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1.
Two pot experiments were carried out under controlled environment conditions in the growth chamber to assess the potential use of alfalfa powders and distiller grains as organic fertilizers. Two types of dehydrated alfalfa powders (one with canola meal protein extraction by-product and one without) and two types of distiller grains (dried distillers grain with distillation solubles added and wet distillers grain without solubles) from wheat-based ethanol production were evaluated. Four different nitrogen (N)-based amendment application rates (0, 100, 200 and 400 kg N ha?1) were used along with urea applications made at the same N rates to a Brown Chernozem (Aridic Haploboroll) loamy textured soil collected from south-central Saskatchewan, Canada. Canola biomass yield, N, phosphorus (P), potassium (K), zinc (Zn), and cadmium (Cd) uptake were measured along with soil properties including pH, salinity, organic carbon, total nitrogen, phosphorus and extractable nutrients and cadmium before and after canola growth in each of the treatments. Application of alfalfa powder and distiller grain amendments resulted in significant canola biomass yield increases along with increased N, P, and K uptake compared to the unfertilized control. However, only a portion of the N added (～30% to 50%) in the organic amendments was rendered available over the five week duration of the experiments. Amendments that had higher N content and lower carbon (C):N ratios such as dried distillers grain with solubles resulted in greater canola N uptake. Reduced germination and emergence of canola seedlings was observed at high rates of addition of distillers grain (400 kg N ha?1), the reason for which is unclear but may be due to a localized salt or toxicity effect of the amendment. The amendment with alfalfa powders and distiller grains resulted in small increases in residual soil nutrients. Effects on pH, salinity, organic carbon and extractable metals tended to be small and often not significant. Alfalfa powders and distillers grains appear to be quite effective in supplying nutrients, especially N, for plant growth over the short-term.  相似文献   

2.
The effects of incorporating or topdressing with cottonseed (Gossypium hirsutum L.) meal with or without soapstock, canola (Brassica rapa L.) meal, urea, or no amendment (control) were investigated using plants of marigold (Tagetes erecta L. ‘Inca II Gold’ or ‘Inca II Yellow’) and redbud (Cercis canadensis L.) in a Norge loam (fine-silty, mixed, thermic Udic Paleustolls) at Stillwater, OK in 2008 and 2009. Fertilizers were applied in May at 4.9 g?m?2 N based on soil test results prior to the study and nitrogen (N) recommendations for turfgrass. Soil nitrate-nitrogen (NO3-N) and phosphorus (P) increased from 2008 to 2009 in marigold plots into which cottonseed meal with soapstock was incorporated, and boron (B) increased in all marigold plots regardless of treatment. In 2009, marigolds grown in plots into which cottonseed meal was incorporated were taller than plants in other treatments except the untreated control. Marigolds in plots in which cottonseed meal was topdressed, cottonseed meal with soapstock was incorporated, or urea was topdressed grew less in height than plants in plots with cottonseed meal incorporated or control plots. Shoot dry weights of marigold plants in plots topdressed with cottonseed meal with or without soapstock, urea, or control plots were lower than those of plants in other treatments. Visual ratings of marigold plants receiving a topdress of urea or no treatment were lower than visual ratings of plants in any other treatment in July, but similar in August to those of marigold plants in plots in which cottonseed meal was topdressed. Some differences within fertilizer treatments occurred between 2008 and 2009 in redbud soil concentration of NO3-N, calcium (Ca), magnesium (Mg), sulfate-sulfur (SO4-S), iron (Fe), B, and copper (Cu). Leaf P concentration differed among fertilizer treatments in 2009. Leaf and total dry weight of redbuds grown in soil incorporated with urea was greater than that of plants in any other treatment. Results indicate that cottonseed and canola meals provide N and other nutrients for growth of landscape plants. Soil incorporated cottonseed meal encouraged more growth of marigold than soil incorporated urea but less growth of redbud.  相似文献   

