膜下滴灌与土壤盐渍化

耕地土壤的盐渍化严重的影响和制约了兵团农业的发展，治盐改土也是兵团农业建设中的重要课题之一。该文主要以大田膜下滴灌对防治土壤盐渍化的作用进行了分析，并提出了盐渍化地区膜下滴灌技术的实施要点以及膜下滴灌技术持续稳健发展的具体建议。     

塔里木灌区防止土壤次生盐碱化的对策

对塔里木灌区内不同土壤、不同灌溉方式条件下土壤总含盐量进行调查，分析了灌区地理位置特殊、气候温差大、降水量少、蒸发量大、排水不畅等造成灌区土壤次生盐碱化的原因，提出疏通排渠，防止淤积，设专人测定排水量、化验水质、检查矿化度等防治对策。     

我国保护地蔬菜土壤次生盐渍化研究报告

近年来,我国保护地蔬菜不同程度的出现次生盐渍化现象,多年来笔者对山东省临沭县蔬菜种植进行了调研。本文就针对此现象进行我国土壤次生盐渍化调研,分析总结,以及今后科学防治措施。     

棉花膜下滴灌效果及经济效益分析

新疆是我国最严重的干旱区之一，农业生产的突出特点是荒漠绿洲，灌溉农业，水资源短缺，成为制约该地区农业生产可持续发展和生态环境改善的瓶颈。棉花膜下滴灌技术是滴灌技术与覆膜植棉技术有机结合（优势叠加）的产物，具有节水、节肥、节地、省机力、增产、增效等诸多优点。同时提高劳动生产率，具有有效防治土壤次生盐渍化，扩大绿洲面积，改善生态等多重作用。通过几年来对棉花膜下滴灌技术的系统全面研究，现就棉花膜下滴灌的效果及经济效益分析如下。一、膜下滴灌效果分析１．节水效果。通过农垦科学院、石河子大学、农八师等单位多…     

合理灌溉 力争水稻高产

水稻灌溉的目的在于供给禾苗生长所必需的水分,溶解土壤中的养分,增加土壤的膨软,利于稻根的发育,防止杂草的发生,争取高产。随着农业生产的发展,稻田灌溉技术在密植、深耕、足肥的条件下,有了新的发展和进步,群众创造了“浅水勤灌”,“先浅后深”,“浅——深——浅”及“水层、湿润、晒田三结合”的灌溉方法,比全期淹灌溉增产,又省     

基于GIS与景观生态学的土壤资源格局分析--以鲁西北地区为例

以1：5万土壤类型图为数据基础，采用景观生态学结构定量分析方法，并以GIS技术为分析手段，对鲁西北地区土壤资源在空间上的分布格局进行了定量研究。其中，主要分析了面积特征、形态特征和类型特征等三大类的景观格局指数。研究结果表明：(1)前述方法能够很好地揭示区域土壤资源的分布格局，其结果对农业生产布局、土地资源开发利用和整治具有一定的指导意义；(2)研究区面积最大的土壤类型主要分布于缓平坡地上，是主要的农业利用土壤，但因所处的地貌类型和潜水条件，在利用过程中，应灌排配套，防止地下水位升高，导致次生盐渍化，而平均形状指数较大的土壤分布主要受微地貌的影响；(3)研究区土壤资源景观类型特征存在着明显的区域差异，而区域主导土壤类型的农业生产条件的好坏将直接影响该区域的土地生产能力。     

盐渍化对沙枣林氮组分的影响

为明确在不同盐渍化水平下土壤氮组分变化规律，采用BREMNER方法探究盐渍化对沙枣林土壤氮组分的影响特征。结果表明，随土层的加深土壤全氮含量、土壤酸解液总氮含量、土壤酸解铵态氮含量、土壤未酸解态氮含量均降低，随盐渍化水平变化：0～30厘米土层土壤酸解液总氮含量中盐渍化>盐渍化>非盐土；0～30厘米土层土壤全氮、土壤酸解铵态氮、土壤未酸解态氮含量中盐渍化>非盐土>盐渍土。故本文选取种植年限相同而盐渍化不同的沙枣人工林为研究对象，探讨盐渍化对土壤有机氮组分的影响，以期为河西地区盐渍化土壤资源的利用与修复提供一定的理论依据。     

稻农采用节水技术影响因素的实证分析——自然因素和经济因素效应及其交互影响的估测

本文对16个省（区、市）25个县（市、区）4686个农户采用旱耕水整、旱育秧、干湿交替灌溉及全程节水等水稻节水技术情况的调查和分析表明：农户人均收入、种稻规模、所在区域等特征因素以及年降雨量、灌溉费等自然因素和经济因素，明显影响稻农采用节水技术；灌溉费与年降雨量存在显著的交互影响；灌溉收费机制对稻农采用节水技术有显著影响。因此，构建与用水量挂钩的收费机制，可有效促进稻农采用节水技术。     

