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1.
Abstract

Many studies have evidenced the negative effects of synthetic fertilizers toward the environment and also the crop products itself. Hence, the improvement of organic fertilizers is necessary to resolve this problem. Seaweeds or marine macroalgae are considered to be an excellent natural resource in different aspects of agricultural fields. Brown macroalgae Turbinaria murayana (TM) is often found in Indonesian coastal areas with high bioavailability throughout the year. This study evaluated the potentials of TM as biofertilizer in tomato plants (Lycopersicum esculentum Mill.). Evaluation of phytohormones present in TM crude extract was conducted with high performance liquid chromatography (HPLC). Macro and micronutrients available in TM crude extract were determined by atomic absorbance spectroscopy (AAS). A concentration of 4% TM crude extract was applied to tomato plants. The vegetative properties of the treated tomatoes were observed such as growth and yield. Current results evidenced the presence of growth-promoting factors (kinetin, gibberellin and ABA) and essential elements (N, P, K, Ca, Fe and Mn) in TM crude extract. Application of 4% TM extract to tomato plants significantly increased vegetative growth compared to untreated plants; plant height, leaf number and branch number, approximately 58.4%, 87.5% and 200%, respectively. Similar results were also found in the response of generative growth. Application of 4% liquid extract significantly improved flower and fruit number compared to control; 53.6% and 125%, respectively. These results suggest that TM crude extract is a potential source for developing organic fertilizers.  相似文献   

2.
Abstract

Heavy metals are often added indiscriminantly to soils in pesticides, fertilizers, manures, sewage sludges, and mine wastes, causing an imbalance in nutrient elements in soils. Heavy‐metal toxicity causes plant stress in various degrees dependent on the tolerance of the plant to a specific heavy metal. The objectives of this study were (i) to show that plant species and soils respond differently to heavy metals and (ii) to show the necessity for proper quantity and balance of heavy metals in soils for plant growth.

Three Fe‐inefficient and three Fe‐efficient selections of soybean, corn, and tomato were grown on two alkaline soils with Cu and Zn ranging from 14 to 340 and Mn from 20 to 480 kg/ha. Heavy‐metal toxicity caused Fe deficiency to develop in these plants. The Fe‐inefficient T3238fer tomato and ys1/ys1 corn developed Fe deficiency on all treatments and both soils. T3238FER tomato (Fe‐efficient) did not develop heavy metal toxicity symptoms on any treatment or soil. The soybean varieties and WF9 corn were intermediate in their response.

The unpredictable response of both the soil and the plant to heavy metals make general recommendations difficult. In order to maintain highly productive soils, we need to know what we are adding to soils and the consequences. Without some control, the continued addition of heavy metals to soils is a crisis in embryo.  相似文献   

3.

Purpose  

Two main pathways of phytoremediation of heavy metal-contaminated soils are phytostabilization and phytoextraction. Some soil amendments can strengthen phytostabilization or phytoextraction through either reducing heavy metal bioavailability in soil or increasing the heavy metal accumulation capacity of the hyperaccumulator (enhancing heavy metal concentration or shoot biomass of the hyperaccumulator). Urea and chicken manure are often used as fertilizers. This research will explore their effects on a newly found hyperaccumulator, Rorippa globosa (Turcz.) Thell., phytoremediating cadmium (Cd).  相似文献   

4.

Purpose

The aim of this work was to select and assess the efficiency of different amendments applied to ordinary chernozems artificially contaminated with heavy metals (Zn and Pb).

Materials and methods

The effect of different amendments on ordinary chernozem contaminated with Zn and Pb acetate salts was studied in a long-term 3-year field experiment. Glauconite, chalk, manure, and their combinations were chosen as ameliorating agents. Spring barley (Hordeum sativum) was used as test culture for three successive years. The heavy metal concentration in all the soil samples decomposed by HF?+?HClO4 was determined by atomic absorption spectrophotometry (AAS). One normal concentration of CH3COONH4 at pH 4.8 was used to estimate the actual mobility of metals. The compounds of heavy metals extracted by 1 N HCl are regarded as mobile compounds. The concentration of metals in the plants was determined using the dry combustion in a mixture of HNO3 and HCl at 450 °C. The content of heavy metals in extracts from soil and plant samples was determined by AAS.

