首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
A plant biological assay or bioassay for determining compost quality and/or maturity has received attention over the past two decades. However, no universal acceptance for compost quality is evident and cress, which was first reported to be used as a plant bioassay, is still the most commonly used. Furthermore, there is evidence indicating that cress is not sensitive enough to distinguish between mature and immature composts. Fourteen seed propagated species were surveyed to see if one or more would be useful as a bioassay for compost quality. The study confirmed that cress is a less sensitive indicator than several species, for example, lettuce, carrot or Chinese cabbage. Amaranthus tricolor was identified as a potential sensitive indicator species since it did not germinate in an immature compost extract. When the compost extract was diluted, the germination index was linear with extract concentration. While cress responded by differences in root growth, amaranthus responded by reduced germination and root growth which gave it a more definitive response. The study concluded that most of the species, including the commonly used cress, are not sensitive enough to detect differences between mature and immature composts. However, Chinese cabbage appears to be the best of the commonly used assay plants. Amaranthus' potential as a sensitive compost maturity indicator was discovered and more studies are needed to confirm this finding.  相似文献   

2.
《Applied soil ecology》1999,11(1):17-28
The objective of this work was to evaluate the effects of turning and moisture addition during windrow composting on the N fertilizer values of dairy waste composts. Composted-dairy wastes were sampled from windrow piles, which received four treatments in a 2×2 factorial of turning (turning vs. no turning) and moisture addition (watering vs. no watering) at two stages of maturity (mature vs. immature). Composts were characterized for their chemical properties. An 84-day laboratory incubation of soils with addition of the composts at two levels was conducted to evaluate the inorganic N accumulation patterns from the variously treated composts. Chemical analyses of variously treated composts did not differ between compost treatments or maturity. In contrast, the inorganic N accumulation patterns differed between soils that received immature versus mature turned composted-dairy wastes. The results suggested that turning was a more important factor than moisture addition affecting the composting process. There was no significant difference in inorganic N accumulation patterns among soils that received different immature composts, while the N accumulation patterns observed for soils that received different mature composts depended on compost treatments. Soils amended with mature composts treated by frequent turning had higher N mineralization potentials (N0), mineralization rate constants (K), and initial potential rates (N0K) in comparison to soils with composts that had not been turned. Soils with mature composts treated by watering had a higher N0, lower K, and therefore similar N0K when compared to soils with composts that had not been watered. Soils that received mature composts treated by watering and frequent turning had higher N mineralization potentials and N0 to total organic N ratios than soil alone, which suggested that intensive management of composting would ensure positive N fertilizer values of dairy waste composts, if the appropriate composting duration is completed.  相似文献   

3.
The influence of immature municipal solid waste-biosolids composts on emergence and mean days to emergence (MDE) of several weed species was evaluated in a pot trial under greenhouse conditions. The experiment consisted of placing a 7.5 cm deep layer of three-day-old immature compost, a mature and stable compost, an artificial medium or control sand as a mulch on ivyleaf morning glory seeds. Immature three-day-old compost decreased percentage emergence, shoot and root dry weight, and increased MDE of ivyleaf morning glory. In an experiment with eight-week-old immature compost utilizing mulching depths of 2.5, 5, 7.5, 10 cm and the untreated control on seeds of three weed species, common purslane did not emerge under any of the immature compost treatments. The MDE of ivyleaf morning glory and barnyard grass increased linearly as immature compost depths increased. Next, eight economically important weed species were sown in pots with either mature or immature (eight-week-old) compost utilizing mulching depths of 2.5 and 10 cm, in addition to an untreated control. Control pots yielded higher percentages of emergence than compost treatments for all species evaluated. Common purslane, large crabgrass, pig-weed, Florida beggarweed, and dichondra did not emerge through a 10-cm deep layer of mature compost mulch, or 2.5 or 10 cm deep layer of immature mulch. Significant compost maturity/depth interactions were observed for percent emergence on common purslane, ground cherry, large crabgrass, Florida beggarweed, and ivyleaf morning glory. A thinner layer was required to suppress germination using immature eight-week-old compost as compared to mature and stable compost. Immature (three-day or eight-week-old) compost containing acetic acid concentrations of 2474 and 1776 mg.kg?1 respectively reduced percentage emergence of several economically important weed species. These studies suggest that immature composts can be used to control weeds under conditions where spatial separation is maintained between the crop and the compost and phytotoxic fermentation products do not affect the health of the mulched plants and where odors associated with such partially stabilized products do not pose problems.  相似文献   

