Zinc Transformation in a Calcareous Soil as Affected by Applied Zinc Sulfate,Vermicompost, and Incubation Time

An experiment was conducted to evaluate the effect of zinc (Zn) rates and vermicompost levels on distribution of Zn forms of a calcareous soil. After incubation periods, soil samples were air dried, and a sequential extraction scheme was used to fractionate Zn into soluble and exchangeable, bound to carbonate, organically bound, bound to manganese (Mn) oxide, bound to amorphous iron (Fe) oxide, bound to crystalline Fe oxide, and residual forms. In untreated soil, Zn was mainly in the residual fraction. Increasing rates of applied Zn significantly increased all forms of Zn. Carbonate and residual forms showed the greatest increase. Application of vermicompost significantly increased all fractions except Mn-oxide form. This increase was more pronounced for organically bound, soluble, and exchangeable forms, indicating an increase in bioavailability of soil Zn. Incubation time significantly decreased soluble, exchangeable, and organically bound forms but increased other forms of Zn, meaning a significant reduction in Zn phytoavailability in soil with time.     

Release of Copper,Zinc, and Manganese from Rock Powder with Organic Materials Applied to Soils

An incubation experiment was conducted using a sandy (Fluvic Cambisol) and a silty (Endostagnic Cambisol) soil to determine the release of copper (Cu), zinc (Zn), and manganese (Mn) from a sulfide-rich rock powder (grain size <0.5 mm), applied either alone or mixed with organic materials. Finely ground legume straw, wheat straw, and cow dung from an organic farm were used as organic materials. Rock powder and organic materials were mixed thoroughly with soils, moistened to field capacity, and incubated for 42 days. Soil samples were collected at weekly intervals for analysis. The solubility of Cu in soils increased over time with the addition of rock powder but decreased significantly if soils were mixed with organic materials. Treatments with organic materials alone show a lower release than the combination treatments with rock powder. These trends were similar for both soils. Although the solubility of Mn was very high in the sandy soil, it was not significantly affected either by the time of incubation or by the treatments applied. Zinc solubility was greater in organic material treatments than in the combined treatments in either soil. There were significant changes in pH with time as pH decreased in rock powder treatments. This study shows that the rock powder used here could be a potential source of soluble Cu, when used in combination with organic manure, though for Zn and Mn results are not conclusive.     

冬小麦种植条件下湖泊底泥农用土壤重金属锌的形态及其影响因素

研究了田间种植小麦条件下,底泥农用前后土壤中重金属锌的形态演变,以及盆栽种植小麦条件下,pH值、碳氮比、质地对底泥农用土壤重金属锌形态演变的影响。结果表明,随着底泥施用量的增加,土壤中可交换态、碳酸盐结合态、铁锰氧化物结合态、有机结合态、残渣态锌含量均有不同程度的增加。高pH、碳氮比为25∶1、粘土质地条件,可以导致土壤中可交换态锌的含量减少。植株中根系>茎叶>籽粒中锌的含量,并随底泥施用量的增加而增加。     

有机物料对稻田土壤团聚体及有机碳分布的影响

通过连续5年定位试验,以紫云英、秸秆和商品有机肥等有机物料还田的稻田土壤为对象,研究有机物料还田后不同物理分组下土壤组成特点和有机碳变化特征。结果表明,稻田土壤团聚体主要分布在2~0.25mm与0.25~0.053mm粒级,团聚体颗粒有机碳含量随着粒径的减小而减少。有机物料还田可提高0.25~0.053mm和0.053mm粒级团聚体有机碳的含量,紫云英、秸秆、商品有机肥等有机物料可通过提高土壤微团聚体有机碳含量而增加土壤碳库。有机物料施用增加土壤轻组组分颗粒含量,减少重组组分颗粒含量,有助于土壤轻组组分的形成。稻田土壤轻组颗粒有机碳含量与0.25mm和0.053mm团聚体颗粒有机碳含量呈显著相关,与2~0.25mm团聚体颗粒有机碳含量呈极显著相关。稻田土壤施用紫云英、秸秆和商品有机肥等有机物料,可有效提高土壤微团聚体和轻组成分颗粒含量,增加土壤微团聚体和轻组有机碳含量,改变稻田土壤有机碳库组成特征。     