Results and discussion

The content of weakly bound metal compounds increased upon the contamination of the soil with Pb and Zn salts, which led to a low quality of barley grown in these soils. Metal concentrations in the barley grain exceeded the maximum permissible concentrations (MPCs). The content of Zn and Pb in grains was higher than the MPC for at least 3 years after the soil pollution. The application of amendments significantly decreased the mobility of metals, and the simultaneous application of chalk and manure was most significant. The share of weakly bound metal compounds in the contaminated soils decreased to the level typical for the clean soils or even below.

Conclusions

The combined application of chalk and manure to Zn- and Pb-contaminated ordinary chernozems decreased the content of weakly bound metal compounds in the soil and lowered their concentrations in barley plants. The polyfunctional properties of the soil components with respect to their capacity for metal fixation were established. The decrease in the intensity of Zn accumulation in grains of barley shows the presence of a barrier at the root–stalk and stalk–grain interfaces.
  相似文献   

5.

Purpose

Cadmium has caused serious environmental problems due to its phytotoxicity, requiring solutions to reduce its concentration in the environment. Because S can alleviate the phytotoxicity caused by heavy metals, the evaluation of the effects of S supply is a promising approach to address this problem. The aim of this study was to determine the influence of S in reducing the phytotoxicity caused by Cd to Panicum maximum Jacq. cv. Tanzania (guinea grass) and to evaluate the potential of this grass for Cd phytoextraction.

Materials and methods

Tanzania guinea grass was cultivated in a nutrient solution to evaluate the combinations of five rates of S (0.1, 1.0, 1.9, 2.8, and 3.7 mmol L?1) and five rates of Cd (0.0, 0.5, 1.0, 1.5, and 2.0 mmol L?1), in a 52 fractional factorial design with six replications. Six plants were grown per pot in two growth periods to evaluate the effect of Cd on the establishment (51 days of age) and on the regrowth (18 days of growth) of the plants. During regrowth, Cd was not supplied in the nutrient solution. At the end of each growth period, growth parameters, concentrations of S and Cd, Cd transport factor, and concentrations of hydrogen peroxide (H2O2), malondialdehyde, reduced glutathione, and oxidized glutathione were evaluated.

Results and discussion

On the establishment of Tanzania guinea grass, application of Cd reduced mass production by 39 % due to the increases in the concentration of Cd (30 times compared with the treatment without Cd) and in lipid peroxidation (124 %). During regrowth, the residual effect of Cd resulted in a lower number of tillers (62 %) and leaves (89 %) caused by the increase in concentrations of Cd, H2O2 (49 %), and lipid peroxidation, which resulted in a 65 % lower dry mass production. The proper supply of S reduced concentration of Cd and tiller mortality rate due to the residual effect of Cd on the regrowth of the grass. Mass production by the roots was 43 % lower because of Cd, but the transport of Cd from roots to shoots increased. The increase in the concentration of glutathione (GSH) associated with a possible higher activity of antioxidant enzymes alleviated the phytotoxic effects of Cd on the guinea grass.

Conclusions

The supply of S reduces the phytotoxicity caused by Cd to guinea grass, especially during the regrowth of the plant, when the concentration of Cd is higher because of the transport from roots to shoots. Tanzania guinea grass showed to be very promising for phytoextraction of Cd due to its high mass production, even when Cd was largely available in the nutrient solution.
  相似文献   

6.

Purpose

The present research aimed to assess the influence of two phosphorous (P) amendments on metal speciation in rhizosphere soil and the soil–plant transfer of metals.

Materials and methods

Complementary experiments were performed: field experiments on a contaminated cultivated soil and laboratory experiments on an uncultivated contaminated soil to highlight the mechanisms involved in metal-phosphorous interactions. In laboratory experiment, P amendments were added at 120 mg P/kg of soluble KH2PO4 amendment and 9,000 mg P/kg of solid Ca5(PO4)3OH amendment.