3.
Overused soil resources and the build-up of organic residues from industrial processes have resulted in increased risk of environmental contamination. Recycling of organic residues from industry by incorporation into agricultural soil, can provide valuable organic amendment as well as supply nutrients to crops. The effect of applying organic amendments to an agricultural sandy soil on the nitrogen nutrition of wheat (Triticum aestivum L.) and residual effects on the growth of a following maize crop (Zea mays, L.), were assessed under semi-controlled environmental conditions and were compared to nitrogen mineralization prediction obtained from an aerobic incubation. Six different organic residues (composted municipal solid waste, secondary pulp-mill sludge, hornmeal, poultry manure, the solid phase from pig slurry and composted pig manure) were added to a Cambic arenosol, incubated or used in pot experiments, to evaluate and try to predict the availability to crop plants of nitrogen released from these materials. Poultry manure was the most effective amendment in making nitrogen available and enhancing nitrogen uptake by wheat plants resulting in greater dry matter yield. The dried solid phase from pig slurry and hornmeal were also beneficial to wheat growth. There was a greater recovery of nitrogen (N), from organic materials studied, by a maize crop. Poultry manure was the residue that provided a greater residual effect on N supply to maize.  相似文献   

4.
An experiment was performed to examine the chemical and biological effects on high clay sodic subsoil following the incorporation and incubation with organic amendments. The main treatments consisted of amendments with wheat shoots, lucerne pellets and peat, and these were compared to gypsum addition. Additional treatments were residues of chickpea and canola, chicken manure and sawdust. All materials were finely ground and added to crushed and sieved soil at the rate of 1% by weight. Wheat, canola and chickpea residues and chicken manure resulted in modest reductions in soil sodicity. Carbon and N mineralization were related to the soluble C/total N ratio in the amendment. The initial mineralization of wheat amendment was rapid due to its soluble C content, but then slowed to have the lowest loss, of around one third of added C, of all the plant residues after 174 days. In comparison, lucerne-amended soil increased total N and lost almost half of its C after the 174-day incubation. The canola stubble amendment showed the highest carbon loss, losing 64% of its added C. The addition of gypsum resulted in high soil electrical conductivity which suppressed respiration, compared to the control soil, indicating a detrimental effect on microbial activity due to the high electrolyte concentration in the soil. The peat amendment, with a low-soluble C content, showed a similar respiration rate to the control soil, confirming that a source of soluble C is important for the initiation of rapid biological activity. Soil pH was significantly increased (by 0.6 of a pH unit) with addition of chicken manure, and still remained higher than control soil after 174 days of incubation. Lucerne was the only plant residue to increase soil pH, with the effect being sustained for 56 days. The study demonstrated how some organic amendments can improve chemical fertility and biological activity in high clay sodic subsoil, and at the same time contribute, after 25 weeks incubation, to an increase in carbon content.  相似文献   

5.
Soil nitrogen (N) availability and crop performance of broccoli (Brassica oleracea var. orion) were observed in a field plot study under different organic amendments addition and chemical fertilizer. The treatments consisted on no amendment; poultry manure based compost, woollypod vetch (Vicia dasycarpa var. lana), a combination of compost with Lana vetch and ammonium sulphate. For almost all sampling dates, the soils treated with vetch (3.6 Mg/ha) combined with compost (9.0 Mg/ha) showed a good performance in replenishing the inorganic N taken up by plants and soil microbes. High yields were achieved with the combination of vetch and compost and moderately high yields were achieved with vetch only and compost only. Yields appeared to be related to quality and N levels in the amendments, and size of existing soil nitrogen pools susceptible to the priming effect.  相似文献   