Yield and Physico-Chemical Composition of Date-Palm (Phoenix Dactylifera) as Affected by Nitrogen and Zinc Application

The present study was carried out to investigate the effect of nitrogen (N) and zinc (Zn) fertilization on yield components and composition of Phoenix dactylifera L. cv. Kabkab during two growing seasons. This study was conducted by using factorial experiment in randomized complete block design with four replications. Aqueous solution of Zn was injected to trunk at the rate of 0, 1.15, and 2.30 g L^?1. N was applied at 0, 160, 345, and 460 g per palm tree. Sources of N and Zn were urea and zinc sulfate heptahydrate (ZnSO₄.7H₂O), respectively. Each year N fertilizer was added in two equal applications, one before flowering and one at fruit setting. N was applied at 1.5 m from the palm trunk. The trees were subjected to the usual farm management, for example, artificial pollination (only one source of pollen grains was used to avoid the metaxenic effects), pruning and irrigation. Results indicated that application of N and Zn had significant effects on fruit set, fruit yield, fruit weight, bunch weight, fruit size, N and Zn leaf contents, total soluble solids (TSS), reducing sugar and total sugar. However, more increments in these parameters were obtained with N in combination with Zn. The suitable combination of the nutrients found for date palm tree under the prevailing conditions was the application of 345 g N and 2.30 g L^?1 Zn for injection.     

多种有机物料混施对苹果幼苗生长、氮素利用及土壤特性的影响

以M9T337苹果幼苗为试材,利用15 N同位素示踪技术,研究了等氮量投入下,不同有机物料单施及混施对苹果幼苗生长、15 N吸收利用及土壤特性的影响.试验设置CK(只施用化学肥料,不施有机物料)、S(秸秆)、B(生物炭)、F(牛粪)、SB(1/2秸秆+1/2生物炭)、SF(1/2秸秆+1/2牛粪)、FB(1/2牛粪...     

Interaction of Iron with Copper,Zinc, and Manganese in Wheat as Affected by Iron and Manganese in a Calcareous Soil

Iron (Fe) availability is low in calcareous soils of southern Iran. The chelate Fe-ethylenediamine di (o-hydroxy-phenylacetic acid) (Fe-EDDHA), has been used as an effective source of Fe in correcting Fe deficiency in such soils. In some cases, however, its application might cause nutritional disorder due to the antagonistic effect of Fe with other cationic micronutrients, in particular with manganese (Mn). A greenhouse experiment was conducted to evaluate the influence of soil and foliar applications of Fe and soil application of manganese (Mn) on dry matter yield (DMY) and the uptake of cationic micronutrients in wheat (Triticum aestivum L. var. Ghods) in a calcareous soil. Results showed that neither soil application of Fe-EDDHA nor foliar application of Fe sulfate had a significant effect on wheat DMY. In general, Fe application increased Fe uptake but decreased that of Mn, zinc (Zn), and copper (Cu). Application of Mn increased only Mn uptake and had no significant effect on the uptake of the other cationic micronutrients. Iron treatments considerably increased the ratio of Fe to Mn, Zn, Cu, and (Mn + Zn + Cu). Failure to observe an increase in wheat DMY following Fe application is attributed to the antagonistic effect of Fe with Mn, Zn, and Cu and hence, imbalance in Fe to (Mn + Zn + Cu) ratio. Due to the nutritional disorder and imbalance, it appears that neither soil application of Fe-EDDHA nor foliar application of Fe-sulfate is appropriate in correcting Fe deficiency in wheat grown on calcareous soils. Hence, growing Fe-efficient wheat cultivars should be considered as an appropriate practice for Fe chlorosis-prone calcareous soils of southern Iran.     

