Economic feasibility of site-specific optical sensing for managing nitrogen fertilizer for growing wheat

A site-specific nitrogen fertilizer application system that uses optical reflectance measurements of growing wheat plants to estimate N requirements has been developed. The machine enables unique applications of liquid N fertilizer at a grid level of 0.37 m². To achieve widespread adoption, the precision application system must be efficient enough to overcome the cost advantage of pre-plant applications of anhydrous ammonia (NH₃) relative to top-dress applications of either dry or liquid N sources on growing wheat. The objective of this research is to determine if the system is more profitable than conventional methods. Data from on-farm N fertilizer experiments were collected across three years and nine locations in the Southern Plains of the U.S.A. Net returns were calculated for each of eight treatments. The site-specific precision system was competitive economically, but it was not unambiguously superior to the conventional alternatives because it could not overcome the cost advantage of NH₃ pre-plant N sources relative to the cost of applying urea-ammonium nitrate (UAN) during the growing season. The value of the precision system is sensitive to the price of UAN relative to the price of NH₃.

延边地区有机苹果梨生产可行性分析

延边是苹果梨的主产区,为生产安全优质的苹果梨,对有机苹果梨生产的可行性进行了分析,结果表明:延边地区的自然环境条件、气象条件适合有机生产,具备有机苹果梨生产的技术基础.同时提出有机苹果梨生产的前景和建议,为今后有机苹果梨的生产提供参考依据.     

Weed eradication feasibility: lessons of the 21st century

The past decade has seen strong controversy concerning the upper bounds for weed eradication. Over this period, two of the most ambitious weed eradication attempts ever have failed. These have, however, provided rich data sets that have supported a productive and highly collaborative research effort. I review this research and present a new algorithm for assessing eradication feasibility, based upon time to maturation, seedbank persistence and membership of one of two contrasting dispersal functional groups. Eight ‘eradication syndromes’ are identified and their relative eradication feasibilities indicated. The syndrome with the highest feasibility includes species that combine long juvenile periods and low seedbank persistence with short‐distance and/or human‐mediated dispersal. At first glance, this may not be a common syndrome. The syndrome with the lowest feasibility comprises plants that combine a short juvenile period and high seedbank persistence with abiotic or non‐human‐mediated biotic dispersal. It includes a number of aquatic perennials that can be dispersed over large distances by floodwaters. Projected costs for a programme targeting a plant species should reflect its syndrome membership. Improved cost estimates will support better decision‐making with regard to programme initiation, maintenance and termination; models are available that can provide estimates of eradication programme duration and cost. Whether eradication has much of a future as a weed invasion management strategy will likely rest upon more timely, better‐informed and shrewder target selection.     

对充分发挥农业基本建设项目作用的分析与思考

如何充分发挥已经建成的农业基本建设项目的作用是一个需要进行认真分析并不断加以总结的问题。在进行农业基本建设项目的建设工作时,不要把精力只放在项目争取和项目工程的建设上,还要在项目建成后对其作用的充分发挥上多下气力、多做文章,这是进行农业基本建设项目建设工作所应当给予关注的重要问题。     

许昌烟区气候变化趋势和不同移栽期下气候适生性的综合评价

分析了2001-2008年许昌气候因素的变化情况,估算了该区不同移栽期的气候适生性指数,并与国外优质烟区气候进行了相似性分析.研究结果表明,2001-2008年烤烟大田生长期温度呈升高趋势,生育前期4-5月降水量有所减少,降水较集中的6-7月降水量有所增加,整个生育期日照时数明显减少,湿度较适宜.许昌烟区在04-15至05-05移栽.气候适生性指数相对较高,变化范围为0.841～0.856.许昌烟区与国外优质烟区(津巴布韦、巴西、美国)的相似度均较高,与巴西和津巴布韦的相似距离均以04-15至04-30移栽相对较小.鉴于蚜虫迁飞高峰期,建议适时晚栽,最迟05-15前移栽完较为适宜.     

广州市森林资源管理信息系统建设可行性研究

文章阐述了以3S技术、网络技术为技术手段建立广州市森林资源综合管理信息系统的可行性,并将使全市的森林资源信息化管理以及林业信息资源的集成、应用与共享成为可能,成为各级政府和林业主管部门更好地了解林业真实状况的手段。     

基于高光谱遥感预测鲜桃产量的现实意义及可行性分析

高光谱遥感技术已经在林业、农业中得到广泛应用,但国内外未见有应用该技术在经济林果产量的监测预测研究的报道。文章分析了利用高光谱遥感技术预测鲜桃产量的必要性和意义,拓宽了遥感应用的思路,并对其可行性进行了深入探讨,认为利用果实成熟前冠层的光谱特征可以预测果实的产量指标,关键是在果树冠层光谱特征中寻找相应的光谱反射率或其衍生指数与果实产量指标之间的相关关系,并建立预测模型。     

高等教育实施质量认证的必要性与可行性分析

本从教育部实施普通高校教学工作水平评估谈起，结合ISC9000系列国际标准的质量认证，对高等教育实施质量认证的必要性与可行性进行分析。作认为，在高等教育迫切需要提高质量的今天，应积极鼓励和提倡高等教育实施ISO9000系列质量认证。     

泗阳第二抽水站反向发电可行性研究

通过对泗阳第二抽水站的水力资源、反向发电运行方式的选择以及反向同转速发电的经济效益等的综合分析，得出泗阳二站反向同转速发电在技术上可行、经济上合理的结论。同时，提出了反向同转速发电方式应采取的技术措施。     

Exploration of Feasibility of Applying on Ground-Source Heat Pump in Western Region of China

The brief introduction to properly applying HVAC to the sustainable west development of China is made in this article. The advantage of GSHP, a branch of HAVC, is also presented briefly here. The emphasis is put on the fact that this system is a green one which sustainable and practicable characters. At the same time, the comparison between the key technique of GSHP and the geological condition that the system should adjust to is made, which reveals the key point of applying GSHP. According to environment condition, three types of areas are divided in the western regions of China. The feasibility of applying GSHP in each area is explained respectively and the related scheme of applying the system is also summed up.