不同生物有机肥施肥方法对压砂西瓜生长及产量的影响

2009年在宁夏中卫香山乡采用田间试验的方法,比较了穴施和条施生物有机肥对压砂西瓜生长及产量的影响.结果表明:与条施生物有机肥相比,穴施条件下,西瓜生育前期叶面积指数增加了80％ ～ 119％；生育中后期主蔓长20.6 cm,增加25.4％；叶片数也较多；单瓜重增加了43％,中心糖含量和边糖含量分别提高了9％和8％；同...     

Greenhouse gas mitigation potential of agricultural land in Great Britain

The aim of this paper is to assess the greenhouse gas (GHG) mitigation potential of croplands and grasslands in Great Britain under different management practices. We consider the feasible land management options for grass and cropland using county level land‐use data with estimates of per‐area mitigation potential for individual and total GHGs, to identify the land management options with the greatest cost‐effective mitigation potential. We show that for grasslands, uncertainties still remain on the mitigation potential because of their climatic sensitivity and also their less intensive management. For croplands in Great Britain, the technical mean GHG mitigation potentials for all cropland management practices range from 17 Mt CO₂‐eq. per 20 yr to 39 Mt CO₂‐eq. per 20 yr. There are significant regional variation in all cases, with the greatest potentials in England, negligible potential in Wales and intermediate potential in Scotland, with country differences largely driven by the areas of cropland and grassland in each country. Practices such as agronomic improvement and nutrient management are the most promising options because of their impact on N₂O emissions and also their larger potential at low cost. In terms of annual emissions from agriculture, calculated mitigation potentials are small, where the technical mitigation potential of agronomy and nutrient management strategies are ca. 4.5 and 3.8%, respectively (agricultural emissions account for ca. 9% or 47.7 Mt CO₂‐eq., of total Great Britain GHG emissions, Department of Energy and Climate Change, UK). However when compared with the land use, land‐use change and forestry sector (LULUCF) emissions, nutrient management would reduce further emission reductions by approximately half of the 2005 LULUCF sink (i.e. ?1.6 Mt CO₂‐eq. per year).     

大通县长宁镇退耕还林(草)后续产业探讨

分析了退耕还林(草)现状,结果表明,退耕还林草的后续产业发展不足,提出发展退耕还林草的后续产业对策。     

规划衔接与建设用地空间管制协调研究

在前人研究的基础上,总结了上一轮土地利用规划实施过程中存在的问题,研究规划衔接的重要性和必要性。从剖析比较各类规划,特别是土地利用总体规划和城乡规划的内容和侧重点差异性的基础上,提出规划衔接的可行性及方法,探讨了规划衔接与建设用地空间管制的主要内容及协调对策,提出了对相关研究和新一轮规划编制的建议。     

农村土地违规建房问题研究

土地作为一种不可再生资源,同时又是人类赖以生存的生产生活资料,应该得到人类的珍惜和保护.但随着我国新农村建设的不断发展,农村土地违规建房问题也凸显出来.通过分析我国农村土地违规建房的根源、现状,梳理出治理违规建房的有效对策,以期为解决农村土地违规建房问题提供一些新思路.     

Synergism between potassium sorbate dips and brief exposure to high CO2 or O2 at curing temperature for the control of citrus postharvest green and blue molds

Synergistic effects and very effective control of citrus postharvest green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, were observed on artificially inoculated ‘Valencia’ oranges and ‘Clemenules’ and ‘Ortanique’ mandarins after a potassium sorbate (PS) treatment was followed by 2 days of storage in atmospheres of elevated CO₂ or O₂ at a curing temperature. A combined treatment consisting of 60-s dips in aqueous solutions of 3% PS heated to 62 °C was followed by 48-h exposure to air, 15 kPa CO₂ or 30 kPa O₂ at 33 °C. Control treatment was a 60-s water dip at 20 °C followed by 24-h exposure to air at 20 °C. Synergism was observed on citrus fruit either incubated at 20 °C for up to 22 days, simulating direct commercialization, or stored at 5 °C for up to 45 days, simulating commercial cold storage. This research offers potential new tools to the citrus industry for implementation of nonpolluting integrated postharvest disease management programs, especially devoted to high added value organic markets or export markets with zero residue tolerance.     