有机物料施用下原生盐碱土胡敏酸结构特征

为研究不同有机物料对原生盐碱土胡敏酸官能团组成的影响,以吉林省大安市原生盐碱地为研究对象,设置空白处理(CK)、颗粒状秸秆处理(KL)、正常玉米秸秆处理(JG)、牧草处理(MC)和羊粪处理(YF),通过红外光谱与主成分分析(Principal component analysis,PCA)相结合,研究不同有机物料施用下土壤胡敏酸红外光谱特征。结果表明,有机物料各处理与CK处理相比增加了土壤胡敏酸中脂肪碳和芳香碳的相对含量,减少了羧基碳的含量。除KL处理外,其他处理均增加了土壤胡敏酸中氨基化合物的相对含量。同时有机物料的施用增加了土壤胡敏酸的脂族碳/羧基碳和脂族碳/芳香碳比值,表征有机物料的施用使得土壤胡敏酸结构缩合度和氧化度下降,脂族性增强,芳香性降低,胡敏酸结构趋于脂族化、简单化、年轻化。对比两种秸秆处理,发现KL处理更有利于土壤新形成结构年轻化、简单化、脂族性强的胡敏酸分子。根据PCA结果,有机物料的施用是土壤中脂族性碳、芳香族碳以及氨基化合物的主要来源之一,为探讨胡敏酸官能团的来源提供依据。通过红外光谱结合PCA,发现了土壤胡敏酸官能团组成对有机物料的不同响应,为研究有机物料的施...     

Effects of Long-Term Inorganic and Organic Fertilization on Soil Micronutrient Status

Soil micronutrients were studied on loess soil with an 18-year long-term experiment. The results indicated that total soil iron and copper contents were similar under all treatments, but total soil manganese and zinc contents were significantly greater at the surface soil in the fertilized plots than in the controls, and total manganese contents were significantly greater in the whole soil profile under manure plus inorganic fertilizers than under controls. Generally, application of inorganic fertilizers had no effects on available soil micronutrient contents. The straw plus inorganic fertilizers significantly increased available manganese content at surface soil and available iron in subsurface soils. However, manure plus inorganic fertilizers significantly augmented soil-available iron contents throughout the profile, and raised available manganese, copper, and zinc contents, respectively, at surface soil relative to controls. The results suggest that long-term input of organic amendments alter the properties of soil and increase its plant-available micronutrient contents.     

Use of Organic Materials as Growing Media for Honeydew Melon Seedlings in Organic Agriculture

An experiment was conducted to determine the possibility of using organic materials for the honeydew melon seedling production. Honeydew melon was grown in nine media with different rates of spent mushroom substrate (SMS), vermicompost (VC), cattle manure compost (CaMC), and coconut fiber (CF). Element sulfur was also added to mixtures at a rate of 1.0 g kg^?1 substrate. The experiment was arranged in a randomized complete block design with three replications. The results determined that all media had desirable physical properties. At the same rates of SMS and VC, CF supported better growth of seedling than CaMC. Seedlings treated with CF had higher morphological growth parameters. It is suggested that CF should be used as an additive for media of SMS and VC. The study clearly indicated that the growing medium with 50% SMS, 30% VC, and 20% CF gave the best condition for honeydew melon seedlings.     

去除有机质对土壤光谱特性的影响

通过野外调查取样和室内理化分析,研究了去除有机质对湖南省几种耕作土壤高光谱特性的影响。结果表明,去除土壤有机质以后,供试土壤的光谱反射曲线形态均有一定的变化,土壤的光谱反射率不管在全波段还是在分波段都有明显的增加;此外,由于有机质是影响和干扰氧化铁光谱特性的一个重要因子,去除土壤有机质以后,几个研究波段的光谱反射率与游离氧化铁、全Fe、无定形氧化铁的相关系数都有显著的提高。     

有机物料对红壤团聚体稳定性的影响

试验设置了对照(CK)、秸秆混匀(M-Str)、秸秆覆盖(Str)、生物质炭混匀(BC)和猪粪混匀(SM)5个处理,采用室内培养法研究有机物料种类与施用方式对红壤团聚体稳定性的影响。结果表明,秸秆混匀与猪粪处理下土壤有机碳(SOC)、热水溶性有机碳(HWC)、土壤抗破碎性和团聚体水稳定性(MWD)显著提高(p0.05),而秸秆覆盖对土壤有机碳和土壤团聚体形成的提升作用不明显(p0.05)。相对于对照处理,生物质炭提高了土壤有机碳含量,但对团聚体稳定性的影响不显著(p0.05)。秸秆混匀和猪粪处理下团聚体稳定性的变化与土壤累积呼吸之间存在线性关系(p0.05)。可见,有机物的性质(秸秆、猪粪和生物质炭)与还田方式(混匀和覆盖)对红壤团聚体的稳定性存在显著差异。     

