Diagnostic Analysis of Farmers' Skimming Well Technologies in the Indus Basin of Pakistan

Farmers are using skimming wells tosupplement their canal deliveries. Toensure sustainable groundwater extraction,proper design and operational guidelinesfor these skimming wells are required. Thestarting point of such guidelines is tolook at farmers' existing groundwaterextraction practices, their extent andassociated problems. For this purpose, afield survey was conducted in the IndusBasin of Pakistan. Participatory ruralappraisal identified several design andoperational problems with farmers' skimmingwells. These include; depth of well,number of strainers, horizontaldistance of strainers, priming, water quality, sand in pumped water,and reduction in well discharge withtime. To investigate these problems,diagnostic analysis was carried out. A testborehole was drilled to get water samplesalong the aquifer depth during drilling.The depth of well was then decided on thebasis of these water quality analyses. Todecide the number of strainers, a pumpingtest was conducted at test borehole toestimate the contribution of individualstrainer and then the numbers wereincreased according to the desireddischarge. Similarly, placing non-returnvalve between blind pipe and strainersolved the priming problem. Operating wellsintermittently rather than continuouslysolved the problems of water quality andreduction in well discharge. The systematicapproach adopted in the study helped thefarmers to rectify the problems.     

晋西残塬区坡面n值及其与土壤侵蚀量关系的初步研究

在野外小区径流试验基础上,通过经转换的Manning公式对不同坡地表面的糙率n值进行了初步研究.同时还探讨了糙率n值与侵蚀量的关系.试验结果表明:糙率n值随林下枯落物量的增加而变大.在8个小区的试验中,裸地上的n值最小,为0.0107;枯落物保持良好膨松状态的山杨林地的n值最大,为0.6377.研究结果还表明:林下枯落物量与水分渗透量呈正相关,与土壤侵蚀量呈负相关关系.     

浅盘与传统普洱茶发酵的微生物群落和化学成分比较研究

传统普洱茶渥堆发酵一般包含数吨茶叶基质,发酵中存在热传递不均匀的问题.为此建立了浅盘普洱茶发酵系统,并比较了浅盘与传统普洱茶发酵的微生物群落结构和化学成分差异.测定发现2种发酵过程化学成分变化规律类似,浅盘发酵出堆样的水浸出物、可溶性糖、茶红素和黄酮质量分数显著高于传统发酵出堆样(p0.05),茶褐素质量分数显著低于传统发酵出堆样(p0.05). 2种发酵过程微生物群落结构不同,传统发酵出堆样品优势细菌为葡萄球菌属(Staphylococcus)、芽孢杆菌属(Bacillus)和考克菌(Kocuria),优势真菌为曲霉属(Aspergillus)、芽生葡萄孢酵母属(Blastobotrys)和根毛霉(Rhizomucor);浅盘发酵出堆样品优势细菌为芽孢杆菌属(Bacillus)和欧文氏菌属(Erwinia),优势真菌为Brunneoclavispora和曲霉属(Aspergillus).审评结果表明, 2种发酵出堆茶样都具有较好的感官品质.今后还应研究优化浅盘发酵的条件,以提高普洱茶品质.     

浅议果树管理

本文通过对果树树苗选择、种植选址、浇水、施肥、用药、修剪、花果管理等阶段的描述,较全面讲解果树种植技术及相关管理要求,对于提高果树种植管理水平和增加经济收入有一定参考价值。     

岱山等边浅蛤形态与重量性状参数的相关性及通径分析

为了研究等边浅蛤数量性状间的相关性及影响产量的因素组成,随机选取130只12月龄浙江岱山野生等边浅蛤的分别测量表型性状壳长(X1)、壳高(X2)、壳宽(X3)、壳顶至壳前(X4)、壳顶至壳后(X5)、韧带长(X6),重量性状活体重(Y1)、软体重(Y2)、壳重(Y3)等性状,并应用遗传相关、多元回归、通径分析等方法进行了分析.结果表明,9个数量性状间的相关系数均达到极显著水平(P＜0.001).对活体重起直接作用最大的是壳长,起直接决定作用,通过壳高的间接决定作用达40.34％.建立了利用形态性状估计重量性状的回归方程,该结果为等边浅蛤选择育种提供了理论依据,即以提高活体重为目标,主要选择壳长,同时加强对壳高的协同选择.计算相关系数,采用通径分析方法计算以活体重(Y)为依变量、其他性状为自变量的通径系数和决定系数.该研究可为等边浅蛤蛤的养殖和选择育种提供理论依据.     

Residency and small-scale movement behaviour of three endemic sparid fishes in their shallow rocky subtidal nursery habitat,South Africa

The residency and small-scale movements of early juveniles (<175 mm fork length) of three sparid fish species were examined in the shallow subtidal zone along a 500 m stretch of rocky coastline near Schoenmakerskop (Eastern Cape Province, South Africa). A total of 12 blacktail (Diplodus capensis), 12 zebra (Diplodus hottentotus) and six white musselcracker (Sparodon durbanensis) were tagged using visible implant elastomer (VIE) tags. Underwater observations in four shallow rocky subtidal gullies and adjacent areas were made using snorkeling gear on a total of 37 days spanning 13 field trips over spring low tide periods between January and August 2006. The VIE tagging method was well suited to individually tag small juvenile fish with minimum disturbance. In general, the degree of residency of juveniles in the shallow rocky subtidal zone was species specific and dependent on the size of individuals. Juvenile zebra displayed the highest degree of residency followed by white musselcracker and blacktail, with re-sightings recorded on 53%, 40% and 10% of observation days, respectively. The high degree of residency by early juvenile sparids renders them vulnerable to localized coastal perturbations and climate change.     