干旱区盐渍化农田景观格局特征分析

干旱区农田土壤盐渍化问题突出且日趋严重,已成为制约绿洲农业发展的主要障碍之一。以玛纳斯县为研究区,运用景观生态学方法和GIS技术,选取相关景观格局指数,对农田盐渍化景观格局及土壤盐渍化程度与景观格局关系进行定量分析。结果表明:(1)研究区以轻度盐渍化农田为主,农田土壤盐分在水平方向的变异程度随着深度的增加而降低,总体来看,农田斑块形状较规则、简单且面积变化幅度较大。(2)类型水平土壤盐渍化程度对农田斑块面积影响显著,随着土壤盐渍化程度增加而农田斑块面积减小。盐渍化程度对类型斑块间距离影响明显,轻度盐渍化程度农田斑块呈集中分布,而其它类型类型斑块间距离较大,相对分散分布。(3)斑块水平土壤深度(0~100cm)范围内,土壤含盐量与农田斑块形状、面积和邻近斑块数关系密切。盐渍化农田盐渍化程度愈重,其农田斑块形状愈复杂,农田斑块面积愈小,农田斑块邻近斑块数愈少。中层盐渍化程度对农田斑块形状和面积影响相对较大,底层盐渍化程度对农田斑块集中连片分布特征影响较大。     

农业清洁生产在北方山区蔬菜生产中的应用

近年来蔬菜生产中由于过分追求产量,大量施用化肥、农药等现代化学合成物质,导致土壤连作障碍发生严重,造成菜地土壤板结,次生盐渍化程度逐年提高,土壤质量逐渐下降,农业环境状况每况愈下,已影响到农业的可持续发展和农产品的质量安全。北方山区马铃薯、胡萝卜、大白菜等种植面积迅速扩大,     

水肥一体化技术的环境效应与经济效应分析——基于山东省苹果种植户的调研数据

目的 绿色农业技术的环境与经济收益核算,对于推进技术应用、解决农业面源污染问题和实现生态文明建设具有重要的参考价值。究竟绿色农业技术有没有顺利实现农户的经济目标与社会的环境目标？现有研究诸多争议与困惑。方法 文章以水肥一体化技术为例,基于山东省649份苹果种植户的实地调查数据,借助内生转换模型,从微观层面探讨了水肥一体化技术的环境效应和经济效应。结果 （1）总体来看,农户采纳水肥一体化技术实现了节肥增收的目的。（2）采纳水肥一体化技术后,样本农户能够节约化肥施用量11.79%~20.98%,提高农产品收入8.15%~9.07%。（3）不同规模农户采纳水肥一体化技术的节肥增收效应存在显著差异。对于采纳水肥一体化技术的规模户而言,其化肥减量作用强度明显高于小规模农户。与此同时,采纳水肥一体化技术只对规模户有明显的农产品增收作用。结论 注重完善市场流通机制下农产品质量监督体系,使绿色农产品能够获得质量溢价的收益。同时创建有利于水肥一体化技术推广应用的土地规模条件,获得规模化带来的节肥增收效应。推动外部性内部化补偿制度实施,政府对具有正外部性行为的农户给予补偿。     

Irrigation Technology Adoption and Gains from Water Trading under Asymmetric Information

We develop a water allocation and irrigation technology adoption model under the prior appropriation doctrine with asymmetric information among heterogeneous farmers and between farmers and water authorities. We find that adverse selection reduces the adoption of modern irrigation technology. We also show that even with asymmetric information, incentives for water trade exist and lead to additional technology adoption with gains to all parties. This suggests that under asymmetric information, a thin secondary market improves the allocation of water resources and induces additional adoption of modern irrigation technologies.     

基于水权交易和面源污染控制的农户灌溉施肥行为模型

将水权交易和面源污染控制有机结合,以种植面积、农业用水定额、污染物浓度为约束条件,运用边际分析方法建立农户灌溉施肥行为模型,分析水权交易和排污控制对农户行为的影响。结果表明:灌溉用水量与农作物价格成正相关,与交易水价和边际灌溉成本成负相关;一定范围内肥料施用量与农作物价格成正相关,与边际施肥成本或边际环境成本成负相关。模型证明,当农业用水定额内水权可交易时,水市场的存在和水价政策将激励农户减少灌水量,节约用水。     

新疆生产建设兵团各师灌溉水价变动对

以新疆生产建设兵团2000~2006年灌溉水价和与之对应的每公顷毛灌溉定额资料为基础,应用计量经济学需求函数模型,建立兵团灌溉水价与灌溉用水量的定量关系,利用以上研究成果对兵团灌溉水价改革进行预测,根据兵团各师农业灌溉节水量测算农业灌溉水价对农业经济的贡献率。结果表明,水价这一经济杠杆对当地农业经济的发展起到了促进作用。     