4.
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 (θv), and saturated hydraulic conductivity (Ksat) 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 (Ksat) 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.  相似文献   

5.
Greenhouse pot trials were conducted to compare the effects of compost sources and planting treatments on turfgrass germination and emergence. Eight seeding treatments and 4 turfgrass types were factorially combined and replicated four times in a completely randomized block design. The seeding treatments were: 1) seed planted on surface of 2.6 cm compost overlying soil, 2) seed planted on soil surface below 0.65 cm compost, 3) seed planted on soil surface below 1.3 cm compost, 4) seed planted on soil surface below 2.6 cm compost, 5) seed planted on soil surface covered with a 2.6 cm straw mat, 6) seed planted below 1.3 cm soil, 7) seed planted below 1.3 cm of 1:1 compost:soil mix, and 8) seed planted on soil surface. Tall fescue (Festuca arundinacea Schreb.), Kentucky bluegrass (Poa pratensis L.), bermudagrass (Cynodon dactylon L.), and zoysiagrass (Zoysia japonica Steud.) were used as the bioassay crops. The experimental design was repeated over time using composts produced with the following feedstocks: yard waste, food waste, dairy manure, biosolids, and paper mill sludge. Emerged seedlings were counted at 11 days for tall fescue, at 3 weeks for Kentucky bluegrass and at 7 weeks for bermudagrass and zoysiagrass. There were significant (P<0.05) effects of seeding treatment x turfgrass type on germination and emergence for each compost type. All of the composts appeared to be well stabilized using routine compost laboratory testing except the biosolids compost, whose use resulted in the lowest overall germination and emergence rate. The highest rates of germination and emergence occurred in the treatments in which the seeds were planted on the surface, regardless of whether the surface was compost or soil. The lowest rate of germination and emergence occurred where the seed was placed under 2.6 cm compost, regardless of compost maturity.  相似文献   

6.
Compost maturity is one of several issues that the composting industry must face as it attempts to provide a high quality product to the agricultural community. In this paper, we examine the potential for using immature compost prepared from a mixture of municipal solid waste (MSW) and biosolids as a mulch for control of weeds in vegetable crop row-alleys. Two field experiments were conducted with 4 and 8-week-old composts in the fall of 1995 and the spring of 1996. The 4-week-old compost was applied to mulching depths of 3.8 (68 t dry weight .ha?1), 7.5 (135 t dry weight .ha?1), 11.3 (203 t dry weight .ha?1), and 15 cm (270 t dry weight .ha?1) in the fall, and at 2.0 (35 t dry weight .ha?1), 3.8, 7.5, and 11.3 cm depths in the spring. Other treatments were paraquat applied at 0.6 kg.ha?1 and an untreated control. All treatments were applied in row-alleys between raised, polyethylene-covered soil beds. The 8-week-old compost was applied to depths of 3.8, 7.5, 11.3, and 15 cm in fall and to depths of 2.0, 3.8, 7.5 and 11.3 cm in the spring. Untreated alleys served as controls. In the fall 1995 experiment under low weed pressures, the 4-week-old compost applied to 7.5 cm or greater depths completely inhibited weed germination and growth for 240 days after treatment. In the spring 1996 experiment, 4-week-old compost completely inhibited weed germination and growth for only 65 days if applied to a depth of 7.5 cm or deeper due to higher prevailing weed pressures, particularly due to yellow nutsedge (Cyperus esculentus L.). In the same spring experiment, a 50 % reduction in percentage weed cover was obtained for 240 days with a 11.25 cm deep layer of mulch compared to the control. In the fall 1995 experiment, 8-week-old compost applied at 7.5 cm or depths completely inhibited weed germination and growth for 240 days. In the spring 1996 experiment, 8-week-old compost applied as a 11.25 cm mulch reduced percent weed cover as compared to the control up to 240 days. In general, weed cover and weed dry weight decreased linearly as the depth of the mulch increased.Under these immature composts, inhibition of germination or subsequent weed growth may have been due to both the physical effects of the mulch and the concentrations of phytotoxic fatty acids during the first few days after mulches were applied. At the time of mulching with the 4-week old compost, acetic acid was present at a concentration of 1221 mg.kg?1 in the fall mulch, and at 4128 mg.kg?1 in the spring mulch. The same concentrations in the 8-week-old compost for the fall and spring mulches were 1118 mg.kg?1 and 3113 mg.kg?1, respectively. In conclusion, immature compost may provide an effective alternative weed control method for row-alleys in vegetable crop production systems. During these experiments, it was observed that man-made contaminants such as glass, hard and soft plastics in the composts were esthetically unacceptable and potentially posed hazards to field workers.  相似文献   

