Effects of Different Seed Stem Sizes on the Changes of Available Elements in Rhizosphere Soil of Fritillaria thunbergii Miq.

[Objectives]This study was conducted to screen suitable seed stems of Fritillaria thunbergii Miq.from different provenances and to provide a theoretical basis for the high-yielding and high-efficiency cultivation of F.thunbergii Miq.introduced to different places.[Methods]F.thunbergii Miq.from four different provenances including Zhejiang,Nantong and Chongqing were introduced and cultivated in Wanzhou of Chongqing.The contents of available Zn,Fe,Mn,Cu,Mo,N,P,K,Ca and Mg in rhizosphere soil of F.thunbergii Miq.during five growing stages were determined after selecting different stem sizes for field cultivation.[Results]Small stems of Pan an and Ningbo provenances(SSG3,121-160/kg)and middle stems of Nantong and Fengjie provenances(SSG2,81-120/kg)showed higher soil availability.[Conclusions]In the process of introduction and cultivation of F.thunbergii Miq.,high yield and high efficiency can be achieved by selecting smaller seed stems of F.thunbergii Miq.

Soil Nutrient Elements of Trampling Disturbance Kobresia humilis Communities along the Highway in Na’qu, Tibet

The change of soil nutrient elements during restoration succession processes of high mountain meadow in Na＇qu County, Tibet, was investigated. The results showed that with the trampling disturbance, the normal structure of soil is violated, soil quality worsened, leading to soil erosion and nutrient loss. The recoverage of soil is lagged behind vegetation when change depends on elements of soil nutrient increase in mass. The content of total nitrogen, total phosphorus and total potassium changed accordingly with total nutrient, and is remarkably correlated to the content of organic matter. The content of available phosphorus is complex and changes with biomass and soil pH. The content of available potassium change was different from that of total nitrogen, total phosphorus and total potassium, and was increasing with trampiing, and the change was relatively little during successive stages.

Effects of biochar-based fertilizers on nutrient leaching in a tobacco-planting soil

Biochar is a soil amendment for increasing soil quality and decreasing nutrient leaching. However, there is little information on the impact of biochar-based fertilizer(BF) on soil nutrient leaching in agricultural soils. We conducted a soil column leaching experiment to study the effects of BF on the leaching of total nitrogen(TN), total phosphorus, and total potassium(TK) in tobacco soils. The distribution characteristics of NH_4^+-N, available P, and available K in soil profiles were analyzed after the application of BF. Biochar was prepared by pyrolysis of fluecured tobacco stems. It was applied at four levels, 0%, 3%,9%, and 15%(w/w), respectively, to the compound fertilizer. Compared with the control, the leaching loss of soil TN decreased by 8.36%, 6.72%, and 6.45%, and the loss of soil TK decreased by 9.18%, 9.31% and 11.82% in the 3%,9%, and 15% BF treatments, respectively. However, BF had no significant effect on the P leaching due to the low movement of P in the soil profile. In addition, the BF addition increased the immobilization of NH_4^+-N, available P, and available K in the soil profile. These results indicate that addition of BF to a tobacco-planting soil reduced nutrient leaching, and suggest that BF could be an effective method of applying biochar to agriculture fields.

Effect of Plant Roots on Soil Nutrient Distributions in Shanghai Urban Landscapes

Twenty-seven surface soil samples were collected from four landscape sites in Shanghai, and seven soil profile samples were gathered from the two older sites for evaluation of horizontal and vertical distribution of soil properties to reveal their relationship with plant roots. Results indicated that urban soil had significant heterogeneities. Soil total nitrogen was significantly correlated with organic matter and total potassium was more abundant than total phosphorus. The available contents of iron, manganese, zinc and copper were higher than the standards for plant growth established by Soltanpour. pH and electrical conductivity increased with increasing soil vertical depth, possibly due to leaching, while the nutrients limiting plant growth such as nitrogen, phosphorus, potassium, iron, copper and zinc had more shallow distributions due to absorption by plant roots. However, with the increasing of soil depth, contents of magnesium, sodium, sulfur and chloride increased due to leaching and bio-cycling, which was further shown by the correlation analysis.

