桉树不同成熟度叶片营养元素内循环特征     

吉玉  田湘  张雨蒙  吴庆标 《森林与环境学报》2021,(3):242-247

揭示桉树人工林不同成熟度的叶片器官所需营养元素变化以及土壤肥力对其影响,对于桉树营林和科学施肥具有重要的生产指导意义。选取广西隆安县小林镇和田东县思林镇的桉树2代萌芽林作为研究对象,测定两个人工林嫩叶、成熟叶、黄叶的C、N、P、K、B、Ca、Mg以及土壤C、N、P、K、Ca、Mg元素含量,并进行相关分析。结果表明,植物叶片的N、P、K、Mg营养元素转移规律是黄叶向成熟叶和嫩叶转移,但C、Ca、B营养元素则是随着叶片的生长发育逐渐积累,黄叶中含量最高,说明施肥时应关注Ca、B元素的持续和有效供给。两片人工林都表现出类似的规律,说明土壤肥力的差异不影响桉树人工林叶片营养元素的内循环规律。桉树嫩叶营养元素含量及其生态化学计量比学特征具有与成熟叶和黄叶不同的表征,在营养物质研究中应予以足够重视。  相似文献   

内蒙古高原紫花苜蓿土壤氮素丰缺指标和推荐施氮量     

米春娇  孙洪仁  王显国  高凯  张玉霞  刘庭玉 《草地学报》2021,29(12):2785-2791

为了给内蒙古高原紫花苜蓿（Medicago sativa L.）测土施氮奠定科学基础，本研究采用“零散实验数据整合法”和“养分平衡-地力差减法”新应用公式，开展了该自然区域紫花苜蓿土壤氮素丰缺指标和推荐施氮量研究。结果表明：内蒙古高原生长第1年紫花苜蓿土壤碱解氮第1~6级丰缺指标为≥48，20~48，8~20，4~8，2~4和<2 mg·kg^-1，土壤全氮第1~5级丰缺指标为≥1.4，0.8~1.4，0.4~0.8，0.2~0.4和<0.2 g·kg^-1，土壤有机质第1~6级丰缺指标为≥17，10~17，6~10，3~6，2~3和<2 g·kg^-1。当紫花苜蓿目标产量9~18 t·hm^-2、氮肥利用率40%时，内蒙古高原紫花苜蓿第1~6级土壤推荐施氮量分别为0，68~135，135~270，203~405，270~540和338~675 kg·hm^-2。  相似文献   

饲料中无机元素分析方法研究进展     

徐祎然  左鹏翔  王志飞 《畜牧与饲料科学》2019,40(7):50-54

饲料中所含的无机元素对动物生长具有重要意义。在饲料中过量添加无机元素会导致环境污染问题,也会通过食物链最终危害消费者的身体健康,因此,对饲料产品中的无机元素进行检测和动态监控尤为重要。综述了近年来饲料中无机元素含量检测主要应用的前处理方法及其含量检测技术,分析了不同前处理方法和含量检测技术的优点和不足,以期为饲料中无机元素分析方法的科学、合理应用提供参考。  相似文献   

Soil protection for a sustainable future: options for a soil monitoring network for Ireland          下载免费PDF全文

L. O'Sullivan  F. Bampa  K. Knights  R. E. Creamer 《Soil Use and Management》2017,33(2):346-363

The increased recognition of the importance of soil is reflected in the UN Post‐2015 Development Agenda with sustainable development goals that directly and indirectly relate to soil quality and protection. Despite a lack of legally binding legislation for soil protection, the European Commission remains committed to the objective of soil protection. However, the achievement of a legally binding framework for soil protection relies on the implementation of a soil monitoring network (SMN) that can detect changes to soil quality over time. As beneficiaries do not pay for the provision of soil information, the options for soil monitoring are limited. The use of existing data sets should be considered first. Using Ireland as an example, this research explored the opportunities for a SMN for Ireland considering three existing national data sets. The options for a SMN are considered in terms of their spatial and stratified distribution, the parameters to be measured and an economic analysis of the options proposed. This research finds that for Ireland, either a 10 or a 16 km² grid interval stratified by land use and drainage class offers the best potential in relation to the spatial distribution of existing data sets to reflect local data at a national level. With existing data, the stratified SIS data using the 16 km² grid offers the best value for money, with baseline costs for analysis, excluding field costs, of between €706 481 and €2.8 million. Acknowledging the impossibility of measuring all parameters with ideal frequency, this study proposes a two‐tier system for optimized monitoring frequency. Parameters must anticipate future policy requirements. Finally, the implementation of a SMN must be accompanied by standardized methods, defined thresholds and action mandates to maintain soil quality within allowable limits.  相似文献   

