Adoption decision and use intensity of soil and water conservation measures by smallholder subsistence farmers in Dedo District,Western Ethiopia

Soil degradation in the highlands of Ethiopia is a serious problem that threatens the sustainability of agriculture. Although efforts have been made to develop and promote several soil conservation technologies, their adoption has not been widespread. This study, based on responses from a sample of 101 households which operate on 204 plots in Western Ethiopia, interviewed in 2003 cropping year, employed a Tobit model to identify the main factors influencing farmers' decision to adopt and intensify the use of improved and indigenous soil and water conservation (SWC) measures. The results suggest that area of cultivated land, land/labour ratio, age and education level of household head and distance of the plot from home and slope of the plot provided statistically adequate predictive power on the use and intensity of SWC measures. These results are discussed and their implications for conservation programs are presented in the conclusion. Copyright © 2006 John Wiley & Sons, Ltd.     

山东省农业污染综合分析与评价

山东省的农业生产在全国占有重要地位,然而农业非点源污染的日益严重使产地环境质量问题日趋突出,对优势农产品的生产与出口构成巨大威胁。从化肥、畜禽粪便、生活排污、秸秆、农药、地膜6个方面分析了目前山东省农业污染的主要影响因素,计算了2001—2006年主要污染源中氮、磷元素的排放量与流失量。结果表明,农业生产过程中农业化学品的大量投入与农业废弃物的大量产出及不合理利用,是目前山东省农业污染发生的主要原因;在对氮、磷流失负荷的贡献上,畜禽粪便、化肥与生活排污是农业污染的3种主要污染源,2006年3种污染源共造成6.73×105t氮素与1.35×105t磷素流失,其中畜禽粪便、化肥与生活排污分别占50.78%,41.99%,7.22%与80.30%,11.78%,7.93%;山东省农业污染在源头预防层次上应重点加强两方面的研究,一是化肥等农用化学品的高效施用技术,二是畜禽粪便等农产废弃物的资源化利用技术。     

Pasture renovation practices of farmers in the neotropical savannahs

Degradation of sown pastures in the neotropics is a well known but poorly documented phenomenon. The paper reports the results of a survey conducted in the eastern savannahs of Colombia to quantify farmers' reactions to perceived pasture degradation. The survey was conducted in an area of 23 644 km². The sample consisted of 46 farms, which had 19 012 ha of Brachiaria decumbens pastures distributed in 374 paddocks. Of these paddocks, 196 had been sown with vegetative seed, and 281 had received modest rates of P fertilization at planting. Pastures sown on flat lands had younger modal ages (three years) and were renovated more frequently than those sown on hilly or dissected savannahs (10 years). These differences were probably a result of variations in infrastructure and relative stage of development of the two topographies, but slight differences in inherent soil fertility may also have played a role. We found no relationship between grazing management and frequency of pasture renovation. Implications for future research on pasture reclamation are discussed. © 1998 John Wiley & Sons, Ltd.     

Cropping strategies,soil fertility investment and land management practices by smallholder farmers in communal and resettlement areas in Zimbabwe

Three smallholder villages located in typical communal (from 1948), old (1987) and new (2002) resettlement areas, on loamy sand, sandy loam and clay soils, respectively, were selected to explore differences on natural resource management and land productivity. Focus group discussions and surveys were carried out with farmers. Additionally, farmers in three wealth classes per village were chosen for a detailed assessment of their main production systems. Maize grain yields (t ha⁻¹) in the communal (1·5–4·0) and new resettlement areas (1·9–4·3) were similar but significantly higher than in the old resettlement area (0·9–2·7), despite lower soil quality in the communal area. Nutrient input use was the main factor controlling maize productivity in the three areas (R² = 59–83%), while soil quality accounted for up to 12%. Partial N balances (kg ha⁻¹ yr⁻¹) were significantly lower in the new resettlement (−9·1 to +14·3) and old resettlement (+7·4 to +9·6) than in the communal area (+2·1 to +59·6) due to lower nutrient applications. Averaged P balances were usually negative. Consistently, maize yields, nutrient applications and partial N balances were higher in the high wealth class than in poorer classes. This study found that most farmers in the new resettlement area were exploiting the inherent soil nutrient stocks more than farmers in the other two areas. We argue that effective policies supporting an efficient fertilizer distribution and improved soil management practices, with clearer rights to land, are necessary to avoid future land degradation and to improve food security in Zimbabwe, particularly in the resettlement areas. Copyright © 2009 John Wiley & Sons, Ltd.     

