半干旱地区海水养殖废水灌溉菊芋效应初探

2004年4~10月,在半干旱的莱州地区布置微区试验,以研究海水养殖废水与微咸水混合灌溉菊芋的作物效应。结果表明:水分临界期淡水灌溉明显促进菊芋茎杆生长,而其它处理茎杆生长受到了不同程度抑制。1∶3,1∶4处理菊芋茎杆的横向生长最快,茎粗分别达到3.0cm和2.97cm;其次为CK1、CK2和1∶2处理,1∶1处理菊芋茎粗最小。未灌溉处理地上部的生物量最高,达到2.92kg/株。CK2次之,而各海水养殖废水与微咸水混合灌溉处理,地上部生物量有所下降,其中1∶3、1∶4处理下降21.6%和17.5%;1∶1和1∶2处理则分别下降26.4%和29.1%。地下部生物量最高,CK2次之,但与其它处理(除1∶4处理)无明显差异;1∶1处理地下部生物量最低。水分胁迫能够促进菊芋茎、叶、根系生长,但限制了块茎的形成和干物质的积累,而低矿化度的海水养殖废水与微咸水混合灌溉促进了菊芋块茎的正常膨大以及干物质的累积,从而取得最高产量。     

莱州湾利用海水资源灌溉菊芋研究

于2002年在半干旱的山东莱州地区,利用海水资源进行了大田灌溉菊芋的试验,结果如下:(1)0～60cm土层内,Na 、Cl-明显地向土壤底层迁移;(2)菊芋的茎部具有明显的贮Cl-、Na 能力,在高比例(海、淡水体积比)矿化水灌溉下菊芋整个植株对K 具有较高的选择吸收性;(3)菊芋地上部和块茎产量在灌溉水中海水比例为30%的情况下,没有减产趋势,在50%海水灌溉下减产幅度分别为37%和32%;(4)利用海水资源对菊芋进行灌溉不影响其块茎中菊糖的含量,菊芋块茎中菊糖含量范围为40%～65%。     

长期咸水滴灌对灰漠土理化性质及棉花生长的影响

为揭示长期咸水滴灌对灰漠土物理化学特性及棉花生长的影响,研究了咸水灌溉11 a后土壤盐分、容重、水力特性、棉花耐盐生理特征及产量.试验设置3个灌溉水盐度水平:0.35 dS·m-1(淡水)、4.61 dS·m-1(微咸水)和8.04 dS·m-1(咸水).研究表明:与淡水灌溉相比,微咸水和咸水灌溉显著增加土壤容重、盐分...     

膜下滴灌棉花耐盐预警值的研究

以不同次生盐渍化膜下滴灌棉田为对象,研究次生盐渍化对棉花生长发育的影响,并以此为基础探讨其状态预警问题.结果表明:在各生育期,土壤盐度与株高、干物质重、叶面积指数均呈极显著的负相关关系.低土壤盐度对棉花生物量和产量不会产生影响,说明棉花具有一定的耐盐性.籽棉产量的降低主要是由于土壤盐度的升高使棉花单株结铃数明显减少造成的.不同生育期棉花耐盐程度不同,各棉田的警度随着生育期的进行有逐渐减轻的趋势;0.6 dS/m以下的土壤盐度在各生育期都不会对棉花生长造成较大危害,2.8 dS/m以上的土壤盐度在前期更易对棉花生长造成严重影响,到吐絮期2.8 dS/m左右的盐度已不能对棉田造成较大危害.     

海冰水灌溉对土壤盐分和玉米产量的影响

渤海海冰盐度一般在4~11 g/kg之间,经处理可以作为农业灌溉用水。采用不同盐度(1、3、5 g/kg),不同灌溉水量(4509、00、1 350 m3/hm2)的海冰水进行农田微区试验。结果表明:(1)灌溉处理的试验终期的土壤盐度没有显著的增加,在降水的淋溶下可以保持在较低水平;在第二年返盐高峰时土壤盐分也保持在较低水平。(2)玉米籽粒产量随灌溉海冰水的盐度增加而轻微下降,在低盐度(1 g/kg)的处理时,随灌溉水量的增加而增加,在高盐度(3、5 g/kg)时则相反。玉米秆的产量也呈现出和籽粒相似的规律。     