Results and discussion

Field-culture results showed the possible food-chain contamination due to Pb, Cd, Cu, and Zn phytoaccumulation by pea and mustard plants from a cultivated agricultural soil. Moreover, P-metal complexes were observed by microscopy in the rhizosphere soil. In laboratory experiments, the application of P amendments significantly increased Pb and Zn level in rhizosphere soil compared to control. Phosphate amendments significantly increased metal-P fraction and decreased “oxides” and “organic matter” fractions of Pb and Zn. Soluble-P amendment was more effective than solid P amendment in changing Pb and Zn speciation. The changes in metal speciation are higher in the rhizosphere soil of pea than tomato. Application of P amendments increased Pb and Zn TF root/soil but decreased TF shoot/root.

Conclusions

The effectiveness of in situ metal immobilization technique varies with the type and quantity of applied P amendment as well as plant and metal type.  相似文献   

7.
The effects of lower field rate (LFR), field rate (FR), and higher field rate (HFR) applications of carbofuran on ammonium (NH4)-nitrogen (N), nitrate (NO3)-N, available phosphorus (P), and available potassium (K) contents in natural soils and those amended with inorganic fertilizers and vermicompost on the growth of tomato plants were studied. The NH4-N, NO3-N, available P, and available K contents increased up to FR but the most significant increase in was observed at LFR of carbofuran application. At HFR there was a significant reduction in nutrient availability. With passage of time all these parameters increase up to 30 days; thereafter, a decrease was observed up to the end of the experiment in both unamended and amended soils. The greater plant growth was observed at LFR of carbofuran application and at HFR the plants exhibited phytotoxicity in the form of marginal leaf scorching in both systems. The morphological growth parameters of tomato plants were positively correlated with nutrients availability.  相似文献   

8.

Purpose

Ornamentals can beautify the environment and resolve heavy metal pollution at the same time. Thus, the present study aimed at studying the growth and physiological response of Tagetes patula on iron ore tailings.

Materials and methods

Pot-culture experiments were conducted to investigate the effect of iron ore tailings both individually as well as in combination with soil (at different proportions) on the growth, pigment production as well as accumulation and translocation of various heavy metals from the tailings.

Results and discussion

The results suggested an increase in growth, chlorophyll content, as well as metal accumulation capacity of T. patula with increasing proportion of tailings in the soil. Furthermore, an increase in antioxidant activities in plants grown on tailings as compared to control was observed which suggests plant efficiency to overcome any stress generated due to excess of heavy metals. The order of accumulation of various heavy metals in the plant parts was observed to be Fe?>?Cr?>?Zn?>?Cu?>?Pb?>?Ni?>?Cd. Both bioaccumulation and translocation values were maximum for Fe and minimum for Ni and Cd, respectively.

Conclusions

The overall study clearly suggests plant ability to grow well on the tailings and survive excess of heavy metals present in the tailings. Thus, the plant qualifies well as a potential tool for phytostabilization of iron ore tailings and probably a source of income generation from wasteland owing to its multiple commercial values.  相似文献   

9.

Purpose

Green areas in urban parks are special ecosystems because of social and ecological benefits.

Materials and methods

We investigated the ecological impacts of green spaces by comparing the properties of soils, with emphasis on metals, in green spaces and bare soil playgrounds in four urban parks in Murcia City (SE Spain).

Results and discussion

Organic matter (OM) contents in green areas are higher than playground soils due to litter decomposition from grass. Cation exchange capacity in green areas ranged from 10 to 14 compared to 2 cmol+kg?1 in playground soils, showing the effect of OM (and clay) contents in green areas due to the presence of vegetation. Soil total metal contents in urban parks are below the environmental threshold values for soils in Spain and other European countries, and come from atmospheric deposition and fertilizers application. Diethylenetriaminepentaacetic acid (DTPA)-extractable soil Cd in green areas (4% of total Cd) is lower than in playground soils (58% of total Cd). We attributed the reduced DTPA- and water-extractable Cd, Co, Cr, Mn, and Mo to the formation of stable complexes between metals and OM produced from the continued decomposition of roots of grasses in green spaces.

Conclusions

Grasses accumulate less metal than soils except in roots where Cr and Zn are higher than soils by as much as 31 and 17%, respectively. We conclude that grasses increased (up to 8×) soil OM content in green areas to significantly increase the ability of soils to accumulate nutrients for plants, and to retain and reduce the mobility and toxicity of metals in soils in urban parks.  相似文献   

10.