Determinants of farmers' willingness to pay for soil conservation practices in the southeastern highlands of Ethiopia

This paper examines the determinants of farmers' willingness to pay for soil conservation practices in the highlands of Bale, southeast Ethiopia. The paper is based on analysis of data collected from 100 randomly selected household heads. The study applied Contingent Valuation Method for the purpose of eliciting farmers' valuation of soil conservation practices in terms of both cash payment and labour contribution. The results reveal that farmers in the study area are less willing to pay cash for soil conservation measures. In terms of labour contribution, however, it was found that they are willing to spend a substantial amount of time per week. Results from logistic regression analysis show that farmers' decisions to participate in soil conservation practices are influenced by a host of factors. The implication is that taking these factors into account while planning soil conservation measures enables policy makers to come up with projects that win acceptance by the local people. Copyright © 2004 John Wiley & Sons, Ltd.     

Farmers' perception of environmental degradation and their adoption of improved management practices in Alxa,China

The environment and the natural resource base have been severely degraded in Alxa League, western Inner Mongolia, China, over the past half‐century. This study reports surveys that reveal farmers' perceptions of environmental degradation and their adoption of improved management practices in this poor and remote desert region. Surveys were made in villages that had been engaged in a large environmental rehabilitation and management project [Alxa League environmental rehabilitation and management project (ALERMP)] and those that had not. The survey results showed that farmers perceived environmental degradation in terms of increased frequency and severity of sandstorms, movement of sand dunes, deterioration of pasture quality and declines in groundwater depth and quality. Farmers had low adoption rates for improved management practices, ranging from zero to a maximum of 28·5 per cent for the most adopted practice. A Tobit model analysis showed that the education level of farmers, the availability of extension services and whether farmers had participated in ALERMP were highly significantly correlated with the farmers' perception of degradation. The farmers' adoption of improved management practices was found to be significantly correlated only with whether they had participated in ALERMP. This shows that specific extension activities of the type possible in large and well‐funded projects are required if farmers are to recognise degradation and adopt improved management practices. The promotion of farmer education and strengthening of extension services are recommended as the best policy strategies for improving environmental management in this region. Copyright © 2009 John Wiley & Sons, Ltd.     

绿色防控技术采纳行为的影响因素和生产绩效研究——基于四川省水稻种植户调查数据的实证分析

绿色防控技术的应用推广顺应了当前农业绿色发展的迫切需要,但现有针对农户绿色防控技术采纳行为的研究在影响因素的综合分析和生产绩效的分析方法上存在不足。本文以四川省水稻种植户为例,对采纳绿色防控技术的影响因素和生产绩效进行定量分析,旨在为促进四川省农业绿色防控技术的有效推广提供政策参考,丰富绿色防控技术应用推广的理论研究。本文基于四川省水稻种植户调查数据,采用Logit模型分析影响农户绿色防控技术采纳行为的主要因素并估算绩效倾向得分,运用DEA-PSM模型分析农户采纳绿色防控技术对生产绩效的影响效应。结果表明:性别为男性、受教育程度越高、种植面积越大、加入合作社、距离乡镇和县城越近、参加过绿色防控技术培训、采纳绿色防控技术生产的安全农产品能够获得市场溢价、认为农业生态环境质量不好、愿意减施农药的农户,采纳绿色防控技术的可能性越大。调查农户的水稻生产绩效介于0.103～1.000,绩效平均值为0.471,在不改变技术水平以及投入规模的情况下,仍有52.9%的绩效提升空间;大部分农户的生产绩效处于0.4～0.6,农户生产效率普遍不高。而从调查区域来看,邛崃、宣汉、泸县的水稻生产绩效均值分别为0.558、0.379和0.467,区域间生产绩效存在显著差异。采用最近相邻匹配法、半径匹配法和核匹配法,测算绿色防控技术采纳对水稻生产绩效的影响效应,结果表明是否采纳绿色防控技术的生产绩效差异较小,且绿色防控技术采纳对水稻生产绩效的影响也不显著。因此,营造农户绿色防控技术采纳的外部环境、激发农户绿色防控技术采纳的内生动力,发挥绿色防控技术的节本增收效应,是推动该技术应用推广的关键。     