Soil and Leaf Micronutrient Composition in Contrasting Habitats in Podzolized Sands of the Amazon Region

Plant macronutrient distribution in podzolized sands of the Amazon caatinga has received attention in several studies;however, the distribution of micronutrients has not been assessed. Soil micronutrient availability has been hypothesized to reflect contrasting habitat characteristics as well as fundamental differences in substrate, and leaf micronutrient composition may reflect the macronutrient content needed to maintain balance for leaf cell functions. In this study, soil and leaf samples were obtained in a toposequence (valley, slope, and mound). Available soil micro- and macronutrients as well as total leaf content were measured by inductively coupled plasma-atomic emission spectrometer and mass spectroscopy. Soil Zn (-1) and B (-1) as well as Cu (-1) levels were very low. Soil Mn was low in the valleys and slopes (0.62-0.87 mg·kg-1), but higher in the mound (6.59 mg·kg-1). Soil Fe (11.48-21.13 mg·kg-1) was well above the critical level in all of the habitats. Leaf micronutrients Cu, B, Zn, and Fe were below the critical levels for tropical crops of 3-7, 20-70, 15-20, and 72 mg·kg-1, respectively. Leaf Mn (88 mg·kg-1) and Al (<50 mg·kg-1) were below the accumulators level. A strong relationship between leaf micro- and macronutrients suggests the maintenance of a homeostatic elemental composition, which may favour photosynthetic function. Therefore, the local distribution of species may be shaped by their abilities to maintain a balance of micronutrient collected through roots under critically low levels of available Zn, B, and Cu whilst excluding potentially deleterious ions of Mn, Fe, and Al.

Poor-Soil Rhizosphere Enriched with Different Microbial Activities Influence the Availability of Base Elements

Understanding the ecology of soil rhizosphere is essential to enhancing soil ecosystem and plants productivity. Poor-soil properties can limit rhizosphere microbial composition, interactions and plants productivity. Furthermore, the presence of plant exudates and microbial interation can change the rhizosphere dynamic. In the current study, we used two types of soils, rich nutrient soil represented by potting-soil and poor-soil represented with nutrient-deprived poor-soil. The two types of soil were inoculated with five microbial combinations using plant growth promoting bacteria (PGPB, Pseudomonas fluorescens) and mycorrhiza, and planted with two-day-old sorghum bicolor and Setaria italica (Foxtail millet) seedlings. Soil elements analyses were conducted 60 days after planting. The availability of exchangeable base alkali elements (Ca, Mg, Na) were measured and compared. Na was exclusively affected by PGPB inoculation in both soil types. Ca and Mg increased highest when associated with arbuscular inoculation, exclusively, in comparison to association with PGPB or Ectomycorrhiza in both soil types when planted with sorghum. Whereas, the same elements Ca and Mg, increased highest when associated with arbuscular mycorrhiza inoculation whether combined with PGPB or ectomycorrhiza when in soil planted with Setaria italica. The mycorrhiza increased Ca and Mg availability when combined with PGPB. Naincrease was associated only with PGPB inoculation solely in both soil types. The use of arbuscular mycorrhiza inoculation combined with PGPB is ecofriendly method to enrich rhizosphere in poor-soil and eliminate the need to use any chemical fertilizers.

Study on the Response of Soil Nutrient Content to Soil Loss in Karst Sloping Land of Southwest China

[ Objective] The study aimed to analyze the response of soil nutrient content to soil loss in karst sloping land of Southwest China. [Method] Choosing a karst sloping land in Nanchuan, Chongqing City as a sampling area, we analyzed the basic physical and chemical properties of soils at different sampling points, as well as the movement of Mg, Cu, Zn, Mg, Mo and Mn in the soils. [ Result] In the sloping land, there was a var- ying decrease in the content of all soil nutrients from the top to the bottom, but there was no obvious deposit at the bottom. In addition, Mg, Cu, Zn, Mg, Mo and Mn content had clear inflections in the sloping land, and these inflections mainly appeared at 15 -25 m. It proved that both surface soil erosion and underground soil leaching occurred at the same time in the karst sloping land. [Conclusion] The research could provide scientific references for the restoration of ecosystem in karst mountainous areas.