7.
Municipal solid waste (MSW) compost from aerobic or anaerobic bioprocesses was evaluated as components of substrates for potted plant production. Experiments were conducted with potted media consisting of MSW compost mixed with other conventional substrates (peat or composted pine bark). Spring barley (Hordeum vulgare L.) and cress (Lepidium sativum L.) were used to evaluate the biological quality of composts. Higher germination rates of spring barley were obtained when MSW compost from aerobic treatment was employed as compared with MSW compost from the anaerobic bioprocess. Improved biological indices were observed when MSW composts were mixed with composted pine bark rather than with peat. Mixtures of 75% aerobic MSW compost and 25% composted pine bark were more favorable for cress growth than peat as sole substrate.  相似文献   

8.
The use of compost with high salt concentration was evaluated, under commercial conditions, as a potential growing media constituent for vegetable transplant production. Two composts were prepared from sweet sorghum bagasse, pine bark, and either urea (compost A) or brewery sludge (compost B) as N source. Three vegetable species — broccoli (Brassica oleracea), tomato (Lycopersicum esculentum), and onion (Allium cepa) with different tolerance to salinity were used. Eleven substrates were formulated and tested: a control consisting of a moss peat-based commercial substrate; compost A; compost B; and, eight mixtures containing 33 or 67% by volume of each compost with either raw peat moss or commercial substrate as diluent. All the substrates prepared had suitable physical, physicochemical and chemical properties for use as growing media, except for the electrical conductivity (ranging from 3.20 to 13.21 dS m?1) which was above the reference levels for soilless cultivation. Broccoli was the least affected by substrate salinity whilst tomato was the most. Onion transplants had an intermediate response to saline conditions. Tomato seed germination was markedly reduced when compost A, with a higher salt concentration, was used at a rate higher than 67%. Media prepared with either of the composts, and mixed with either a commercial substrate or peat in a rate up to 67%, did not cause any detrimental effect on the growth and nutritional status of broccoli, tomato and onion transplants, despite the high initial salinity of the substrates. These composts appear to be acceptable substitutes for Sphagnum peat in seed sowing mixtures.  相似文献   