艾比湖自然保护区盐生植物的分布及其水分利用效率

以艾比湖自然保护区内盐生植物为研究对象,采用野外调查与室内实验相结合的方法,揭示土壤盐含量与盐生植物数量分布及水分利用效率之间的关系。结果表明:(1)采集的9个土壤样地可划分成高、中和低盐度区3种类型;(2)拒盐和泌盐植物的丰富度在土壤盐分梯度上没有显著性差别,稀盐植物的丰富度在高盐度区显著高于中、低盐度区(高中低)(P0.05),拒盐、泌盐和稀盐植物的多度在中盐度区均显著高于高、低盐度区(中高低)(P0.05)。在高、中盐度区,盐生植物的多度和丰富度为:稀盐拒盐泌盐植物;相反,在低盐度区,泌盐拒盐稀盐植物;(3)稀盐和泌盐植物的δ~(13)C值在盐分梯度上存在显著性差异(P0.05);拒盐植物的δ~(13)C值在土壤盐分梯度上无显著性差异(P0.05);(4)中盐度区泌盐植物的δ~(13)C值显著低于拒盐和稀盐植物外(P0.05),在高盐度和低盐度区,3种盐生植物的δ~(13)C值没有显著性变化(P0.05);(5)拒盐、稀盐和泌盐植物的脯氨酸、可溶性蛋白质、可溶性糖和硝酸还原酶活性在3个土壤盐分梯度上均无显著性差异(P0.05);(6)同土壤盐分条件下,除可溶性蛋白质、可溶性糖和硝酸还原酶活性在少数情况下3种盐生植物间有差别外,大多情况下植物抗胁迫生理指标在3种盐生植物间没有显著性变化(P0.05);(7)抗胁迫生理指标、δ~(13)C值、多度和丰富度之间的关系随盐生植物种类迥异。综合以上分析,盐生植物在土壤盐分梯度上的分布、水分利用效率均与盐生植物的类型有关,其变化可能受内部生理调节、盐分的运输规律等多种因素的综合影响。     

滨海盐碱地“台田-浅池”改良措施的研究进展

滨海盐碱地是我国一类重要的土地资源,但其特殊的土壤理化性质严重制约植物的生长。长期以来,国内外学者已对我国滨海盐碱土的理化性质和水盐运动进行了深入研究,并据此提出了相应而有效的滨海盐碱土物理、化学、生物方面的改良措施。近年来,“台田-浅池”型综合土地利用模式（挖土成池,筑土为台,台田种植,浅池养殖）是我国一种新型的滨海盐碱地综合改良模式,它集合了国内外优秀的滨海盐碱地改良方法,并创新性的将新型水资源---海冰水应用在滨海盐碱地的改良利用中,目前已经在土地利用变化和优化配置、台田修筑、盐碱地改良、土壤水盐运动、海冰水灌溉、作物种植、耐盐植物筛选、咸淡水混合养殖等多方面进行了综合利用试验,并在降低土壤盐度,增强土壤肥力,提高作物产量,增加经济效益等方面取得了良好的效果。未来,提高土壤肥力、选择适宜作物品种、使用风能太阳能等清洁能源、协调生态发展、实现滨海盐碱地可持续利用是“台田-浅池”综合利用模式研究的新方向。     

不同灌溉量对春小麦生长及产量构成的影响

在大田条件下,研究不同灌溉量对干旱半干旱地区春小麦生长及产量构成的影响,以期为春小麦节水灌溉提供理论依据.结果表明,灌溉量为4 286 m3/hm2(常规对照灌溉量4 495 m3/hm2,减少209 m3/hm2)未对春小麦生长及产量造成不利影响;灌溉量为3 6 70 m3/hm2(比常规灌溉量减少825 m3/hm2)对春小麦生长产生了部分不利影响,但没有使产量明显降低;灌溉量为3 060 m3/ hm2(比常规对照减少1 435 m3/hm2)使春小麦株高降低、干鲜重减少、产量明显减少,对春小麦生长及产量产生明显不利影响.综合考虑,正常年份宁夏引黄灌区春小麦适宜灌溉量在3 900～4 200 m3/hm2,尚有200～5 00 m3/hm2的节水潜力.     