Comparative study on active soil organic matter in Chinese fir plantation and native broad-leaved forest in subtropical China

Active soil organic matter (ASOM) has a main effect on biochemical cycles of soil nutrient elements such as N, P and S, and the quality and quantity of ASOM reflect soil primary productivity. The changes of ASOM fractions and soil nutrients in the first rotation site and the second rotation site of Chinese fir plantation and the native broad-leaved forest were investigated and analyzed by soil sampling at the Huitong Experimental Station of Forestry Ecology (at latitude 26°48′N and longitude 109°30′E under a subtropical climate conditions), Chinese Academy of Sciences in March, 2004. The results showed that values of ASOM fractions for the Chinese fir plantations were lower than those for the broad-leaved forest. The contents of easily oxidisable carbon (EOC), microbial biomass carbon (MBC), water soluble carbohydrate (WSC) and water-soluble organic carbon (WSOC) for the first rotation of Chinese fir plantation were 35.9%, 13.7%, 87.8% and 50.9% higher than those for the second rotation of Chinese fir plantation, and were 15.8%, 47.3%, 38.1% and 30.2% separately lower than those for the broad-leaved forest. For the three investigated forest sites, the contents of MBC and WSOC had a larger decrease, followed by WSC, and the change of EOC was least. Moreover, soil physico-chemistry properties such as soil nutrients in Chinese fir plantation were lower than those in broad-leaved forest. It suggested that soil fertility declined after Chinese fir plantation replaced native broad-leaved forest through continuous artificial plantation.

山东省苹果园土壤酸度与果实营养元素相关性分析

对山东省17个县市区77个苹果园土壤pH值和果实中氮、磷、钾、钙、镁、铁、锌、铜和硼等多种营养元素的分布特征和相关性进行了调查研究。结果表明,山东苹果园土壤pH值平均为5.50,pH值在4.5~5.5的酸性土壤果园占42.86%,是山东苹果产区分布最广的一类果园;泰沂山区的沂源、沂水2个县pH值均在5.5以上,土壤酸化程度较弱;在烟台地区,除海阳市外,其余7个县区果园为酸性土壤,其中牟平区、栖霞市果园土壤pH值最低;威海地区中,环翠区pH值低于5.0,而文登区和荣成市pH值高于5.5,土壤酸化程度差异明显。土壤pH值影响果实中多种营养元素含量高低,在大量元素方面,土壤pH值与果实中氮含量呈显著负相关关系,在中微量元素方面,与钙、镁、铁含量呈显著或极显著正相关。苹果园土壤大面积酸化以及随之可能产生的果实钙、镁等多种元素减少问题应得到重视,建议在苹果园土壤管理中控制氮肥的投入,重视钙、镁、铁肥的补充,以确保苹果优质生产。

新疆巴楚县域农田土壤微量元素含量分布特征

采集了巴楚县域农田土壤样品300份,并对其进行有效铁、有效锰、有效铜、有效锌含量测定,以明确土壤中微量元素的含量,探索土壤微量元素结构特征以及成因,为巴楚县耕地土壤微量元素管理提供理论参考。结果表明,巴楚县域农田土壤有效铁含量为4.51~20.00 mg/kg,平均为12.37 mg/kg,其中含铁量丰富的占67.4%,中等的占32.6%;有效锰含量为1.01~9.97 mg/kg,平均为5.26 mg/kg,其中含锰量中等的占56.0%、缺乏的占44.0%;有效铜含量为1.00~6.00 mg/kg,平均为3.39 mg/kg,其中含铜量极丰富的占77.3%、丰富的占19.0%、中等的占3.7%;有效锌含量为0.50~2.00 mg/kg,平均为1.19 mg/kg,其中含锌量丰富的占57.6%、中等的占35.6%、缺乏的占6.8%。巴楚县域农田土壤中的微量元素含量为有效铁>有效锰>有效铜>有效锌。综合考察各农田区域土壤微量元素含量,恰尔巴格乡的综合评价得分最高,表现较好。建议在作物栽培过程中,应充分考虑不同乡镇的土壤微量元素含量,适当补充微量元素,以达提质增效之目的。