乌南油田N_2~1油藏储层非均质性研究

乌南油田N12主要为一套三角洲前缘-滨浅湖亚相的沙泥沉积,储层属于特低孔特低渗储层。利用储层的测井物性解释资料,结合岩心分析资料,对研究区N12储层的层内、层间、平面非均质性进行了研究。研究表明,总体储层非均质性强。层内非均质性与沉积微相密切相关,单砂层垂向上渗透率以正韵律和反韵律为主,夹层多。各沉积微相非均质性强弱依次为:水下分流河道、河口坝、远沙坝-席状沙、坝核、坝缘、沙滩。层间渗透率差别大,Ⅰ、Ⅱ油组非均质性最强,单层层数越多,层间非均质性越强。储层平面非均质性变化受沉积相控制,渗透率平面变化较大,砂体相变较快,连通性较差。     

盐碱地咸水灌溉枸杞种植条件下土壤盐分变化

In order to utilize the wasted saline-sodic soils under shallow groundwater condition,a 3-year field study was carried in a field cropped with Lycium barbarum L.and irrigated by drip irrigation with saline groundwater under the water table depth of 30-40 cm in the northern Yinchuan Plain,China.Effects of cropping duration (one,two,and three years) on soil salinity,soil solution composition,and pH in three adjacent plots were investigated in 2008.Results showed that a high irrigation frequency maintained high soil water potential and subsequently facilitated infiltration and downward movement of water and salt in the crop root zone.Salt accumulated on the edges of the ridges,and soil saturated-paste electrical conductivity (ECe) was higher in the edge.Concentrations of Na+,Ca2+,Mg2+,Cl-,and SO42- in the soil increased with the soil depth as did the ECe,while HCO3- and pH had a relative uniform distribution in soil profile.As planting year increased,the ECe and soil salts in the field had a decreasing tendency,while in the root zone they decreased immediately after irrigation and then remained relatively stable in the following growing seasons.HCO3- and pH had little change with the planting year.Results suggested that the application of drip irrigation with saline water could ameliorate saline-sodic soil and provide a relatively feasible soil environment for the growth of salt-tolerant plant Lycium barbarum L.under the saline-sodic soils with shallow groundwater.     

珠江口浅海4种经济虾类的食性和营养级研究

[目的]分析珠江口浅海重要经济虾类摄食习性的基本特征及营养级变化的基本规律,为珠江口及其邻近海域生态系统结构、能量流动和海洋生物食物网研究及增殖放流提供科学依据,也为开展南海近海生物资源养护工作提供技术支撑.[方法]对2011~2012年在珠江口浅海拖网捕获的中国对虾(Fenneropenaeus chinensis)、长毛对虾(Penaeus penicillatus)、近缘新对虾(Metapenaeus affinis)和刀额新对虾(Metapenaeus ensis)4种经济虾类样品的胃含物进行鉴定和生物学测定,并根据胃含物中饵料生物的重量组成和出现频率,分析这4种经济虾类饵料生物的生态类群及食物组成的季节变化和营养级.[结果]珠江口浅海4种经济虾类均以底栖生物和浮游生物为主要营养饵料,兼食小型游泳动物(包括幼鱼),饵料生物种类在春末夏初期间比秋末冬初更广泛.4种经济虾类的平均营养级为2.43,按食性可划归为第三营养级,属低级肉食性动物.[结论]珠江口浅海的中国对虾、长毛对虾、近缘新对虾和刀额新对虾的营养级与经济鱼类在同一层次,是对该海域鱼类资源的重要补充,其中以浮游生物为主要饵料的长毛对虾可作为珠江口浅海兼具生物净水功能的主要增殖放流品种.     

沙障对不同林龄雨养梭梭林冠下浅层土壤含水量的影响

[目的]分析不同林龄雨养梭梭林冠下浅层土壤含水量在布设沙障后的变化,为沙障生态功能的评价及梭梭生长发育状况的预测提供理论依据。[方法]对5年生幼年林和25年生中年林在布设沙障后冠下0—50cm的土壤含水量、表层结皮厚度、近地表风速等因子进行测定分析。[结果]沙障通过降低近地表气流流速,加速结皮形成等方式提高了梭梭冠下0—50cm的浅层土壤含水量。沙障对5年生梭梭冠下土壤含水量的空间分布格局影响不大,但使25年生梭梭冠下土壤含水量随着与主干距离的增加而单调增加,表现为"干岛效应"。在垂直分布上,25年生梭梭冠下土壤含水量在塑料网沙障区与对照区间呈显著相关(p0.05),而在麦草沙障区与对照区间相关性不显著,其最大土壤含水量的出现深度下降至30—40cm处。[结论]布设机械沙障对退化梭梭林的恢复将起到一定的促进作用,且对中年林梭梭土壤水分的影响大于对幼年林。