华北地区新农居适宜性建筑材料研究

从理论和实践两方面分析适宜技术理论,解析其灵活的、因地制宜的设计思想,并针对华北地区现在正在建设的新农居建筑材料进行相关的研究与分析。     

丘陵红壤旱地花生木薯间作适宜间距研究

在丘陵红壤旱地花生主产区,以花生、木薯纯作为对照,通过不同花生木薯间作研究了木薯对花生负面空间影响距离和木薯间作适宜行距,及间作木薯对土地利用率的影响。结果表明:花生间作木薯(不明显降低花生产量的前提下)种植系统中木薯对花生的负面影响空间距离为40 cm左右,木薯间作适宜行距不低于374 cm;且花生木薯宽行间作可明显提高丘陵红壤的土地利用率,纯收入提高58.3%。     

基于CLIMEX和GIS的黑脂大小蠹在中国的适生区域预测

 黑脂大小蠹是美国东南部地区危害松危杉类针叶树种的害虫。为了解黑脂大小蠹在我国潜在危害范围和程度,研究采用CLIMEX模型与ArcGIS分析相结合的预测方法,通过选择黑脂大小蠹适生且危害严重的3个基准点与中国气候点的数据进行比较,分析了基准点与我国的701个气候点气候数据的相似程度,确定黑脂大小蠹在我国的潜在适生范围。结果表明黑脂大小蠹在我国可能适宜其定殖的地区范围较广,其中,贵州、四川东部、重庆、湖北、湖南北部、安徽、江苏、上海、浙江等华中地区是黑脂大小蠹的潜在最适生区。     

适合与甘蔗间套种春大豆品种筛选初报

【目的】筛选出适合与甘蔗间套种的春大豆品种,为生产上大面积推广甘蔗春大豆间种提供参考。【方法】2011年利用9个春大豆品种进行不同甘蔗间作模式（甘蔗行距分别为1.2和1.0 m）的筛选试验,调查大豆田间农艺性状及产量性状,并进行相关性分析。【结果】甘蔗行距1.0和1.2 m栽培模式春大豆生育期和产量间的相关系数分别为0.78（P =0.0142）和0.69（P =0.038）。华春2号在1.2和1.0 m栽培模式下的产量均最高,分别为2222.22和2083.33 kg/ha。在甘蔗行距为1.2 m的栽培模式下,桂春10号和泉豆7号产量较高;而在甘蔗行距为1.0 m的栽培模式下,桂春10号和华春5号产量较高。【结论】华春2号、桂春10号和泉豆7号适宜与甘蔗在行距1.2 m栽培模式下间作,华春2号、桂春10号和华春5号适宜与甘蔗在行距1.0 m栽培模式下间作。     

Timing and intensity of precommercial thinning in Pinus sylvestris stands

The effects of timing and intensity of precommercial thinning were studied in three Scots pine artificially regenerated stands on Vaccinium forest sites in southern Finland. A two-level factorial design (3×3) was used in each stand: thinning at dominant height of 3, 6 and 9 m to 1000, 1600 and 2200 stems ha^?1. The effects of the treatments were analysed after a period of 23–25 yrs when the dominant height was 14–15 m. Early thinning resulted in the highest standing volume and amount of merchantable wood, and also in slightly accelerated height development. Thinning to 1000 stems ha^?1 caused a considerable production loss, but there were no differences between the densities of 1600 and 2200 stems ha^?1. Branches became thicker after early thinning, but the differences between the treatments were negligible for crop trees. Crown ratio was lowest as the result of early or moderate thinning (2200 stems ha^?1).     