6.
土壤改良剂对土壤紧实度及燕麦生长状况的影响   总被引：5，自引：1，他引：4  
研究了不同土壤改良剂(聚丙烯酸钾,聚丙烯酰胺,腐殖酸钾,聚丙烯酸钾十腐殖酸钾,聚丙烯酰胺十腐殖酸钾)对土壤紧实度及燕麦生长状况的影响.结果表明,各改良剂处理均能减小土壤紧实度,表现为:聚丙烯酸钾十腐殖酸钾＞聚丙烯酰胺十腐殖酸钾＞聚丙烯酸钾＞聚丙烯酰胺＞腐殖酸钾＞对照,土壤紧实度均随着土壤深度增加而增加;土壤改良剂对燕麦株高和干物质量具有显著的提高作用,复配处理株高优于其他单施处理;土壤改良剂处理下籽粒产量均显著高于对照,其中聚丙烯酸钾十腐殖酸钾和聚丙烯酰胺十腐殖酸钾籽粒产量较其他处理高,分别为4 694.2和4 566.9 kg/hm2,较对照增产21.66％和18.36％,生物产量的增产效果表现同籽粒产量;各土壤改良剂处理水分利用效率均显著高于对照,其变化趋势与产量变化趋势一致,复配处理效果更佳.  相似文献   

7.
Increasing the retention of nutrients by agricultural soils is of great interest to minimize losses of nutrients by leaching and/or surface runoff. Soil amendments play a role in nutrient retention by increasing the surface area and/or other chemical processes. Biochar (BC) is high carbon-containing by-product of pyrolysis of carbon-rich feedstocks to produce bioenergy. Biosolid is a by-product of wastewater treatment plant. Use of these by-products as amendments to agricultural soils is beneficial to improve soil properties, soil quality, and nutrient retention and enhance carbon sequestration. In this study, the adsorption of NH4-N, P, and K by a sandy soil (Quincy fine sand (QFS)) and a silty clay loam soil (Warden silty loam (WSL)) with BC (0, 22.4, and 44.8 mg ha?1) and biosolid (0 and 22.4 mg ha?1) amendments were investigated. Adsorption of NH4-N by the QFS soil increased with BC application at lower NH4-N concentrations in equilibrium solution. For the WSL soil, NH4-N adsorption peaked at 22.4 mg ha?1 BC rate. Biosolid application increased NH4-N adsorption by the WSL soil while decreased that in the QFS soil. Adsorption of P was greater by the WSL soil as compared to that by the QFS soil. Biosolid amendment significantly increased P adsorption capacity in both soils, while BC amendment had no significant effects. BC and biosolid amendments decreased K adsorption capacity by the WSL soil but had no effects on that by the QFS soil. Ca release with increasing addition of K was greater by the WSL soil as compared to that by the QFS soil. In both the soils, Ca release was not influenced by BC amendment while it increased with addition of biosolid. The fit of adsorption data for NH4-N, P, and K across all treatments and in two soils was better with the Freundlich model than that with the Langmuir model. The nutrients retained by BC or biosolid amended soils are easily released, therefore are readily available for the root uptake in cropped soils.  相似文献   

8.
High pH soils limit availability of pH sensitive nutrients including phosphorus (P), even though abundant levels are present. Application of such nutrients to the soil is ineffective because they quickly get tied up in unavailable forms. Elemental sulfur (S) application in a narrow band to lower root zone pH and increase nutrient availability to the crop is a possible economically feasible solution. A four year field study was conducted in which S was applied to sugarcane (Saccharum spp.) at rates up to 1120 kg S ha?1 each of the 1st three years in a band using different application methods. Sulfur application effects on soil pH were gradual, causing only a slight reduction in the application zone after one year; but was long lasting, resulting in continuing substantial declines in soil pH in an adjacent zone four years after the first S application. Soil available P, sulfate (SO4)-S, and salinity levels increased with increasing S applied. Sugarcane plant growth, as indicated by leaf area index during the grand growth period responded to moderate S application levels. Sugarcane yields increased linearly in the plant crop, but showed quadratic responses to S applications in the 1st through 3rd ratoon crops. Initial soil available P levels prior to the first treatment application were at the critical level considered adequate for crop requirements, yet growth and yield increases in response to S application suggest that the critical available soil P levels for sugarcane may be higher than previously established. Sulfur application at rates beyond those necessary to produce maximum yields resulted in salinity problems which probably reduced yields. The ‘stool splitter’ application method, which slices the plant stool using a coulter and places the fertilizer directly in the middle of the furrow caused crop damage and stand loss which persisted for the remainder of the sugarcane crops. Based on the results of this study, a single application of elemental S at up to 1120 kg S ha?1 directly below the seed cane at planting is recommend for sugarcane on a calcareous soil, with no additional applications in later crops.  相似文献   

