土壤风蚀对边际耕地质量影响评价——以河北省丰宁坝上高原为例

文章在综合分析河北省丰宁坝上区域自然环境条件与土地利用特征的基础上,在暗栗钙土区域布设6个旱耕地样区,并在每个样区用梅花布点法布设12个观测样点,采集土壤样品并进行化验分析,依据《农用地质量分等规程》和综合比较研究法,综合评价了土壤风蚀对耕地质量等级的影响。结果表明,丰宁坝上区气候条件是边际耕地形成的主因;冬春季松散、干燥、裸露的耕地表土遭受风蚀,致使耕作层有机质、黏粒、粉粒含量分别减少了约46%、31%和26%;研究区耕地土壤风蚀平均速率为3.67mm/a,可使耕地质量等级每年降低0.75%,且随时间耕地质量等级将呈现加速下降趋势;现有的土壤质地划分方法难以刻画风蚀对表土层土壤质地的影响,亟待研发更为详细的土壤质地划分方案。     

四川省土壤侵蚀空间分布规律研究

为了摸清四川省土壤侵蚀空间分布情况,依据全国土壤侵蚀分级系统、强度划分体系,利用GIS分析方法对全省土壤侵蚀类型与强度进行了分析。研究结果表明:①土壤侵蚀类型分水蚀、冻融侵蚀和风蚀三类,但侵蚀类型的空间差异明显,水蚀严重区位于川东,冻融侵蚀作用影响区为川西,风蚀影响区为川北一带;②水力侵蚀为土壤侵蚀最主要的类型,影响面积占总面积的87.7%,冻融次之,风蚀影响面积最小;③侵蚀强度分析显示水力侵蚀强度最大,风蚀强度次之,冻融侵蚀对土壤的破坏程度最小;④土壤侵蚀的分布与地貌、海拔、坡度、坡向等地形因素及与人类的活动密切相关。     

夏季果树管理之我见

果树的夏季管理措施是否到位,特别是果树管理中的修剪、地下管理、果实套袋、病虫害防治等方面的管理与技术不仅对当年的产量和果实品质影响极大,而且对果树的生长发育带来影响,甚至影响到来年果树的花芽多少、产量高低。可见加强果树的夏季管理十分重要。     

保护性耕作技术

<正>保护性耕作是一项通过对农田实行免耕少耕和秸秆留茬覆盖还田、控制土壤风蚀水蚀和沙尘污染、提高土壤肥力和抗旱节水能力以及节能降耗和节本增效的先进农业耕作技术。其核心技术包含秸秆及残茬覆盖技术、免(少)耕播种技术、深松技术和杂草及病虫害防治技术。秸秆及残茬覆盖技术是保护性耕作的基础,秸秆覆盖的好坏,直接关系着保护性耕作技术实施的成败。免(少)耕播种技术是保护性耕作技术实施的保     

组织嵌入如何影响果农绿色生产行为?——基于有调节的中介效应模型

文章基于陕西、山西、甘肃三省的607户苹果种植户调研数据,构建果农职业化水平指标体系,利用因子分析法测度果农职业化水平,并采用Bootstrap法实证检验组织嵌入对果农绿色生产行为的影响及其路径。研究结果表明:组织嵌入对果农测土配方施肥技术、物理防治技术采纳有显著的正向影响,而对水肥一体化技术采纳、生物防治技术采纳没有直接影响;职业化水平在组织嵌入影响果农水肥一体化技术采纳、中高收入果农组测土配方施肥技术、中低收入果农组生物防治技术采纳的过程中发挥正向中介作用;苹果收入占比在职业化水平影响果农测土配方施肥技术、生物防治技术采纳的过程中发挥正向调节作用。苹果产业组织应发挥其服务功能,加强绿色生产技术培训,进一步提升果农职业化水平。     

