农业可持续性初探

农业可持续发展关系到中国农业经济发展的未来,也是解决中国＂三农＂问题的根本。文章从中国农业可持续发展的内涵出发,探索了中国农业可持续性的特征以及影响农业可持续发展的因素。     

气候变化对山东省农业生产影响研究

从山东省1985～2009年年平均气温入手,得出山东省的年平均气温有逐年升高的趋势;进而从农业生产入手,运用计量经济学中的回归分析方法分析了影响山东省农业生产的主要因素为化肥施用量与农业机械总动力,其同时也能增加温室气体的排放,导致气候变暖;最后根据模型给出了农业生产的几个建议。     

Soil Organic Carbon,Biochar, and Applicable Research Results for Increasing Farm Productivity under Australian Agricultural Conditions

The conversion of vegetative biomass waste to biochar (biologically derived charcoal) is a source of carbon (C) that can be used to increase the level of soil organic C (SOC) in agricultural soils. This review collates available research into the effects of biologically derived C species with respect to the direct and indirect effects on agricultural productivity and their potential for use in Western Australian agricultural systems. There is a growing requirement to quantify the effect of specific biochar applications for agroecological purposes and to verify biosequestered C for climate-change-mitigation activities. This work provides a review and assessment of safe biochar application rates and examines the present levels of scientific uncertainty surrounding the efficacy and reliability of applying biochar to soils in relation to crop productivity.     

Using the VS‐Fast methodology for soil degradation assessment: a case study from Senegal

Soil degradation threatens sustainable food production and accelerates global warming. Poorer countries, whose agricultural sectors are highly dependent on their natural resource bases, are hit particularly hard by declining soil productivity. Calls for soil‐quality monitoring are therefore, justified and this could inform decision‐makers on the preparation of appropriate interventions. However, the provision of monitoring methodologies is not an easy task. Soil degradation affects several soil characteristics that at larger scales cannot be evaluated with models or remote‐sensing techniques. Therefore, this study focuses on investigating the use of field‐based soil assessment methodologies to differentiate degrees of soil degradation. Specifically, we test the Visual Soil Field Assessment Tool (VS‐Fast) for detecting and monitoring soil degradation using a cross‐section of 71 sites in Senegal, the soil quality of which were classed by local experts. We found low correlation between VS‐Fast classes and expert assessments. By using an ordered logit model to quantify class boundaries, we show that experts categorized areas as ‘degraded’ for a wider range and higher VS‐Fast scores than the corresponding VS‐Fast class. Yet, from general linear models and analysis of variance procedures we found that areas classed by experts as ‘degraded’ had statistically significant lower VS‐Fast scores compared to those that were judged as ‘normal’ and ‘good’, while differences of the VS‐Fast scores between the latter two were negligible. It is remarkable that the visual assessment, the cheaper component of the VS‐Fast score, performs better in differentiating degradation status than its measured counterpart. The results support the need to investigate the applicability of other VSA methodologies that only use field observations and tactile methods.     

贵州省农业产业结构研究

运用产业结构相似系数、产业结构变化系数和描述产业结构稳定性的熵来对贵州省农业产业结构现状进行分析与评价,其研究成果对确定贵州省农业产业结构调整方向和发展贵州省农业农村经济有一定的参考价值。     

沈阳沈北新区气候变暖对农业的影响

[目的]研究近38年沈阳沈北新区气候变暖对农业的影响。[方法]利用沈阳沈北新区1971~2008年气温资料,采用常规统计方法,分析了在气候变暖的环境下沈北新区气温、活动积温的变化趋势,并讨论了气候变暖对农业的影响。[结果]近38年来沈北新区年平均气温、年平均最高气温、年平均最低气温和稳定通过≥0℃、≥10℃活动积温均呈现明显的升高趋势,气候倾向率分别为0.4、0.3、0.1℃/10a和79.1、76.7（℃.d）/10a。最寒冷的12和1月呈下降趋势,其他各月均呈上升趋势。最高气温大于最低气温的升温幅度,夏季升温幅度大于冬季,这一分析结果与很多学者研究的结果有所不同。气温升高、热量资源增加农业复种指数提高,中晚熟品种栽培界限北移,设施农业迅速发展,同时也增加了旱涝灾害的风险和促进了病虫害的加重。[结论]该研究为提高气候变暖对农业生产影响的认识和增强当地农业生产适应气候变化的应变能力提供科学依据。     

呼和浩特周边农田土壤中多环芳烃污染特征与生态风险评价

[目的]为呼和浩特市农田土壤污染预警和农业规划用地提供科学理论依据.[方法]对呼和浩特市农田土壤60个采样点位中15种多环芳烃进行污染特征、 来源解析和生态风险评价.[结果]ΣPAHs含量范围为114~948μg/kg,平均含量为338μg/kg,参照相关研究评价标准判定,呼和浩特市农田土壤中70%以上属于轻微污染,不存在严重污染点位;研究区农田土壤中高分子量多环芳烃污染占总含量的74%,以近郊农田土壤污染最为严重;定量解析来源主要是煤、焦炭和木材的燃烧以及汽车尾气的排放.[结论]采用生态效应区间法评价和苯并(a)芘毒性等效当量法评价均证明呼和浩特市农田土壤存在一定的潜在生态风险,其中苯并[a]芘、二苯并[a,h]蒽等高分子量多环芳烃是主要潜在的污染物.     

Another Way to Establish the Harmonious Extension-System of Water-Saving Agro-Technique

从理论基础、技术集成、参与部门等方面来认识节水农业推广体系的系统性，分析了现在节水农业技术推广体系中问题的根源是利益的分配与不满足问题，实质是协调与相互配合程度不够。提出了从培育市场需求拉动建立协调的节水农业技术推广体系的必要措施。     

黄土高原水土保持对农业持续发展的作用

通过大量事实分析了水土流失的危害及水土保持对农业可持续发展的作用,充分说明了水土保持是黄土高原农业走持续发展道路的可靠保证,也是改善生态环境和生产条件并防止山区水旱灾害,促进群众脱贫致富的根本途径。     

自主创新出成果科技服务出效益

通过原始创新、集成创新和引进、吸收再创新,四川省农科院在农业“高产、优质、高效、生态、安全”方面取得了丰硕的成果。通过强化科技服务,取得了显著的经济社会效益。最后,总结了主要做法和体会。