9.
Application of byproduct amendment containing silicon, calcium, magnesium, and potassium has been shown to improve acidic soil quality in Jiaodong Peninsula of China. In this study, we explored the influences of amendment supplemented with and without urea on the physicochemical properties as well as microbial activities of acidic soil from Jiaodong over a 120-day period. With the amendment, the electronic conductivity and pH of soils changed. The amendment treatment significantly reduced inorganic nitrogen content and increased microbial biomass nitrogen content during the whole incubation period. The microbial biomass, activities of phenol oxidase and dehydrogenase were increased by the addition of amendments, while the soil respiration, catalase and urease activity were declined. Our results indicated that application of byproduct amendment could improve the chemical and biological properties of the acidic orchard soils from Jiaodong over a short time period of investigation.  相似文献   

10.
以内蒙古河套灌区苏打碱化土为研究对象开展田间试验,设置常规施肥(CK)、生物炭+常规施肥(BC)、牛粪+常规施肥(CD)、玉米秸秆+常规施肥(SW)和羊粪+常规施肥(GM)5个处理,研究不同有机物料添加对碱化土壤有机碳(SOC)库和化学性质的影响。分别于2019年和2020年收获季采集0—30 cm耕层土壤,分析不同有机物料添加下SOC及其活性碳组分和主要盐碱指标的变化特征及其相关关系。结果表明:与CK相比,2019年和2020年各有机物料添加处理下SOC平均增幅分别为22.7%和17.2%,土壤有机碳储量(SOCs)平均增幅分别为22.9%和18.2%;4种有机物料均提高了碱化土壤活性有机碳组分含量,其中,CD和GM处理下各活性碳组分含量增幅较其他处理更高;2019年各有机物料添加处理下碳库管理指数(CPMI)较CK提高53.8%~108.3%,2020年提高71.3%~144.1%(P＜0.05),CD和GM对CPMI的提升作用更明显。土壤化学性质方面,2020年各有机物添加处理下pH均显著下降,BC和CD处理下碱化度(ESP)分别显著下降36.9%和29.3%,CD处理下蔗糖酶活性提高36.7%(P＜0.05)。主成分分析(PCA)表明,影响苏打碱化土SOC含量变化的主要因素为活性有机碳组分和ESP。牛粪和羊粪施用对苏打碱化土有机碳库质量提升作用较好,生物炭施用对盐碱化指标改良效果最明显。  相似文献   

11.
Canola (Brassica napus L.) is a very important agricultural and industrial crop. Hence, the effects of chemical and biological treatments on canola oil production and nutrient uptake, under calcareous conditions, were evaluated in a field experiment. Phosphorus (P) fertilizer and sulfur (S)-oxidizing bacteria (Thiobacillus sp.) increased canola oil production by a maximum of 548 and 335 kg ha?1, respectively. P-solubilizing bacteria (Bacillus sp.) and Thiobacillus sp. enhanced the uptake of different nutrients including nitrogen (N), P, potassium (K), zinc (Zn), and manganese (Mn). Monthly measurements of soil P indicated that soil P fluctuations can be managed using the applied treatments for proper P fertilization in canola production. The results indicated the important role of chemical and biological (Bacillus sp.) P sources and S-oxidizing bacteria for canola growth and oil production as they resulted in significant increase in canola oil production and nutrient uptake. This can be very beneficial for the farmers and industry.  相似文献   