Sand-dust storms in and around the Ordos Plateau of China as influenced by land use change and desertification

The occurrence of sand-dust storms induced by wind erosion is a process that accelerates land degradation and can also be considered as an indicator of desertification. Thus, it is of significance both in theory and in practice to reveal the interaction between these two phenomena. Based on data from the Ordos Plateau and its surrounding areas, a study has been made of the effect of land degradation and land use changes on sand-dust storms. In this study, we report a non-linear relationship between sand-dust storm frequency and the index of land degradation (I_d), which is defined as the percentage of the area of total land that is desertified. Using this non-linear relationship, a threshold at I_d = 30% is established such that, when I_d < 30% sand-dust storm frequency does not change with increasing I_d but when I_d > 30%, sand-dust storm frequency increases rapidly. This existence of such a threshold means that sand-dust storm frequency would increase abruptly when the human-induced I_d exceeds 30%. The time series of annual number of sand-dust storm days in the neighbouring area has been compared to the time series in the annual number of strong wind days and the time series in the area of cultivated land in Yikezhao Meng, and a multi-regression equation has been established. Based on the equation, the relative contributions of the variations in land use and in annual number of strong wind days to the variation in annual number of sand-dust storm days have been estimated as 59.7% and 40.3%, respectively, indicating that the frequency of sand-dust storms may be effectively decreased by reducing the area of cultivated land and restoring the natural steppe vegetation in ecologically fragile areas in arid and semi-arid climates.     

山东省化肥使用时空分异及潜在环境风险评价

为了更为系统地认识农田化肥过量使用对生态环境的潜在威胁机理,加强化肥使用风险管控,该研究以山东省为实证对象,对其化肥使用的时空分异和环境风险进行评价。通过综合考虑化肥使用的强度、效率、环境安全阈值、环境效应权数及作物复种指数等因素,构建了化肥使用面源污染环境风险评价指数模型。结果表明:山东省的化肥使用明显过量。634.1 kg/hm~2的化肥使用强度是中国生态县建设标准250kg/hm~2的2.5倍。化肥使用强度最高的枣庄市878.7 kg/hm~2,是最低的滨州市473.7 kg/hm~2的1.85倍,区域差异不太悬殊。2012年山东省化肥污染的环境风险指数是0.75,总体处于中度风险程度。但是,烟台市处于严重风险,潍坊、济宁和枣庄处于重度风险。同时山东省存在磷肥污染严重环境风险,氮月巴污染重度环境风险,钾肥污染中度环境风险。山东省过量的化肥使用不仅存在较为严重的环境污染风险,并对生态环境产生了不利影响。国家和地方应该尽快实行地区化肥使用总量控制和分区管控指导,确保农业健康可持续发展。     

