浅层咸水灌溉对冬小麦和土壤安全性的研究

主要研究利用浅层地下咸水灌溉冬小麦及土壤的安全性。试验采取3因素多水平组合设计,利用2.5~6.0g·L-1不同矿化度咸水对冬小麦进行灌溉。试验结果表明:冬小麦产量与咸水矿化度呈负相关关系r=-0.8542、r=-0.8457,与咸水灌溉量呈正相关关系r=0.7487、r=0.7401。利用小于4.0g·L-1咸水灌溉对土壤具有一定的脱盐作用,咸水矿化度为6.0g·L-1时土壤中的盐分积累达到85.5%。矿化度5.0g·L-1以上的咸水不宜直接灌溉农田,需经淡水与咸水调配后,矿化度在4.0g·L-1以下方可灌溉农田。     

盐碱地施用脱硫石膏对土壤养分及油葵光合特性的影响

通过分析宁夏平罗西大滩不同改良年份盐碱地土壤养分含量,测定油葵(Helianthus annuus)光合日变化曲线、光响应曲线和油葵产量,研究了施用脱硫石膏对盐碱地土壤改良及油葵光合特性的影响.结果表明,在盐碱土壤上施用燃煤电厂脱硫石膏后,土壤电导率、pH值随土壤改良年限增加而逐年下降,土壤有机质含量、碱解氮、有效磷和速效钾则逐年上升.随着土壤改良年限增加,油葵叶片净光合速率、蒸腾速率、气孔导度、胞间二氧化碳浓度均明显下降,气孔限制值和水分利用效率也明显下降(P<0.01).同时,随着改良年限增加,油葵叶片暗呼吸速率、光饱和点和最大净光合速率增加,而光补偿点降低.施用脱硫石膏后油葵盘径、百粒重和产量随土壤改良年限增加也显著提高(P<0.05).因此,施用燃煤电厂脱硫石膏能够显著地改良盐碱地土壤、提高油葵叶片光合能力,从而促进作物生长、提高作物产量.图2表3参29     

膜下滴灌棉田不同土层盐分变化及其对棉花生长的影响

研究选择两种不同盐分含量土壤（中度盐渍化EC25：4-7 dS.m-1和轻度盐渍化EC25：1-4 dS.m-1）,通过对棉田整个生育期的土壤盐分含量测定,研究棉田不同土层盐分变化及其对棉花生长的影响。结果表明：两种不同盐分含量土壤,盐分降幅较大的在0-20、40-80 cm土层为膜下滴灌棉田盐分积聚区。整个生育期土壤盐分变化趋势相似,都表现为土壤盐分前期（现蕾期）快速下降后期有所增加;中度盐渍化和轻度盐渍化棉田的单株干物质积累量差异不显著,单位面积的干物质积累和籽棉产量差异显著,其主要原因是两种盐分土壤棉花的成活率差异较大。     

中新生态城土壤质量现状及改良利用途径

对中新生态城区域内土壤的紧实度、有机质、碱解氮、土壤盐分、酸碱度、地表水、地下水进行了调查取样分析,结果表明该区土壤容重在1.3～1.7g/cm3,有机质含量大多为中等或低水平（5.5～19.1g/kg）,速效氮与土壤有机质含量相关性达显著水平（r=0.98）。盐分垂直分布上表现为果园、农田土壤盐分含量小于1.5g/kg,荒地和水库含量在5.0～6.4g/kg之间,垫土区、养殖池和盐场盐池土壤通体盐分含量高（大于10g/kg）,且存在表聚现象,超出了一般植物生长的极限。土壤酸碱度为7.81～9.05,水库、养殖池、盐场、荒地、沟塘水的矿化度均在10g/L以上,蓟运河水和农田沟渠为5000mg/L～8500mg/L,果园灌溉水的矿化度也在2000mg/L以上,地下水矿化度高,埋藏浅。并针对以上特点提出其土壤改良利用途径和绿化建设模式。     