保水剂对宁南山区马铃薯产量及土壤水分利用的影响

在宁南半干旱黄土丘陵区探讨大田施用PAM、沃特保水剂对马铃薯产量和土壤水分利用的影响.结果表明:PAM、沃特均可促进马铃薯生长、提高块茎产量,其中PAM 9.0 kg/hm2(P3)和沃特15 kg/hm2(W1)、沃特30 kg/hm2(W2)、沃特60 kg/hm2(W3)处理马铃薯生物量和块茎产量显著高于CK(P<0.05),增产效果最明显.幼苗期、块茎形成期和块茎生长期各处理耗水量无显著差异,淀粉积累期CK耗水量极显著高于施用保水剂处理(P>0.01).保水剂处理耗水量随着马铃薯生物量的增加而增大,降雨对土壤水分的补充随生物量的增大而减少.利用有序聚类分析得出,淀粉积累期降雨对土壤0～60 cm的水分储量有明显的补充,施用PAM和沃特两种保水剂,0～140 cm各层土壤储水量恢复相近,而140 cm以下土层沃特的恢复能力优于PAM,平均每20 cm土层储水量较PAM高6.2 mm.随着PAM施用量的增加水分利用效率提高,沃特保水剂则相反.沃特15 kg/hm2和PAM 9 kg/hm2处理水分利用效率、水分产出效率最高.通过对马铃薯产量和水分利用特征得出,PAM的用量为9 kg/hm2、沃特15 kg/hm2为最佳用量.     

不同盐度施氮水平下盐地碱蓬幼苗生长及光合色素含量分析

以盐生植物盐地碱蓬为试验材料,以NaCl模拟不同盐度环境,采用盆栽试验方法研究了不同盐度施氮水平下,盐地碱蓬幼苗生长及光合色素含量的变化。结果表明：① 轻度、中度及重度盐环境下施适量氮（0.3 g·kg^-1、0.6 g·kg^-1、1.2 g·kg^-1）可以促进盐生植物盐地碱蓬幼苗的生长,在高盐高氮条件下,施氮对盐地碱蓬幼苗生长的影响与盐度有关;② 不同盐度环境下施氮所能达到的最高干物质产量及最高施氮限量也不同,表现为轻度盐环境（含NaCl 2.5 g·kg^-1）＞中度盐环境（含NaCl 5 g·kg^-1）＞重度盐环境（含NaCl 7.5 g·kg^-1）,随着施氮量的增加氮素生产力均表现出下降的趋势;③ 同一施氮水平下,随着盐度的增加盐地碱蓬幼苗叶片渗透势显著下降,并且同一盐度环境下,随着施氮量的增加叶片渗透势也呈现出下降趋势,渗透调节能力增大;④ 3个盐度环境下,施氮均可增加盐地碱蓬幼苗叶片光合色素含量,从而提高光合效率,增强幼苗对盐渍环境的适应能力。     

Candidate halophytic grasses for addressing land degradation: Shoot responses of Sporobolus airoides and Paspalum vaginatum to weekly increasing NaCl concentration

In many arid and semiarid regions worldwide, high levels of soil salinity is a key driver of land degradation, as well as a key impediment to re-establishing plant cover. Combating land degradation and erosion associated with soil salinity requires experimental determination of plant species that can grow in soils with high levels of salinity and can be used to re-establish plant cover. Herein, we evaluated the responses of untested candidate cultivars of two halophytic grass species to high soil salinity: alkali sacaton (Sporobolus airoides Torr.) and seashore paspalum (Paspalum vaginatum Swartz). We evaluated the growth responses of both species in a greenhouse under control (no-salt) and various levels of NaCl salinity (EC 8, 16, 24, 32, 40, and 48?dSm^?1) using Hoagland solution in a hydroponics system in a randomized complete block design trial. At all salinity levels, sacaton grass had a greater shoot height, shorter root length, lower shoot fresh and dry weights, and poorer color and general quality compared to seashore paspalum. The shoot fresh and dry weights of both grasses were greatest at the low to medium levels of salinity, with the greatest response observed at EC 16?dSm^?1. At the highest level, salinity significantly reduced shoot fresh and dry weights of both grasses. Because growth of both halophytic species exhibited high tolerance to salinity stress and were stimulated under low to medium levels of salinity, both species could be considered suitable candidates for re-establishing plant cover in drylands to combat desertification and land degradation associated with high levels of soil salinity.     

