Compost Effects on Soil Physical Properties And Field Nursery Production

Field production of ornamental shrubs often results in significant topsoil removal and degradation of surface soil physical properties. Building soil organic matter through compost amendments is one way to ameliorate effects from topsoil removal in woody ornamentals production. We amended field soils with three composts to evaluate their effects on soil physical properties and shrub biomass production. Specifically, we applied either duck manure-sawdust (DM), potato cull-sawdust-dairy manure (PC) or paper mill sludge-bark (PMB) composts to a Plano silt loam soil using two application methods: 2.5 cm of compost incorporated into the top 15 cm of soil (incorporated-only) or 2.5 cm of compost incorporated plus 2.5 cm of compost applied over the soil surface (mulched). We grew three shrub species from liners: Spirea japonicum ‘Gumball’, Juniper chinensis ‘Pfitzeriana’, and Berberis thunbergia ‘Atropurpurea’. Shrub species and soil amendment treatments were established in triplicate in a randomized split plot design. Total soil carbon (TC), bulk density (ρb), aggregate stability, soil moisture retention capacity (MRC), volumetric moisture content (θ_v), and saturated hydraulic conductivity (K_sat) were measured over three years (1998 to 2000). We measured above and below ground shrub dry matter production at the end of the first (1998) and second (1999) growing seasons. Mulched treatments resulted in 15%-21% higher TC than the incorporated-only and no-amendment control treatments. Bulk density decreased with increasing TC contents. Greater aggregate stability and the formation of larger aggregates were related to increased TC. Field moisture retention capacity tended to be higher in the incorporated treatments compared to the mulched and nonamended control treatments. Compost amended treatments increased saturated hydraulic conductivity (K_sat) sevenfold over the nonamended control. There were no compost effects on shrub biomass until the second year of growth. Barberry was the only species to respond significantly and positively to compost application. Specifically, mulched DM compost produced 39-42% greater total Barberry biomass than the other compost treatments and the nonamended control. Our findings showed that compost effects on soil physical properties differed among composts and their subsequent effects on shrub growth were species specific.     

Effects of Municipal Solid Waste Compost on Soil Properties and Vegetables Growth

ABSTRACT

This work investigates the impact of municipal solid waste compost (MSW-compost) application (0, 50, and 100 t/ha) on the growth, and on nutrient and trace elements content in lettuce and tomato plants grown in large, 40-L pots. Our findings showed inhibition of plants’ growth with increasing dose of MSW-compost, compared to plants receiving conventional fertilization. Growth inhibition was associated with a sharp decrease in soil NO₃–N content. On the other hand, a slower decrease in soil NO₃–N content occurred in non-planted pots amended with MSW-compost. These findings provide evidence that N immobilization and/or decreased N mineralization were responsible for inhibited growth by constraining N availability. With regard to the other macro-nutrients, K, P, Mg, Ca, and Fe, their contents in leaves of both crops were maintained at optimum levels. Higher zinc and copper content was measured in leaves of both crops but they did not exceed the optimum range for growth. No accumulation of trace elements was found in the fruits. The content of heavy metals in the tissues of plants grown in MSW-compost amended soil, remained at levels similar to those of the non-amended soil, suggesting that they do not pose a significant risk either for plant growth or public health. The findings of our study suggest that further emphasis should be given on the investigation of the factors regulating N mineralization and availability in order to avoid reductions in crop yield.     

The Effects of Municipal Solid Waste Compost And Compost Tea on Mineral Element Uptake And Fruit Quality of Strawberries

Three levels of municipal solid waste compost (MSWC) and two application rates of compost tea made with MSWC were applied to strawberries for two years. The highest level of application of MSWC significantly increased the concentrations of most extractable soil mineral elements except for Ni which was increased in the highest compost tea application rate. Despite large differences in soil mineral element concentrations among treatments, plant and fruit uptake were generally unaffected by treatments. Notably however, compost tea applications increased fruit Na levels perhaps due to increased uptake of Na by leaves compared to roots. Generally, the composts and compost teas produced fruit of equal quality in terms of total antioxidant capacity and vitamin C but all treatments failed to provide sufficient N to strawberry plants and all fruit appeared to have leather rot; consequently, yield was decreased.     

