中水灌溉对绿地土壤影响的研究进展

污水再利用是解决现代城市缺水问题的最有效途径之一.综述了近年来国内外中水(再生水)灌溉时绿地土壤物理、化学特性方面的研究成果,结果表明中水灌溉会对土壤理化性质产生一定影响,中水中的一些有害成分会发生积累,但不至于对绿地生态系统造成不利影响,使用中水灌溉绿地是切实可行的.     

秋播甜玉米氮磷钾营养特点及施肥对其影响研究

田间试验结果表明,甜玉米生长发育过程中,植株的P含量从苗期到收获基本没有明显变化而NK含量随着生长期后延不断下降,但NPK养分积累随生物量增加而不断增加.施NK显著提高植株NK含量和NPK吸收累积量,施P对提高植株P含量和累积量效果不明显.从苗期植株NK含量约6倍于收获期,吐丝到成熟收获期间NK吸收累积量出现突跃式增长的营养特点分析认为,甜玉米的苗期(6～10叶)和吐丝期是两个重要的营养敏感期,在优质丰产栽培技术中需提供充足的土壤养分供应.     

叶绿素仪(SPAD)在茶树氮素营养诊断中的适用性研究

测定叶片氮素含量是诊断茶树氮素状况的一项重要方法。本文利用盆栽试验,通过不同的供氮水平,研究了利用叶绿素仪(SPAD-502)进行茶树氮素营养快速诊断的适用性。结果表明,茶树新梢产量与氮素用量、成熟叶氮素含量之间呈线性加平台的反应关系,成熟叶的SPAD值与其全氮含量呈显著线性正相关,并与茶树产量存在着比较明显的关系拐点,初步显示SPAD可以较好地表征茶树的氮素营养状况,有可能作为快速诊断方法用于指导茶树施肥,但是还需要通过大田试验进行进一步验证。本文还探讨了测定位点、叶位、天气状况、田间原位或离体测定方式、表面清洗以及样本量等因素对SPAD测试精度的影响。     

桔梗的营养价值及其综合开发研究

以桔梗为主要原料,详细论述了药食两用桔梗资源的药用价值和食用价值。研究了桔梗的性质、功能、提取、加工利用,并阐明了其广阔的开发前景。     

我国农田土壤污染的环境成本分析

从粮食减产及质量下降的直接损失和生物多样性降低的间接损失2个方面,计量了我国农田土壤污染的环境成本。结果表明,1990~2005年我国粮食生产造成的农田土壤污染的环境成本约为208.54亿元/a,其中粮食减产及质量下降的直接损失为21.61亿元/a,农田生物多样性降低的间接损失为186.93亿元/a。     

Effects of nutrition spatial heterogeneity on root traits and carbon usage by roots of Cercis chinensis seedlings in split root rooms

In natural ecosystems, nutrition available for plants shows great spatial heterogeneity. Much is known about plant root responses to the spatial heterogeneity of nutrition, but little is known about carbon usage in roots in nutrition-deficient patches and its effect on root longevity. In this study, split-room boxes were used for culture of Cercis chinensis seedlings, and the small rooms were supplied with different nutrition levels. The number of the first-order roots in the rooms with nutrition supply was significantly higher than that in the rooms with deficient nutrition. Specific root length (SRL) of the first-order roots in the rooms with deficient nutrition reached its peak at day 64 after nutrition treatment. There was no significant SRL differences between the two order roots during the experiment. Biomass of the first-order roots in the rooms without nutrition supply was significantly less than that of the first-order roots in the rooms with nutrition supply from day 64 to 96. The total biomass of the lateral roots in the rooms without nu-trition supply decreased from day 64 to 96. The activities of the enzymes in roots in the rooms without nutrition supply increased and the activities of alkaline invertases in roots in the two sides of split box did not change significantly. The activities of the enzymes in roots in the rooms without nutrition supply increased gradually. These results suggest that nutrition spatial heterogeneity induced the changes in root traits and plants actively controlled carbon usage in roots in nutrition-deficient patches by regulating the activities of invertases and sucrose synthases, resulting in the reduction in carbon usage in the roots in nutrition-deficient patches.     

玉米副产物的饲用价值

本文主要介绍了玉米加工的副产物的种类、数量及常见几种主要玉米副产物的营养价值,并进一步阐述了其饲用畜禽的饲用价值。     

氟的营养作用及在生产中的应用研究进展

氟作为动物体中一种必需的微量元素,在生产上有很重要的作用。过去一直以为氟是一种有毒有害的元素,而忽视了它的营养价值。自从认识到氟的营养作用之后,人们对氟的研究越来越多,氟的营养作用也被人类所发现。在生产上应用即要考虑其营养作用也要注意其中毒症,用量过多或过少都会严重影响动物生产性能的发挥。     

植物铁蛋白在人类铁营养中的作用

铁是人体所必需的微量营养元素,铁缺乏是世界上最主要的营养问题之一。笔者综述了铁的生理功能与吸收机制、植物铁蛋白的结构与功能,以及植物铁蛋白铁的饮食利用度。展望了应用天然的或转基因植物的铁蛋白作为铁补充剂改善人类铁营养缺乏问题的前景。     

不同栽培条件下水稻分蘖角度动态变化分析

110161沈阳市东陵路120号沈阳农业大学水稻研究所