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1.
Bulking agents and bedding materials used on farms for composting manures affect the time required for composts to mature. The effects of these materials on guidelines for the use of composted manures in potting mixes are not fully known. Several chemical and biological compost characteristics were mentioned and a cucumber plant growth greenhouse bioassay was performed on samples removed from windrows during composting of: (i) dairy manure amended with wheat straw; (ii) dairy manure amended with sawdust (mostly Quercus spp.); and (iii) pig manure amended with sawdust and shredded wood (mostly Quercus spp.). Dry weights of cucumber seedlings grown in fertilized and unfertilized potting mixes amended with composts (30%, v/v) having stability values of <1 mg CO2-C g-1 dw d−1, did not differ significantly from those in a control peat mix. Only the most mature dairy manure-wheat straw compost samples consistently established sufficient N concentrations in cucumber shoots in unfertilized treatments. For the dairy manure-wheat straw compost, all possible subset regression analyses of compost characteristics versus cucumber plant dry weight revealed that any of several compost characteristics (electrical conductivity-EC, compost age, total N, organic C, C-to-N ratio, ash content, CO2 respirometry, Solvita CO2 index and the Solvita® Compost Maturity Index) predicted growth of cucumber in the unfertilized treatments, and thus maturity. In contrast, at least two characteristics of the dairy manure-sawdust compost were required to predict growth of cucumber in the unfertilized treatments. Effective combinations were EC with compost age and the Solvita® maturity index with total N. Even five compost characteristics did not satisfactorily predict growth of cucumber in the non-fertilized pig manure-wood compost. Nutrient analysis of cucumber shoots indicated N availability was the principal factor limiting growth in potting mixes amended with the dairy manure-sawdust compost, and even more so in the pig manure-wood compost even though the compost had been stabilized to a high degree (<1 mg CO2-C g−1 dw d−1). Maturity of the composted manures, which implies a positive initial plant growth response of plants grown without fertilization, could not be predicted by compost characteristics alone unless the bulking agent or bedding type used for the production of the composts was also considered.  相似文献   

2.
Stability significantly affects the potential for beneficial utilization of composts but is difficult to measure by farmers and compost producers. A simple four hour test (the Solvita® maturity test) that measures CO2 evolution and ammonia emission from compost samples was compared to a traditional three-day, 25°C, CO2 evolution rate procedure and to measurements of ammoniacal nitrogen concentrations in manure composts to assess the reliability of this test. Three composts — 1) Dairy manure amended with wheat straw, 2) The same dairy manure but amended with sawdust and 3) Swine manure amended with sawdust and ground wood pallets — were composted in windrows for 120 days. Samples were removed weekly to biweekly. CO2 evolution rates of the three composts decreased from initial means (n=6) of 3.41, 3.42 and 9.35 to 0.63, 0.76 and 0.31 mg CO2-C g?1 VS day?1, for the dairy manure-straw, dairy manure-sawdust, hog manure composts, respectively. The corresponding mean Solvita CO2 test values for these composts increased from 3.4, 3.0 and 3.2 to 6.8, 6.5 and 7.0, respectively. Correlation analysis between CO2 evolution rates and Solvita CO2 test values gave linear correlation coefficients (r) of ?0.82, ?0.78, and ?0.87 for the straw-amended dairy manure, the sawdust-amended dairy and the hog manure composts, respectively. The Solvita NH3 test gave highly significant correlations (p<0.0001) with ammoniacal-N concentrations (correlation coefficients (r) = ?0.43, ?0.64 and ?0.65, respectively). The Solvita® maturity index, a combination of Solvita CO2 and NH3 values, correlated significantly with both CO2 evolution rate and ammoniacal-N concentrations. However, the Solvita CO2 index alone was the best predictor of compost CO2 evolution rate or stability. The Solvita Maturity test, which combines the Solvita CO2 and NH3 tests, provided useful information about the potential for the development of a toxic response in plants due to excessive concentrations of ammoniacal-N present in some stable compost samples that would not have been detected if the CO2 stability test were used by itself. We conclude that the Solvita maturity test provided a simple, inexpensive relative test of compost stability and NH3 emission for diverse samples of composted manures. Even so, it did not accurately predict their CO2 evolution rates measured by respirometry nor their ammoniacal-N concentrations. The test would be most useful for on-farm applications.  相似文献   