Growth and chemical composition of soybeans as affected by trifluralin and soil salinity

The combined effects of 0, 1 and 2 ppm trifluralin and five soil salinity levels (0.35, 2, 4, 6 and 8 mS/cm) on growth and chemical composition of soybeans [Glycine max (L.) Merr.] were studied in a glasshouse experiment. Analyses of variance indicated that the interaction of soil salinity and trifluralin was not significant for root and top dry weights and root nodulation. Root dry weight was not affected by trifluralin, whereas 2 ppm trifluralin significantly reduced top dry yield and root nodulation. Shoot and root yields and root nodulation were reduced with increasing soil salinity. Trifluralin at 1 ppm significantly decreased P concentration and at 2 ppm substantially increased N concentration. Moreover, there was a general trend of an increase in N concentration and a decrease in P concentration with salinity. The concentration and uptake of Cl and Na increased with increasing soil salinity. Probably large accumulations of Cl and Na and/or water stress caused by high salinity were responsible for growth reductions in salinized media.     

伊犁绿洲土壤盐渍化与浅层地下水水化学特征分析

根据2009年伊犁河流域土壤盐分与地下水条件的监测和取样分析资料,运用相关分析法与主成分分析法,对伊犁河流域土壤盐分与地下水埋深、矿化度、电导率、p H值与主要离子之间的关系进行了分析。结果表明:1研究区土壤盐分垂直分布呈现强烈表聚性;研究区内58.18%地下水样为淡水,40.00%为微咸水,1.82%为咸水,地下水矿化度平均值为2.50 g·L-1左右,属于微咸水;研究区地下水矿化度、电导率与主要离子组成呈现强烈的空间变异性。2研究区垂直河道方向的各采样线土壤盐分与地下水矿化度的变化趋势基本相似;地下水埋深与矿化度受到灌区农业活动的影响,导致研究区土壤次生盐渍化。3主成分分析结果表明,影响研究区土壤含盐量的地下水环境因子可以归纳为地下水矿化度、EC、Cl-、Mg2+、Na+与地下水埋深。     

Detecting soil salinity with arid fraction integrated index and salinity index in feature space using Landsat TM imagery

Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context(vegetation cover,moisture,surface roughness,and organic matter)and the weak spectral features of salinized soil.Therefore,an index such as the salinity index(SI)that only uses soil spectra may not detect soil salinity effectively and quantitatively.The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance.The normalized difference vegetation index(NDVI),as the most common vegetation index,was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas.Therefore,the arid fraction integrated index(AFII)was created as supported by the spectral mixture analysis(SMA),which is more appropriate for analyzing variations in vegetation cover(particularly halophytes)than NDVI in the study area.Using soil and vegetation separately for detecting salinity perhaps is not feasible.Then,we developed a new and operational model,the soil salinity detecting model(SDM)that combines AFII and SI to quantitatively estimate the salt content in the surface soil.SDMs,including SDM1 and SDM2,were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFII and SI using a scatterplot.The SDMs were then compared to the combined spectral response index(COSRI)from field measurements with respect to the soil salt content.The results indicate that the SDM values are highly correlated with soil salinity,in contrast to the performance of COSRI.Strong exponential relationships were observed between soil salinity and SDMs(R2>0.86,RMSE<6.86)compared to COSRI(R2=0.71,RMSE=16.21).These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively provide information on soil salinity.     

干旱荒漠区新垦绿洲土壤改良措施对盐分变化的影响研究——以克拉玛依农业开发区为例

针对克拉玛依新垦绿洲土壤粘重、板结、有机质含量低的实际情况,分别以有机肥、粉煤灰、草炭和沙作为土壤改良材料,测定了不同改良措施对土壤盐分动态变化的影响。研究表明:施肥改良措施对土壤盐分的表聚具有明显的抑制作用。其中,粉煤灰对土壤的改良效果最好,在灌溉的条件下可以将表土层盐分充分淋洗到土壤下层,脱盐率达50%;掺沙次之,有机肥在一定程度上也降低了土壤表层的盐分;草炭与对照措施下土壤的盐分变化规律基本相似,脱盐率大致相同。由此表明,草炭对土壤基本上没有改良压盐的作用。     

黄河三角洲农田灌溉前后土壤盐分时空变异特征研究

分别采用传统统计学和地统计学方法,定量分析了灌溉前、后黄河三角洲田块尺度下不同深度土层含盐量的空间变异性并分析空间分布特征。结果表明:除灌溉前0～10cm土层土壤含盐量呈强变异性外,其余各土层含盐量均表现为中等变异强度;灌溉前土壤盐分主要积聚在0～ 10 cm和40～60cm土层,灌溉后主要积聚在40～60 cm土层;灌溉使得0～10 cm和10 ～ 20 cm土层土壤含盐量降低,脱盐效果较好;除灌溉后0～10 cm土层的土壤盐分含量呈现弱空间相关性之外,其它土层均呈现强空间相关性;灌溉后与灌溉前相比,除40～60cm层土壤含盐量外,其余各土层土壤含盐量明显降低、土壤含盐量的等值线密集程度减弱、空间分布趋势明显变平缓;灌溉前各土层土壤含盐量高值区均分布在试验区中部偏北,而低值区则分布在试验区西北角,灌溉后除0～ 10cm土层土壤含盐量高值中心分布在试验区中北部外,其余各土层均分布在试验田块的中南部或中部,而低值中心的空间分布规律相似,主要分布在试验田的北部。     