Purpose

Southern China is an important agricultural production base, as well as an important mineral resource area. There is a big challenge of heavy metal pollution in the soils of this area. Base on the characterizations of cotton and our present results, we discussed the potentiality to remediate the heavy metal-polluted soils through planting cotton in southern China.

Materials and methods

This paper summarises recent research to provide a better understanding of the status and the causes of heavy metal pollution in southern China, compare the applicability of different remediation methods in this area, evaluate tolerance and accumulation of cotton to heavy metals, and discuss the socioeconomic benefits of cotton planting for remediation of heavy metal-polluted soils.

Results and discussion

Human activity could be causing heavy metal pollution in southern China, as lead pollution is the most prevalent and cadmium pollution is the most severe in this area. Physical and chemical methods are used to remediate the heavy metal-polluted soils in southern China, by which treated polluted soils could not satisfactorily address the problems of economic feasibility, “secondary damage” and “secondary pollution”. The use of plants can green the environment to a certain extent, so the phytoremediation method is widely accepted. Cotton does not reach the standard of hyperaccumulation plants but has a relatively large biomass and shows more excellent tolerance ability and enrichment ability to heavy metals. Especially, the Cd concentration is lower in cotton fibre than in other cotton organs.

Conclusions

Cotton may be a potential crop to ameliorate the heavy metal pollution of farmland in southern China. In addition, cotton remediation combining with multiple repair measures of heavy metal pollution would obtain better repair effect and ecological benefits, and agronomic management practices could also effectively enhance cotton-remedied heavy metal-polluted soils.
  相似文献   

11.

Purpose

At the global scale, soil contamination with persistent metals such as lead (Pb), zinc (Zn), and copper (Cu) induces a serious threat of entering the human food chain. In the recent past, different natural and synthetic compounds have been used to immobilize metals in soil environments. However, the mechanisms involved in amendment-induced immobilization of metals in soil remained unclear. The objective of the present work was therefore to determine the mechanisms involved in metal-phosphates formation in the rhizospheric soils of pea and tomato currently cultivated in kitchen gardens.

Materials and methods

Pea and tomato were cultivated on a soil polluted by past industrial activities with Pb and Zn under two kinds of phosphate (P) amendments: (1) solid hydroxyapatite and (2) KH2PO4. The nature and quantities of metal-P formed in the rhizospheric soils were studied by using the selective chemical extractions and employing the combination of X-ray fluorescence micro-spectroscopy, scanning electron microscopy, and electron microprobe methods. Moreover, the influence of soil pH and organic acids excreted by plant roots on metal-P complexes formation was studied.

Results and discussion

Our results demonstrated that P amendments have no effect on metal-P complex formation in the absence of plants. But, in the presence of plants, P amendments cause Pb and Zn immobilization by forming metal-P complexes. Higher amounts of metal-P were formed in the pea rhizosphere compared to the tomato rhizosphere and in the case of soluble P compared to the solid amendment. The increase in soil-metal contact time enhanced metal-P formation.

Conclusions

The different forms of metal-P formed for the different plants under two kinds of P amendments indicate that several mechanisms are involved in metal immobilization. Metal-P complex formation in the contaminated soil depends on the type of P amendment added, duration of soil-plant contact, type of plant species, and excretion of organic acids by the plant roots in the rhizosphere.  相似文献   

12.
Abstract

The combined action of a soil conditioner and a controlled‐release fertilizer was followed by conducting soil column leaching and tomato growth experiments. The change in soil water‐holding capacitiy and the release of potassium sulfate (K2SO4) from conventional and controlled‐release forms was evaluated using leaching experiments in soil columns. Tomato growth was followed by the comparison of biomass yields on a dry matter basis with experiments where different combinations of controlled‐release or conventional fertilizer rates and soil conditioner applications. It was demonstrated that the combined usage of controlled‐release fertilizers and soil conditioners increased tomato yield and enhanced the nutritional status of the tomato plants in comparison to conventional fertilizer materials.  相似文献   

13.

Purpose

The subject of this study is the sediment and wild lotus plants in unmanaged ponds, near Yichang City, contaminated by heavy metals. The objective is to determine the extent and frequency of heavy metal accumulation by lotus root in the ponds of rural areas and its significance to food safety and human health.