Forty years of irrigation development and reform in China

This study reviews 40 years of irrigation development in China including the transformation of the institutional and incentive structures in irrigation management. After rural reforms in the 1970s, irrigation investments slowed until the late 1990s. In North China, farmers became major investors in groundwater irrigation, leading to property rights’ transfer of tube wells from collective to private ownership. Despite positive effects in cropping patterns, farmer income and development of groundwater markets, privatisation has accelerated groundwater table deterioration. Since the middle of 1990s, Water User Associations have replaced village collective management of surface irrigation. This approach was adopted by most provinces by early 2001 with mixed results; only institutions with water‐saving incentives realised efficient irrigation. The Government is reforming water price policies to provide water‐saving incentives to farmers while not hurting their income. While China has focused on water rights and markets, and despite regulations and pilot projects, full implementation of water rights has been slow. Research reveals greater policy scope for expanding irrigation technologies that generate real water saving to rural areas. Given pressure associated with water scarcity and concern for food security, further effective reforms in irrigation and policy incentives are expected. The Government has also initiated some pilot projects to resolve increasing water scarcity problems through adjusting agricultural production activities.     

Technology Adoption under Production Uncertainty: Theory and Application to Irrigation Technology

We propose a theoretical framework to analyze the conditions under which a farmer facing production uncertainty (due to a possible water shortage) and incomplete information will adopt a more efficient irrigation technology. A reduced form of this model is empirically estimated using a sample of 265 farms located in Crete, Greece. The empirical results suggest that farmers choose to adopt the new technology in order to hedge against production risk. In addition, we show that the farmer's human capital also plays a significant role in the decision to adopt modern, more efficient irrigation equipment.     

北方半干旱区氮肥不同配施方式对小南瓜产量的影响

小南瓜是北方半干旱区增加经济产值的适生作物之一。研究选用日本赤甘栗品种,采用田间小区试验,研究了在两种灌溉方式(灌溉、灌溉施肥)和四个牛粪氮添加水平(25、50、75、100 kg N/hm~2)处理下氮肥不同配施方式对小南瓜产量的影响。结果表明,在小南瓜生长前期,滴灌施肥方式可有效促进叶绿素的积累及叶片的复壮,有利于植株生长。单施有机肥组,随着牛粪氮添加水平的增加小南瓜产量未见明显增加,平均产量为10 t/hm~2;有机肥结合灌溉施肥组,随着牛粪氮添加水平的增加小南瓜产量显著增加,最高达到21.5 t/hm~2。当总氮添加量为100~140 kg/hm~2,有机无机肥配比为3:7~5:5时,小南瓜产量比单施牛粪肥增产60%,平均达到16 t/hm~2。     

Impacts of climate change on lower Murray irrigation*

This article evaluates irrigated agriculture sector response and resultant economic impacts of climate change for a part of the Murray Darling Basin in Australia. A water balance model is used to predict reduced basin inflows for mild, moderate and severe climate change scenarios involving 1, 2 and 4°C warming, and predict 13, 38 and 63% reduced inflows. Impact on irrigated agricultural production and profitability are estimated with a mathematical programming model using a two‐stage approach that simultaneously estimates short and long‐run adjustments. The model accounts for a range of adaptive responses including: deficit irrigation, temporarily following of some areas, permanently reducing the irrigated area and changing the mix of crops. The results suggest that relatively low cost adaptation strategies are available for a moderate reduction in water availability and thus costs of such a reduction are likely to be relatively small. In more severe climate change scenarios greater costs are estimated. Adaptations predicted include a reduction in total area irrigated and investments in efficient irrigation. A shift away from perennial to annual crops is also predicted as the latter can be managed more profitably when water allocations in some years are very low.     

Policy interventions to promote the adoption of water saving sprinkler systems: the case of lettuce on the Gnangara Mound

The potential for improving irrigation scheduling decisions and adoption of more efficient irrigation systems is explored using a bioeconomic simulation model of lettuce production on the Gnangara Mound near Perth, Western Australia. Sandy soils with poor water and nutrient holding capacity are associated with declining marginal productivity of water at high water use, which would create an incentive to reduce water use and to adopt closer sprinkler spacing if farmers had correct information about the declining marginal productivity of water. Incorrect perceptions regarding water–yield relationships lead to over use of water by up to 50 per cent and reduce profits by 475 per crop hectare (12 per cent) in the short run, and remove the incentive to adopt more efficient systems in the long run. Higher water prices create an incentive to reduce irrigation scheduling time in the short term and to adopt more uniform sprinkler systems, and tend to reduce the discrepancies associated with poor information about the marginal productivity of water. The low level of adoption of efficient irrigation systems in the region might be explained partly by historically poor water governance and insufficient extension regarding water productivity and technology.