三种有机物料对稻田土壤汞甲基化及水稻汞积累的影响

施用有机物料是水稻生产过程中提高产量的一条重要途径，明确有机物料的施用对糙米Hg积累的影响，对于Hg污染稻田的安全利用具有重要的指导意义。本研究采用盆栽实验，设置等量（3%，w/w）的油菜秸秆、猪粪和水稻秸秆生物炭，对比分析3种有机物料的施用对水稻产量及其对Hg在稻田系统的迁移转化的影响。结果表明，3种有机物料的施用均显著提高了水稻产量，但对土壤Hg甲基化和糙米Hg的积累影响则并不一致。油菜秸秆、猪粪和水稻秸秆生物炭处理下水稻产量分别提高17.6%、33.0%和39.9%。与相同水平土壤Hg处理相比，施用猪粪提高了土壤Hg的生物有效性，促进了土壤MeHg的生成，提高了糙米THg的富集系数，使糙米THg和MeHg的含量分别提高了34.5%和30.3%；施用油菜秸秆降低了土壤Hg的生物有效性，抑制了土壤Hg甲基化过程和水稻对Hg的富集，糙米THg和MeHg的含量分别降低了34.6%和36.2%；施用水稻秸秆生物炭降低了土壤Hg生物有效性和糙米THg的富集系数，糙米THg和MeHg的含量分别降低了46.9%和48.4%。因此，在Hg污染稻田中应慎重施用猪粪，可选择施用水稻秸秆生物炭和油菜秸秆，达到提高产量和阻控糙米Hg积累的双重效果。     

接种微生物条件下牛粪＋麦秸堆腐过程有机组分的动态变化

大量排放的畜禽粪便若利用不当则会对环境构成威胁,经微生物发酵、制成高效有机肥料是粪肥与秸秆综合利用的一种重要方式。试验以牛粪添加不同比例的小麦秸秆为原料,在接种和非接种微生物的条件下进行堆腐,研究了腐解过程有机组分及腐殖物质的动态变化。结果表明,随着腐解进行,乙醇溶性组分含量逐渐降低;水溶性组分含量先升高再降低;半纤维素和纤维素含量随腐解进行呈现一定波动,但总体呈降低趋势;木质素含量呈增加趋势;全碳含量降低,腐殖物质碳占全碳的比例逐渐增加,H/F比值逐渐升高。秸秆的加入比例越高越有利于木质素的积累,牛粪所占比例越大则越有利于腐殖物质的形成。接种微生物可促进有机物料中各有机组分的分解,并有利于腐殖物质的形成。     

牛粪与秸秆配施对棕壤镉赋存形态及玉米吸收镉的影响

以受镉(Cd)污染的棕壤为供试土壤,采用盆栽方法,研究牛粪与秸秆不同配比对土壤Cd形态及作物吸收Cd的影响。结果表明:(1)与对照相比,牛粪与秸秆氮含量比1∶1,3∶1,5∶1的3个处理分别使可交换态Cd含量下降34.39%,28.04%,20.11%,使有机结合态和残渣态Cd含量显著增加。土壤中可交换态Cd含量与pH呈极显著负相关关系,而残渣态Cd含量与pH呈极显著正相关关系。(2)与对照相比,牛粪与秸秆氮含量比1∶1,3∶1,5∶1的3个处理使土壤pH分别提高0.36,0.17,0.16个单位。(3)牛粪与秸秆配施降低了玉米各部位对镉的吸收,并使Cd主要积累在玉米的根、茎、叶部位,降低了籽粒中Cd含量。牛粪与秸秆氮含量比1∶1,3∶1,5∶1的3个处理使籽粒Cd含量浓度分别减少79.64%,72.70%,56.38%。     