12.
ABSTRACT

Soil chemical properties are closely related to crop production levels. Understanding the relationships between soil nutrients and different yield levels is important for improving the efficiency of fertilization management programs. The objectives of this study were to understand the key soil nutrient requirements for different crop yield levels using 10 experimental wheat-maize rotation sites and to optimize fertilization applications in North China. The results found significant differences between the soil chemical properties among the study sites, with average contents in the range of 10.07–14.72 g/kg for soil organic carbon (SOC), 0.38–1.29 g/kg for total nitrogen (TN), 56.43–89.77 mg/kg for available nitrogen (AN), 17.36–48.54 mg/kg for available phosphorus (AP), 79.4–184.5 mg/kg for available potassium (AK), 0.78–5.97 mg/kg for soil Cu, and 0.75–2.20 mg/kg for soil Zn. The soil pH values were 6.46–8.19. Significant correlations (p < 0.05) were found between high-level yields and higher contents of SOC, TN, AN, and AP when a suitable soil pH were present. The higher levels of soil SOC and TN were important for maintaining high-level yields in these regions. Soil AN and pH are two key limitations that could significantly (p < 0.05) improve medium-level yields. Although some soil indicators, including SOC, TN, AN, AP, soil pH, soil Zn, and Cu could significantly influence low-level yields, soil amendments with C, N, and available P and having a suitable soil pH were especially important for improving low-level yields. These results could be used to improve conventional methods of fertilization management and increase the efficiency of fertilizer use in North China.  相似文献   

13.
Imbalanced fertilizer use with intensive cropping has threatened the sustainability of agroecosystems, especially on acid soils. An understanding of the long-term effects of fertilizers and amendments on soil health is essential for sustaining high crop yields. The effects of application of fertilizers, and amendments for 46 years on soil properties and maize yield in an acid Alfisol were investigated in this study. Ten fertilizer treatments comprising different amounts of NPK fertilizers, farmyard manure (FYM) and lime, and one control, were replicated three times in a randomized block design. At 0–15 cm soil depth, bulk density was least (1.20 t/m3), porosity (49.8%) and water holding capacity (61.7%) were greatest in 100% NPK + FYM, corresponding to the largest organic carbon content (13.93 g/kg). Microbial biomass C and dehydrogenase activity in 100% NPK + FYM were 42% and 13.7% greater than 100% NPK, respectively. Available nutrients were significantly more with 100% NPK + FYM and 100% NPK + lime than control and other fertilizer treatments. At 15–30 cm depth, the effect of various treatments was comparable to the surface layer. Grain yield declined by 55% and 53% in 100% NPK(-S) and 100% NP, respectively, compared with 100% NPK, whereas 100% N as urea alone eventually led to crop failure. Soil porosity recorded the greatest positive correlation (r = .933**), whereas bulk density recorded a negative significant correlation (r = −.942**) with grain yield. The results suggest that integrated use of FYM/lime with chemical fertilizers is a sustainable practice in terms of crop yield and soil health, whereas continuous application of urea alone is detrimental to the soil health.  相似文献   

