成龄梨树缺硼症识别与施硼技术

1缺硼症状新梢由顶端开始枯死,并逐步回枯,叶片稀疏,受害小枝的叶片变黑但不脱落,或顶梢呈丛状生长;开花不良,坐果率低;果实表面开裂并有小疙瘩,果肉失水,变干变韧,果实近萼处组织粗糙、变麻,随后木栓化,有时出现浅色凹陷,凹陷的皮下有木栓化组织,果实风味变差,经常是未成熟即变黄,而且黄的程度参差不齐,失去商品价值;枝的皮部出现溃疡等.砂质土壤、石灰质土壤及干旱土壤梨园都容易缺硼.     

栽花三则文辑

（一）植料的酸碱度 不少初学种花的朋友皆忽略所用泥土或植料的酸碱度（pH值）是否适合该品种。像康乃馨、石竹、兔仔花、紫薇等花卉均喜欢在pH值7以上的植料中生长。假如所含的石灰质稍多，也不成问题的。但如是栀子花、杜鹃、含笑、山茶或黄钟花等品种，便会引致黄化病。     

木纳格葡萄优质高产栽培技术

一、栽植技术 1.园址选择 园址最好选择北纬40°左右的地段;选择石灰质砂性土壤和砾石土壤,沙壤土亦可。土壤盐碱总含量≤0.4%,pH值7.0～8.3。     

枸杞盆景的制作

枸杞是茄科,属落叶灌木。丛生,枝条细长。花紫色,花期5月—10月。浆果深红色或橙红色,有时还会出现一株树上花果并存的现象。枸杞萌芽力很强,喜光稍耐荫,喜温暖但耐寒,发芽早落叶迟,果实不脱落,观赏期长。每年春秋两次生长新叶,两次开花、坐果,而且叶小而密,花多而小,果繁而艳,     

栾树的培植技术

栾树（Koelrenteria paniculata）又名灯笼树，属无患子科栾树属。落叶乔木，其树形高大而端正，树皮灰褐色，小枝稍有棱。无顶芽，皮孔明显。奇数二回羽状复叶，枝叶茂密而秀丽，春季红叶似醉，夏季顶端的大圆锥花序，黄花满树。秋叶鲜黄，蒴果膨大，成熟时红褐色或桔红色，果皮薄膜质，三角状卵形，似灯笼。种圆形，黑色。栾树适应性强，喜光，耐寒，耐干旱，耐瘠薄、石灰质土壤。耐一定盐渍及短期水涝。     

由石灰性冲积物发育而来的排水不良和排水良好的土壤中游离氧化物的分布

A study on the distribution of free iron and manganese oxides was conducted in soils developed on calcareous alluvial deposits under subhumid climatic conditions, in Western Greece. Soil samples from two well drained soils and from two poorly drained soils, classified as Alfisols, were collected and used in this study. After certification of soil homogeneity the acid ammonium oxalate and dithionite-citrate-bicaxbonate methods were used to extract free iron and manganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonate method (Fed) were significantly higher than the iron oxides extracted by the ammonium oxalate method (Feo), indicating that a considerable fraction is present in crystalline forms, independent of drainage status. A confirmation of free iron oxides and fine clay was detected. The ratios Feo/Fed and (Fed-Feo)/total Fe (Fet) could not be used to distinguish the well drained soils from the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.     

石灰质土壤大田中榅桲无性系对缺铁黄化症的抗性评价

据《Scientia Horticulturae》(2012年5月)的一篇研究报告,来自西班牙科尔多瓦大学园艺学院的研究人员对石灰质土壤中榅桲无性系对缺铁黄化症的抗性进行了田间评价。试验为期3年。黄化症严重程度用SPAD指标表示,植株生长势由枝条长度表示。结果表明,两个无性系被鉴定为最抗,余下的为易感或中度抗性。榅桲黄化症随季节和年份变化而逐渐增强,夏季和     

柳树的种植及病虫害防治

柳树是我国的原生树种,适应性非常强,既耐湿,又抗旱,又能耐低温,抗风性也很好.柳树冬季落叶后可修剪、整枝.耐旱,耐水湿,为湿生阳性树种.喜生于河岸两旁湿地,短期水淹及顶不致死亡.高燥地及石灰质土壤也能适应.发芽早,落叶迟,生长快速,但不及旱柳耐寒.寿命短,30年后渐趋衰老但并不是说柳树适应性很强,在种植过程中就可以疏于管理,掌握和运用柳树栽培技术和病虫害防治方法是确保柳树的健康成长必不可少的重要条件.     

素雅可人的武陵雪花石

武陵雪花石是湖南省常德市了具特色的观赏石种之一。雪花石为石灰质岩,属单矿物沉积岩。由黑色的石灰岩基质与魄的方解石晶体聚合而成,其中,白色方解石晶体往往以斑块状,点状条索状形式组成黑底白纹的图案,犹如片片雪花,故名“雪花石”.     

Application of NaHCO3/ DTPA Extractant-ICP Spectrometry Technique in Soil Test for Availability of Nutrients and Heavy Metals

Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test.