西南区域水稻关键生育期界限温度起始期的预测研究

保证作物安全生产是种植制度的根本要求,也是作物稳产、高产的基础。本文基于西南水稻种植区317个气象台站1961-2015年的日平均气温和最高气温资料,分析了近55年来该区域不同保证率下水稻安全播种期、水稻开花期高温热害和低温冷害的最早发生期,并建立了西南区域水稻各关键生育期界限温度起始期预测模型。预测结果表明：80%~95%保证率下,云南南部的水稻育秧安全播种期最早,平均在2月20日左右;云南北部、四川攀西南部和盆地中部、重庆大部和贵州部分地区在3月10日-4月10日;而其余大部地区在4月10日-5月20日。80%~95%保证率下中稻开花期高温热害主要发生在四川盆地、重庆、贵州北部和东南部,大部地区最早出现在7月15日-8月20日。80%~95%保证率下再生稻或晚稻开花期低温冷害最早出现在云南和贵州大部、四川攀西地区,平均在6月20日-7月15日;四川盆地西部、贵州东北部平均为8月1-20日;其余大部地区在8月20日-9月20日。基于纬度、经度和海拔高度建立的西南区域水稻各关键生育期界限温度起始期预测模型,简单实用,可为西南水稻安全生产、防灾减灾等提供理论依据。     

Rice-residue biochar influences phosphorus availability in soil with contrasting P status

ABSTRACT

Thermo-chemical conversion of crop residues to produce biochar is an emerging strategy in the context of sustainable phosphorous (P) use and residue management. An incubation study for 90 d was conducted to investigate the effects of rice-residue biochar (0, 10, 20 and 40 g kg^?1) in combination with inorganic-P (KH₂PO₄) (0, 25 and 50 mg kg^?1) on phosphorous availability in medium- and high-P status soils. Increasing biochar addition rates alone or in combination with inorganic-P resulted in a significant increase in P pools, i.e. plant available P or Olsen-P (from 8 to 132 mg kg^?1 in medium-P and 15 to 160 mg kg^?1 in high-P soils), microbial biomass P and various mineral-bound inorganic-P fractions in the order (Ca-P > organic-P > Al-P > loosely held/soluble-P > Fe-P > reductant soluble-P). Further, lower phosphatase activity (19–50%) with increasing rates of biochar addition in both soils elucidates the ability of biochar to act as a long-term source of available P in the experimental soils. The results demonstrate that rice-residue biochar can directly or indirectly enhance the status of available P in soils and hence can be used as a beneficial amendment to meet the crop P demand.     

生态技术在设施农业中的应用探析

阐述了生态工程技术在设施农业应用的重要性与发展前景。并简析了实际生产中设施生态农业模式内涵及其发展过程中存在的问题,提出相应建议     

徐州市不同功能城区绿地土壤的理化性质分析

以徐州市三环路内不同功能区的绿地土壤为研究对象,通过对城区土壤的理化性质与养分状况等指标进行测定分析,并与该地区自然土壤进行了对比,研究其变化的趋势.结果表明:该绿地土壤的容重较大,孔隙度和田间持水量少,有机质缺乏,养分含量不均,pH值明显向碱性的方向演变.     

建设生态型城市实现可持续发展

以水为中心进行生态环境建设是北京建设现代化和生态型城市的重要途径。在总结北京市生态建设的成就和分析现实存在问题的基础上,提出了北京建设生态型城市在水利方面要达到的目标和工作任务以及要妥善处理好四个关系。     

Soil sulphur status following long-term annual application of animal manure and mineral fertilizers