碱性矿化水淋洗对土壤盐碱化及小麦生长的影响

为探讨不同矿化度的水对土壤盐渍化的影响及相应的淋洗分数,采用土柱模拟方法,以小麦为指示作物,设计1.0 g/L,1.5 g/L两种矿化度,按3750 m3/hm2灌溉量,分一水、二水两种灌次,秋后进行人工淡水淋洗。结果表明,在半干旱气候条件下,开发碱性矿化水灌溉矿化度不宜超过1.5 g/L,否则有引起碱化的危险。干旱期用碱性矿化水灌溉抗旱时,在同等灌水量的情况下,一水灌溉比二水灌溉积盐轻。各种人工淋洗处理比CK洗盐效果好,其中以等量淋洗综合效益最好。     

长期灌溉微咸水的土壤安全性

以天津市静海县朱家村的重壤质浅位厚层夹粘土壤为模拟试验用土,并施用沸石、磷石膏等不同的土壤改良剂,探讨了连续多年灌溉浅层地下微咸水(4.7g/L)对土壤物理性状、化学性状的影响,评估了长期灌溉微咸水的安全性及土壤改良剂对长期灌溉微咸水安全性的影响。     

不同覆盖措施对滴灌盐渍土水盐分布及枸杞生长的影响

宁夏吴忠引黄灌区边缘土壤次生盐渍化严重.为了解滴灌条件下不同覆盖措施对土壤盐分抑制和水分保蓄的效果,以枸杞(Lycium barbarum L.)为试验对象,设置生草覆盖(CG)、黑膜覆盖(HM)、草帘覆盖(CL)和对照(CK,不覆盖)4个处理进行田间试验.在枸杞生长旺季测定土壤水分、盐分、pH及枸杞株径、株高、冠幅等指标.结果表明,物理覆盖(HM和CL)措施能够显著减缓枸杞根区土壤水分耗散,相对CK处理,HM和CL处理土壤质量含水率分别提高29.6%和13.3%,而CG处理土壤含水率无显著提高.经过一个生育期的改良,各处理均由原来的重度盐土转变为中度盐土,HM、CL、CG和CK盐分相对初始值分别降低45.9%、65.2%、47.4%和44.5%;受灌溉水pH的影响,HM、CL、CG和CK的p H从初始值8.03分别增加到8.23、8.17、8.32和8.37.CL处理盐分降低幅度最大,p H增加幅度最小,且与其余处理有显著差异.枸杞株径、株高和冠幅3个生长指标的主成分分析表明,HM和CL处理枸杞生长状况均好于CK和CG处理,且两者之间没有显著差异.综合考虑土壤水分保蓄、盐分抑制效果及枸杞生长情况,该地区盐渍土滴灌植被建设时最佳覆盖措施为草帘覆盖.     

内蒙古阴山北麓马铃薯应用PBAT/PLA全生物降解地膜可行性分析

内蒙古阴山北麓作为内蒙古的粮食主产区,普遍存在农田残膜污染的问题。应用全生物降解地膜是解决农田残膜污染的重要途径,研究聚己二酸对苯二甲酸丁二醇酯/聚乳酸(PBAT/PLA)全生物降解地膜增温保墒性能、降解性能及其产量经济效益对于解决农田残膜污染、保护生态环境、实现农业绿色高质量发展具有重要意义。本研究在马铃薯田开展了3种PBAT/PLA全生物降解地膜、1种普通PE地膜和裸地处理(分别标记为F1、F2、F3、CK和OF)的覆膜栽培试验和降解地膜填埋试验。结果表明,各覆膜处理5—6月土壤温度逐渐升高,7—8月中旬达到作物生育期峰值,随后降低至较低水平。与普通PE地膜相比,3种全生物降解地膜在马铃薯发芽、幼苗期(5—6月)平均土壤温度和土壤含水量未形成显著差异(P0.05),能够满足马铃薯生育前期的生长需求。F1和F2处理在作物覆膜后42—56 d进入诱导期,当季作物收获前均能进入破碎期,降解率为34.21%—42.74%,填埋365 d后基本降解完全;F3处理覆膜后68—84 d进入诱导期,作物收获前降解率为15.47%—28.04%,填埋365—540 d基本降解完全。3种全生物降解地膜作物产量和经济效益分别为49.64—58.53 t·hm~(-2)和1.6×10~4—2.4×10~4 yuan·hm~(-2),未与普通PE地膜形成显著差异(P0.05)。F1和F2处理作物产量和经济效益显著高于裸地(P0.05),其中作物产量分别提高36.85%和38.27%,经济效益分别增加1.43×10~4 yuan·hm~(-2)和1.5×10~4 yuan·hm~(-2);与普通PE地膜相比,作物产量分别增加4.1%和5.18%。根据降解性能和作物产量综合评价,在内蒙古阴山北麓马铃薯种植条件下,F1和F2处理具有较好的降解性能,且在提高作物产量、保护耕地生态环境方面具有较好效果。     

