Effect of fertilization and irrigation schedule on water and fertilizer solute transport for wheat crop in a sub-humid sub-tropical region

In order to increase the water and fertilizer use efficiency and decrease the losses of water and fertilizer solutes (N and P), it is necessary to assess the influence of level of fertilization and irrigation schedule on movement and balance of water and fertilizers in the root zone. With this goal, the reported study was undertaken to determine the effect of fertilization and irrigation schedule on water movement and fertilizer solute transport in wheat crop field in a sub-tropical sub-humid region. Field experiments were conducted on wheat crop of cultivar Sonalika (Triticum aestivum L.) during the years 2002–2003, 2003–2004 and 2004–2005. Each experiment consisted of four fertilizer treatments and three irrigation treatments during the wheat growth period. During the experiment, the irrigation treatments were: I₁ = 10% maximum allowable depletion (MAD) of available soil water (ASW); I₂ = 40% MAD of ASW; I₃ = 60% MAD of ASW. The fertilizer treatments during the experiment were: F₁ = control treatment with N:P₂O₅:K₂O as 0:0:0 kg ha⁻¹; F₂ = fertilizer application of N:P₂O₅:K₂O as 80:40:40 kg ha⁻¹; F₃ = fertilizer application of N:P₂O₅:K₂O as 120:60:60 kg ha⁻¹ and F₄ = fertilizer application of N:P₂O₅:K₂O as 160:80:80 kg ha⁻¹. The results of the investigation revealed that low volume high frequency irrigation results in higher deep percolation losses than the low frequency high volume irrigation with different levels of fertilization for wheat crop in coarse lateritic soil, whereas different levels of fertilization did not significantly affect soil water balance of the wheat crop root zone during all the irrigation schedules. Level of fertilization and irrigation schedule had significant effect on nitrogen leaching loss whereas irrigation schedules had no significant effect on nitrogen uptake under different levels of fertilization. On the other hand, the leaching loss of phosphorus was not significantly influenced by the irrigation schedule and level of fertilization of wheat crop. This indicated that PO₄–P leaching loss was very low in the soil solution as compared to nitrogen due to fixation of phosphorus in soils. From the observed data of nitrogen and phosphorus use efficiency, it was revealed that irrigation schedule with 40% maximum allowable depletion of available soil water with F₂ fertilizer treatment (N:P₂O₅:K₂O as 80:40:40 kg ha⁻¹) was the threshold limit for wheat crop with respect to nitrogen and phosphorus use, crop yield and environmental pollution.     

关于确保大气自动监测网点正常运转的探讨——以日本电气化学计器株式会社产品为例

文章探讨和分析了日本DKK（日本电气化学计器株式会社）产品SO2（二氧化硫,英文Sulfur Dioxide的缩写）、NOx（氮氧化物,英文Nitrogen Oxides的缩写）、SPM（空气中的飘尘,英文Suspended Particulate Matter的缩写）监测仪器安全有效运转的途径。     

陕西地震现场应急技术系统在汶川地震中的应用

"十五"期间,国家在31个省(直辖市、自治区)建立了全国一体化的地震应急与救援指挥技术体系,其中包括地震现场应急技术系统.在四川汶川8.0级大地震中,陕西省地震局现场应急技术系统重点完成现场通信保障、协助现场考察等工作任务.通过对现场工作的总结分析,旨在把汶川8.0级地震现场工作中应急技术系统一些好的做法继续发扬,对在实际工作中发现的问题,提出一些改进参考建议,以便日后现场应急系统能更好地为大震现场工作服务.     

油库设备焊割动火的安全防护

总结了油库设备焊割动火作业中油蒸气的清除、隔离方法及其组织实施要点,有利于油库整修改造过程中焊割动火作业的安全管理。     

推进湖北省清洁生产工作的思路与建议

全面推进清洁生产,从源头上减少污染物的产生是推进"循环经济"的重要方略.本文回顾了我国以及湖北省开展清洁生产的概况,分析了湖北省开展清洁生产的有利条件,并在此基础上提出了完善政策法规、建立清洁生产基金、积极引导企业开展清洁生产、扶持清洁生产技术服务机构、做好部门协调及省地分工工作等加快湖北省清洁生产工作的思路与建议.     

HG220/100型锅炉工作安全阀热态校验的安全可靠性分析

指出了HG220/100型锅炉热态校验工作安全阀时各级过热器及联箱的超压所导致的安全问题,对超压原因进行了分析,并提出了改进措施。     

无氧作业及其安全措施探讨

以煤化工为例,根据H₂、CO等可燃气爆炸相图,对无氧作业理论依据、控制条件和安全措施进行探讨。     

浅析构建环境知识产权对环保工作的促进

环境知识产权是一种可延续的有期限群体性权利。通过对环境知识产权的定义、特性的阐述,阐明环境知识产权的必然性与可行性,进而通过构建环境知识产权,以期更好地推进环保工作进程。     

中国工业污染物排放密度的影响因素分析——基于污染供需分析框架的实证研究

本文在污染供需分析框架下,选取中国2001-2006年34个工业产业的面板数据,分析影响工业废水、工业二氧化硫和工业烟尘等三种污染物排放密度的主要因素。实证研究结果显示：污染密度均与能源消耗密度、相对工资水平和国有资本比重正相关,与企业规模、环境管制指标和外资比重负相关。要解决环境污染的问题,建立政府引导、企业为主和社会参与的节能减排机制才是根本出路。为此需要做到：（1）鼓励节能型技术的研发和应用;（2）强化对地方政府的环境管制政策执行力度的监督;（3）加强对中小企业的监管力度;（4）理顺政府对环保信息的披露机制;（5）充分发挥社会公众和非政府组织的监督作用;（6）提高外资进入的环境标准。     

基于工作难度对知识员工工作特征的研究探讨

知识员工的工作关键不在于数量而在质量,难度是表征质量的重要变量。本文在综述工作特征研究的基础上,提出从工作难度这一基础管理变量出发研究知识员工工作特征。通过对从事典型知识型岗位的工作者进行问卷调查,采用结构方程模型分析形成的知识工作难度因素结构,不仅为知识工作的评级和测量提供了可行框架,而且为进一步研究知识员工工作特征提供了有利途径。