山东省种植区地下水硝酸盐污染空间变异及分布规律研究

近年来,我国部分地区地下水硝酸盐污染态势十分严峻,特别是集约化种植区由于施用大量氮肥导致的硝酸盐污染更为严重。为控制污染,应掌握地下水硝酸盐污染的空间变异规律与分布特征。采用地统计学方法,对山东省种植区地下水硝态氮含量数据进行空间变异分析。结果表明,不同区域地下水硝态氮含量存在一定的差异,存在明显的趋势效应以及变异性,且含量随地下水深度增加而减少。通过相关性分析,获得与地下水硝态氮含量相关性最高的两个因子（土壤有机质含量和全氮含量）,并作为协克里金（Cokriging）插值方法中的协同因子,对山东省地下水硝酸盐污染进行插值。经比较分析,协克里金法比普通克里金法（Ordinary Kriging）的精度高,减少了80%的平均误差。协克里金法空间插值结果表明,空间分布规律表现在从西南到东北逐渐升高的方向性效应,而地下水硝态氮含量较高的区域主要分布在潍坊、青岛、烟台种植区,如青岛的平度、莱西,潍坊的寿光等农业较发达的种植区。     

山东省高速公路两侧土壤的铅污染及绿化带的防护作用

汽车尾气会对高速公路两侧土壤和绿化树木带来一定程度的Pb污染,而两侧的绿化带可对Pb污染起到防护作用,目前这方面的研究还很少。本文对山东省5条主要高速公路两侧土壤和绿化树木叶片Pb含量进行取样测定,研究了山东省高速公路两侧Pb污染现状,并对不同模式绿化林带对公路Pb污染的防护作用进行了评价。结果表明,山东省高速公路两侧土壤存在一定程度的Pb污染,主要集中在路侧50 m范围内;高速公路Pb污染与车流量之间呈显著正相关,车流量对Pb污染有一定指示作用;高速公路Pb污染也明显增加了绿化带内侧树木叶片的Pb含量,车流量较大的公路对树木的污染也越重;在不同绿化模式下,两侧林带对公路Pb污染的防护作用存在较大差别,宽度过大的林带并不是防护Pb污染的理想措施。     

基于ISM模型的山东省农村生活环境污染影响因素分析

农村生活环境污染影响因素复杂多样。通过实地调研,从生活污水、生活垃圾、生活能源和农村厕所4个层面,识别出影响山东省农村生活污染的11个具体因素,运用ISM模型分析山东省农村生活污染的影响因素及其层次关系。结果表明:11个影响因素之间相互关联,构成一个5层级的影响因素递阶结构,其中卫生知识和环保意识是表层直接影响因素;户主受教育程度、家庭经济水平、所在村对环境保护的重视程度、非农业就业经历、政府投入和基础设施投入是中层间接影响因素;年龄、城镇化水平和人口居住密度是深层根源影响因素。     

Determinants for adoption of physical soil and water conservation measures by smallholder farmers in Ethiopia

Adoption rates of soil and water conservation measures remain below the expected levels in Ethiopia despite the considerable investments in reducing land degradation and improving soil fertility. This constitutes one of the key research agendas in the country. This paper underscores the need for investigating the factors hindering or facilitating the adoption of soil and water conservation measures. The study results presented in this paper are based on cross-section data collected from 408 households in eastern Ethiopia, including field observations of 790 plots selected using a multi-stage sampling procedure. A multivariate probit model was employed to analyse the determinants of adoption of three soil and water conservation measures (stone bund, soil bund, and bench terracing) at the plot level. The study findings reveal that household, socioeconomic, and institution characteristics were the key factors that influenced the adoption of soil bund, stone bund, and bench terracing conservation measures. Furthermore, there was a significant correlation among the three soil and water conservation measures, indicating that the adoption of these measures is interrelated. In particular, the results show that there was a positive correlation between stone bunds and soil bunds. However, the correlations between bench terracing and stone bunds as well as bench terracing and soil bunds were negative (implying substitutability). These results imply that the Government and other relevant organizations that are responsible for reducing land degradation in order to increase agricultural production should support the establishment and strengthening of local institutions to facilitate the adoption of soil and water conservation measures.     