不同灌水频率条件下设施土壤水盐运移特征

为了寻求防治设施土壤次生盐渍化的最适灌水频率,通过野外调查与室内土柱模拟试验相结合的方法,分析了不同灌水频率条件下设施土壤剖面水分、盐分及主要离子的变化特征。结果表明,各灌水处理土壤剖面水分变化主要集中在0~20 cm深度土壤,30和40 cm深度土壤为土壤水分的"过渡层",提高灌水频率可使上部土壤含水量增高至0.36 cm~3·cm~(-3)。当灌水总量一定时,1次·(5 d)~(-1)处理不利于土壤剖面水分蓄存。1次·(5 d)~(-1)处理对土壤剖面盐分的淋洗效果优于其他处理,但其质量中心深度为23.71 cm,存在返盐风险。就1次·(5 d)~(-1)处理而言,除对Na+淋洗率较低外,其余离子的淋洗率均高于其他处理,其中NO_3~-淋洗率可达65.68%。根据各灌水处理土壤剖面中的水盐分布状况,提出1次·(10 d)~(-1)为此次试验条件下的最适灌水频率。     

水稻秸秆沟埋还田对麦田土壤环境的影响

通过大田试验,采用秸秆沟埋还田方式,设置沟埋深度分别为20、30、40、50 cm及对照5个处理,将上季作物秸秆进行全量还田(秸秆沟埋量为2 kg.m-1),研究水稻秸秆沟埋还田对麦田土壤含水量、温度、容重和孔隙度等的影响。结果表明,降水结束后12 d内,沟埋深度20和30 cm处理土壤含水量(与埋草沟边水平距离10 cm处)显著下降(P<0.05);而沟埋深度40和50 cm处理土壤含水量(与埋草沟边水平距离10 cm处)与对照差异未达显著水平。埋草沟秸秆下层土壤温度变化较小,秸秆对下层土壤具有保温作用;除沟埋深度20 cm处理外,其他不同沟埋深度处理均能明显降低秸秆上层土壤容重,增加土壤总孔隙度,使耕层土壤疏松。     

内蒙古河套灌区秋浇对不同类型农田土壤盐分淋失的影响

秋浇是河套灌区传统的秋后淋盐、春季保墒的一种特殊灌溉制度 ,秋浇对不同类型农田盐分损失影响的试验结果表明 ,秋浇前白菜地土壤含水率最高 ,向日葵地最低 ,秋浇后 5种农田土壤含水率均较高 ,且彼此间无显著性差异。秋浇后不同土壤剖面盐分的损失量按照表层 (0～ 40cm)、中层 (40～ 80cm)、深层 (80～ 1 2 0cm)依次递减(向日葵地除外 )。不同农田的盐分淋失量按照白菜地、向日葵地、玉米地、小麦 -玉米地、小麦地依次递减。非生长季灌溉下 ,农田土壤 0～ 1 0 0cm土层中盐分的淋失量与土壤储水量的增加量 (灌溉前土壤含水率 <2 50 g·kg- 1 ,r =0 .990 2 )密切相关 ,但与灌溉前土壤盐分初始含量无显著性关系     

