Managing secondary dryland salinity: Options and challenges

Salt occurs naturally at high levels in the subsoils of most Australian agricultural land. As a result of clearing native vegetation, groundwater tables have risen, mobilising the stored salt and causing adverse impacts on farmland, infrastructure, water resources, and biodiversity. The main action required to prevent groundwater tables from rising is establishment of perennial plants, either herbaceous (pastures or crops) or woody (trees and shrubs). Recent technical and economic research has emphasised how difficult it will be to establish sufficient perennials to get control of groundwater tables. Where watertables are already shallow, the options for farmers are salt-tolerant plants (e.g. saltbush for grazing) or engineering (e.g. deep open drains). The existing options for farm-level salinity management are reviewed, with mixed but somewhat disappointing findings regarding their suitability for addressing salinity. However, there are also a number of good prospects for development of new and better options for plant-based management of salinity, and these are described.     

户营小型拖拉机难以更新的机理探讨

在分析农户使用、更新小型拖拉机经济行为的基础上，推证并建立了户营小型拖拉机的作业成本随使用年限增加而变化的规律，进一步提出户营小型拖拉机在作业量充足条件下的“成本均等理论”和在作业量欠充足条件下的“成本递减理论”，并通过实地采样加以验证。据此阐述了户营小型拖拉机难以更新的机理，得出在经济欠发达地区户营小型拖拉机基本上不存在最佳更新期的结论。     

农业机器人移动平台的研究现状与发展趋势

简要介绍了农业机器人在农业信息化智能化中的重要地位以及机器人移动机构的类型,综述了当今农业机器人移动平台的研究现状,展望了今后这一领域的发展趋势。     

ANSYS软件参数化建模研究

大型通用有限元ANSYS软件在结构分析、结构优化设计等工程问题上有广泛的应用。优化设计成功与否的关键是参数化建模与形成分析文件,本文详细讨论了参数化建模的细节与注意事项以及分析文件的形成,为结构优化设计人员提供帮助。     

安溪铁观音营销经验与优化建议

安溪铁观音是中国传统名茶,历经30多年发展—调整—再发展的历程,以其独特的品质风味赢得了人们的青睐,成为大江南北家喻户晓的茶叶领军品类.当前,茶叶产销形势发生了深刻的变化,安溪铁观音面临更加激烈的竞争与挑战.近年来,安溪铁观音市场出现回暖局面,为推进安溪铁观音高质量发展,文章从运用定位工具重塑品牌形象、创新销售渠道、洞...     

中西方历史灾荒成因比较研究

灾荒的发生主要与灾害的严重程度和社会对灾民的救助有关。通过对比研究中国和古代欧洲国家之间灾荒的发生演变情况,结果显示中西方灾荒的发生具有显著的原因差别:中国的灾荒主要是由于社会救助不力造成的,在原因层面属于弹性灾荒;欧洲的灾荒主要是因为灾害的强度导致的,属于刚性灾荒的范畴。     

2022年度国家自然科学基金土壤学项目受理与资助分析

本文分析了2022年度国家自然科学基金土壤学的项目受理与资助情况,以环境地球科学学科土壤学有关的D0701环境土壤学、D0709基础土壤学、D0710土壤侵蚀与土壤肥力等三个二级申请代码为重点,对面上、青年科学基金、地区科学基金、国家杰出青年科学基金、优秀青年科学基金和重点等类别的项目的申请、受理、评议、资助立项、研究队伍、分类属性、关键词数据云等方面进行了统计与分析,旨在为今后的相关申请提供参考。     

Can supplemental food increase winter survival of a threatened cottontail rabbit?

Populations of New England cottontails (Sylvilagus transitionalis) have declined substantially in recent decades in response to habitat loss and fragmentation. Among some remnant populations, cottontails occupy small patches of thicket habitat where they experience high mortality rates as a consequence of limited food during winter. This limitation causes rabbits to forage away from cover where they are exposed to predators. Although conservation efforts are emerging to reverse the decline of New England cottontails, most are directed toward improving long-term viability by increasing the abundance of suitable habitats. Such efforts do little to improve the short-term survival of remaining cottontails. To address this immediate need, we evaluated the use of supplemental food as an approach to improve overwinter survival rates. We speculated that by positioning feeders in close proximity to escape cover, rabbits would be less vulnerable to predators. We evaluated this approach using eastern cottontails (Sylvilagus floridanus) as a research surrogate because this species is readily available and has similar habitat requirements to New England cottontails. Transmitter-equipped eastern cottontails were randomly assigned to either a fed or unfed group. Remotely-triggered cameras were also used to gauge use of feeders by cottontails and visits by other species. Winter survival rates were substantially greater for fed rabbits (70%) than for unfed rabbits (32%). Cameras revealed that rabbits were the most frequent consumer and that there was only limited carnivore activity near feeders. We conclude that supplemental feeding may improve survival of remaining New England cottontails as efforts to increase habitat availability continue to develop.     

土壤功能及其分类与评价研究进展

土壤功能及其分类与评价相关研究,可以为农业、环保、国土资源等部门制定土壤资源合理利用与管理提供科学依据。国际上对土壤功能有着不同的划分与评价方法,我国也正在进行探索性研究,本文对土壤功能分类与评价的研究背景与意义进行了阐述,分别整理了国内外土壤功能的概念与发展,归纳了土壤功能分类与评价的研究进展。不同学者根据其研究需要对土壤功能有不同划分,主要集中在作物生长、缓冲过滤、栖息地和基因库、自然景观和文化遗产、原材料生产、建设承载等几个方面;在已有土壤功能评价的研究中,有的学者在整体上对土壤的不同功能进行评价,有的则选择其中一到两个功能进行深入研究。最后,讨论了我国土壤功能分类与评价的研究方向。