‘奥斯特’北美冬青叶片主要营养元素含量的年变化规律研究

以7年生‘奥斯特’北美冬青为试验材料,测定叶片中N,P,K,Ca,Mg,Mn,Fe,Zn,Cu,B元素含量,分析叶片主要营养元素年动态变化规律,为树体营养诊断和合理施肥提供科学依据。结果表明:(1)叶片中营养元素含量高低为NKPCaMnMgZnFeBCu;(2)随着时间推移,叶片中各营养元素年动态变化出现规律性波动,其中N,P,K,Cu含量总体呈下降趋势,Ca,Mg,Mn,Fe,Zn,B含量总体呈上升趋势。初步认为:N,P,K,Ca,Mg,Zn,Fe,Cu元素营养诊断可在8月7日到8月26日期间进行,Mn,B元素可提前至6月26日到7月16日期间进行。     

山银花叶片营养元素含量季节动态变化的研究

以5年生山银花(灰毡毛忍冬)品种‘金翠蕾’为试验材料,研究山银花叶片中10种营养元素含量的季节动态变化规律。结果表明:3月至12月期间,施肥处理与对照(不施肥)的山银花叶片中10种营养元素含量的季节动态变化规律有差异,两者叶片中N、P、Mg、Ca、Cu、Fe、B含量的季节动态变化呈现相同的趋势,N、P、Cu含量整体呈下降趋势,施肥处理的叶片营养元素含量比对照的高;Ca、Fe则呈上升趋势,但施肥处理的叶片Ca含量比对照的低,而Fe含量则比对照的高;Mg、B呈"上升—下降"趋势,峰值出现在盛花期后的7—8月,7月前施肥处理叶片B含量比对照的高,而7月后又比对照的低;施肥处理与对照的叶片中K、Mn、Zn含量的季节动态变化趋势不相同,整体变化无规律,有多次起伏,但峰值也是出现在盛花期后的7—8月,其中施肥处理叶片中K含量在5—7月有明显上升的过程,其平均含量比对照高105.8%。3月至12月期间,施肥处理的叶片P、N、K、Fe、Cu、Mg平均含量比对照的高,而Ca、Zn、Mn、B的平均含量则比对照的低。施肥与不施肥处理叶片营养元素含量的季节变异系数最大的是P,说明P在山银花生长发育中起着重要调控作用。施肥处理与对照叶片营养元素含量之间相关性表现不一致,元素之间存在促进或拮抗作用。     

红锥不同种源叶片养分含量分析

对红锥3个不同种源2 a生苗的叶片进行营养元素含量测定分析,结果表明:与大多数植物体内营养元素含量适宜范围相比,红锥叶片营养元素N、Ca、Mg、Zn、Fe、B含量在适宜范围之内;Cu的含量只有浦北种源在正常范围之内,博白和东兰种源处于缺乏状态;Mn含量处于安全水平之下;P和K的含量严重缺乏。常量元素中含量最高的是N,其次是Ca,最低的是Mg和P;微量元素中含量最高的是Fe,其次是Mn,最低的是Cu;叶片中N、P、Ca、Mg、Cu、Fe、Mn和B营养元素含量在不同种源间的差异均达到显著或极显著的水平。不同种源叶片内矿质元素含量变幅不同,变幅最大的是B,其次为P,再次为Cu,最小的是N、Zn和K;大部份元素之间有显著或极显著的正相关,表明元素间存在着相互的协同作用。     