Effect of spacing on 23-year-old lodgepole pine (Pinus contorta Dougl. var. latifolia) in southern Sweden

Abstract

The objective of this study was to compare volume growth and external timber quality properties of lodgepole pine (Pinus contorta Dougl. var. latifolia) stands planted in different spacings (1.41×1.41, 2.00×2.00, 2.83×2.83, 4.00×4.00) in southern Sweden. In northern Sweden lodgepole pine has been grown for a long time and shows superior volume production compared to Scots pine (Pinus Sylvestris L.). The Swedish Forestry Act restricts establishment of lodgepole pine plantations in southern Sweden. However, it is important to increase the knowledge about lodgepole pine and its potential use also in this part of the country. Two experiments in southern Sweden were studied. Each trial was designed as a random block experiment with two blocks. Both investigated stands had an age of 23 years at the time of assessment. The mean diameter and the volume production differed significantly between the spacings. The highest volume production was found in the narrowest spacing, 313% compared to the widest spacing. Significant differences between spacings were also found concerning external quality traits. The frequency of dominant and co-dominant trees without defects was 24% in the most open spacing compared to 46% in the narrowest one. Under current circumstances approximately 2500 seedlings/ha in the initial stand seems to be a reasonable compromise between growth, diameter development and timber quality.     

广德县山核桃生态区划的初步研究

在分析山核桃生物生态学特性的基础上,根据地域分异原则和自然条件,并按照山核桃的生态适应性,将广德全县区划为3种类型,即：适宜种植区（Ⅰ区）、较适宜种植区（Ⅱ区）、不宜种植区（Ⅲ区）。讨论了各类型亚区内的自然因子、适宜程度及原因,并对广德县今后推广发展山核桃提出了若干建议。     

安徽省宣城市特色烟种植潜力定量评价

通过对宣城地区的自然条件、土壤条件和社会经济条件调查,利用3S技术和定量方法综合评价了安徽省宣城市种植"焦甜香"型特色烟叶的潜力。结果表明:宣城市总体上适宜种植特色烟且潜力较大,适宜面积3.84万hm2,占土地面积的3.11%,其中,一等、二等、三等适宜面积分别为0.74、1.27和1.83万hm2,但各地区应采取不同的发展战略。     

温室分层土壤条件下滴头流量和间距对湿润体的影响

基于温室田间土壤大多容重分层和不均匀的特点,进行了原状分层、分层筛分均质和筛分均质3种土壤对湿润体影响的对比研究。试验地土壤为粉土(中国制分类),原状分层和分层筛分均质土壤0~20 cm容重为1.44 g/cm3,20~40 cm为1.63 g/cm3,40~60 cm为1.55 g/cm3,筛分均质土壤采用0~60 cm平均容重1.54 g/cm3。滴头流量设2.7 L/h和1.4 L/h二种,滴头间距有30,50,70,100 cm四种,采用剖面法观测土壤含水率和湿润体发展。试验结果表明:①湿润体在现场原状分层土壤、分层均质和均质土壤中有很大的区别,分层筛分均质和筛分均质土壤中均为碗状原状,而分层土壤的湿润体形状在灌水量较小时为碗状,随灌水时间的延长,其形状逐渐变为椭柱体;②土壤容重分层情况对湿润锋的运移影响很大,分层土壤由于20~40 cm容重较大纵向湿润锋发展缓慢,灌水历时8 h时最大纵向湿润锋分别为27 cm和25 cm,且原状分层土壤灌水量较大时出现0 cm深度处横向湿润锋小于-7~-13 cm深度处湿润锋现象;而筛分均质土壤中纵向湿润锋明显大于分层土壤,灌水历时8 h时最大纵向湿润锋为32 cm;③原状分层土壤湿润体内平均含水率高于分层筛分均质和筛分均质土壤,但各组均高于田持,土壤含水率均匀度均在82%以上。基于这种结果,建议设计湿润比应根据温室土壤特点和设计灌水量进行现场测试确定,这样更符合实际情况。     

不同行距对机插秧产量的影响

[目的]探讨机插秧适宜的栽插密度。[方法]12011～2012年以常规粳稻南粳46为试验材料,采用两种不同行距的插秧机进行栽插,研究不同行距对产量的影响。[结果]8行25cm栽插行距比6行30cm栽插行距具有较明显的增产优势,主要表现在密度、基本苗和成穗数增加,对穗型的影响较小,可显著提高单位面积总颖花量,从而提高单产。[结论]该研究可为机插秧的高产栽培提供参考。