Materials and methods

The study area is located in the middle reaches of Yangtze River. The 11 sampling sites selected (Z1–Z11) were unmanaged ponds, and the lotus root samples were from wild plants. The lotus root and soil samples were processed using wet digestion, according to the national standard method; we tested concentration of heavy metal (Pb, Cd, Cr, As, Cu, and Zn). Both a single-factor index and an integrated pollution index were used to assess the heavy metal pollution of soil and wild lotus root. Correlation was used to examine the relationship of lotus root concentration to sediment concentration for each heavy metal.

Results and discussion

Cadmium (Cd) and arsenic (As) in both soil and pond sediment exceeded standards. The maximum single pollution index (SPI) for Cd and As was 1.16 and 1.15, respectively. The maximum integrated pollution index (IPI) for heavy metals was 2.17 for soil and 2.10 for sediment (moderate pollution). The heavy metal content in some samples of lotus root exceeded the national food standard and pose a health risk. The significant correlations of heavy metal concentrations (Pb, Cd, and As) in pond sediment with those in the surrounding soil show that the ponds act as sinks for agricultural nonpoint source pollution (NPS). The heavy metal concentrations in the peel of the edible tuber were 1.3～9.0 times higher than those in the inner flesh.

Conclusions

While Cd, Pb, and As concentrations in the sediment did not violate soil standards, concentrations in the lotus root did violate food standards. This species could be proposed as a suitable heavy metal bioindicator for the early stages of pollution from agricultural NPS.
  相似文献   

14.

Purpose

Environmental chemistry of antimony (Sb) is still largely unknown. Many questions remain about its availability to plants and effects of fertilizers on mobility of Sb in the rhizosphere soil. In this work, we focused on the following problems: (1) uptake of Sb by wheat seedlings grown in soil enriched with this metalloid and (2) impact of soil amendments on the plant growth, Sb uptake from soil, and its transfer from roots to upper plant parts.

Materials and methods

To obtain further information on the possible transfer of Sb into plants, greenhouse pot experiments were carried out. Soil was spiked with 15 mg kg?1 of Sb and amended with either chicken manure or natural growth stimulator Energen. Wheat Triticum aestivum L. seedlings were grown in the soil during 17 days. Plants together with rhizosphere soil were collected several times in the course of the experiment. The ICP-OES and ICP-MS techniques were applied to determine the concentrations of macro- and trace elements in the plant and soil material.

Results and discussion

Growth of wheat seedlings in Sb-spiked soil resulted in Sb accumulation in roots and leaves of the plants. Energen and especially chicken manure were capable of stimulating transfer of Sb to more mobile and, as a consequence, more available to the plants form, thus enhancing both uptake of Sb from soil and its transfer from roots to upper plant parts. The accumulation of Sb by plants led to a decrease of Sb concentration in the rhizosphere soil with time, and the most significant decrease was observed after amendment of soil with fertilizers.

Conclusions

Fertilizers may be used to increase phytoextraction of Sb and its removal from contaminated soils. However, such an amendment of soil should be done with caution in order to exclude or at least reduce the negative effects on plants.  相似文献   

15.

Purpose

Metal distribution patterns among geochemical fractions are informative for metal phytoavailability. Compost added to polluted soils may adsorb metals on the less phytoavailable fractions. A bioassay experiment was conducted to establish possible correlations between metal concentrations in different soil fractions and metal contents in edible plant parts and to investigate the influence of different compost loads on heavy metal availability to plants.

Materials and methods

Chinese cabbage plants were grown in pots with sandy and clayey soils and soils mixed with different doses of biosolid compost spiked with soluble heavy metal salts (Cd, Cu, and Pb). The metals’ distribution pattern in the soil and mixed samples was determined by sequential extraction procedure (modified BCR protocol). The studied fractions, from most to least bioavailable, were water-extractable (WE), exchangeable-adsorbed (EXC), associated with carbonates and acetic acid-soluble forms (CARB), occluded by reducible (hydro)oxides of Fe and Mn (RO), and associated with organic matter (OM) and a residual fraction (RES). Metal concentrations in soil extracts and in the digested plant tissue were measured by ICP-AES.