白云石粉与氧化镁肥对植烟土壤与烟叶钙镁营养元素的影响

研究施用白云石粉与氧化镁肥对植烟土壤交换性钙、镁含量和烟叶钙、镁等营养元素的影响,为烟区优化施肥措施提供科学支撑。在植烟土壤交换性钙、镁偏低的典型区域,采用随机区组试验设计,设置不同白云石粉、氧化镁肥施用量,通过田间小区试验,测定各处理烟草不同生育期土壤交换性镁、交换性镁、速效氮磷钾与烟叶钙、镁、氮、磷、钾的含量,观测最大叶长、最大叶宽、株高、茎围、节距等农艺性状。结果表明,施用3000 kg/hm^(2)白云石粉在烟叶生长48、68 d和烟叶收获后的土壤交换性镁含量均显著高于其他处理,在烟叶收获后的土壤交换性钙含量显著高于其他处理,该处理在烟叶收获后上部烟叶和中部烟叶的镁含量、上部烟叶的钙含量也高于其他处理。针对植烟土壤交换性钙、镁偏低的区域,施用白云石粉3000 kg/hm^(2)有利于提升植烟土壤交换性钙、交换性镁和烟叶钙、镁含量。

不同海拔的大别山山核桃林地土壤性质和叶片营养元素分析

为了比较不同海拔大别山山核桃林地土壤性质和叶片营养元素的差异及相关性,为大别山山核桃林地科学施肥和养分管理提供参考,采用酸度计法、重铬酸钾容量法、半微量凯氏定氮法、碱解扩散法、盐酸氟化铵浸提-分光光度法和醋酸铵-火焰光度计法分别测定了不同海拔大别山山核桃林地0~30 cm土层p H、有机质、速效氮、速效磷、速效钾,采用原子吸收分光光度法测定了土壤和叶片的氮、磷、钾、钙、镁、锌含量,并进行显著性分析和相关性分析。结果表明:(1)不同海拔大别山山核桃林地土壤速效磷、全氮、全磷、全钾、钙、镁和锌含量存在显著性差异(P<0.05),大别山山核桃叶片钾、钙和镁含量存在显著性差异(P<0.05)。(2)不同海拔大别山山核桃林地土壤p H随着海拔升高而降低,而有机质和氮含量随着海拔升高而升高;叶片钾含量随海拔升高而升高,钙和镁含量则是随着海拔升高而降低,其余营养元素受海拔影响较小。(3)大别山山核桃叶片营养元素之间、土壤营养元素之间、以及叶片与土壤之间存在一定相关性,其中土壤间相关性达到显著水平的有2对,叶片间相关性达到显著水平的有4对,土壤和叶片间相关性达到显著水平的有2对(P<0.05)。大别山山核桃林地土壤平均p H值为5.18,偏酸性;有机质含量均值为5.07%;速效氮、速效磷含量较高,速效钾较匮乏;微量元素平均含量依次为Mg>Ca>Zn。建议增施生石灰进行土壤改良,减少氮肥施用,增施磷钾肥,尤其是钾肥,将化学肥料和有机肥料混合增施,保持土壤养分平衡。

寒地黑土养分元素地球化学特征及丰缺评价——以抚远市为例

本文以黑龙江省抚远市为例,基于近年土地质量地球化学调查资料成果,采用地统计分析和GIS分析等相结合,揭示研究区黑土表层土壤中N、P、K、Ca、Mg等13项养分元素及土壤有机质的含量和分布特征及在不同土壤类型分布区含量特征,统计得出表层土壤养分元素背景值,并依据相关标准对各养分元素指标丰缺现状进行评价。研究结果表明,抚远地区表层土壤中有机质含量富足,N、P含量较丰富,K元素适中,Ca、Mg、B、Zn较缺乏,S、Fe、Mn、Cu元素含量分异较大,且等级中等以上均大于60%;土壤养分地球化学综合评价表明,该地区土壤养分丰富-较丰富约占77.1%,较缺乏区仅占1.2%,土壤肥力良好,可为该区现代农业发展和黑土地保护利用提供参考资料。