Spatial Variation of Soil Urease Activity Around Irrigated Date Palms

The inhibition of soil urease activity by the accumulation of soluble salts in a coastal region of the Sultanate of Oman susceptible to salinization was investigated . Soil transects around six individual date palms (Phoenix dactylifera L.) growing on commercially managed farms were intensively sampled and assayed for soil urease activity . Activities ranged from 0 . 10 to 39 . 85 mu g NH + 4 released g 1 soil h 1 at 37 C . Soil collected from within 70 cm of the palms h ad a higher urease activity than soil from a distance 1 . 5 m . Multiple regression analysis showed that more than 75 % of the variance in soil urease activity was accounted for by soil physi cochemical properties , except in sandy soils low in organic carbon ( C ). The soil properties most closely associated with urease activity were soil organic C , salinity , and texture . A scattergram of urease activity against salinity showed high variabil ity in activity at low salinities ( 0 . 5 dS m 1 in 1 :5 soil to water extracts ) and severe inhibition at salinity values 12 dS m 1. In nonsaline soils , variation in urease activity was closely associated with variations in organic C and clay con tents , whereas at saline conditions , only soil salinity was significantly associated with urease activity .     

Soil Microbial Biomass Under the Canopy of Coastal Sand Dune Shrubs

Coastal sand dunes are affected by seasonal fluctuations in salinity due to seawater spray and precipitation. Salinity was found to be very high in summer soil samples and was about 15-20 times lower in the preceding rainy winter. High microbial biomass values of 234.6 and 173.1 mugC g-1 dry soil were found under Artemisia monosperma and Retama raetam, respectively, even at elevated salinity. The metabolic quotient for CO2, which may serve as an indicator for changes in microbial diversity or environmental stress, was unexpectedly high (58.5 and 48.8 mug mg-1 d-1 under A. monosperma and R. raetam, respectively) in low-saline samples from the winter when compared to the summer (a maximal value of 20 mug mg-1 d-1), probably indicating a shift in community structure. It may be concluded that even under hostile conditions in poor sandy soils and with high salinity the presence of perennial shrubs creates favorable niches for microorganisms and affects their activity.     

Effects of water salinity and N application rate on water- and N-use efficiency of cotton under drip irrigation

In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the effect of irrigation water salinity and nitrogen（N） application rate on soil salinity and cotton yield under drip irrigation during the 2011 and 2012 growing seasons. The experimental design was a 3×4 factorial with three irrigation water salinity levels（0.35, 4.61 and 8.04 dS/m） and four N application rates（0, 240, 360 and 480 kg N/hm2）. Results showed that soil water content increased as the salinity of the irrigation water increased, but decreased as the N application rate increased. Soil salinity increased as the salinity of the irrigation water increased. Specifically, soil salinity measured in 1：5 soil：water extracts was 218% higher in the 4.61 dS/m treatment and 347% higher in the 8.04 dS/m treatment than in the 0.35 dS/m treatment. Nitrogen fertilizer application had relatively little effect on soil salinity, increasing salinity by only 3%–9% compared with the unfertilized treatment. Cotton biomass, cotton yield and evapotranspiration（ET） decreased significantly in both years as the salinity of irrigation water increased, and increased as the N application rate increased regardless of irrigation water salinity; however, the positive effects of N application were reduced when the salinity of the irrigation water was 8.04 dS/m. Water use efficiency（WUE） was significantly higher by 11% in the 0.35 dS/m treatment than in the 8.04 dS/m treatment. There was no significant difference in WUE between the 0.35 dS/m treatment and the 4.61 dS/m treatment. The WUE was also significantly affected by the N application rate. The WUE was highest in the 480 kg N/hm2 treatment, being 31% higher than that in the 0 kg N/hm2 treatment and 12% higher than that in the 240 kg N/hm2 treatment. There was no significant difference between the 360 and 480 kg N/hm2 treatments. The N use efficien