14.
Ethanol production results in distiller grain, and biodiesel produces glycerol as by-product. However, there is limited information on effects of their addition on evolution of N2O and CO2 from soils, yet it is important to enable our understanding of impacts of biofuel production on greenhouse gas budgets. The objective of this study was to evaluate the direct effects of adding wet distillers grain (WDG), thin stillage (TS), and glycerol at three rates on greenhouse gas emissions (N2O and CO2) and nutrient supply rates in a cultivated soil from the Canadian prairies. The WDG and TS application rates were: 100, 200, or 400 kg N ha?1, whereas glycerol was applied at: 40, 400, or 4,000 kg C ha?1 applied alone (G???N) or in a combination with 300 kg N ha?1 (G?+?N). In addition, conventional amendments of urea (UR) and dehydrated alfalfa (DA) were added at the same rates of total N as the by-products for comparative purposes. The production of N2O and CO2 was measured over an incubation period of 10 days in incubation chambers and Plant Root Simulator? resin membrane probes were used to measure nutrient (NH 4 + -N, NO 3 ? -N, and PO 4 ?3 -P) supply rates in the soil during incubation. Per unit of N added, urea tended to result in the greatest N2O production, followed by wet distillers grain and thin stillage, with glycerol and dehydrated alfalfa resulting in the lowest N2O production. Cumulative N2O production increased with increasing the rate of N-containing amendments and was the highest at the high rate of UR treatment. Addition of urea with glycerol contributed to a higher rate of N2O emission, especially at the low rate of glycerol. The DA and WDG resulted in the greatest evolution of CO2 from the soil, with the thin stillage resulting in less CO2 evolved per unit of N added. Addition of N fertilizer along with glycerol enhanced microbial activity and decomposition. The amendments had significant impacts on release of available nutrient, with the UR treatments providing the highest NO 3 ? -N supply rate. The TS treatments supplied the highest rate of NH 4 + -N, followed by WDG compared to the other amendments. The WDG treatments were able to provide the greatest supply of PO 4 ?3 -P supply in comparison to the other amendments. Microbial N immobilization was associated with glycerol treatments applied alone. This study showed that the investigated biofuel by-products can be suitable soil amendments as a result of their ability to supply nutrients and N2O emissions that did not exceed that of the conventional urea fertilizer.  相似文献   

15.
The result of intensive agriculture in cities is the decline in crop yields and depletion of the resource base. The aims of this study were to assess effects of nitrogen (N) or phosphorus (P) fertilization on bioavailable aluminum (Al) and their contribution on Al and nutrient uptake in Hibiscus sabdariffa. A pot experiment was led to supply a tropical soil with N and P fertilizers. P amendment decreased Al in soil solution, not N amendment. Fertilizers had effects on Al and nutrient uptake in roots and leaves of Hibiscus sabdariffa. The results also showed that the uptake of Al and nutrients depends on Al in soil solution or N supply or P supply. Only P uptake in roots and leaves was explained by combined effects of a nutrient supply × exchangeable Al. Furthermore, P supply does not limit the translocation of Al in shoots of plants in acid soils.  相似文献   

16.
Large quantities of organic by-products are generated by the sugarcane industry during sugar extraction process. These by-products may be used as soil amendments to improve soil quality, as nutrient leaching is common in mineral soils of Florida in USA due to their sandy texture and frequent rain events. A soil column study was designed to evaluate the effects of bagasse application at 85 t ha-1 of fresh bagasse, 170 t ha-1 of fresh bagasse, and 170 t ha-1 of fre...  相似文献   

17.
A three-year field experiment was carried out to study the effects of green manure application on the soil microbial biomass carbon, nitrogen and soil enzyme activities in order to provide a theoretical basis on low-carbon agriculture, environment-friendly agriculture and promote the sustainable development of tobacco production. Six treatments were set and were: check (CK) (contrast, no application of green manure), T1 (application of ryegrass only 1 year), T2 (application of ryegrass 2 years), T3 (application of oats 2 years), T4 (application of ryegrass 3 years), and T5 (application of oats 3 years), which was based on continuous planting oats and ryegrass (Lolium multiflorum L.) in our experiment. The results showed that soil microbial biomass carbon, nitrogen, and the activity of soil urease, acid phosphatase (ACP), sucrase, and catalase increased with each year and with the application of green manure. Compared with the control, after the application of green manure the content of soil microbial biomass carbon and nitrogen increased 1.94%–93.07% and 2.30%–145.07%, respectively, and the activity of soil urease, ACP, sucrase, and catalase increased 1.45%–56.52%, 2.34%–33.17%, 0.96%–172.66%, and 3.33%–85.71%, respectively. Correlation analysis indicated that soil microbial biomass carbon and soil enzymes activity had certain relevance that showed the dynamic process of soil microbial biomass and enzyme activity were coordinate with the decomposition process of green manure and the absorption of mine nutritional to tobacco plant. The results demonstrate that continuous application of green manure could increase soil biological fertility level.  相似文献   