盐碱草原土壤特性及生物量空间异质性研究

土壤盐分是土壤特性中最活跃和复杂的一部分。受土壤性质、气象、地形、地下水文及长期地球化学过程等自然条件和耕作、灌溉等人类活动因子的影响,土壤水分、盐分的变异状态在一定程度上反映了土壤各层的盐渍化程度和状态。而土壤盐分与水分、土壤物理性质等有十分密切的联系,因此,运用地统计学研究采用振动深松集成技术改良盐碱化草原前后土壤水分、盐分等特性的空间变异规律,以地理信息系统ArcGIS为平台,建立土壤水分、盐分等图形数据和属性数据相结合的信息数据库,建立其空间分异模型和空间分布图,直观的表现各特性的空间变异规律。结果表明,采用振动深松集成技术后土壤盐分含量在空间上有递减,平均ρ（土壤盐）由5.60g.L-1下降到3.73 g.L-1;土壤容重、土壤硬度分别降低13%和24%,利于牧草根系生长,生物量变异结果显示,改良前后的草层高度和产量空间分布逐渐达到了均一化,牧草产量达到了2738.1 kg.hm-2,实现了植被全覆盖,盐碱化草原得到了恢复。     

Effect of sewage water on the growth and yield parameters of wheat and blackgram with different fertilizer levels

Impact of biologically treated domestic sewage water was studied on the growth and yield attributing characters of wheat and blackgram under different fertilizer levels in the field condition. There was no significant difference on the yield and yield attributing characters of wheat. However, yield attributing characters like number of tillers/plant, panicle length (cm), number of grains/panicle and 1,000 grain weight showed increasing trend to the tune of 13.29, 1.59. 5.49 and 3.79 per cent respectively over the tubewell irrigated crop. Yield was also increased to the tune of 3.63 per cent when the crop was irrigated with sewage water. Interactions between irrigation and fertilizer levels were also insignificant. However, sewage water with N60P45K45 responded better on tillering, panicle length, number of grains/panicle and yield of wheat. In case of blackgram, treated sewage water had no significant effect on the grwoth and yield attributing characters, rather sewage water had some negative effect on these parameters. Interactions between irrigation and fertilizer levels were insignificant. But tubewell irrigation with N10P10K10 was more responsive on growth parameters. When the crop was grown with tubewell irrigation and without fertilizer, yield attributing characters were more positively responded.     

Geochemical and Geophysical Monitoring of Salinewater Intrusion in Korean Paddy Fields

The saline water intruded zone in paddy fields near the seashore can be diagnosed accurately by joint exploration with geophysical and geochemical methods. Using the electromagnetic (EM) sounding technique, the weakly consolidated zone which introduces saline water into such an area of near seashore paddy fields in Korea was detected from the variation of electrical conductivity distribution following field irrigation. Vertical electrical sounding (VES) with Schlumberger array and chemical analysis of top soils, and groundwater in the study area verified the intruded zone near the surface. The VES results showed that the intrusion of seawater occurred in the form of a channel down to 30 m below sea level. Geochemical analysis of the top soil samples for the six major elements found in seawater indicated that the region showing high concentrations is concordant with the weakly consolidated zone near the surface. The degree of contamination in the study area was investigated by comparing the soil data with those from a nearby old reclamation field. If remediation work is not done for this intrusion zone, the sodicity degree in the paddy soil is expected to increase compared with the reference site data.     

Effect of water quality on yield of sugar beet and sweet sorghum

To study the effects of quality of water on soil and plant, an experiment was conducted at Rudashat Drainage and Reclamation Experiment Station in 1999. Four irrigation water salinities (2, 5, 8 and 11 ds m(-1)) and two sugar crops (sugar beet and sweet sorghum) were used in this experiment. The results showed that under the same water quality, sweet sorghum used 2700 cubic meter per hectare less water than sugar beet. As the quality of irrigation water decreased, the soil salinity and exchangeable sodium percent increased which caused yield reduction for both plants. Sugar beet by accumulating Na and Cl in its leaves tolerated salinity but its usage as a forage crop caused some limitations, whereas sweet sorghum by not accumulating Na and Cl escape salinity and it can be used as a forage crop without any limitation.     