Effect of Municipal Solid Waste Compost on Mine Soils As Evaluated by Chemical,Biological And Biochemical Properties of Soil

Composts are increasingly used in land rehabilitation because they can improve soil quality and reduce the need for inorganic fertilizers. Their use contributes to an integrated approach to waste management by promoting recycling of nutrients and minimizing final disposal of organic residues that, due to their composition, can pose problems to agricultural soils. We investigated whether compost from mixed municipal solid waste (MSW) could be used to remediate two soils from a mine contaminated with trace elements. One of the soils was less acidic and had a greater content of Cu and Zn while the other had more Pb and a lower pH. The effect of MSW was evaluated by plant growth, trace element leachability, ecotoxicity of soil leachates, and biological and biochemical properties of soils. Growth of perennial ryegrass (Lolium perenne L. cv. Victorian) was stimulated in the MSW compost-amended soils compared with respective controls or with acidic soil when limed. After ryegrass had been growing for 119 days, the amount of water-extractable Zn was lower in MSW compost-amended soils, while the opposite was true for water-extractable Cu. Water-extractable Pb increased following MSW compost application to one soil and decreased in the other. The greatest dehydrogenase activity was obtained in amended limed soil, while the number of culturable bacteria and fungi and the activities of cellulase and β-glucosidase were similar in soil that was limed or following MSW compost application. In contrast, urease activity was repressed in limed or MSW compost-amended soils. Leachates from unamended soils were toxic towards Daphnia magna. Liming the very acidic soil led to a decrease in the toxicity of the leachate, but it was only in MSW compost-amended soils that ecotoxicity was no longer detected.     

Modification of Soil Water Retention and Biological Properties by Municipal Solid Waste Compost

A compost originating from the organic fraction of MSW, separately collected, was added to a loamy soil at different application rates. Modifications of soil physical and biological properties were studied after compost addition. Water retention properties, after compost addition to soil, were monitored. Organic carbon mineralization was followed during a six-month incubation. Enzyme activities were assayed immediately after compost addition, as well as after incubation of soil-compost mixtures. These properties provided information about the modification of overall microbiological activity and specific nutrient cycles in the amended soil. Water retention, carbon mineralization and most enzyme activities after incubation were increased by compost incorporation. The additivity or nonadditivity of compost effects on soil properties was discussed.     

Effect of Compost and Hydroabsorbent Polymer on Tree Growth and Soil Properties in a Tropical Urban Environment

Horticultural application of hydroabsorbent polymer (HP) has drawn research attention due to its perceived benefits to plant growth. Few studies have compared the use of compost and HP amendments on tree establishment in tropical urban environments. An experiment was conducted to assess the effect of compost (40% v v^–1) and HP (3 and 5 kg m^–3) on the growth of two native tree saplings (Calophyllum soulattri and Syzygium myrtifolium) in loamy and sandy soils. The HP treatments significantly affected soil pH and extractable phosphorus (P) and potassium (K), whereas combined application of compost and HP (5 kg m^–3) resulted in significantly higher nitrogen (N) in both soil types. Plant diameter and height were significantly higher following HP application. This experiment demonstrates the efficacy of HP that can cater the plant requirements at the initial growth stages which are crucial for their successful establishment in tropic urban degraded soils.     

Municipal Solid Waste Compost Improves Crop Productivity in Saline-Sodic Soil: A Multivariate Analysis of Soil Chemical Properties and Yield Response

A pot experiment was conducted in sandy clay loam saline-sodic soil to assess the effects of farm yard manure (FYM), municipal solid waste (MSW) composts and gypsum application on nitrate leaching, soil chemical properties and crop productivity under rice-wheat cropping system. It also aims at establishing the correlation between soil phsico-chemical properties and yield response using principle component analysis and Pearson correlation analysis. The MSW was decomposed aerobically, an-aerobically and co-composted. Maximum nitrate leaching was observed during rice (75.9 mg L^?1) and wheat (37.2 mg L^?1) with an-aerobically decomposed MSW as compared with control treatment. Results revealed a decrease in soil pH (?6.95% and ?8.77%), electrical conductivity (EC) (?48.13% and ?51.04%), calcium carbonate (CaCO₃) (?40.30% and ?48.96%), and sodium adsorption ratio (SAR) (?40.27% and ?45.98%) with an-aerobically decomposed MSW compost during rice and wheat, respectively. In this treatment, organic matter (OM) (93.55% and 121.51%) and cation exchange capacity (CEC) (19.31% and 31.79%) were the highest as compared with control treatment during rice and wheat, respectively. Rice and wheat growth were significantly (p≤ 0.05) increased by an-aerobically decomposed MSW followed by co-compost, aerobically decomposed MSW, FYM, gypsum and control. Furthermore, Pearson correlation coefficients predicted significant positive correlation of yield with soil OM, and CEC while inverse relationship was observed with EC, pH, CaCO₃, and nitrogen use efficiency. Soil amelioration with organic and gypsum amendments was further confirmed with principal component analysis. This study has proved an-aerobically decomposed MSW as an effective solution for MSW disposal, thereby improving soil chemical properties and crop productivity from sandy clay loam saline-sodic soil.     