春小麦套种玉米吨粮田技术

建设吨粮田的产量指标一般为亩产８５０公斤一１０００公斤，其中小麦２５０公斤一３５０公斤，玉米６００公斤一７００公斤。全套技术包括备耕播种、共生期管理、麦收后管理、土壤培肥四个环节，共１８条措施，现将操作技术介绍如下：一、备耕播种：１．选地与整地选排灌良好的砂质土壤，盐分含量低，最好是肥沃的壤土。如果是粘土，无风蚀，最好秋深翻冬灌，有利于土壤的充分熟化，砂性土壤，易遭风蚀时则春翻，春翻一定要早。结合深翻施足基肥，砂性土壤中施牛粪、猪粪２０００公斤一２５００公斤／亩，秋翻不宜压碳铵，春翻可压碳铵１５…     

油田城市地表土壤石油污染特点及其防治对策

油田城市石油对土地的污染,不仅造成了石油资源的浪费,而且破坏生态环境、危害人类健康;分析了石油污染的特点,对油污土壤的防治措施进行了探讨,提出预防第一,治理第二的指导思想和净化土壤与原油回收同时进行的处理原则;在目前使用的物理、化学和生物三大类方法中,提倡利用生物技术治理油污土壤。     

无公害水产品生产中的病害防治技术

<正>近年来,随着消费者对水产品质量安全的要求越来越高,以及市场准入制度的建立,发展无公害水产养殖,生产出具有无污染、高品质能被国内外市场认可的水产品,除水质、土壤、大气等环境条件必须符合要求的基础上,对生产投入品(饲料、肥料、渔药)都具有较高的要求,其中病害防治用药是最关键的技术措施。根据笔者的实践,在无公害水产品养殖生产过程中,防治病害应注意以下几个问题。     

新疆棉农棉花技术需求调查研究

先进技术的采用是降低棉花生产成本,提高棉花生产能力,提高棉农收益的根本举措。文章以新疆棉农棉花技术需求为研究对象,通过实地调查获取相关数据,采用描述统计分析方法,研判棉花技术需求的优先序。结果表明:新品种技术、病虫害防治技术、科学施肥是棉农急需的技术;而农户在技术选择的过程中受文化程度、技术获取渠道、机械化程度和农民专业合作社的推广等因素的影响。通过加强技术培训力度、加大棉花技术培训绩效、创新棉花生产技术服务模式和加强棉花技术推广支持等措施,有助于提高农户对棉花生产技术的认知与需求,优化棉花生产服务模式,推动新疆棉花技术创新。     

丘陵地区提高柑橘果实品质及产量措施

影响柑橘果实品质及产量除气候因素外,最重要的因素有品种、土壤条件、肥水、修剪等管理水平。通过改良土壤、加强肥水管理、合理修剪、综合防治病虫、适时采收等措施可达到提高柑橘果实品质及产量的目的。     

小浪底库周与移民安置区环境影响研究

分析了小浪底工程对库周及移民安置区土地、生物、水资源以及公共卫生的影响,对该区的可持续发展提出了水土保持、调整农业结构、防止水土流失、小流域综合治理、建立保护区、加强环境管理等相应的对策。     

Household adoption behaviour of improved soil conservation: the case of the North Pare and West Usambara Mountains of Tanzania

The mountains in the northeastern part of Tanzania have been experiencing declining soil fertility and severe soil erosion due to increased cultivation and other factors attributed to population pressure. This study gives the main results of an analysis of household adoption behaviour towards the use of improved soil conservation measures. An interdisciplinary analytical framework for analyzing household adoption behaviour is presented. The framework links three components of the adoption decision process: the perception of the erosion problem, the decision to use improved conservation measures and the level of investment or effort devoted to soil conservation among adopters. Data collected from a random sample of 300 heads of households was used to estimate logit models of perception of the erosion problem and of adoption of improved conservation measures, and a Poisson regression model of effort devoted to conservation. The results show that participation in promotional activities of soil and water conservation (SWC) programmes influences the adoption decision process at all three stages. Also, ranking of soil erosion as the priority problem in agricultural production, participation in labour-sharing groups and having off-farm income influence the willingness and ability to use improved soil conservation technologies and the level of soil conservation effort.     

