Impacts of Institutional Reforms on Irrigated Agriculture in Pakistan

Poor functioning of theirrigation system in Pakistan has been asource of concern for the last few decades,during which time it has been the subject ofconsiderable external assistance andinternal policy reforms. Consequently, thegovernment of Pakistan introducedinstitutional restructuring in irrigationand drainage subsectors to impartnecessary improvements. Under thesereforms, management at secondary canallevel has recently been handed over to theFarmers Organizations (FOs) of selecteddistributaries in pilot areas. This studywas designed to evaluate a farmer-manageddistributary in southern Punjab. Fieldmeasurements revealed that hydraulicaspects of the irrigation service deliveredby the FO management has been significantlyimproved and as a result highlyproportionate and equitable waterdistribution was observed, particularly atthe tail reaches of the distributary. Dueto effective FO management farmers'interventions to increase the outletdischarge by illegal means has been almosteradicated. As a result of theseimprovements imparted by the FO in systemmanagement, the extent of irrigated area hasincreased on average by 6 to 7%, evenunder severe drought-like conditionsprevailing in the country during recentyears. Further cost recoveries haveincreased by an amount of 14% for summerand 23% for winter growing seasons,respectively, from the irrigated area of thedistributary. Thus experience from Hakra4-R distributary has shown that even underundesirable natural circumstancesIrrigation Management Transfer (IMT) wasquite effective in achieving the keytargets of the institutional reformslaunched at pilot scale in the country.     

Introduction of Irrigation Service Fee (ISF) in Indonesia: Institutional development in action for resources management

The inability to properly maintain irrigation systems over time forced the Government of Indonesia (GOI) to seek cost recovery from water users through introduction of an irrigation service fee. The plan is to introduce this fee in all of the technical irrigation systems of Indonesia, covering about 4 million hectares, over a 12 year period. Design and Introduction of this service fee in 4 pilot areas of the 4 major rice producing provinces (West, Central and East Java, and South Sulawesi) during 1989–1991 has shown that users are willing to pay. Results of first ISF collection from over 11,000 farmers in Central and East Java in pilot systems was an encouraging 95%. However that acceptance to pay by users depends on their structured and systematic involvement in defining systems needs. They need to understand a differentiation in payment if service levels are different. They appreciate use of collected funds in the system where collected. They understand the organization of water users associations but this requires their active role in fee determination and collection. They understand the establishment of federations of these associations. ISF requires also active involvement of Local Government officials as facilitators and intermediaries between service receivers (the water users) and service providers (personnel of the Public Works irrigation department) in the introduction period. This article describes the experience of the first 21 months of the ISF project, the concept developed, the principles used as basis for ISF, the introduction at the field level, issues related to acceptance by users and by the institutions involved, and the first results.Abbreviations/Acronyms DGWRD Directorate General of Water Resources Development (Ministry of Public Works) - EOM Efficient Operation and Maintenance - Gabungan group of WUAs - IPAIR Indonesian abbreviation for ISF - ISF Irrigation Service Fee - Juru gate keeper - PBB land tax on irrigated lands - PPL agricultural field extension agent - P3A Indonesian abbreviation for Water Users Associations - PU Indonesian abbreviation for Public Works - SM Special Maintenance - WUA Water Users Associations     

祁连山东段高寒植被类型对土壤理化特征的影响

[目的]探讨祁连山东段不同高寒植物的土壤理化特征,为区域水资源合理利用提供理论依据.[方法]对祁连山东段6种灌丛植被和高寒草地的土壤基本性状、土壤持水能力和土壤渗透性进行了相关指标的测定.[结果]①祁连山东段高寒植被的土壤容重随着土层深度的增加而增大,土壤含水量则随着土层深度的增加而降低.②祁连山东段土壤总孔隙度随着土...     

基于FEM-SPH耦合的卷辊式耕层残膜回收部件结构优化与试验

针对棉田耕作层内残膜力学性能差及膜土分离困难,残膜拾净率低和回收的残膜含土量高等问题,该研究对卷辊式残膜回收部件进行优化。在分析起膜捡膜工作过程和建立卷辊弹齿与膜土团聚体之间动力学关系的基础上,采用有限元法(finite element method,FEM)和光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)耦合算法,建立卷辊弹齿-膜土团聚体接触计算模型,探究卷辊弹齿与膜土团聚体之间相互作用机理,分析卷辊弹齿接触膜土团聚体后残膜受力程度和土壤扰动程度的变化规律。以卷辊回转半径、弹齿直径、弹齿顶端折弯角为试验因素,以残膜平均峰值应力及土壤最大应变为指标开展仿真试验,分析各因素对指标的影响规律并对卷辊弹齿结构参数进行优化,获得卷辊弹齿最优结构参数为：卷辊回转半径100 mm、弹齿直径5 mm、弹齿顶端折弯角42°,此时残膜平均峰值应力为0.1201 MPa,土壤最大应变为3.7584。为了验证优化后卷辊弹齿的捡拾作业性能,以拾净率和含土率为试验指标进行田间试验,结果表明：机具拾净率为80.34%,含土率为37.13%,与初代研制的样机相比拾净率提升了8.74个百分点,含土率下降了12.18个百分点,机具作业性能明显提升且试验指标达到设计要求。本文建立的有限元模型可为残膜回收机关键部件的结构优化提供参考。     