9.
A pot experiment was conducted to determine the effects of the application of composted tea leaves (TC), coffee waste (CC), and kitchen garbage (KC) on the nitrogen and nitrate accumulated in radish (Raphanus sativus L. cv. ‘radicula pers’), Chingensai (Brassica campestris L. cv. ‘Choyo No. 2’), and spinach (Spinacia oleracea L. cv. ‘Ban chu paruku’) as compared with the effect of inorganic 15N labeled fertilizer (IN) application. The compost was applied at the rate of 24 g kg?1 soil, corresponding to about 250 to 300 kg N ha?1; the A value method was used to estimate nitrogen uptake. Dry matter production was significantly higher in the IN and TC treatments than in the KC and CC treatments for all the species and tissue. Of the composts used, TC was most effective in increasing N uptake and N content in the vegetables. The composts derived N recovery as a percentage of total N uptake varied with plant species, 50.8%-62.9% in radish root, 35.3%-60.4% in radish leaf, 29.9%-48.2% in spinach leaf, and 31.3%-54.8% in Chingensai leaf. The N-use efficiencies of IN, TC, CC, and KC were 6.3%, 6.3%, 5.3%, and 6.6% in radish root; 13.6%, 9.7%, 8.4%, and 6.7% in radish leaf; 22.4%, 14.4%, 3.6%, and 5.8% in spinach leaf; and 61.2%, 39.5%, 25.5%, and 21.5% in Chingensai leaf, respectively. Nitrate accumulation in edible portions was highest in plants provided with IN as compared with those grown with composts, and nitrate content in radish root was markedly higher than that in the leaf. It is observed that the fate of compost derived N differed noticeably with vegetable species, plant part, and compost source.  相似文献   

10.
The physical parameters of four different Elephant grass “Miscanthus ogiformis” ‘Giganteus’ composts and four of the most used types of peat products in Denmark, along with a wood fiber growing medium (Culti), were compared to determine possible physical differences, and to test whether compost could be used as an alternative substrate to peat. The Miscanthus straw was composted with three different N sources: ammonium sulfate, liquid pig manure and urea plus tap water (as a control). Compared to peats, the composts tested had low total bulk density, high air-filled porosity and a high diffusion coefficient of oxygen. None of the 9 products tested had the optimum levels of all the different physical parameters. Mixing the tested compost and peat will possibly increase the air-filled porosity of the substrates compared to pure peat, and brings the substrates physical parameters closer to the ideal recommended range. These compost media require further investigation before they can be used directly as an alternative to peat in greenhouse production.  相似文献   

11.
Abstract

Municipal solid waste composts are often inadequately stabilized for agricultural purposes. In addition, compost quality may be even more reduced by loss of nitrogen (N) during the composting process. We have utilized a compost with a high content of soluble sugars (11 mg g‐1, DM, indicating immaturity) and a low ? concentration (0.95%, DM). The compost had a low level of heavy metals. Results obtained in a germination bioassay conducted with cress, ryegrass and sunflower in a compost‐sand mixture reflected the immaturity of the compost. Such composts should be fortified with ? (in a complete fertilizer, when possible), at the same time avoiding an intimate contact with the soil (e.g., plowing down). When the compost (and raw wastes and wastes at the 4th week of composting) was mixed with a soil at a heavy rate (2.5 % w:w), ryegrass seedling emergence in pots was not affected, but the plantlets’ fresh weight in the compost treatment was significantly lower than that in the control (soil) and lower than that in the raw wastes, probably due to the lower ? concentration. As expected, plantlet fresh weight was notably increased by the combination of compost and wastes with a complete fertilizer. The application of compost in combination with a complete fertilizer or urea did not affect either dry matter production or nutrient uptake of ryegrass, despite the combination's being applied just at sowing (in pots). Results obtained in these experiments indicate that combining immature composts with urea [supplemented with phosphorus (P) and potassium (K), when possible] at a ratio of about 50:1 (about 200 kg urea per 101 compost) could be sufficient to prevent negative results in crop establishment. Such practices could contribute to overcoming the limited fertilizing capacity of the composts.  相似文献   

12.
Abstract

Two composts were tested in eleven different Malus domestica orchards: one was a sewage sludge and bark compost with a low heavy metal content, the other was a municipal solid waste compost with a higher concentration of metals. For six years the zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), cadmium (Cd), and chromium (Cr) content were monitored in the soil, both in ‘total’ and EDTA extractable form, and in leaves and fruits. The resulting data demonstrate clearly that the sewage sludge and bark compost did not cause any significant increase of heavy metal levels in soil and plants; this compost can thus be used to fertilize the soil with no danger either to the environment or to crops. In contrast, the municipal solid waste compost led to a notable accumulation of all the metals examined in the soil and, above all in the case of Pb and Cd, also in the vegetation and the fruits.  相似文献   