基于社会燃烧理论的耕地非农化驱动因素分析

中国耕地非农化现象日益明显。基于社会燃烧理论分析了耕地非农化的驱动原理,建立了耕地非农化影响机制模型,并运用SPSS 19.0软件对分类驱动因素进行了主成分及回归分析。结果表明,人均GDP和固定资产投资所占GDP比重等经济发展变量对耕地非农化水平的正向影响最大;粮食单产、总产等农业技术变量对耕地非农化水平具有最大的逆向影响。最后在模型拟合的基础上提出了相应的对策与建议,旨在为合理有效保护耕地提供参考。     

太原经济技术开发区用地效益评价

通过对太原经济技术开发区的实际调查和对2002—2011年10 a间的相关统计及国家商务部历年发布的国家级经济技术开发区发展报告的信息进行分析,从开发区土地利用现状、年度建设用地供给、科工贸收入、工业总产值、GDP、税收收入、国内外资金利用等方面,综合评价了太原经济技术开发区的经济效益和用地效益。结果表明,该区独立运行10 a来成绩显著,整体效益逐步提高,在山西所有开发区中经济效益名列前茅,在全省经济技术开发区中每年的综合评价都名列第1;与国内中西部或中部的同类开发区相比,该区经济总量和单位面积产生的效益排名中后;与国内先进经济技术开发区相比,差距较大;该区内部分企业规模大、影响广泛,经济效益和用地效益均好,起到了带头和示范作用,但仍有部分企业规模小、投入水平低、建设周期长、产生效益低,影响了全区整体效益的发挥。建议开发区管委会引导入区企业加大投入,加快建设步伐,及早产生经济效益;尽快实施扩区计划,保证经济快速、健康发展;落实土地供给和退出政策,使有限的土地发挥更大的效益。     

The effect of life history events on carcass merit and price of cull dairy cows

Cull dairy cows contribute almost 10% of national beef production in the United States. However, different factors throughout the life of dairy cows affect their weight and overall body condition as well as carcass traits, and consequently affect their market price. Therefore, the objectives of this study were: (1) to assess relationships between price ratio and carcass merit of cull dairy cows sold through several sites of an auction market and (2) to investigate the effect of animal life history events and live weight on sale barn price (BP) and price ratio (as a measure of relative price), as an indicator of carcass merit. Data from 4 dairy operations included 3,602 cull dairy cow records during the period of 2015 to 2019. Life history events data were collected from each dairy operation through Dairy Comp software; live weight and price were obtained periodically from the auction market, and the carcass data were provided by a local packing plant. Cow price in dollars per unit of live weight ($/cwt) and price ratio were the 2 outcome variables used in the analyses. Price ratio was created aiming to remove seasonality effects from BP (BP divided by the national average price for its respective month and year of sale). The association between price ratio and carcass merit traits was investigated using canonical correlation analysis, and the effect of life history events on both BP and price ratio was inferred using a multiple linear regression technique. More than 70% of the cows were culled in the first 3 lactations, with an average live weight of 701.5 kg, carcass weight of 325 kg, and dressing percentage of 46.3%. On average, cull cows were sold at $57.0/cwt during the period considered. The canonical correlation between price ratio and carcass merit traits was 0.76, indicating that price ratio reflected carcass merit of cull cows. Later lactations led to lower BP compared with cows culled during the first 2 lactations. Injury, and leg and feet problems negatively affected BP. Productive variables demonstrated that the greater milk production might lead to lower cow prices. A large variation between farms was also noted. In conclusion, price ratio was a good indicator of carcass merit of cull cows, and life history events significantly affected sale BP and carcass merit of cull cows sold through auction markets.