Differential Soil Acidity Tolerance of Tropical Legume Cover Crops

In tropical regions, soil acidity and low soil fertility are the most important yield‐limiting factors for sustainable crop production. Using legume cover crops as mulch is an important strategy not only to protect the soil loss from erosion but also to ameliorate soil fertility. Information is limited regarding tolerances of tropical legume cover crops to acid soils. A greenhouse experiment was conducted to determine the differential tolerance of 14 tropical legume cover crops to soil acidity. The acidity treatments were high (0 g lime kg^?1 soil), medium (3.3 g lime kg^?1 soil), and low (8.3 g lime kg^?1 soil). Shoot dry weight of cover crops were significantly affected by acidity treatments. Maximum shoot dry weight was produced at high acidity. Jack bean, black mucuna, and gray mucuna bean species were most tolerant to soil acidity, whereas Brazilian lucern and tropical kudzu were most susceptible to soil acidity. Overall, optimal soil acidity indices were pH 5.5, hydrogen (H)+ aluminum (Al) 6.8 cmol_c kg^?1, base saturation 25%, and acidity saturation 74.7%. Species with higher seed weight had higher tolerance to soil acidity than those with lower seed weight. Hence, seed weight was associated with acidity tolerance in tropical legume species.     

Changes in Chemical,Physical and Biological Properties Of Passively-Aerated Cocomposted Poultry Litter And Municipal Solid Waste Compost

Cocomposting of poultry litter with municipal solid waste compost (MSW) was evaluated as a means to stabilize nitrogen and phosphorus in poultry litter and to produce a stable organic soil amendment. Four passively aerated compost piles were established by mixing fixed weight ratios of MSW and composted poultry litter (21:1, 6:1, 3:1, 1:1); moisture was adjusted to 50 percent by weight at pile establishment. These ratios represented a range of initial C:N (26-12) and C:P (150-50) ratios. Composting process parameters monitored over eight months included temperature, oxygen and moisture contents, pH, electrical conductivity, C:N:P ratios, microbial respiration and diversity. Initial feedstock ratios had no significant effect on temperature in the thermophilic phase of composting. After one year of composting, microbial respiration in 21:1 and 6:1 mixtures was high relative to 3:1 and 1:1 mixtures suggesting slow maturation in piles with high MSW content. Salmonella sp. and coliform organisms were detectable for up to 47 days. Results suggest that MSW has potential as a carbon feedstock for poultry litter composting when used in moderate amounts.     

Organic By-Product Effects on Soil Chemical Properties And Microbial Communities

Soil management practices that contribute to increased soil productivity and longterm sustainable agricultural production have been neglected over the last four decades. The need to increase soil productivity led to the evaluation of a system of disposing of large quantities of organic by-products and poultry litter on agricultural land. Our objectives were to evaluate the effects of applying noncomposted municipal solid waste (MSW), amended with either poultry litter (PL) or NH₄NO₃ to adjust C:N ratios in the soil surface in either the spring or fall. Changes in soil chemical properties, bacteria population shifts, changes in species richness and evenness of indigenous soil bacteria, and response by cotton (Gossypium hirsutum L.) were evaluated. Soil P, K, Ca, and Mg were increased in the surface 0–15 cm by a factor of three or four times by application of organic by-products. After two annual applications, soil Cu increased slightly, Zn doubled, Co and Cr decreased, while Pb increased by a factor of two. Soil organic matter content increased on average by 89 percent for treatments containing newsprint, yard trimmings, and cotton gin trash. Newsprint plus NH₄NO₃ resulted in a shift to more Gram positive bacteria, while newsprint plus poultry litter resulted in a shift to more Gram negative bacteria. Both N sources resulted in a reduction in Bacillus sp. Shifts in the bacterial populations and changes in species richness (number of species detected) and evenness (relative abundance of each species) were induced by organic by-product additions. These shifts appear to be the result of increased substrate for C mineralization rather than any properties of biological control. Shifts in the microbial community structure towards Gram negative organisms may benefit plant growth and may be useful as an indicator of soil quality.     