无翼坡垒植物与土壤营养元素及化学计量学特征

为探讨无翼坡垒Hopea exalata土壤、根系和叶片营养元素含量及化学计量特征,以甘什岭省级自然保护区无翼坡垒群落为研究对象,根据物种胸径划分等级,选择幼树(2.5 cm≤DBH 7.5 cm)、小树(7.5 cm≤DBH 12.5 cm)和大树(17.5 cm≤DBH 22.5 cm)3个等级,比较其土壤-根-叶片元素含量及化学计量比的差异,探讨随林龄的变化及相互间的关系。结果表明:1)C、N、P含量表现为叶片根系土壤,土壤全N、全P和全Ca含量以大树最高;随着等级的增长,根系C和Mg含量呈上升趋势,N、P和K含量呈下降趋势;叶片C、P和K含量呈上升趋势,N、Ca和Mg含量呈小幅度下降趋势。2)不同等级土壤C/N、C/K比值以大树最高,叶片中C/N、C/K、Ca/K、Ca/Mg比值显著高于土壤和根系,根系和叶片的N/P、N/K、Ca/K和Ca/Mg均高于土壤。3)不同等级叶片N/P均大于16,表明无翼坡垒植物主要受P限制。PCA分析结果表明,土壤C、全P、全K、全Ca、根系K、Mg、C/K、K/Mg、叶片N、Mg、C/N、C/K、N/K、K/Mg为主要影响因子,土壤全Mg、根系P、Ca、N/P、K/P、叶片Ca、K/P和Ca/K为重要影响因子,反映了无翼坡垒土壤-根-叶C、N、P含量之间以及化学计量比之间也均存在显著相关关系。     

茂名小良桉树营养元素含量的测定

为研究广东省茂名市小良水土保持试验推广站桉树的化学成分,测定了小良5种桉树的8种营养元素的含量。结果表明：同一品种桉树同一器官中各营养元素含量比较,4种大量营养元素含量总体表现为K〉Ca〉Mg〉P,4种微量营养元素含量绝大部分植物以Mn含量最高,Cu含量最低;4种大量元素P、K、Ca、Mg含量都表现为叶最大,枝次之,根和干中的含量较小;而4种微量元素Cu、Fe、Mn、Zn在植物各器官含量的高低排序缺乏一致规律;不同种桉树间的营养元素含量差别总体上缺乏一致规律。     

油橄榄生长期叶内大量元素动态变化规律研究

以佛奥、鄂植、柯基3个油橄榄品种为试验材料,3-10月测定其主要生长期叶内大量元素N、P、K、Ca和Mg的含量,分析叶片营养元素的动态变化规律,为树体营养诊断和合理施肥提供科学依据。结果表明,(1)油橄榄叶片中大量元素含量从高到低依次为NCaKPMg。(2)油橄榄在不同生长期对营养元素的需求不尽相同,从开花授粉期到油脂积累期对N、P元素需求较大,开花授粉期和坐果期对Mg元素需求多,果核硬化期到成熟期对K元素消耗大,果实成熟期到采收期对Ca元素有一定需求。(3)除柯基品种N含量较其它2个品种有显著差异外,3个品种在其余大量元素差异均不明显。     

不同施肥处理后中林-46杨叶片中营养元素变化趋势研究

通过对不同施肥处理后中林-46杨叶片中营养元素诊断研究表明:(1)不同营养元素浓度具有不同的季节变化趋势。(2)施肥后叶片中营养元素N、P、K相关系数分别为0.8247、0.6930、0.1566,即此林分N、P缺乏,K较丰富;施N肥有利于P、K、Ca、Mg的吸收,施P有利于N、Ca、Mg的吸收,施K有利于N、P、Mg的吸收。(3)N、P、K、Ca、Mg的适宜浓度为1.95%、0.17%、1.33%、0.84%、0.13%。     

油橄榄叶片营养诊断样品适宜采集期研究

为了确定油橄榄叶片营养诊断样品采集的适宜期,采用定点定期连续采集叶片方法,测定并比较分析了莱星和鄂植8号2个油橄榄品种叶片中的N、P、K、Ca、Mg、Zn、Mn、Fe、B和Cu养分含量的动态变化特征。结果表明:2个油橄榄品种叶片营养元素含量其年变化总趋势在品种间表现较一致;油橄榄叶片营养元素含量在周年内变化趋势因元素种类不同而异;在油橄榄年生育周期内,各元素含量变化相对平稳的时期分别为:N元素12~2月,P元素11~4月,K元素4~6月和9~12月,Ca元素11~3月,Mg元素10~12月,Zn元素3~6月,Mn元素11~1月,Fe元素5~9月,B元素12~1月,Cu元素4~6月和10~2月。综合分析结果表明,油橄榄叶片营养分析的采样适宜期为:N、P、K、Ca、Mg、Mn、B和Cu元素在11~12月取样,Zn、Fe在5~6月取样。     