青藏高原涅如藏布流域生态环境现状与对策

分析了青藏高原涅如藏布流域生态环境的主要问题———水土流失,流域水土流失特征为风力侵蚀和水力侵蚀面积广、侵蚀强度以轻度侵蚀和中度侵蚀为主;自然因素是造成水土流失的主导因素;讨论了高原流域生态环境保护的主要对策。     

A model of shifting cultivation: can soil conservation reduce deforestation?

Shifting cultivators manage soil not only by adjusting soil use on already‐cleared lands, as in continuous cultivation, but also by clearing forests to obtain new fertile soils. This study examines the crucial link between on‐farm soil conservation and deforestation in shifting cultivation by modeling forest clearing as an investment in soil for a private farmer. More generally, by doing so the study attempts to integrate deforestation and soil conservation models which have been separately developed in the literature. Our policy goal is to arrest tropical deforestation—as destruction of global commons—caused by land degradation in shifting cultivation while improving the well‐being of poor shifting cultivators. Our integrated approach enables joint policy analyses of deforestation and land degradation. Three welfare‐enhancing policies are considered. The first is agricultural and nonagricultural subsidies affecting farm and nonfarm income opportunities. The second is fiscal and tenure policies affecting discount rates. Our question is whether the link between forest clearing and soil fertility alters the outcomes of these two standard macroeconomic policies commonly found in the literature. The third policy (or program) is various soil conservation measures affecting soil regeneration and erosivity on already‐cleared lands. This article examines a very important question which has received little attention in previous theoretical works: can soil conservation reduce deforestation? This study confirms anti‐deforestation effects of the promotion of nonfarming activities—a common and often emphasized finding in previous works—among shifting cultivators. More importantly, it also demonstrates that improving various soil conservation measures not only discourages forest clearing among shifting cultivators but also tends to have greater effects on forest protection than promoting nonfarming activities. Contrarily, agricultural price subsidy or technological progress gives rise to the opposite outcome, and lowering the farmer's discount rate or improving tenure security encourages him/her to clear more forests just to accumulate soil.     

A Metamodeling Approach to Evaluate Agricultural Policy Impact on Soil Degradation in Western Canada

A novel approach for integrating economic and environmental models is described in the context of evaluating soil degradation impacts of agricultural policy in western Canada. The key element of this approach is the development of metamodels, which are statistical summary functions of simulation data obtained from carefully designed experiments with physical process models. The metamodels are in turn used to predict the soil degradation impacts of farmers'land management responses to policy options. The metamodels provide flexibility to perform repeated policy scenarios without having to rerun the time-and resource-consuming physical process simulation models. The estimated wind and water erosion metamodels are very robust, with the majority possessing R-square values in the range of 0·80 to 0·97. The efficiency of the metamodels in facilitating the integration of a policy modeling system is described and applied to a scenario of increased crop residue management. Using regional aggregates of net farm income, total economic, surplus (consumer plus producer surplus) and total soil loss the economic and environmental tradeoff between the status quo and a no-till policy scenario is evaluated. The model-predicted economic welfare and environmental quality interaction suggests a clear win-win situation for society under this alternative policy scenario.     

Strategies to increase agricultural productivity and reduce land degradation: evidence from Uganda

This paper estimates a structural econometric model of household decisions regarding income strategies, participation in programs and organisations, crop choices, land management, and labour use, and their implications for agricultural production and soil erosion; based upon a survey of over 450 households and their farm plots in Uganda. Many factors have context-specific impacts and involve trade-offs between increasing production and reducing land degradation. Government agricultural extension and training programs contribute to higher value of crop production in the lowlands, but to soil erosion in the highlands. By contrast, non-governmental organization (NGO) programs focusing on agriculture and environment help to reduce erosion, but have less favourable impacts on production in the lowlands. Education increases household incomes, but also reduces crop production in the lowlands. Poverty has mixed impacts on agricultural production, depending on the nature of poverty: smaller farms obtain higher crop production per hectare, while households with fewer livestock have lower crop production. Population pressure contributes to agricultural intensification, but also to erosion in the densely populated highlands. Several household income strategies contribute to increased value of crop production, without significant impacts on soil erosion. We find little evidence of impact of access to markets, roads and credit, land tenure or title on agricultural intensification and crop production and land degradation. In general, the results imply that the strategies to increase agricultural production and reduce land degradation must be location-specific, and that there are few 'win-win' opportunities to simultaneously increase production and reduce land degradation.     