Short-Term Effects of Hazelnut Husk Compost And Organic Amendment Applications On Clay Loam Soil

The experiment was carried on a clay loam soil to examine the short-term effects of hazelnut husk compost (HHC) and organic amendments on selected soil physical properties between 2001 and 2003. The amendments were only applied in 2001. The experimental design was replicated five times as a randomized complete block with four organic amendments: HHC, peat, farmyard manure (FM), chicken manure (CM) and soil (control). Amendments were applied at rates of 0, 12.5, 25, 50, 75 and 100 tons ha^?1 (dry weight) replicated. The effect on the soil's physical properties such as bulk density, water retention characteristics, pore ratio, structural stability, and soil organic carbon were determined. All amendments and their rates had a positive effect on the physical properties of the soil. HHC decreased the bulk density of soil. The effect depended on year since application. Moreover, HHC increased soil total porosity, the amount of water held at field capacity and wilting point of soil. The 75 ton ha^?1 application was most effective. Its effects on these soil properties were more obvious at the end of the second year. HHC did not affect macropore/micropore ratio of the soil until the third year, due to an increase in micropore number. Although the effects of the other organic amendments on structural stability of soil were more obvious in the second year, the effect of HHC increased in the third year, due to its high C/N ratio. The 75 ton ha^?1 application of HHC increased the structural stability of the soil the most. HHC had the highest organic carbon content. The effects of HHC on physical productivity of soil generally were clearer at the end of the second year. For this reason, it is recommended that HHC should be reapplied after two years as organic fertilizer. Further studies should be carried out to determine the long-term effects of HHC on physical productivity of soils.     

Soil Phosphorous Influence on Growth and Nutrition of Tropical Legume Cover Crops in Acidic Soil

In tropical regions, use of cover crops in crop production is an important strategy in maintaining sustainability of cropping systems. Phosphorus (P) deficiency in tropical soils is one of the most yield-limiting factors for successful production of cover crops. A greenhouse experiment was conducted to evaluate influence of P on growth and nutrient uptake in 14 tropical cover crops. The soil used in the experiment was an Oxisol, and P levels used were low (0 mg P kg^?1), medium (100 mg P kg^?1) and high (200 mg P kg^?1). There was a significant influence of P and cover crop treatments on plant growth parameters. Phosphorus X cover crops interaction for shoot dry weight, root dry weight and root length was significant, indicating different responses of cover crops to variable P levels. Based on shoot dry weight efficiency index (SDEI), legume species were classified into efficient, moderately efficient or inefficient groups. Overall, white jack bean, gray mucuna bean, mucuna bean ana and black mucuna bean were most P efficient. Remaining species were inefficient in P utilization. Macro- and micronutrient concentrations (content per unit dry weight of tops) as well as uptakes (concentration x dry weight of tops) were significantly (P < 0.01) influenced by P as well as crop species treatments, except magnesium (Mg) and zinc (Zn) concentrations. The P x crop species interactions were significant for concentration and uptake of all the macro and micronutrients analyzed in the plant tissues, indicating concentrations and uptake of some nutrients increased while others decreased with increasing P levels. Hence, there was an antagonistic as well as synergetic effect of P on uptake of nutrients. However, uptake of all the macro and micronutrients increased with increasing P levels, indicating increase in dry weight of crop species with increasing P levels. Overall, nutrient concentration and uptake in the top of crop species were in the order of nitrogen (N) > potassium (K) > calcium (Ca) > Mg > sulfur (S) > P for macronutrients and iron (Fe) > manganese (Mn) > zinc (Zn) > copper (Cu) for micronutrients. Interspecific differences in shoot and root growth and nutrient uptake were observed at varying soil P levels     

城市生活垃圾堆肥对土壤环境容量的影响

本文分析了不同量的城市生活垃圾堆肥(以下简称垃圾堆肥)施入农田土壤后,土壤理化性状、作物生长效应及重金属在土壤中积累等情况。阐述了垃圾堆肥对土壤环境容量影响因素，为制定垃圾堆肥施入标准提供了科学依据。     

Soil pH Buffering Capacity and Nitrogen Availability Following Compost Application in a Tropical Acid Soil