红锥人工幼林营养特性研究

对不同月份红锥叶片中营养元素含量的变化及其结构进行研究,结果表明,叶片中N、P、K、Ca、Mg、Mn、Fe、Cu、Zn营养元素含量呈季节性变化,普遍地在生长初期（春季）较高,生长旺期（夏季）最低,而秋冬季生长缓慢时由于积累所致而略有回升;叶片中常量元素含量以N、K、P较高,依次排序为：N〉K〉P〉Mg〉Ca,微量元素含量以Mn、Fe为高,依次排序为：Mn〉Fe〉Zn〉Cu,N、P、K、Ca、Mg、Mn、Fe、Zn、Cu比例为：7.40∶1.00∶5.96∶0.30∶0.51∶1.10∶0.16∶0.05∶0.01;根据研究结果及南方山地的土壤特点,红锥人工幼林的施肥时间宜在春季或春夏之交季节,在肥种及配比上,应在施用大量元素N、P、K、Mg、Ca的基础上配施微肥Zn,配比为N∶P∶K∶Ca∶Mg∶Zn=7.40∶1.00∶5.96∶0.30∶0.51∶0.05.     

茂名小良桉树营养元素的测定

为研究茂名小良水保站桉树的化学成分,测定了小良5种桉树的8种营养元素的含量,其中K、Ca、Mg、Cu、Fe、Mn、Zn的含量采用火焰原子吸收光谱法进行测定,P含量采用钼酸铵分光光度法测定。结果表明：同一品种桉树同一器官中各营养元素含量比较,四种大量营养元素含量总体表现为K>Ca>Mg>P,四种微量营养元素含量绝大部分植物以Mn含量最高,Cu含量最低;四种大量元素P、K、Ca、Mg含量都表现为叶最大,枝次之,根和干中的含量较小;而四种微量元素Cu、Fe、Mn、Zn在植物各器官含量的高低排序缺乏一致规律;不同种桉树间的营养元素含量差别总体上缺乏一致规律。     

马尾松、桉树及其混交林土壤养分变化特征及评价

研究马尾松纯林、桉树纯林和3种不同模式混交林土壤养分含量的变化规律,并对其土壤养分状况进行主成分综合排序。结果表明：土壤有机质、全 N、全 P、水解 N、速效 P 和速效 K 皆表现为随土壤深度增加而减少,全 K 则表现相反;在各林分中,桉树纯林的土壤有机质、速效 P 含量最高,混交林次之。混交林则土壤全 N、全P 和速效 N 含量总体上大于纯林。马尾松纯林除在浅层土中速效 P 含量最高外,其他养分指标都低于桉树纯林和混交林。土壤养分综合评价为桉树纯林＞混交林 A＞混交林 C＞混交林 B＞马尾松纯林,表现为桉树纯林养分状况最好,马尾松纯林最差,与针阔树种的生长特性和凋落物养分归还能力有关。混交林中种植密度较大的混交林A 养分状况相对较好,表明其养分储存能力较好,消耗较少。而相同种植密度下,混交林 C 的林分土壤养分状况优于混交林 B。     

3种桉树幼苗叶片养分变化及其转移特性

我国桉树人工林面积已超过了100万hm2,成为我国南方面积最大的人工林树种之一,并以每年约10万hm2的速度发展.     

养分胁迫对桉树幼苗叶片营养吸收的影响

通过设置Ca、Mg、Cu、Zn和B等中微量元素不同的浓度梯度(缺乏、低量和过量),调查养分胁迫对桉树幼苗矿质营养吸收的影响.试验结果表明:(1)各元素养分胁迫对桉树幼苗叶片营养元素含量的影响不同;(2)CK(未浇灌营养液)处理桉树营养元素总量最低,浇灌营养液各处理比CK(未浇灌营养液)处理提高36.03-43.55倍;...     