土壤环境污染与农产品质量

通过分析土壤污染的原因、特点、我国土壤污染现状以及与农产品质量关系,提出了协调人与自然关系,积极研究土壤环境污染的控制方法与修复技术;加强无污染生产资料的开发技术研究,减轻土壤环境污染;走节约资源,提高效率,减少污染的绿色农业发展之路,确保粮食生产和农产品食用安全。     

不同养分管理对东北东部半山区地下饮用水硝态氮的影响

为了探讨不同养分管理方式对东北东部半山区村镇地下饮用水水质的影响,该文在辽宁省清原满族自治县选择典型地下饮用水源区域,通过近2 a的田间试验,研究结果表明：常规养分管理和农田养分管理施氮量分别为240 kg/hm2和192 kg/hm2,与常规养分管理相比,农田养分管理处理氮肥农学生产力显著高于常规养分管理处理,提高了22.47%;浅地下水埋深区,地下水硝态氮质量浓度增幅为深地下水埋深区1.6倍;减N 20%农田养分管理措施实施后,区域地下水硝态氮质量浓度较常规养分管理措施削减了51.19%。因此,采取农田养分管理措施降低了农田施肥对浅层地下饮用水源地污染风险,这对于村镇地下饮用水水源地的保护及村镇居民安全饮水具有重要意义。     

规模养猪场户清洁生产认知与行为的影响因素及其作用机理——基于山东省509家规模养猪场户的调查数据

生猪养殖是重要的环境污染源,规模养猪场户实施清洁生产行为是防治生猪养殖污染的重要途径。为从根本上降低生猪养殖污染,避免废弃物末端治理带来的弊端,实现环境效益与经济效益相统一。依据计划行为理论,利用山东省17地市509份问卷调查数据,运用结构方程模型,实证研究了规模养猪场户清洁生产认知与行为的影响因素及其作用机理。结果表明,由如何看待清洁生产和对生猪养殖污染熟悉度组成的规模养猪场户清洁生产态度,以及由年龄、受教育年限和生猪养殖出栏量组成的规模养猪场户禀赋特征对清洁生产认知具有显著的正向影响;由政府对清洁生产支持力度和经营组织对清洁生产的要求组成的外部规范对清洁生产认知有正向影响,但并不显著;规模养猪场户清洁生产认知对源头预防行为、过程控制行为和末端治理行为有显著的正向影响;规模养猪场户清洁生产态度、禀赋特征及外部规范约束对清洁生产行为有间接影响。其作用机理为：规模养猪场户清洁生产行为受制于认知程度,而认知程度又是行为主体态度、外部规范和主体自身禀赋特征共同作用的结果,而三者产生的作用条件又归因于外界环境（政府机构、经营组织、上下游企业等）与行为主体间的不断沟通。可见,规模养猪场户清洁生产行为作用机理并非单个因素间简单的线性作用,而是全产业链参与者与其所处环境间相互作用的结果。因此,应当根据认知与行为的影响因素和作用机理,提高规模养猪场户对清洁生产的积极态度,加强外部规范性,强化主体自身良好的禀赋,通过较高的认知水平正向作用于行为的形成和完善,并最终从根本上降低生猪养殖污染,实现经济效益与环境效益相统一。     

湖北省三峡库区农业面源污染解析

湖北省三峡库区农业面源污染物类型复杂,来源不明,底数不清,导致防控措施不力。采用综合调查法对4个库区县（区）2007年农业面源污染情况进行调查,运用排污系数法测算污染物负荷量,采用等标污染负荷法进行评价与源解析。结果显示,湖北省三峡库区2007年农业面源TN、TP和COD的排放/流失总量分别为2918.08、346.22、12461.10t.a-1;主要污染物是TN和TP,其等标污染负荷量分别为5836.16、3462.20m3.a-1,两者等标污染负荷比和为91.80%;库区内主要农业污染源是种植业和畜禽养殖业,其等标污染负荷比分别为56.08%和34.37%,而农村生活污染源只有7.99%;4个县（区）污染负荷的比重为夷陵区〉巴东县〉秭归县〉兴山县。因此,针对湖北省三峡库区农业面源污染的控制策略：防控的污染物主要是TN和TP,防控的重点源为种植业和畜禽养殖业,防控的重点区域为夷陵区。     