Tropical acid soils are highly weathered as they exist under tropical environment with high rainfall and temperature throughout the year, which affects nitrogen availability. Soil organic nitrogen is important in estimating soil nitrogen availability. The combined use of urea and compost in this study was carried out to decrease sole dependence on urea, buffer soil acidification, and reduce nitrogen losses through leaching. Thus, soil buffering capacity, incubation, and organic nitrogen fractionation studies were conducted to determine soil buffering capacity, availability of total nitrogen, organic fractions nitrogen, and inorganic nitrogen in soil after 90 days of incubation following compost. Soil pH, buffering capacity, total nitrogen, organic nitrogen fractions, exchangeable ammonium, and available nitrate were higher in all treatments with compost and combined use of urea and compost. Total hydrolyzable nitrogen, ammonium-nitrogen, (ammonium + amino sugar)-nitrogen, amino sugar-nitrogen, and amino acid-nitrogen were higher in soils with urea and compost suggesting that decomposition of soil organic fractions nitrogen into inorganic nitrogen (ammonium and available nitrate was affected by the addition of urea and compost. Urea can be amended with compost to regulate availability nitrogen in soil for crop use.     

MSW Compost Application on Tomato Crops in Mediterranean Conditions: Effects on Agronomic Performance and Nitrogen Utilization

A two-year field experiment (2001 and 2003) was carried out in a Mediterranean environment to study the effects of municipal solid waste (MSW) compost application compared with mineral nitrogen (N) fertilization on the agronomic performance and N utilization of a tomato crop, in rotation with durum wheat. The research was conducted in the south of Italy where five N treatments and two soil tillage depths (40-45 cm and 10-15 cm) were compared. The N treatments were: MSW compost at 140 kg ha^?1 (Ncom); mineral N fertilizer at 140 kg ha^?1 (Nmin); MSW compost combined with mineral N fertilizer (Nmix) (70 kg ha^?1 as organic N plus 70 kg ha^?1 as mineral N); mineral N fertilizer at 70 kg ha^?1 combined with two applications of foliar fertilizer (Nfito) (3 kg ha^?1 as hydrolyzed proteins), and an untreated control (Contr). During cropping cycles, growth parameters and plant N status (SPAD readings and petiole nitrate content) were determined; at harvest the marketable, overripe, green fruit, total yield, yield components, quality performance, total and fruit N uptake, and N efficiency were recorded. In addition, at the beginning and at the end of the two-year experiment, soil chemical characteristics and mineral N was measured, allowing for the calculation of the mineral N deficit in the soil. The results of this research indicate that the application of MSW compost to tomato plants can serve as a N source in Mediterranean conditions, especially when MSW compost is combined with mineral N fertilizer and deeper soil tillage is applied. In fact, deeper soil tillage increased total yield 7.0 t ha^?1 compared to surface tillage, whereas soil amended with MSW compost increased total yield compared to the untreated control by approximately 6.4% when used alone and 11.1% when combined with mineral N fertilizer. Nitrogen utilization parameters and Harvest Index varied significantly across years and N treatments. Petiole nitrate content and SPAD readings did not vary between Nmin and Nmix treatments, but they were significantly different from the untreated control. This indicates that plant N status was an effective tool to monitor N supply. After the two-year experiment, the Nmix treatment was statistically not significant in total yield (86.1 and 88.2 t ha^?1, respectively), marketable yield (66.9 and 67.7 t ha^?1) and quality compared to the Nmin treatment. Furthermore, the Nmix treatment ensured the least N deficit in the soil, indicating that MSW applications were effectively used as alternative organic supplements. Finally, the results indicated a positive effect of MSW application on organic carbon content in the soil and did not show any significant increase of the heavy metals at the end of the two-year experiment.     

Soil Hydraulic Properties: Influence of Tillage and Cover Crops

Understanding the effects of cover crops and tillage on soil physical properties is important for determining soil productivity. This study was conducted at Lincoln University's Freeman Center, USA to evaluate the effects of tillage and cover crop management on soil hydraulic properties. The field site included three replicate blocks in a randomized complete block design with each plot measuring 21.3 m in length and 12.2 m in width. Treatment factors were tillage at two levels(moldboard plow tillage vs. no tillage) and cover crop at two levels(cereal rye(Secale cereal) cover crop vs. no cover crop). Soil samples were collected in late spring/early summer from each treatment at 10-cm depth increments from the soil surface to a depth of 40 cm using cores(76.2-mm diameter and 76.2-mm length). Soil bulk density was 13% lower with tillage compared with no-tillage. Volumetric water content was significantly higher at 0.0 and -0.4 k Pa pressures with tillage compared with no tillage. Tillage increased the proportion of coarse mesopores by 32% compared with no tillage, resulting in 87% higher saturated hydraulic conductivity(K_(sat)). Cover crop increased the proportion of macropores by 24% compared with no cover crop; this can potentially increase water infiltration and reduce runoff. As a result of higher macroporosity, Ksat was higher under cover crop compared with no cover crop. This study demonstrated that tillage can benefit soil hydraulic properties in the short term, but these effects may not persist over time. Cover crops may slightly improve soil hydraulic properties, but longer term studies are needed to evaluate the long-term effects.     