印度西部5种热带干落叶林中凋落物中生物元素和返回到绿叶中的季节性变化(英文)

本文对印度西部5种热带干落叶林中凋落物里生物元素的季节性变化和它们返回到新鲜叶中季节性变化进行研究。对5个树种:阿拉伯金合欢(Acacia nilotica L.)、金合欢(Acacia leucophloea Roxb.)、柚木(Tectonagrandis L.f.)、绒毛野独活(Miliusa tomentosa Roxb.)和紫矿(Butea mono-sperma Lain.)中凋落物的成熟叶、枝和再生部分的N、P、Ca、Mg、K和Na的浓度,以及老叶和幼叶中浓度间的关系进行调查。对这些树种的总干物质进行记录,并分析它们所含的N、P、Ca、Mg、K和Na的含量。其中阿拉伯金合欢叶子中N的含量最高,而金合欢的叶子里Ca和Mg含量最高。叶中含P最多的是阿托伯金合欢、金合欢和紫矿,而含P最少的是柚木和绒毛野独活。K和Na含量在这些树种中没有明显的区别。观察发现,N、P和K的浓度随季节变化大,但Ca和Mg则不然。唯有钾在所有树种中都是最稳定的,吸收N和P可以用于来年新叶的生长。从老叶和凋落物中吸收的营养会支持新叶的生长,并增加土壤的肥力。图1表4参30。     

大花序桉幼苗营养吸收及分配规律研究

对大花序桉幼苗生物量及营养元素进行测定,结果表明,大花序桉苗木平均单株生物量大小排序为茎>根>叶。幼苗主要营养含量和吸收积累规律为K>N>P>Fe>Mn>Zn>B>Ca>Cu>Mg。大量元素N、P、K贮量最高的部位均为茎,根部和叶中含量相近。大花序桉苗期叶片对主要营养元素N、P和K的吸收分配间存在相互促进的关系;Mg与Ca,Cu与P、K,Zn与N、K、Cu、Fe,Fe与N呈现互相促进关系;Mn与N、Fe、K、Cu,B与P、Cu为相互抑制关系。据此,大花序桉苗期以氮、磷、钾肥为主,其中要求养分K₂O>N>P₂O₅,并有针对性地添加铁肥、锌肥和铜肥。     

新造林地土壤肥力变化规律研究

从不同森林类型土壤肥力状况的角度,对梧州共青林场新造未成林地的土壤营养元素含量进行对比研究,探讨了林地采伐更新为红锥（Castanopsis hystrlz）林和荷木（Schima superba）林后其森林土壤肥力的变化情况。结果表明,随着红锥林和荷木林的生长发育,各林地养分状况明显降低。和对照林地相比,土壤pH值、...     

Nutrient cycling and distribution in different-aged plantations of Chinese fir in southern China

The distribution in tree biomass and understorey vegetation and annual biological and geochemical cycling of total nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) were measured in young, middle-aged and mature plantations (8-, 14- and 24-years old) of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) in southern China. Although >98% of nutrients occurred in the soil, soil nutrient content decreased with plantation age. Nutrient outputs from the soil exceeded inputs in stands of all ages but the net soil nutrient loss increased significantly for N, P and Ca with plantation age. Comparison of nutrient fluxes showed that the smallest (and hence limiting for nutrient cycling) fluxes were litter decomposition in the young plantation in contrast to canopy fluxes (apart from for Mg) in the middle-aged and mature plantations. Nutrient use efficiency, release of nutrients from litter decomposition and nutrient return, particularly in litterfall, increased significantly with plantation age. These results suggest that, as stand age increases, nutrient cycling in Chinese fir plantations is increasingly dominated by biological processes and becomes less dependent on external nutrient sources in rainfall and the soil. It therefore appears that prolonging the rotation length of Chinese fir plantations by approximately 5 years could be beneficial for maintaining the soil nutrient status for successive plantings.     