平原农区空心村典型土壤的重金属污染评价——以山东省禹城市为例

空心村整治是农村土地综合整治的重要内容,在以土地可持续利用为核心的目标导向下,揭示空心村内典型土壤重金属污染情况是整治工作特别是构建耕层土体的先导环节。本文以黄淮海平原农区的禹城市为例,分析典型空心村在整治时可能涉及的村内道路、晾晒场院、坑塘底泥、林地表土、院落农地、院落实土、土墙墙体等7种土壤的As、Cd、Cr、Cu、Ni、Pb、Zn含量,利用单项污染指数和综合污染指数,按照有关国家标准,评价其重金属污染程度,为空心村改造中土壤的安全、合理利用提供依据。结果表明:前述7类参试土壤中,除院落农田的污染指数为0.85(污染等级为Ⅱ,属"较清洁"土壤)外,其余6类的综合污染指数均0.7(污染等级为Ⅰ,属"清洁"土壤),可直接用于空心村整治中的耕层土体重构。本研究基于整治利用导向进行了平原农区空心村典型土壤类型划分,揭示了其重金属污染状况,对于科学开展空心村整治、建设更加安全的高标准农田具有重要参考价值。     

基于SWAT模型的东北水稻灌区水文及面源污染过程模拟

灌区水文过程对于面源污染物的迁移、转化起到了重要的驱动作用。为揭示东北水稻灌区的水文及面源污染过程,该文在多年试验的基础上,运用修正的SWAT模型对其开展了模拟研究。2009-2011年在吉林省前郭灌区针对水稻生育期及冻融期内的灌区水文过程和农田面源污染物迁移、转化过程开展了系统的监测与试验。水稻生育期内,各级排水系统表现出不同的水文过程:末级排水沟中,由田间通过表层渗流进入排水沟的高浓度的水被灌溉退水所稀释,汇流排水沟的槽蓄量则在很大程度上影响了排水过程及污染物的对流和掺混过程。根据水稻灌区水文特性,以汇流排水沟为子流域,分别采用非稳定渗流公式和马斯京根法描述子流域中稻田向排水沟的渗流排水过程以及向子流域出口的排水汇流过程。试验和模拟结果表明:铵氮(NH4+)、硝氮(NO3-)和化学需氧量(COD)的浓度变化主要取决于排水过程,表层渗流和深层渗流过程决定了排水沟中NH4+和NO3-浓度过程,而排水沟中COD浓度还受到灌溉退水的影响。采用溴(Br-)作为示踪剂,通过测定土壤含水率、温度及示踪剂浓度变化,研究了冻结期的水文过程和面源污染物迁移过程,示踪试验结果显示,冻融期土壤中水流运动受到土壤基质势、温度势及重力势的影响,冻土中平衡状态下基质势为土壤温度的函数,土壤中污染物渗出通量与水分渗出通量表现出线性关系。基于水稻灌区下垫面产汇流特性和冻融期土壤对于灌区水文过程以及面源污染物迁移的影响机理,在SWAT模型模块修订的基础上,模拟了东北地区水稻灌区面源污染迁移流失过程,模拟流量、NH4+、NO3-、COD浓度与实测值符合较好,表明改进的模型能够用于东北地区水稻灌区的水文及面源污染过程模拟。     

山东省农业信息化建设与利用问题探析

农业信息化是现代农业发展过程中的一个重要特征,是促进农民增产增收的重要保证。分析认为山东省农业信息化建设成果的应用效率低主要是信息内容的实用性差、服务面窄,以及当前农业“从业人员”的信息素养低。提出应在政府的主导下,加快涉农信息资源的整合与传播,建立专家咨询系统,增强信息的实用性,同时加快农业信息化专业人才培养,提高农民的信息素养。