3.
The capability to determine nitrogen availability of composts is necessary to ensure that such materials will provide sufficient fertilization to the growing crop and cause minimal environmental degradation. A greenhouse study using tall fescue as a bioindicator was used to evaluate nitrogen availability of two biosolids composts, two mixed yard waste-poultry manure composts, and one commercially-processed poultry litter. Five inorganic nitrogen (as NH4NO3-N) treatments applied at 0, 22.5, 45, 67.7, and 90 mg N/kg soil were employed to establish an N calibration curve. Yield, fescue biomass total nitrogen (as total Kjeldahl N (TKN)), and soil TKN and KCl extractable NO3?-N and NH4+-N concentrations of the organically amended treatments were compared to the inorganically fertilized treatments to determine amendment N mineralization rates and N fertilizer equivalent values (NFEV). Nitrogen mineralization rates were greatest in the poultry litter (21%) and Panorama yard waste compost (5%) amended pots. The NFEV of these amendments were 49% and 10%, respectively. Wolf Creek biosolids compost and Huck's Hen Blend yard waste compost immobilized N (?5% and 0.18%, respectively), and had percent NFEV of ?0.66% and 0.19%, respectively. Rivanna biosolids compost immobilized N (?15%), but the NFEV was 30% due to the relatively high inorganic N content in the amendment. Nitrogen mineralization and NFEV were generally greater in amendments with greater total N concentrations and lower C:N values. The total N concentration and C:N values were less reliable variables in predicting N mineralization and percent NFEV when a significant portion of the total N was in the inorganic form. Nitrogen equivalency value and N mineralization for each amendment increased with time of sampling, indicating the potential for early season N insufficiency to plants fertilized with compost due to lack of synchrony between N mineralization and plant N needs.  相似文献   

4.
Composting inside high-rise, caged layer facilities can produce atmospheric ammonia (NH3) concentrations exceeding standards for human and poultry health. Control measures that reduce NH3 volatilization are necessary for in-house composting to be sustainable. Due to differences specific to in-house composting — low carbon to nitrogen ratios of composting material, continuous manure addition, and frequent turning — it is not known whether NH3 control measures used previously for poultry manure will work. The objectives of this study were to evaluate various amendment and process controls on NH3 produced during simulated in-house composting in the lab, and to evaluate select chemical control measures during composting inside a high-rise layer facility. Ten amendments (aluminum sulfate; chloride salts of aluminum, calcium, magnesium, and potassium; gypsum; sodium bisulfate; zeolite (clinoptilolite); straw; and cellulose) and four process controls (moisture; temperature; turning frequency; and particle size) were evaluated in lab incubations in 1 L vessels wherein samples of poultry manure compost were incubated to simulate composting. Vials of boric acid solution were used to capture NH3 evolved during incubations. With the exception of zeolite and cellulose, all amendments reduced NH3 capture. Low moisture and temperature also reduced NH3 capture, although managing temperature and moisture to achieve low NHg would adversely impact microbial activity and other desired benefits of composting. When evaluated inhouse, aluminum sulfate, calcium chloride and magnesium chloride did not reduce NH evolution from compost measured on three different dates with a gas sensor. Spatial variability along treated segments of windrow apparently masked amendment effects. At the end of a six-week composting cycle, total nitrogen content was higher in compost treated with aluminum sulfate than control or chloride salt treatments. Aluminum sulfate and process controls such as moisture content, carbon source and particle size have potential to reduce NH3 loss from poultry manure composted inside high-rise layer structures. In-house compost management to reduce NH3 volatilization must consider the cost of amendments, effectiveness, and impacts on the composting process.  相似文献   

5.
Assessment of compost maturity is important for successful use of composts in agricultural and horticultural production. We assessed the “maturity” of four different sawdust-based composts. We composted sawdust with either cannery waste (CW), duck manure (DM), dairy (heifer) manure (HM) or potato culls (PC) for approximately one year. Windrows were turned weekly for the first 60 days of composting, covered for four winter months and then turned monthly for six more months. We measured compost microbial respiration (CO2 loss), total C and N, C:N ratio, water soluble NO3-N and NH4-N, dissolved organic carbon (DOC), pH and electrical conductivity at selected dates over 370 days. Compost effects on ryegrass biomass and N uptake were evaluated in a greenhouse study. We related compost variables to ryegrass growth and N uptake using regression analysis. All composts maintained high respiration rates during the first 60 days of composting. Ammonium-N concentrations declined within the first 60 days of composting, while NO3-N concentrations did not increase until 200+ days. After 250+ days, DM and PC composts produced significantly more ryegrass biomass than either CW or HM composts. Total C, microbial respiration and water-extractable NO3-N were good predictors of compost stability/maturity, or compost resistance to change, while dissolved organic carbon, C:N ratio and EC were not. The compost NO3-N/CO2-C ratio was calculated as a parameter reflecting the increase in net N mineralization and the decrease in respiration rate. At ratio values >8 mg NO3-N/mg CO2-C/day, ryegrass growth and N uptake were at their maximum for three of the four composts, suggesting the ratio has potential as a useful index of compost maturity.  相似文献   

