract： [Objective] The aim was to evaluate heavy metal environmental quality of irrigation water in vegetable farmlands of Shandong Province.[Method]Heavy metal contents including Hg,Cd,As,Cr (+6),Pb,Cu and Zn in irrigation water of main vegetable farmlands of Shandong Province were investigated by randomly sampling,and the environmental quality conditions of these heavy metals were evaluated by methods of single quality index and complex quality index. [Result] The results showed that the average contents of heavy metals in irrigation water of Shouguang,Laiyang,Jinxiang and Zhangqiu were all far lower than the limit values prescribed by "Farmland Environmental Quality Evaluation Standards for Edible Agricultural Products" (HJ332-2006),and no heavy metal was found beyond the limit value in every sample.The single quality indices of the 7 elements in the studied 4 places were all lower than 0.5.The comprehensive quality index of the seven elements was 0.317 8 in Shouguang,0.320 4 in Laiyang,0.232 6 in Jinxiang,and 0.260 7 in Zhangqiu.The environmental quality of irrigation water in the studied four places were all set at the first class. [Conclusion] The environmental quality of irrigation water in the 4 places belonged to clean level and were fit for the plantation of no pollution vegetables.