Compost Amendment to Sandy Soil Affects Soil Properties and Greenhouse Tomato Productivity

Sandy soils, with low productivity, could be improved by compost application to sustain crop production. This study aimed to examine the effect of three compost types (vegetable, fruit and yard waste compost, garden waste compost, and spent mushroom compost) on basic properties of a loamy sand and greenhouse tomato productivity. Disturbed and intact soil samples were taken from a decade-long compost field experiment on loamy sand with three compost types at application rate of 30 m³ ha^?1 yr^?1 (7.5 ton ha^?1 yr^?1). The soils were characterized for chemical and physical properties. Tomato was planted in a greenhouse using soil samples from the field and vegetative and yield parameters (plant height, stem diameter, leaf number, and fruit yield), water productivity, and harvest index were evaluated. All compost types significantly increased soil total carbon, total nitrogen, pH, electrical conductivity and significantly decreased bulk density, with no effect on plant available water compared to the control. Fresh and dry fruit weights were significantly increased after compost addition. Plant height, leaf number, stem diameter, and total biomass did not significantly improve after compost addition. Spent mushroom compost had greater effect in improving tomato productivity. A decade-long application of composts on loamy sand improved basic chemical and physical properties which were reflected in increased fruit yield in tomato. Since no negative effect of compost was observed, we suggest that sandy soils may serve as a safe end use option for these composts and potentially support crop growth.     

The Effects of Short-Term Compost Application On Soil Chemical Properties and on Nutritional Status of Maize Plant

Compost may improve the soil quality and contribute to C sequestration. The short-term effects of compost application on soil properties of soil cropped with maize are reported here. Soil plots to which mature compost was added (at 50 Mg ha^?1 and 85 Mg ha^?1) were analyzed for total organic carbon (TOC), nutrients, heavy metals and other soil properties. In addition, maize plants were weighed at the end of the trial and analyzed for carbon (C), nitrogen (N), phosphorus (P) and heavy metals. The results demonstrate that soil amended with compost has an increased TOC content. The increase was proportional to the amount of compost used. At the highest dose used, compost also increased soil N and P content and the pH. Moreover, after compost application, the total heavy metal contents in soils did not increase. There was no difference between the maize yield from compost treated plots and the control plots. However, maize grains were found to be C, N and P enriched due to the increased nutrient status of the amended soil. In conclusion, the addition of mature compost improves soil properties by increasing the soil TOC content and this depends on the characteristics and the amount of compost used.     

Application of High Copper and Zinc Compost and Its Effects on Soil Properties and Growth of Barley

Abstract

A compost of high copper (Cu) and zinc (Zn) content was added to soil, and the growth of barley (Hordeum vulgare L.) was evaluated. Four treatments were established, based on the addition of increasing quantities of compost (0, 2, 5, and 10% w/w). Germination, plant growth, biomass production, and element [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), Cu, manganese (Mn), and Zn] contents of soil and barley were determined following a 16‐week growing period. Following harvesting of the barley, analysis of the different mixtures of soil and compost was performed. Micronutrient contents in soils as affected by compost additions were determined with diethylene–triamine–pentaacetic acid (DTPA) (Cu, Mn, Fe, and Zn) or ammonium acetate [Ca, Na, Mg, K, cation exchange capacity (CEC)] extractions, and soils levels were compared to plant uptake where appropriate. Increasing rates of compost had no affect on Ca, Mg, or K concentration in barley. Levels of Cu, Zn, Mn, and Na, however, increased with compost application. High correlations were found for DTPA‐extractable Cu and Zn with barley head and shoot content and for Mn‐DTPA and shoot Mn content. Ammonium acetate–extractable Na was highly correlated with Na content in the shoot. High levels of electrical conductivity (EC), Cu, Zn, and Na may limit utilization of the compost.     

城市污泥堆肥商品化应用问题的探讨

讨论了国内外城市污泥的各种处理方法的利弊 ,城市污泥土地利用的可能性和有效性 ;论证了城市污泥堆肥商品化的可行性和必要性 ,并对污泥堆肥商品化应用中的安全性及质量控制等问题进行了探讨。