施用畜禽粪便和化肥对土壤活性有机碳库和团聚体稳定性影响

活性有机碳含量和土壤团聚体的形成与稳定在长期人为扰动土壤上有重要作用。通过分析稻麦轮作土壤上长期(20年)施用畜禽粪便和化肥土壤活性有机碳含量、团聚体稳定性及活性有机碳与团聚体稳定性的关系,研究了人为扰动下土壤施肥管理对土壤活性碳和团聚体稳定性的影响。研究结果显示,与施用化肥比较,施用畜禽粪便显著提高了土壤总有机碳(SOC)和颗粒有机碳(POC)、可溶性有机碳(DOC)、热水提取态有机碳(HWOC)及土壤碳水化合物态碳(SCC)等活性有机碳库含量(p0.05),其中HWOC含量是施用化肥处理的1.7～2.4倍。施用畜禽粪便土壤团聚体稳定性指数大团聚体颗粒百分含量(PMI)、抗糊化指数(ASI)和标准化平均重量直径(NMWD)指数分别是施用化肥土壤的1.31,3.39,2.14倍,显著高于施用化肥土壤(p0.05),其中施用猪粪处理土壤团聚体稳定性最高。稳定性评价指数PMI、ASI以及NMWD间有极显著相关(p0.01)。SOC和POC含量与土壤团聚体稳定性指数间没有相关性(p0.05);SCC与团聚体稳定性指数间相关性较弱;DOC和HWOC与团聚体稳定性指数间则表现为显著或极显著相关。研究结果说明,施用畜禽粪便比化肥更有利于提高人为扰动土壤中总有机碳和活性有机碳含量及土壤团聚体稳定性,土壤活性有机碳是团聚体形成与稳定过程中重要影响因素,但受土壤发育母质等因素影响,不同土壤上其作用效果有一定差异。     

不同有机肥输入量对黑土密度分组中碳、氮分配的影响

为阐明不同有机肥施用量对黑土密度组分中碳、氮分配特征的影响,探讨合理调控土壤质量的施肥模式。以黑龙江省海伦国家野外科学观测研究站上进行了10年的田间定位试验土壤为研究对象,采用密度分组和腐殖质化学分组相结合的方法,探讨和分析不同有机肥施用量下土壤各密度组分中有机碳、氮的消长变化以及重组中腐殖物质的组成特征。结果表明:与试验初期相比,经过10年单施化肥处理,土壤总有机碳和全氮、各密度组分中有机碳氮以及腐殖物质各组分的含量均显著下降,而有机无机配施能够提升土壤总有机碳和全氮的含量水平,改善密度组分中有机碳氮的分配特征,土壤总有机碳、全氮和各密度组分中有机碳氮对不同有机肥施用量的响应有所差异。随着有机肥施用量的增加,土壤总有机碳和全氮的含量呈逐渐升高的趋势,二者与有机肥施用量之间达到极显著的线性相关(P<0.01);低量有机肥(7.5,15t/(hm2.a))配施化肥仅增加了土壤游离态轻组有机碳、氮的含量,并未造成闭蓄态轻组和重组中有机碳、氮的积累,而高量有机肥(22.5t/(hm2.a))配施化肥后,促进了土壤各密度组分中有机碳、氮的形成和积累;此外,低量有机肥有利于土壤富里酸的积累,高量有机肥有助于胡敏酸和胡敏素的积累,从而提高了土壤有机质的腐殖化程度,增强了土壤有机质的稳定性。在东北黑土区,加大有机肥的施用量是提高土壤肥力和土壤固碳能力的有效途径。     

Soil Organic Carbon and Soil Physical Characteristics as Affected by Land Uses under Semiarid Irrigated Conditions