Factors affecting farmers’ acceptance of conservation measures—A case study from north-eastern Germany

Intensive forms of agriculture have been proven to cause severe environmental effects, such as soil erosion by water and wind, or the pollution of ground and surface water with nutrients and pesticides contributing to the deterioration of natural habitats and the loss in biodiversity. In order to avoid or mitigate these detrimental environmental effects, a number of conservation measures can be undertaken by farmers. However, the adoption of these measures is highly dependent on the assumed benefits and risks attached as well as the personal perception and attitude of the individual farmer.This paper presents the outcome of a survey conducted in north-eastern Germany aimed at analysing farmers’ acceptance of different conservation measures. Eleven farmers, managing more than 80% (about 13,000 ha) of the agricultural land in the chosen case study region were interviewed. Respondents were asked about their personal experiences with different environmental measures and requested to assess these measures, e.g., regarding costs, time and labour demands, attached risks, or effectiveness. They also ranked these factors in terms of importance for decision making on adoption or rejection of a new measure. The findings show that, despite of the general assumption that farmers’ decisions are mostly driven by economic rationality, costs were not the most important factor. Other factors, like associated risks, effectiveness, or time and effort necessary to implement a certain measure were equally or even more important depending on the specific situation.     

The estimation of agricultural policy effects on soil erosion—An application for the bio-economic model MODAM

As agricultural policies affect land use, they have effects on the amount of soil erosion in agricultural regions through changes of the economic conditions of agricultural production. Prices of inputs and outputs, regulations and incentives can change, forcing or encouraging farmers to adopt new crop rotations. This paper shows how a bio-economic model can be used to describe and estimate the effects of policies on agricultural production and the risk of soil erosion at the example of a region in North-Eastern Germany. The model uses both an assessment tool that is based on a fuzzy-logic approach for the estimation of soil erosion risk of cropping practices, and a linear programming model, that simulates farmers’ economic behaviour under the assumption of gross margin maximisation being the main goal of farmers’ actions.The analysed policy options were both a targeted and an untargeted incentive programme for reduced tillage, and a restriction option where high erosive crops are not allowed on high erodible field types. The results show that policy changes can have an impact on soil erosion. Furthermore, soil conservation policies are shown to have different levels of efficiency in terms of reduced soil erosion related to the costs of the policy. In the case of this study, a restriction option was more efficient than the incentive options. The results of such simulations can serve as a decision support for the development of soil conservation policies and help to foresee the effects of general changes of agricultural policies.     

Land management,erosion problems and soil and water conservation in Fincha’a watershed,western Ethiopia

The knowledge of soil erosion processes, attitude towards rational use of resources and institutional support affect the capability of farmers to implement soil and water conservation (SWC) measures. This research was conducted to determine soil erosion problems and the factors that affect the adoption of SWC measures in Fincha’a watershed, western Ethiopia. A total of 50 farmers were interviewed using a semi-structured questionnaire, and two group discussions were held with 20 farmers. Moreover, transects were walked to classify erosion features, and a quantitative erosion survey was made on 19 farm plots during the rainy season of 2004. The results showed that crop fields are affected by annual soil losses ranging from 24 to 160 Mg ha⁻¹. Farmers are well aware of these erosion problems, and related the soil loss to steep slopes and a decline in soil fertility. However, they did not invest much in SWC measures, but apply soil management practices to sustain crop yields. The wealth status of farmers, land tenure arrangements and lack of access the farmers have to information are the major factors affecting SWC adoption. High labour demand of SWC measures, lack of short-term benefits and free grazing have negatively affected SWC adoption. Soil erosion problems in Fincha’a watershed have both on-site and off-site effects that require integrated SWC planning at watershed scale.