植被和梯田措施对坡沟系统细沟侵蚀调控作用

坡沟系统作为黄土丘陵沟壑区基本的地貌单元,也是黄土高原侵蚀泥沙的主要来源区。植被和梯田作为坡面水土流失治理的主要措施,对于土壤侵蚀控制和生态恢复发挥着重要的作用,定量评估林草、梯田对坡面细沟侵蚀的调控作用以及多措施协同配置问题对于黄土高原水土流失治理和生态保护具有重要意义。为了揭示植被和梯田的格局和配置对坡沟系统细沟侵蚀的协同调控作用,该研究采用人工模拟降雨,结合三维激光扫描技术,分析了坡面4种措施：上坡位植被（措施A）、下坡位植被（措施B）、梯田（措施C）、梯田+植被（措施D）对细沟侵蚀发生和演变过程的影响。结果表明：1）相同植被覆盖度下,下坡位的植被布设细沟最大长度较上坡位的植被布设细沟最大长度减小量更大;2）第1次降雨中,侵蚀率最大值达到3 500 g/min以上,第2次降雨过程中侵蚀率最大值仅为1 100 g/min以上,在各产流时间内第2次降雨侵蚀率均为第1次降雨侵蚀率的1/3～1/2;3）对于各措施下细沟沟长发育率由大到小表现为措施A(6.55 cm/min)、措施C(5.71 cm/min)、措施B(3.60 cm/min)、措施D(2.69 cm/min);4）梯田与植...     

盐生植物做除虫杀菌剂应用展望

盐生植物做除虫杀菌剂,用于生产绿色食品,解决农药在植物体内的残留问题,使人们重新认识植物源除虫杀菌剂的作用。重点阐述了可用于除虫杀菌的盐生植物的种类和性能,盐生植物除虫杀菌剂的制作及使用方法。面对在农产品贸易中苛刻的农药残留标准,使用植物源农药,减少化学农药的施用量,生产绿色无公害食品,盐生植物具有极大的潜在威力。     

罗玉沟流域水土保持植被工程效果评价

选取8个与植被工程效果紧密相关的评价指标,建立工程实施效果的评价指标体系,评价甘肃藉河流域罗玉沟世行二期项目实施情况。采用层次分析和综合指数相结合的方法,将罗玉沟流域水土保持植被工程实施效果综合指数等间距地划分为5个等级。结果表明：罗玉沟流域植被工程实施综合效果总体处于“良好”等级,但仍存在林分结构布局不合理、草地盖度偏小等问题,结合工程现状提出了今后的改进方向。     

新疆北屯绿洲弃耕农田的植被变化特征

在北屯绿洲选择了3组不同年限的次生盐渍化弃耕农田,分别计算了样地内每种植物的重要值,采用Shannon-Wiener指数、Pielou指数、Simpson指数测定了生物多样性.结果表明:3组群落组成存在显著差异,优势种更替明显.3组群落构成依次为,一年生草本、一年生草本 多年生小半灌木、多年生草本 灌木.物种多样性表现为2年群落＞5年群落＞13年群落;群落均匀度表现为2年群落＞5年群落,而5年与13年群落相当,但是生态优势度却表现出与物种多样性相反的趋势,即2年群落＜5年群落＜13年群落.     

Resistance and resilience of soil biological indicators: A case study with multi-walled carbon nanotube

Soil ecosystem is experiencing stresses due to climate change, and soil inhabitants try to demonstrate their inherent resistance and resilience against those stresses. Application of nanomaterials as agricultural inputs could bring shifts in resistance and resilience patterns of soil microbes and associated enzymes, especially under short-term heat stress. With this background, the impacts of multi-walled carbon nanotube (MWCNT) on the resistance and resilience of soil biological indicators were evaluated. An incubation experiment was conducted with varied MWCNT concentrations (0, 50, 100, 250, and 500 mg kg^-1 soil) for 90 d after 24-h heat stress at 48 ±2 ℃ to assess the impacts of MWCNT on soil enzyme activities and microbial populations vis-à-vis their resistance and resilience indices under short-term exposure to heat stress. Enzyme activities were reduced after exposure to heat stress. Resistance indices of enzyme activities were enhanced by MWCNT application on day 1 after heat stress, whereas there was no recovery of enzyme activities after 90-d incubation. Like soil enzyme activities, resistance index values of soil microbial populations followed the similar trend and were improved by MWCNT application. Multi-walled carbon nanotube has the potential to improve resistance indices of soil enzyme activities and microbial populations under heat stress, although they could not recover to their original state during periodical incubation after heat stress. This study helps to understand the relative changes of biological indicators under MWCNT and their ability to withstand heat stress.