ABSTRACT

Rice-Wheat rotation is the dominant land use in the state of Punjab, resulting in over exploitation of ground water resources. Thus, it is necessary to evaluate other land uses that requires less water and are sustainable. The present investigation was planned with four land uses viz., fallow (FLU), rice-wheat (ALU), grasses (GLU) and pear (PLU) with respect to their effect on soil organic carbon and soil physical characteristics in surface and subsurface depth in district Ludhiana, Punjab. The soil organic carbon (SOC) content was higher by 10, 30.9 and 24.9% under rice-wheat, grasses, and pear than that under fallow. The grasses showed higher soil moisture characteristics curve (SMCC) and lower bulk density (Db) than that under rice-wheat. The larger mean weight diameter (MWD) were observed under pear, grasses and fallow than that under rice-wheat by 0.21, 0.51 and 0.41 mm, respectively. The saturated hydraulic conductivity (K_s) was higher in magnitude by 56.1, 55.4 and 28%, respectively under PLU, GLU and FLU over ALU. Of the evaluated land uses, pear and grasses proved to be more sustainable by retaining more moisture, maintaining better soil physical characteristics and SOC under semiarid irrigated conditions in the state on long term gradual response.     

Effects of Manure and Chemical Fertilizer on Nitrogen Transformations and Functional Bacteria in a Black Soil of the Song-nen Plain

Intensities of ammonification, nitrification, denitrification, and the numbers of functional bacteria were measured in a black soil of the Song-nen Plain under different fertilizer managements over a period of 3 years. The six fertilizer managements were as follows: no fertilizer applied, manure at low and high rates, chemical fertilizer at low and high rates, and manure and chemical fertilizers in equal ratio. Manure increased the numbers of ammonifying and nitrifying bacteria and the intensities of ammonification and nitrification, whereas chemical fertilizer increased numbers of denitrifying bacteria and intensity of denitrification. Average denitrifying intensities ranged from 52.5% to 61.1%. There might be some coupling relation between nitration and denitrification in black soil.     

Effects of Green Manures and Zinc Fertilizer Sources on DTPA-Extractable Zinc in Soil and Zinc Content in Basmati Rice Plants at Different Growth Stages

Rice is very sensitive to low zinc(Zn) supply in submerged paddy soils and Zn deficiency is one of the major limiting factors in determining rice production in India. A field experiment was conducted during the summer-rainy seasons of 2009 and 2010 at the research farm of the Indian Agricultural Research Institute, New Delhi, to determine the effects of summer green manure crops and Zn fertilizers on diethylenetriaminepentaacetic acid(DTPA)-extractable(available) Zn concentration in soil and total Zn content in Basmati rice cultivar Pusa Basmati 1 at periodic intervals. Summer green manure crops included Sesbania aculeata(Dhaincha),Crotalaria juncea(Sunhemp), and Vigna unguiculata(Cowpea) and the Zn fertilizers used were ethylenediaminetetraacetic acid(EDTA)-chelated Zn, ZnSO_4·7H_2O, ZnSO_4·H_2O, ZnO, and ZnSO_4·7H_2O + ZnO. Beneficial effects of summer green manure crops and Zn fertilizers on DTPA-extractable Zn concentration in soil and total Zn content in dry matter of Basmati rice at periodic intervals were observed, with significant increases in all the determined parameters, in comparison with those in the control(no Zn application or summer fallow). The rate of increase varied among summer green manure crops and Zn fertilizers during both years. Among the summer green manures, incorporation of S. aculeata led to a significant increase in mean Zn content in Basmati rice grain and straw when compared with C. juncea, V. unguiculata, and summer fallow treatments. Among the Zn fertilizers, significant increases in Zn content in Basmati rice dry matter and DTPA-extractable Zn concentration in soil during various growth stages of the plant were recorded with EDTA-chelated Zn application, followed by the application of ZnSO_4·7H_2O, ZnSO_4·H_2O, ZnSO_4·7H_2O + ZnO, ZnO,and no Zn. The highest mean Zn content in Basmati rice grain and straw was recorded with EDTA-chelated Zn application in 2009 and 2010, respectively. The application of ZnSO_4·7H_2O was the second best treatment after EDTA-chelated Zn; however, it was statistically inferior to EDTA-chelated Zn. The lowest values were recorded with the control(no Zn application) during both years of study. The amount of Zn concentration in soil was found to be significantly positively correlated with the Zn content in Basmati rice dry matter during both years. Significantly higher levels of residual fertility in soil after the harvest of Basmati rice were observed with application of EDTA-chelated Zn and incorporation of S. aculeata when compared with those of other Zn sources and summer green manures.