广西十五时期农业科技进步贡献率测算与分析

以《中国农村统计年鉴》数据（1998～2005年）为依据,根据朱希刚提出的我国农业科技进步贡献率测算方法,对十五（2000～2004）时期全国和广西的农业科技进步贡献率作了测算,并对二者的测算结果进行了对比分析,在结果分析的基础上,提出加快广西农业科技进步速度,提高农业科技进步贡献率的有关建议。     

Analysis of hyperspectral reflectance data for monitoring growth and development of lesquerella

Seed oil from lesquerella (Lesquerella fendleri (Gray) Wats.) is currently being developed as a biorenewable petroleum substitute, but several issues related to crop management and breeding must be resolved before the crop will be commercially viable. Due particularly to the prominent yellow flowers exhibited by lesquerella canopies, remote sensing may be a useful tool for monitoring and managing the crop. In this study, we used a hand-held spectroradiometer to measure spectral reflectance over lesquerella canopies in 512 narrow wavebands from 268 to 1095 nm over two growing seasons at Maricopa, Arizona. Biomass samples were also regularly collected and processed to obtain aboveground dry weight, flower counts, and silique counts. Partial least squares regression was used to develop predictive models for estimating the three lesquerella biophysical variables from canopy spectral reflectance. For model fitting and model testing, the root mean squared prediction errors between measured and modeled aboveground dry weight, flower counts, and silique counts were 2.1 and 2.3 Mg ha⁻¹, 251 and 304 flowers, and 1018 and 1019 siliques, respectively. Analysis of partial least squares regression coefficients and loadings highlighted the most sensitive spectral wavebands for estimating each biophysical variable. For example, the flower count model heavily emphasized the reflectance of yellow light at 583 nm, and contrasted that with reflectance in the blue (483 nm) and at the red edge (721 nm). Because of the indeterminate nature of lesquerella flowering patterns, remote sensing methods that monitor flowering progression may aid management decisions related to the timing of irrigations, desiccant application, and crop harvest.     

黄淮海平原农业用地适宜性综合评价研究——以聊城市为例

以地处黄淮海平原中部的山东省聊城地区为案例区,通过对农业用地自然因素、环境条件进行综合评价,研究黄淮海平原典型农业区的农业用地适宜性程度．结果表明聊城市的土地质量中等偏上,符合当地实际情况,并初步验证运用GIS技术进行农业用地的适应性研究的科学性,并针对分析结果提出了相关建议.     

四川省农业继续教育存在的问题及对策

分析了四川省农业行业人才队伍现状与农业继续教育现状,对四川省落后的农业继续教育现状进行了数据调查和问题分析,提出了发展四川农业继续教育的对策。     

海南农业突发事件中的乡镇政府形象调查与分析

通过对＂香蕉致癌＂事件中海南乡镇政府形象的实证分析,认为乡镇政府形象建设状况虽然总体良好,但仍存在个别问题,提出了提开政府形象透明度、维系政府形象美誉度等相关建议,以期塑造阳光政府、服务政府和互动政府的形象。     

玉米精准作业智能空间决策支持系统的研究与应用

为解决玉米精准施肥、土壤肥力评价、地力等级分类和产量预测等问题,将具有空间信息处理功能的地理信息系统、具有空间信息分析功能的空间数据挖掘技术、人工智能领域中的专家系统技术与传统的信息管理系统、决策支持系统有效集成,并将GIS中的统计分析方法与数据可视化结合起来,研制了玉米精准作业智能空间决策支持系统。该系统极大提高了农业管理部门进行农业生产决策的能力。     

青海省农民专业合作经济组织发展问题分析

通过对青海农民专业合作经济组织发展状况的研究,分析了发展过程中存在的问题,并结合实际,提出了相关对策。     

改革开放以来我国农业扶持政策的调整及效果研究

农业的发展离不开国内政策的支持。改革开放以来我国的农业扶持政策经历了不断调整和改进的过程,对农业的扶持力度也不断加大,但其中还存在一定的问题和不足。对改革开放以来我国的农业扶持政策进行概括性总结,并对其实施效果和存在的问题进行一定的分析和探讨。     

Development and performance assessment of a DC electric variable-rate controller for use on grain drills

Site-specific crop management is a technology that modulates the application rate of field inputs such as seeds, fertilizers, and herbicides based on the needs of each management zone within a field. There are two methods available for changing the seeding rate in fluted-feed-roll type seed drills: (1) changing the active feed-roll length and/or, (2) changing the seed meter drive shaft speed. A possible method to develop a variable-rate seeder is to add a controller to a conventional grain drill which can change the speed of the seed meter drive shaft on-the-go. This was explored in the present study with the following main objectives: (a) to design a DC electric variable-rate controller to change a grain drill from a uniform to a variable-rate seeder, and (b) to determine the response time of the system. A motor control circuit was designed which used the output signals of two encoders as feedback. The system was consisted of: (1) a DC motor with a fixed-ratio gearbox, (2) encoders for sensing the rotational speeds of the grain drill drive wheel and the motor, (3) a GPS receiver, (4) a pulse-with-modulation (PWM) DC motor controller, and (5) a laptop. Dynamic tests were conducted at application rates of 87.5 (low) and 262.5 (high) kg ha⁻¹. Sigmoid equations were best fitted to the transition data from low-to-high and high-to-low seeding rates. Our findings showed that the response times of low-to-high and high-to-low transition rates were 7.4 and 5.2 s, respectively.     

The use of mobile devices with multi-tag technologies for an overall contextualized vineyard management

This paper describes a Viticulture Service-Oriented Framework (VSOF) which turns around context elements or tags that are placed in the field and which can be decoded by mobile devices such as mobile phones or PDAs. The tags are used to automatically associate a field location to the relevant database tables or records and also to access contextual information or services. By pointing a mobile device to a tag, the viticulturalist may download data such as climatic data or upload information such as disease and pest incidence in a simple way, without having to provide coordinates or any other references, and without having to return to a central office. This work is part of an effort to implement a large-scale distributed cooperative network in the Douro Demarcated Region in Northeast Portugal, a region in which the effort makes particular sense due to the extremely variable topography and mesoclimates. The possibility of exchanging contextualized information and accessing contextualized services in the field, using well-known devices such as cell phones, may contribute to increase the rate of adoption of information technology in viticulture, and contribute to more efficient and closer-to-the-crops practices.