柳树幼苗渗透调节物质对中、碱性钠盐响应的差异性

世界土壤盐渍化问题日益严重.中国拥有面积广大的盐碱地,它严重地制约着中国农业的可持续发展.中国北方内陆盐碱地土壤含有NaCl、Na2SO4、Na2CO3、NaHCO3 多种盐分,类型复杂多样.柳树是我国重要的造林绿化和水土保持乡土树种,对改良盐碱地美化生态环境具有重要作用,因此研究柳树耐碱性及其适应盐碱生理差异性具有重要意义.以盐柳1号（Salix psammophila）为试验材料,分别以中性盐NaCl 和Na2SO4、碱性盐NaHCO3 和Na2CO3 混合模拟盐、碱胁迫（两者物质的量比均为9∶1）,各设计了5 个梯度处理,总共胁迫14 d 后,研究盐与碱胁迫下柳树幼苗叶片含水量、脯氨酸、可溶性糖和可溶性蛋白的变化情况.结果表明：随着盐浓度的升高柳树叶片中的含水量呈减少趋势,在碱性盐胁迫下叶片含水量下降趋势更大,盐浓度达到200 mmol·L^-1 时,叶片含水量达到最低为23.8%,仅为对照的32%（P〈0.01）达到极显著性差异,并且相比于中性盐在碱性盐胁迫下叶片损失水分更多.同样在碱性盐胁迫情况下随着盐浓度升高,柳树叶片中的三种渗透调节物质脯氨酸、可溶性糖和可溶性蛋白含量均增加,其中,碱性盐浓度达到200 mmol·L^-1 时植物叶片中脯氨酸质量分数为100.38 μg·g^-1 达到最大值为对照的3.18 倍（P〈0.01）达到极显著性差异,为同浓度中性盐胁迫下的1.57 倍（P〈0.05）.当碱性盐浓度达到150 mmol·L^-1 时,柳树叶片可溶性糖质量分数是2.4 mg·g^-1 为对照的1.86 倍（P〈0.05）达到显著性差异水平,为同等浓度中性盐胁迫下的1.69 倍（P〈0.05）,叶片可溶性蛋白质量分数为7.84 mg·g-1 为对照的1.67 倍（P〈0.05）差异显著,为同等浓度中性盐胁迫下的1.56 倍（P〈0.05）.综上所述,从渗透胁迫角度分析,碱性盐胁迫比中性盐胁迫是两种不同性质的胁迫,并且碱胁迫对柳树造成的危害损伤更大.     

Irrigation with domestic wastewater: responses on growth and yield of ladyfinger Abelmoschus esculentus and on soil nutrients

Domestic wastewater is generated continuously and in large quantities. It can serve as an alternative water nutrient source for irrigation. In the present study Abelmoschus esculentus L. (Ladyfinger) was irrigated using untreated wastewater (T1), treated wastewater (T2) and rainwater (T3) in pot experiments. The effect was seen on nutrient fortication, growth and yield of the plant and the nutrient status of the soil. Additionally the build up of Cr, Cu and Zn from the irrigation water were anlayzed in different parts of the plant biomass and in the soil. The sapling survival rate was found to be 87% in T1 followed by T2 and T3. Root shoot ratio under different treatments was found in the order T3 (0.46) >T2 (0.35) >T1 (0.31). The chlorophyll a, b and carotene content in the leaves (mg g(-1)) was found to be 6.3, 0.5, 0.9 under T1, 4.8, 0.4, 0.8 under T2 and 3.2, 0.3, 0.5 under T3 respectively and all the three varied in the order T1>T2>T3. The same trend was found in case of total dry matter (g) T1 (6.3) >T2 (3.7) >T3 (2.3) at p < or = 0.05. There was a considerable increase in nutrients in the soil under T1 and T2 as compared to T3 after final harvest. The organic matter (%), NO3-N and PO4(3-) (mg kg(-1)) content post harvest soil was found to be 3.4, 71, 90 under T1 and 2.9, 52, 63 under T2 respectively. Also, there was an increase in cations Na, K, Ca and Mg in the soil irrigated with T1 and T2 after the final harvest. Thus irrigation with wastewater generally increased soil fertility. Only a small percentage of the heavy metal was bioaccumulated by the plant parts from the irrigation water. There was hardly any metal accumulation in fruits. Bulk of the metal ions remained in the soil.