13.
Long-term effects of compost application are expected, but rarely measured. A 7-yr growth trial was conducted to determine nitrogen availability following a one-time compost application. Six food waste composts were produced in a pilot-scale project using two composting methods (aerated static pile and aerated, turned windrow), and three bulking agents (yard trimmings, yard trimmings + mixed paper waste, and wood waste + sawdust). For the growth trial, composts were incorporated into the top 8 to 10 cm of a sandy loam soil at application rates of approximately 155 Mg ha?1 (about 7 yd3 1000 ft2). Tall fescue (Festuca arundinacea Schreb. ‘A.U. Triumph’) was seeded after compost incorporation, and was harvested 40 times over a 7-yr period. Grass yield and grass N uptake for the compost treatments was greater than that produced without compost at the same fertilizer N rate. The one-time compost application increased grass N uptake by a total of 294 to 527 kg ha?1 during the 7-yr. field experiment. The greatest grass yield response to compost application occurred during the second and third years after compost application, when annual grass N uptake was increased by 93 to 114 kg ha?1 yr?1. Grass yield response to the one-time compost application continued at about the same level for Years 4 through 7, increasing grass N uptake by 42 to 62 kg ha?1 yr?1. Soil mineralizable N tests done at 3 and 6 yr. after application also demonstrated higher N availability with compost. The increase in grass N uptake accounted for 15 to 20% of compost N applied after 7-yr. for food waste composts produced with any of the bulking agents. After 7-yr, increased soil organic matter (total soil C and N) in the compost-amended soil accounted for approximately 18% of compost-C and 33% of compost-N applied. This study confirmed the long-term value of compost amendment for supplying slow-release N for crop growth.  相似文献   

14.
Sixteen composts consisting of 14 commercial samples, one immature yard waste compost and one raw material of mostly grass clippings were evaluated for their stability. In a three-day incubation test, the commercial composts yielded from 9 to 99 mg CO2/kg/ hr, with a mean CO2 production rate of 61 mg CO2/kg/hr. By contrast, the immature compost produced 684 mg CO2/kg/hr and the raw material, 1,433. The low CO2 production rates of the commercial composts along with dark brown color and lack of unpleasant odors in moist conditions indicated that these composts were indeed stable. We devised a quick chemical test to predict compost stability. Several compost properties were measured: (i) total (C, N and C:N), (ii) water-soluble (C, N and C:N), (iii) NaOH-soluble C, humic and fulvic acids, and optical absorbances at 465 nm (E4) and 665 nm (E6) of the NaOH-soluble fractions. Water-soluble fraction, particularly water-soluble C and the C:N ratio, best separated stable from unfinished composts. However, water-soluble organic N in some stable composts was less than 0.01 g/kg, making measurement difficult. Thus, alternatively a ratio of water-soluble C:total organic N ≤0.70, based on Mean (0.32) + 2*SD (0.19), is suggested as a predictor of compost stability. Also, compost stability can be predicted by NaOH-soluble C:water-soluble C ≥6.0, but not by (humic acid:fulvic acid) or (E4:E6) of any NaOH-soluble fractions.  相似文献   

15.
Two composts produced at different times of the year from garden waste, sewage sludge and wood ash were evaluated for use as ornamental plant substrates. The maturity and lack of phytotoxicity of both composts, as well as the absence of E. coli, were first confirmed by use of laboratory procedures and rapid test kits. A greenhouse experiment was then carried out with two ornamental species, Petunia sp. and Tagetes sp., to evaluate the suitability of the composts as plant substrates. The performance of the composts as well as mixtures of each with 25, 50 and 75% acid peat moss was compared with that of a commercial universal substrate. Addition of the peat to the composts improved some of the physical and chemical properties. However, the results of the pot experiments indicated that under the experimental conditions used, the compost produced from green waste was suitable for use as a plant substrate, without the need for addition of other components; this appears to be an effective way of utilizing the type of urban waste considered in the study.  相似文献   