Nutrient export and harvest residue decomposition patterns of a Eucalyptus dunnii Maiden plantation in temperate climate of Uruguay

The potential export of nutrients from Eucalyptus plantations harvested for pulp production may be high. However, depending on the harvest method, the nutrients from the residue can be recycled. The aims of this study were (i) to quantify the content and distribution of nutrients in different residue components at harvest for a Eucalyptus dunnii Maiden plantation; and (ii) to quantify the decomposition rates of the harvest residues, and the return of nutrients to the soil in the temperate climate conditions of Uruguay. Six trees of a 9-year-old E. dunnii plantation with average diameter at breast-height (DBH) were harvested, and the biomass produced and the N, P, K, Ca and Mg contents in commercial and non-commercial logs, leaves, branches, bark and litter were estimated. Decomposition of the remains of leaves, branches, non-commercial logs, bark and litter was studied in the field for 2 years. Although commercial logs accounted for 61% of the biomass produced, only 27% of the N, 35% of the P, 18% of the K, 16% of the Ca and 41% of the Mg present in the forest were exported with the product. When logs are exported without de-barking in the site, the nutrient export would increase to 41%, 55%, 46%, 68% and 66% of the total extraction of N, P, K, Ca and Mg, respectively. Residue decomposition showed that the leaves lost the highest proportion of biomass (half life 0.86 years), and bark was most resistant to decomposition in the field (half life 5.36 years). As regards the nutrients, K was lost most rapidly and Ca showed the slowest loss, while N, P and Mg losses were generally more gradual, and proportional to the decomposition rate.     

Biomass production,nutrient cycling and distribution in age-sequence Chinese fir(Cunninghamia lanceolate) plantations in subtropical China

Biomass production and nutrient(N, P, K, Ca and Mg) accumulation, distribution and cycling were quantified in young, mature and over-mature(10-, 22-, and34-year old) Chinese fir [Cunninghamia lanceolate(Lamb.) Hook] plantations in southern China. Total stand biomass of young, mature and over-mature stands was 38,104 and 138 t ha-1respectively. Biomass production increased significantly with age. Stem wood represented the highest percentage of stand biomass, accounting for 41,55 and 63 % in the young, mature and over-mature plantations respectively. Nutrients concentration was highest in live needles and branches, and lowest in stem wood. The plantations accumulated more N, followed by K, Ca, Mg,and P. Nutrient return amount, nutrient utilization efficiency, nutrient turnover time, the ratio of nutrient returnand uptake increased with stand age, which implies that young Chinese fir deplete soil nutrients to maintain growth,and efficiently utilize nutrients to decrease dependence on soil nutrients as they age. Harvesting young Chinese fir plantations would therefore lead to high nutrient loss, but prolonging the rotation length could improve soil recovery,and help sustain productivity in the long-term. Improved nutrient return through litterfall as stands get older may also be beneficial to nutrient pool recovery.     

Growth and mineral nutrient analysis of teak (<Emphasis Type="Italic">Tectona grandis</Emphasis>) grown on acidic soils in south China

Teak (Tectona grandis L.f.) is widely planted in the world due to its high market demand, economic, ecological and social value. Its plantations have mostly been established and expanded into sites that are acidic to severely acidic in southern China. But, there are no available and specific evidence-based nutrient management techniques. To better recognize and understand the relationship between teak tree growth and nutrient content in the foliage and soil and establish nutrient norms are critical to optimally manage these young plantations. We studied the foliar nutrient and soil chemistry in 19 representative teak plantations aged 5–8 years. Regression analysis indicated that the mean annual increment of teak volume was linearly and positively correlated with foliar N, Ca, Fe and B concentrations, with soil base saturation percentage, available P and Zn concentrations, and negatively correlated with soil Al concentration. Only if the Ca and Mg contents in soil were enhanced, could the increase in soil base saturation percentage benefit teak growth. A revised classification of low-and high-yielding stands was established by using a sorting method of principal components over 6 foliar macro and 8 micro elements in a Diagnosis and Recommendation Integrated System (DRIS). Specific DRIS norms for teak plantations in acid soils were derived. The nutrient balance of N, P, K Ca, Mg, Zn, B with Fe or Al, Ca with Mg, and Fe with Al provided a key to promote the growth of teak in acid soils. Meanwhile, soil Zn was also found as a primary trace element that affected teak growth in this study.