阔叶红松林的生物量和营养元素含量的研究   总被引：6，自引：0，他引：6  

詹鸿振  刘传照 《林业科学》1990,26(1):80-85

一、研究内容和方法我们于1985—1987年对小兴安岭阔叶红松林的生物量进行了研究。生物量的测定是在凉水自然保护区的阔叶红松林内进行的。林龄220年,组成8红2椴,林分平均高23.1m,平均直径37.4cm。其中红松平均高27.2m,平均直径45.2cm,密度622株/ha,针  相似文献   

Essential Factors and Sustainable Development of Green Agriculture     

WANG Hong 《东北农业大学学报(英文版)》2009,16(2):83-90

This paper discussed the definition and essential factors of green agriculture, including green ecological environment, green material energy input, application and the popularization of green agricultural technology, the green behavior of worker, green policy regulations guarantee, fund support, supply and the production of green agriculture products, as well as the concept of green agriculture, structural mechanism and function. And finally existing problems in present green agriculture and five suggestions of green agricultural sustainable develonment were proposed.  相似文献   

Factors influencing decline in soil pH in Hawaiian Eucalyptus and Albizia plantations     

C. Rhoades  D. Binkley 《Forest Ecology and Management》1996,80(1-3):47-56

Soil pH declined from 5.9 to 5.0 in 8 years beneath plantations of Eucalyptus saligna (Sm.) in Hawaii. In stands of Albizia falcataria, (L.) Fosberg, the soil pH change was more dramatic, declining from 5.9 to 4.6. We measured several components of soil acidity beneath four mixtures of the two tree species to gain insight on the processes responsible for the decline in soil pH. These components were studied using an empirical method of comparing acid quantity, degree of neutralization (depletion of base cations), and acid strength. The decline in soil pH differed between species as a result of differences in the degree of neutralization of the soil exchange complex; the larger decrease in soil pH under Albizia was produced by greater acidification of the exchange complex. Empirical titration curves suggested that differences in acid strength moderated the divergence in soil pH beneath the species. Had the acids accumulating in the soil under Albizia been as strong as those in the Eucalyptus soil, the difference in soil pH would have been greater. Though the two species had contrasting effects on soil pH, the differences in degree of neutralization, responsible for the pH decline, were small compared with differences in the amount of cations stored in tree biomass. Continued supply of nutrient cations (from weathering or fertilization) will ultimately control both the extent of soil pH decline and the level of productivity sustained by the forest.  相似文献   

Effects of 'Agri-SC' soil conditioner on soil structure and erodibility: some further observations     

M.A. Fullen  A.M. Tye  K.E. Cookson 《Soil Use and Management》1995,11(4):183-185

Abstract. In field and laboratory experiments the conditioner‘Agri-SC’has shown improvements in the structure of loamy sand soils in east Shropshire, UK. It resulted in statistically significant decreases in soil bulk density values and increases in soil porosity and aggregate stability. Further experiments are in progress on both loamy sand and silt loam soils.  相似文献   

越桔对长白山区酸性土壤的适应性   总被引：15，自引：1，他引：14  

李亚东  郝瑞 《园艺学报》1994,21(2):129-133

在长白山区３种类型的酸性土壤上栽培越桔，研究结果表明，｀北空＇、｀美登＇、｀斯卫克＇在暗棕色森林土上生长结果较好，树体营养关系合理；在草甸沼泽土上３个种生长结果均较差，｀北空＇在水湿地潜育土上生长旺盛，但产量低，综合分析认为，矮丛越桔类型品种对我国长白山区酸性土壤条件的适应性较强，半高丛越桔则适应性差，针对长白山不同类型的土壤，以美登最为适宜暗棕色森林土栽培，斯卫克次之；水湿地潜育土可栽培美登品种  相似文献   

海南半干旱地区芒果间作柱花草及作物效益初探   总被引：12，自引：4，他引：8  

白昌军  刘国道  何华玄  王东劲 《草地学报》2003,11(4):350-357

1998～2001年在海南东方干旱半干旱燥红土芒果与柱花草及作物间作示范区的实践表明，在芒果园间作扁豆、柱花草、番薯和花生可显著提高芒果挂果率，芒果收入比芒果单种分别增加97．79％、98．53％、54．41％和48．28％，果园综合收入比芒果单种分别增加108．55％、98．53％、97．98％和91．58％，同时，果园间作可显著提高果园土壤有机质、全氮、速效磷的含量和土壤pH值，间作扁豆使土壤有机质含量增加53．3％，间作柱花草使土壤全氮增加43．92％，速效磷增加78．16％，从而达到了以短养长、增加农民收入、提高土壤肥力和持续管理利用的目的。  相似文献