黄河流域(济南段)土壤元素分布特征及作物营养元素分析

【目的】探究黄河流域(济南段)的土壤元素含量及分布特征,了解人类活动对土壤元素含量的影响,为土地利用和土壤改良提供基础数据。【方法】采集调查区土壤样品,分析29种土壤元素指标,用统计学、空间分析和变异系数等方法分析元素在不同土壤类型、不同土地利用类型及不同行政区的分布特征,农作物营养元素区域差异化及影响因素。【结果】黄河流域(济南段)内元素背景值明显偏高的有Hg、As、Cd、S、Corg、Co、N、B、CaO、Se、F,大多数元素变异系数在0.25以下,部分有害元素变异系数大于0.4。不同行政区表层土壤中大多数元素的变异系数较小,即元素分布均匀,MgO变异系数达0.7以上,说明人为因素对此类元素的影响较大。不同土壤类型中的S、Corg和N等元素有明显差异,其中农村宅基地中的CaO、Zn、MgO和Na_(2)O偏高。调查区表层土壤全氮含量以中等丰度为主,占调查区面积的62.60%;全磷含量丰富,中等以上等级区面积占调查区总面积的80.69%;全钾以二级较丰富为主,面积占调查区76.87%。黄河流域(济南段)广泛分布的土壤类型为普通潮土,成土母质含丰富CaCO_(3),使pH高于7.5。【结论】黄河流域(济南段)内大多数元素区域分布均匀,土壤污染压力较小,与直管区工业发展程度整体不高的背景相吻合。Hg元素变异系数较高(>0.4),说明人类活动对土壤质量产生了影响。大部分地区N、P、K等较富集,适合发展种植业。

水城区猕猴桃产业园区土壤养分元素地球化学特征及地质环境

[目的]根据一系列土壤养分元素地球化学指标,对示范园区耕地土壤养分质量进行分类评价,并探讨养分元素在不同地层的分布情况。[方法]以六盘水市名优特色红心猕猴桃产区水城区产业园区的米箩镇、猴场镇园区土壤养分元素有机质、阳离子交换量、全氮、全磷、全钾、碱解氮、有效磷、速效钾、硼、有效硼、钼、有效钼、碘、氟等为研究对象,运用地球化学分析方法、GIS等技术手段研究该区土壤中养分元素及其地质环境。[结果]园区土壤以酸性为主,适宜猕猴桃种植,保肥能力强,有机质含量丰富;除全钾含量很低,4级(较缺乏)与5级(缺乏)累计占比89.72%,全氮、全磷含量丰富,碱解氮含量适宜,速效磷含量缺乏,变异系数2.07,分布不均,局部可能较缺乏,速效钾供给能力好,总体适中;钼、有效钼、氟、碘含量丰富,氟含量相对偏高,硼、有效硼含量缺乏;硼在灰岩发育地层含量相对较高,全氮、碘、钼及有机质在峨眉山玄武岩组更易富集,含量普遍丰富。龙潭组发育的土壤具有更高的硒含量和有机质含量。[结论]建议后期提高土壤中磷有效量,增施钾肥、硼肥,红心猕猴桃是否适宜在峨眉山玄武岩组地层种植有待进一步研究。

基于水系沉积物地球化学背景特征的生态环境评价

本文通过对额尔古纳地区1∶25万区域化探数据分析研究,探讨用水系沉积物地球化学背景特征评价研究区生态环境。参照生态环境地球化学评价方法,对研究区的生态环境进行评价,得出研究区的生态环境总体较好,局部存在轻度至重度污染,并重点圈定了F、As元素土壤污染区域。特征植物营养元素相互间搭配平衡关系较差,说明该区的土壤环境不能很好地为植物生长提供适宜的营养补给条件。测区生命必需元素均在正常范围之内,适宜人类生活和工作。综合分析认为,造成研究区内污染状况的原因可能与矿业开采、人类活动及地质背景等因素有关。区域化探数据结合生态环境地球化学评价方法可以应用于内蒙古生态环境评价。