 In agricultural systems with low S inputs, crops rely on the release of S from organic forms in the soil. In the Askov long-term experiments, started in 1894 on both sandy and loamy soils, soil S status following long-term application of animal manure and mineral fertilizers was investigated in the growing season of 1995. In a field trial with oil-seed rape (Brassica napus, L.) soil analysis, leaf tissue analysis, yield and S removal in plant material was used to characterize differences in availability of soil S. One half of all plots received 63 kg S ha^–1 as gypsum. Long-term fertilization with animal manure or NPK fertilizer increased the content of soil organic C in both soils and of organic S in the sandy soil compared with unfertilized plots. Although dry matter yields were unaffected, the S uptake in harvested crop parts increased considerably after S application. The amounts of N and S in harvested seeds and straw were closely related, but the N : S ratio decreased when S was applied. Soil and plant analyses both indicated that critical levels of S concentrations were reached, and that S application was capable of raising S concentrations well above the critical level. Because no additional mineralization from residual organic S took place, it was concluded that the residual S effect from long-term annual applications of animal manure or mineral fertilizers did not significantly increase the level of soil S available for crops with a short growing season, such as oil-seed rape. Received: 9 January 1998     

国外低影响开发雨水资源利用对中国海绵城市建设的启示

[目的]研究美国、英国、德国、日本、新加坡和澳大利亚的低影响开发雨水资源利用情况,为中国海绵城市建设在管理、技术等方面提供一定依据。[方法]通过调查研究,从政策法规、应用技术、管理体系、公众意识等方面系统地梳理国外低影响开发雨水资源利用经验,并结合国内实际,探讨促进中国海绵城市建设发展的建议。[结果]针对目前中国海绵城市建设遇到的城市内涝、缺水及生态环境问题,可从制定和完善相关政策法规,加强先进技术的研发和应用,创新融资渠道、优化管理体系,提升公众意识等方面进行改进。[结论]合理借鉴国外已经成熟的低影响开发雨水资源利用经验,能够更好地推进中国海绵城市建设。     

Estimating population size in the subdesert mesite (Monias benschi): new methods and implications for conservation

The subdesert mesite, a terrestrial non-passerine bird endemic to the Mikea Forest of southwest Madagascar, is currently classified as globally threatened (category: Vulnerable). However, accurate assessment of threat in accordance with the IUCN Red List criteria (A, B and C) requires data on effective population size, area of habitat occupied and rate of decline, none of which is available for this species. Here we present the first empirical estimates of its population size using five complementary methods, three incorporating data on territory size and two using data gathered during call-playback surveys conducted throughout its entire global range. Estimates vary from 98,000 to 152,000 individuals, with the most reliable possibly being that generated by distance sampling (115,000). This figure is more than an order of magnitude greater than the only published estimate of <10,000 individuals. By analysing data on forest cover change, we estimate the population of the subdesert mesite to have declined by, at most, 10% in three generations. Although the rate of deforestation in 1994-1999 is double that calculated for 1962-1994, it is deemed unlikely that the population will decline by 20% over the next three generations. As such the species fails to meet criterion A. Although the subdesert mesite's range and area of occupancy are small, they are not fragmented and do not comprise fewer than 10 locations. Consequently, this species does not meet criterion B. Further, the species fails to meet criterion C, for which a maximum of 10,000 mature adults is required. According to IUCN (2000 Red List of Threatened Species) this species should therefore be downlisted in status. We discuss why it still warrants conservation attention and suggest the need for modifications to the criteria thresholds in relation to basic information about the ecology and taxonomic distinctness of species.     

Classification of pedogenic cementation in Podzols by pocket penetrometry

According to the German Soil Taxonomy, the formation of cemented horizons in Podzols is restricted to the precipitation of iron oxides. However, in iron‐poor sandy substrates, also illuviation of only organic compounds can form cemented horizons with penetration resistances of up to 14 kg cm⁻². We present a reproducible field test for classifying pedogenic cementation in Podzols and suggest considering cemented horizons (Bmh and Bhm) in the upcoming edition of the Guidelines for Soil Mapping.     

延安飞马河试验示范区农业生产的调查研究

在考察和调查的基础上 ,对陕西省延安市郊飞马河农果复合生态农业试验示范区的农业气候、土壤和水等自然资源和社会经济情况 ,农业生产中存在问题与农田种植结构布局特点 ,农业生产技术应用 ,以及农业发展方向进行分析研究 ,为促进该地区农业生产进一步发展提供参考