土壤的农业化学研究的任务

在米丘林文库中,保留着一篇未完的论文稿:“向科学家要求些什么”。在这篇论文里,米丘林对于那些不能给最需要的农业问题以适当解決的学者,愤怒地写道:“例如,第一个问题:园艺家应该知道,这个区域的土壤是否适宜栽种这些植物?土壤中缺乏什么?它需要加入那些物质?并且,土壤中有什么是过多的?”     

伟大的战略 跨世纪的工程

<正>在全党和全国人民正以饱满的热情迎接党的十五大召开之际,江泽民总书记、李鹏总理等党和国家领导人就治理水土流失,建设生态农业问题作了重要批示,要求“再造一个山川秀美的西北地区”,黄土高原水土流失治理“争取15年初见成效,30年大见成效.”江泽民总书记和李鹏总理的批示,高瞻远瞩,高屋建瓴,涵盖历史,充分肯定和高度赞扬了延安、榆林地区及黄土高原治理水土流失,建设生态在业所取得的巨大成就,并对今后进一步加快水土流失治理开发步伐,改善生态环境,促进区域经济持续、快速、协调发展指明了方向,提出了殷切的希望和要求.这充分体现了党的第三代领导集体对水土保持工作的重视、支持和关心,对水土流失区广大人民群众的巨大关怀,是对全国特别是对水土流失区广大干部群众的巨大鼓舞和鞭策.我们一定要认真学习、深刻领会、坚决贯彻执行.     

施用重金属含量高的污泥的土壤重金属的有效性

<正> 为了确定Cd、Cu、Ni和Zn对生长在施用污泥的土壤上的玉米的有效性,于1984年,在就地侧渗能控制的小区进行田间试验。这些小区设在三种土壤上。这三种土壤为Bojac壤质砂土,Davidson粘壤土和Grosecloge细壤土。来自主要处理工业废水的     

被土壤吸附的六价铬的最佳提取剂的选取

通过研究土壤中磷酸盐与Ｃｒ（Ⅵ）的竞争吸附作用，查明０．１ｍｏｌ／ＬＫＨ２ＰＯ４－Ｋ２ＨＰＯ４溶液是提取被土壤吸附的Ｃｒ（Ⅵ）的最佳提取剂。     

氨的固定对土壤微生物氮的测定的影响

The effect of ammonium fixation on the estimation of soil microbial biomass N was studied by the standard fumigation-incubation(FI) and fumigation-extraction (FE) methods,NO3-N content of fumigated soil changed little during incubation,while the fixed NH4^ in soils capable of fixing NH4^ increased with the increase of K2SO4-extractable NH4-N.one day fumigation increased both extractable NH4^ and fixed NH4^ ,However,prolonged fumigation gave no further increase.One day fumigation caused significant loss of NO3-N,while prolonged fumigation caused no further loss.For soils tested,the net increases of fixed NH4^ in fumigated soil equaled to 0-94% of NH4-N flush measured by the FI metod,and 1-74% of extractable N measured by the FE method.depending on different soils.It is concluded that the ammonium fixation was one of the processes taking place in soils during fumigation as well as incubation ofter fumigation and should not be neglected in the estimation of microbial biomass nitrogen by either FI or FE method.     

土壤Se的分级与Se的植物有效性的关系

Nine soils with distinct properties and Se levels were selected to test a fractionation procedure of soil Se based on sequential extraction. Soil Se was fractionated into readily available Se (fraction Ⅰ, extracted by 0.5 M NaHCO₃), slowly available Se (fraction Ⅱ, extracted by 0.1 M NaOH-0.1 M Na₄P₂O₇), amorphous oxide-occluded Se (fraction Ⅲ, extracted by acid ammonium oxalate), free oxide-occluded Se (fraction Ⅵ, extracted by dithionite-citrate-bicarbonate buffer solution) and residual Se (fraction Ⅴ, determined by HNO₃-HClO₄ digestion of the final soil residue). The recovery of soil Se (the sum of all fractions over total soil Se determined independently) by this procedure was from 88.1% to 110.9%, mean 99.2%±6.4% for the test soils. The sum of fractions Ⅰ and Ⅱ, provided a good measure of available Se in soils and the percentage of fraction Ⅰ plus Ⅱ over the total soil Se, tentatively defined as Se availability index, could be used to indicate soil Se status and predict Se deficiency.     

基于PLC的模糊控制灌溉系统的研制

该文利用模糊控制技术实现灌溉实时控制。利用MATLAB语言对其进行仿真，得到了较为合理的模糊控制算法。并将这些模糊控制算法通过以可编程控制器PLC为核心的硬件控制电路应用于实际的灌溉控制，通过实际温室育苗调试，能够较好地满足温室育苗使用要求。     

关于盐碱地的田间管理措施的简介

盐硷土其所以需要改良,是因为这种土壤含有不同程度的盐分,影响着农作物的正常生长和发育。盐硷严重的地区,往往是寸草不生的光板地。     

植物的营养和肥料的施用

李森科院士认为矿质养分必须经过微生物的改造和转化才能被植物所利用。因此,以此