Results and discussion

The highest compost doses (72 and 115 Mg ha?1) enhanced cabbage yield significantly. No excessive phytoaccumulation of metals was observed in plants grown in the clayey soil or its mixtures with compost. The compost dose of 72 Mg ha?1 was optimal in decreasing Cu accumulation by plants grown in sandy soil, and 28.8 Mg ha?1 was found to be effective in reducing Cd and Pb uptake. Metals were accumulated in plants primarily from the WE, EXC, and CARB fractions, whereas other fractions decreased phytoaccumulation. Compost addition suppressed heavy metal mobility, but different fractions were active in pollutant sorption, depending on soil type and metal.

Conclusions

Compost addition increased metal proportions in the RO and OM fractions, reducing metal phytoavailability. This is especially important for sandy soils with low adsorption ability and higher vulnerability to metal pollution than clayey soils. A compost dose of 20% v/v (or 28.8 Mg ha?1) effectively reduced plant accumulation of Cd and Pb. We propose using the first three steps of the modified BCR protocol as a three-step sequential-extraction procedure for the most phytoavailable fractions of heavy metal: WE, EXC, and CARB.  相似文献   

16.

Purpose

Identifying the spatial distribution and degree of heavy metal contamination in the soils is required for urban environmental management. Magnetic measurement provides a rapid means of determining spatial distribution and degree of soil pollution and identifying various anthropogenic sources of heavy metals. The purpose of this study was to characterize the magnetic signature of heavy metal contamination and identify the sources of heavy metals in urban soils from steel industrial city.

Materials and methods

A total of 115 urban topsoils from Anshan city, Northeast China, were collected and determined for magnetic properties and heavy metal concentration. Magnetic susceptibility (χlf) and saturation isothermal remanent magnetization (SIRM) were determined as proxy for ferrimagnetic mineral concentration. Magnetic minerals were identified by using Curie temperature, X-ray diffraction (XRD), and scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS). The Pearson’ correlation and matrix cluster analyses were used to establish the relationship between magnetic parameters and heavy metal concentrations.

Results and discussion

Urban topsoils exhibit characteristic magnetic enhancement. The magnetic measurement in particle size fractions indicates that 50–2 μm fraction has the highest low-field magnetic susceptibility (χlf), while <2 μm has the highest frequency-dependent magnetic susceptibility (χfd) value. The soil χlf and SIRM values are significantly correlated with the contents of metals (Fe, Pb, Zn, Cu, and Cr) and Tomlinson pollution load index (PLI), which indicates that χlf and SIRM could be served as better indicators for the pollution of heavy metals in the urban topsoil. Spatial distribution maps of χlf, SIRM, and PLI indicate that the pollution hotspots tend to associate with the regions within and close to steel industrial zones. XRD and Curie temperature analyses indicate that the main magnetic minerals of urban topsoils are magnetite (Fe3O4), hematite (α-Fe2O3), and metallic iron. Magnetic minerals mostly occur in the pseudo-single-domain/multidomain (PSD/MD) grain size range, which is the dominant contributor to the magnetic enhancement of topsoils. SEM observation reveals that magnetic particles in soils exist in irregular-shaped particles and spherule. Results reveal that heavy metals from industrially derived and traffic emissions coexist with coarse-grained magnetic phases.

Conclusions

It is concluded that the magnetic measurement could be regarded as a proxy tool to detect the level of heavy metal pollution and identify the source of heavy metals in urban soils. Magnetic properties provide a fast and inexpensive method to map the spatial distribution of long-term pollution from steel industrial origin on region scale.
  相似文献   

17.
In the present study, the effectiveness of biofertilizer containing plant growth promoting rhizobacteria was evaluated on growth and physiology of cotton under saline conditions. Cotton plants were exposed to different levels of NPK (50%, 75%, and 100% of recommended levels) along with coating with biofertilizer under saline (15 dS m?1) and non-saline conditions. It was observed that the biofertilizer seed coating improved growth, physiological (relative water content and chlorophyll content index), and ionic (K+/Na+) characteristics under saline and non-saline conditions. However, shoot growth (shoot fresh and dry weight) and leaf gas exchange characteristics (CO2 assimilation rate, A; intercellular CO2 concentration, Ci; transpiration rate, E; stomatal conductance, gs) were decreased by biofertilizer coating under saline condition. Increasing levels of NPK fertilizer increased shoot growth, whereas root growth was maximum at 75% NPK level under saline conditions. The results of the study indicate that the biofertilizer application was very effective for cotton plant in non-saline conditions but not very effective in saline conditions.  相似文献   

18.