18.
梁鹏飞  郭全恩  曹诗瑜  南丽丽 《土壤》2023,55(1):140-146
针对兰州新区城市绿化带土壤盐分含量高严重影响苗木和草坪成活率的问题，以兰州新区绿化带盐渍化土壤为研究对象，采用温室盆栽法，以不施肥为对照(CK)，研究了添加禾康(T1)、乳酸菌(T2)、磷石膏(T3)、炭基肥(T4)、免申耕(T5)和磷酸脲(T6) 6种盐碱土改良剂对草坪根际土壤化学、生物学特性的影响。结果表明：与CK处理相比，施用6种改良剂均能降低草坪根际土壤pH，提升有机质、速效磷、微生物生物量碳氮磷含量及碱性磷酸酶、脱氢酶活性；显著降低土壤细菌群落丰富度和多样性指数(Chao1和Shannon-wiener)；根际土壤细菌群落均以变形菌门、拟杆菌门、放线菌门、芽单胞菌门和酸杆菌门为主，其中T4、T6处理显著提高了变形菌门的相对丰度，T2处理显著增加了放线菌门的相对丰度，T1处理显著提升了芽单胞菌门和酸杆菌门的相对丰度。冗余分析和Monte Carlo置换检验结果显...  相似文献   

19.
 Sludge amendments increase the input of carbon and nutrients to the soil. However, the soil concentrations of heavy metals and xenobiotica can also increase due to sludge amendments, with possible effects on soil microorganisms and soil fertility. Therefore, we studied the effects on soil microorganisms and soil chemistry in two arable soils after 12 and 16 years of sewage sludge amendment (0, 1 and 3 dry matter ha–1 year–1). The sludge amendments were combined with nitrogen addition at three rates according to crop requirements, and all combinations were replicated 4 times, giving a total number of 36 parcels at each experimental site in a non-randomised block design. Univariate data evaluation as well as principal component analysis and discriminant function analysis (DFA) were used to identify differences between treatments in microbial and chemical parameters. The DFA showed that acid and alkaline phosphatase, potential ammonium oxidation and total nitrogen were the most important parameters to discriminate between a priori defined groups of sludge treatments. Among the heavy metals, copper showed the highest increase in soil concentration with sludge amendments, but this increase was still not high enough to have a significant influence on the measured parameters. None of the xenobiotica investigated was found in high soil concentrations. In conclusion, the present study showed that the sewage sludge affected several of the biological and chemical parameters investigated. However, no severe negative effects on soil microorganisms were detected at these moderate levels of sludge amendment. Received: 3 December 1998  相似文献   

20.
采用室内恒温(25℃)培养的方法,研究施用不同用量的柳枝稷茎、叶对土壤有机碳(SOC)和微生物量碳(MBC)的影响,柳枝稷茎、叶在土壤中分解特性。结果表明:柳枝稷茎、叶施入土壤培养90d后,随着柳枝稷茎、叶施入量的增加,SOC和MBC含量明显增加。在柳枝稷茎、叶施用量相同的条件下,施入柳枝稷叶后,土壤微生物量碳的含量高于施用茎的含量,而施用叶的土壤中有机碳的含量低于施入茎的土壤有机碳的含量。柳枝稷茎、叶在土壤中的分解率具有一定的差异,且与施用量有关。在相同的柳枝稷茎、叶施用量条件下,叶在土壤中的分解率高于茎的分解率,表明了茎中的有机碳在土壤中周转期比叶中的长,说明施用柳枝稷的茎可以有效地促进土壤有机碳的累积。  相似文献   

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