16.
Four containerized deciduous ornamental shrubs [deutzia (Deutzia gracilis L.), silverleaf dogwood (Cornus alba ‘Elegantissima’), red-osier dogwood (Cornus sericea L.), and ninebark (Physocarpus opulifolius L.)] were grown during each of two separate growing seasons using 12 different immature (nonaged) composts as media (year one, 12 weeks from start of windrowing; year two, 16-weeks) and also two control nursery mixes (100 percent ground pine bark; and 80:15:5 by volume of pine bark:sphagnum peat:top soil). The compost formulations (volume basis) consisted of spent mushroom substrate (50 percent), waxed corrugated cardboard, 0 percent, 25 percent, or 50 percent), and/or pulverized wood wastes (50 percent, 25 percent, and 0 percent). Supplemental N was added to some composts as poultry manure (18 kg·m?3), soybean wastes (24·kg·m?3), or both at the same application rates. Despite the immaturity of the compost media and the presence of high initial contents of soluble salts primarily from the spent mushroom substrate (EC ≤6.4 dS·m?1, 1:1 v/v medium:water extracts), the top dry weight (averaged over two seasons) of each of the four species grown in compost media, regardless of waxed corrugated cardboard (WCC) level, exceeded that obtained in 100 percent pine bark. Compared with the 0 percent WCC compost, plants of all four species grew better in 25 percent and/or 50 percent WCC compost media and growth in these treatments was more (silverleaf dogwood), similar (deutzia and red-osier dogwood), or less than (ninebark) that in the 80:15:5 nursery mix. Rapid leaching of the potentially toxic soluble salts from the containerized compost media within days after planting minimized any adverse effects on the plants. There was no difference in foliar concentrations of N, P, K, Ca, Mg, Fe, Mn, and Zn due to WCC level, or to the N supplements which had little or no effect on growth. The foliar contents of heavy metals (Cu, Ni, Cr, Cd, Co, and Pb) were low and/or below detection limits.  相似文献   

17.
Four locally composted green waste composts (GWCs) namely Almukhasib, Growers, Plantex, and Super were screened to determine whether they meet the standards. All composts showed normal physical properties, except for the bad smell from sulfur reducing bacteria in Almukhasib compost, and light brown color Plantex. The germination indexes of the composts comparable to the standard (90%) were 98% for Plantex followed by Growers (77%), and 5% for both Super and Almukhasib. The chemical and physical properties vary considerably as follows: pH 3-10.5 (standard 5-8), electrical conductivity (EC) 0.4-10.2 mScm?1 (standard 0.04.0 mScm?1), moisture content (MC) 29-43.7% (standard 35-60%) and water holding capacity (WHC) 92-200%. Wide ranges in the chemical properties were expressed as total nitrogen concentration 5705-16401 mgkg?1 (standard <500 mgkg?1), organic matter 17-67.6% (standard 35%). Although, there are significant variations in the concentration of the heavy metals among the tested composts, the concentrations of these metals (Zn, Ni, Pb, Hg, As, Cd, and Cr) were lower than the recommended levels. The average of the bacterial colony forming unit per gram dry weight ranged between 464-2292 cfu/g, whereas the fungal cfu were 14-4308 cfu/g (standard < 1000 cfu/g). The most probable number (MPN) for coliform bacteria was 64-1549 cfu/g dry weight. Aspergillus niger was the predominant fungus recovered from all compost samples (100%) followed by A. fumigatus (50%), A. sparsus (50%), yeasts (50%), A. flavus (37.5%), and the remaining A. restrictus, A. ochraceous, Cladosporium spp., and Penicillium spp. is 25% each. The results showed that the physicochemical properties and microbial contamination of the screened composts were considerably varied and did not meet many of the acceptable limits in Oman, which render them unsafe for handling or unsuitable as direct fertilizer for plant growth or for soil bioremediation, which suggests mixing the composts with vermiculite and soil in order to improve their general characteristics. Therefore, there is evident need for urgent development of proper composting techniques, standard laboratory testing methods for high quality control measures, and adopting strong legislation. The use of certified and high grade mature green waste compost is a priority.  相似文献   