Purpose

Degraded soils, such as those encountered in areas of mine activities, need to be ameliorated by liming to correct soil acidity and by addition of organic inputs to improve soil properties and fertility.

Materials and methods

Non-amended mine soil and soil amended with stabilized sewage sludge were incubated for 45 days. Soil physicochemical and biological indicators were periodically measured along incubation and other enzyme activities at the end of incubation. In improved soils, a study of plant development in 250-g pots was carried out with three vegetal species: tomato, rye grass and ahipa. Germination and mortality rates, biomass production and photosynthetic pigments were measured.

Results and discussion

Soil incubation with sewage sludge slightly increased soil pH and led to an enhancement of soil electrical conductivity, organic carbon and dehydrogenase activity, especially for the higher doses (5 and 10%). However soil respiration was more promoted with the 2% dose, pointing to a possible toxic effect of the sludge. At the end of incubation, physicochemical and biological properties were in general enhanced. Biomass production was improved in tomato and rye grass by sewage sludge addition (more at the 2% dose), whilst ahipa growth was not affected by sewage sludge treatments. Tomato mortality reached 73% with high sludge doses (10%).

Conclusions

According to this set of parameters, amendment with sewage sludge of a limed acid mine soil would be considered as a good strategy for soil amelioration in view of plant establishment and development.  相似文献   

19.
Glasshouse experiments were conducted to assess the influence of arbuscular mycorrhizal (AM) fungi (Glomus mosseae and Gigaspora margarita) and organic fertilizers (cow dung, horse dung, goat dung and poultry manure) alone and in combination on the reproduction of the nematode Meloidogyne incognita and on growth and water loss of tomato. Meloidogyne incognita decreased water loss of tomato from the first week onwards after inoculation. AM fungi increased water loss of both nematode-infected and uninfected plants. Glomus mosseae was better at improving growth of tomato and reducing galling and nematode multiplication than G. margarita, but the rate of water loss was similar with both fungi. Addition of organic fertilizers improved growth of tomato, but decreased the rate of water loss. There was less galling and nematode multiplication with poultry manure, which improved tomato growth more than goat dung, while cow dung was the least effective organic fertilizer. Greatest plant growth and least nematode reproduction were observed in plants inoculated with M. incognita along with G. mosseae and poultry manure.  相似文献   

20.
有机无机肥料配合施用对设施菜田土壤N2O排放的影响   总被引：11，自引：3，他引：8  
采用静态箱气相色谱法研究了有机无机肥料配合施用对设施菜田土壤N2O排放的影响。结果表明: 1）设施芹菜和番茄施基肥后57 d（灌溉后13 d）出现土壤N2O排放通量峰值,追肥后（施肥与灌溉同步）1 d出现土壤N2O排放通量峰值; 芹菜季和番茄季施用基肥后20 d内N2O排放量分别占当季总排放量的40%65%左右,是土壤N2O主要排放期。2）施用基肥后至定植灌水前各处理土壤N2O排放量逐渐降低,灌水后N2O排放通量迅速上升。各处理土壤N2O排放通量与土壤含水量之间呈显著相关,相关系数在0.43~0.72之间。3）土壤N2O排放主要发生在番茄季,番茄生育期各处理土壤N2O总排放量是芹菜生育期的3.1倍; 各处理土壤N2O排放通量与5 cm土层温度之间总体上呈显著相关,相关系数在0.40~0.58之间。4）设施菜田大幅减施化肥的有机无机肥配合施用模式可显著降低土壤N2O排放量和肥料损失率,芹菜季和番茄季土壤N2O排放量较习惯施肥处理分别降低66.3%和85.1%,肥料损失率分别降低45.2%和74.9%。5）等氮量投入时,施用秸秆较施用猪粪可有效降低土壤N2O排放,芹菜季和番茄季分别降低43.4%和74.2%。  相似文献   

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