Apriori算法在重庆垫江南部土壤养分元素组合研究中的应用

研究基于重庆垫江南部地区3250份土壤表层样品的54类地球化学数据,应用Python编程语言进行Apriori关联规则算法研究,尝试通过大数据分析的方法提取出隐藏在数据集中的土壤养分元素与其他各元素之间的组合规律,为垫江地区的土地利用规划、生态环境保护、现代农业发展以及土地污染防治等工作的开展提供科学依据。通过Apriori方法进行的重庆垫江南部土壤元素数据分析最终反映出各元素之间共存在八种关联关系。Fe、Zn、Co、V、Mg、Cu六类土壤养分元素的关联性极强,会出现共同富集的现象;土壤中Mo、Ca元素的缺乏与Li、I、U、P元素的匮乏存在一定关联;其他土壤养分元素则相对独立,无法建立与其他元素之间的关联规则。相较于传统地球化学分析方法,关联规则算法具有快捷、准确、完全基于数据深入挖掘等特点,对于未来土壤养分元素多寡的指示以及富集等级的划分具有重要的学术与应用价值。

云贵高原茶园土壤养分状况及其对茶叶品质的影响

为揭示云贵高原茶园土壤环境因子与茶叶品质之间的关系,更科学地为茶叶品质优化提供理论依据,以贵州省3个主要茶产区的茶园土壤和茶叶为研究对象,于2022年6月采集52份土壤样品和对应采样点的茶叶样品,测定土壤中养分和微量元素含量以及茶叶品质参数。结果表明,贵州省茶园土壤Fe、Cu、Zn、Mn、Mo含量分别为82.67~135.80、0.53~1.68、2.94~5.60、16.26~97.80、0.03~0.07 mg/kg,微量元素含量丰富,能够为茶树提供丰富的微量元素来源;SOM、pH分别为49.59~68.64 g/kg和4.45~4.70,能够为茶树提供良好的生长环境。作为典型的Mn富集植物,贵州省茶叶中Mn的富集系数最高,Mo和Fe富集系数较低,Zn和Cu在不同种植地区有差异。随机森林结果表明,对茶叶中的游离氨基酸含量影响较大的是茶园土壤中的Zn、TP和TN,对茶多酚含量影响较大的是土壤TN、pH和TP,对咖啡碱含量影响较大的是土壤pH、TK和TN,对茶叶水浸出物含量影响较大的是土壤TK、Mn和Fe。研究显示,土壤养分含量对茶叶品质影响较大,微量元素对茶叶品质影响较小。

不同施肥组合对科尔沁沙地南缘沙地土壤健康指标的影响

为研究不同施肥组合对沙地土壤改良的效果,以辽宁省阜新市彰武县的沙地土壤为考察对象,开展了试验研究。试验以不施肥为对照(CK)处理,设置生物有机肥分别与含腐殖酸肥料(OH)、含聚谷氨酸肥料(OP)和中微量元素肥(OM)混施3个施肥处理,测定施肥后6、12、18个月的土壤中微生物数量和土壤理化性状的变化。结果表明:不同施肥处理的土壤中微生物数量均呈现细菌>放线菌>真菌的变化趋势,其中OH处理的细菌数量最多,3个取样时间的细菌数量平均值为1.510×10^(7)cfu/g,是CK处理的5.2倍;施肥处理的土壤中全磷、全钾和有机质含量均得到提高,OP处理的全钾含量平均值最高,质量分数为5.96 g/kg;施肥处理的土壤pH均呈下降趋势;施肥处理的地上部植物生物量提高。施用不同组合的肥料可以有效提高土壤微生物的数量,改善土壤理化性状,提高地上部植物生物量,是一种合理的沙地改良措施。