18.
Little is known about the effects of compost application to reclaim artisanal mining sites for agriculture in Central Africa. A field experiment was therefore conducted to examine the effects of locally available organic household waste composted under traditional (pit under leaf shade) versus improved management (pit under double plastic sheeting) and mixed with either Tithonia diversifolia biomass or Minjingu Phosphate Rock (13–15% P) on climbing bean sown on degraded Technosols (former Tantalum mining sites) and un‐mined control soils (Cambisols). Both soil types were derived from pegmatite. After 6 months of composting, nutrient concentrations in traditional compost were 0.27–0.32% N, 0.06–0.08% P, and 0.20–0.22% K. Comparative values in amended compost were 1.02–1.65% N, 0.10–0.31% P, and 0.41–1.13% K. In farmyard+solid waste, composted under traditional system, dry matter was 65.4%, pH 6.7, and C : N ratio 13.0, as opposed to 81.5% DM, a pH of 8.6, and a C : N ratio of 8.6 in farmyard+solid waste+Minjingu phosphate under improved compost, and 68.3% dry matter, a pH of 8.4, and a C : N ratio of 7.4 for Tithonia +farmyard+solid waste under improved conditions. Compared to bean (Phaseolus vulgaris L.) grain yields of 0.28 (mined soil) and 0.11 (unmined soil) without amendments, the application (on a dry matter basis) of 5 t compost ha−1 led to yields of 3.54 t DM ha−1 for improved compost Tithonia +farmyard+solid waste on mined soil versus 2.26 t DM ha−1 (P < 5%) for the same treatment at the un‐mined sites. The yield obtained for farmyard+solid waste+Minjingu phosphate composted under improved conditions averaged 3.06 t DM ha−1 at mined sites compared with 2.85 t DM ha−1 at un‐mined sites (P > 5%). All amendments were more effective in enhancing bean yields on Technosols with significant positive effects with improved compost than on Cambisols.  相似文献   

19.
Managing municipal solid waste (MSW) compost for agricultural use requires an understanding of waste stream components and how they affect the value of the finished product. We evaluated the influence of disposable diaper content in MSW compost because of the recent concern of the environmental impact of this product. To determine the potential effect of disposable diapers on MSW compost, the ‘normal’ concentration of soiled, disposable diapers in a waste stream was raised from 2 percent to 8 percent. Previous observations indicated that the diapers disassociated during in-vessel digestion and most of the components could not be distinguished from the primary compost. The objective of this study was to examine the effect of additional diapers on the agricultural value of mature MSW compost. Loamy sand and silt loam soils were amended with MSW compost at a rate of 20 percent. Comparisons between the two composts and their interactions with soil type were made on the basis of water retention characteristics; germination and emergence of corn, soybean, radish and lettuce; and yield and element uptake by corn and lettuce at two moisture regimes. Differences between the compost amended soils suggested that the primary benefits of additional diapers were increased nutrient availability and soil water retention, and the foremost concerns were excess total soluble salts and boron.  相似文献   

20.
Prolonged curing of compost reduces risks of phytotoxicity but may also have an undesirable effect on suppressiveness against soil-borne diseases. In a previous study, this effect was demonstrated for a compost produced from a mixture of yard waste and biosolids, against Sclerotium rolfsii. The aim of the present study was to demonstrate that similar effects of prolonged curing may be exhibited by additional types of composts and pathosystems. Therefore, we investigated the effect of curing of three types of composts against S. rolfsii and Pythium aphanidermatum. These plant pathogens are subjected to different suppression mechanisms. The prolonged curing was characterized and validated by measurements of a range of chemical and spectroscopic parameters. All three composts were suppressive against both diseases before curing. At high inoculum levels, suppression against P. aphanidermatum was lost for the cured biosolids and straw and manure based compost. Loss of suppression was associated with a decrease in basal and substrate induced respiration. For S. rolfsii suppression was lost with curing for all three composts and was associated with a decrease in dissolved organic carbon and NH4+ concentration, a decrease in pH and an increase in NO3? concentration.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号