6.
针对奶牛养殖场粪便含水率高,堆肥处理成本高的特点,采用以干燥玉米秸秆为调理剂,在较高初始含水率条件下（70%～80%）,进行了强制通风堆肥槽和翻转式堆肥仓的对比试验,并且探讨了晾晒脱水作为预处理对堆肥效果的影响。结果表明,各处理堆体升温迅速,且均在50℃以上维持8～12d,满足堆肥无害化的卫生标准（GB7959—1987）要求。至堆肥结束时,各处理含水率均降至40%以下,C/N均降至20以下,WSOC均低于16g·kg-1,NH4＋-N含量均低于0.4g·kg-1;除采用堆肥槽在初始含水率为65%下堆肥NH4＋-N/NO3--N〉3尚未腐熟完全外,其他处理NH4＋-N/NO3--N均小于0.5,腐熟情况较好;所有处理的GI均大于50%,其中采用堆肥槽在较高初始含水率堆肥和晾晒预处理后堆肥GI已达80%,基本消除了植物毒性。采用较为开放的堆肥槽时,以玉米秸秆作调理剂,在较高的初始含水率条件下堆肥效果更好;以晾晒脱水作为预处理后堆肥,可减少所需调理剂的用量,节约了堆肥的成本。  相似文献   

7.
Seafood processing generates a substantial volume of wastes. This study examined the feasibility of converting the fish waste into useful fertilizer by composting. Groundfish waste and chitin sludge generated from the production of chitin were composted with red alder or a mixture of western hemlock and Douglas-fir sawdust to produce four composts: alder with groundfish waste (AGF); hemlock/fir with groundfish waste (HGF); alder with chitin sludge (ACS); and hemlock/fir with chitin sludge (HCS). The resulting AGF had a higher total N and a lower C:N ratio than the other three composts. A large portion of the total N in the AGF, HGF, and HCS composts was in inorganic forms (NH4+-N and NO3?-N), as opposed to only two percent in the ACS compost. Alder sawdust is more quickly decomposed, which favored N retention and limited nitrification during the composting period. It was less favorable than the hemlock/Douglas fir sawdust for composting with chitin sludge. Corn growth on soil amended with compost was dependent upon both compost type and rate. Nitrogen and P availabilities in all composts except the ACS were high and compost addition enhanced corn yields, tissue N and P concentrations, and N and P up-take. Neither the total N concentration nor the C:N ratio of the composts was an effective measure of compost N availability in the soil. Because soil inorganic N test levels correlated well with the corn biomass, tissue N and N uptake, they should be an effective measure of the overall compost effects on soil N availability and corn growth response. Phosphorus concentration, which increased linearly with increasing compost rates, was related to soil P availability from compost additions and correlated well with corn biomass, tissue P concentration and P uptake under uniform treatments of N and K fertilizers. Composting groundfish waste with alder or hemlock/Douglas-fir sawdust can produce composts with sufficient amounts of available N and P to promote plant growth and is considered to be a viable approach for recycling and utilizing groundfish waste.  相似文献   

8.
Manures lose N through volatilization almost immediately after deposit. Attempts to control losses include the addition of a C source to stimulate nitrogen immobilization. Composting is a treatment process that recommends the addition of carbonaceous materials to achieve a C:N ratio of 30:1 to stimulate degradation and immobilize nitrogen. Dairies near cities may be able to reduce N loss from manures by composting with urban carbonaceous residues such as municipal solid waste (MSW) or MSW compost that, by themselves, have little agronomic value. Studies were conducted using a self-heating laboratory composter where dairy solids were mixed with MSW compost to determine the reduction of N loss during composting. One-to-one mixtures (v/v) of dairy manure solids and MSW compost were composted and NH3 volatilization, CO2 evolution and temperatures were compared to composting of manure alone. Addition of MSW compost resulted in increased CO2 evolution and reduced N loss. Nitrogen loss from composting dairy manure alone was four to ten times greater than that from composting dairy manure mixed with MSW compost. Adjustment of the C:N ratio to 25 by adding MSW compost to manure appeared to be the major factor in reducing N losses.  相似文献   

9.
A field experiment was carried out in northern Vietnam to investigate the effects of adding different additives [rice (Oriza sativa L.) straw only, or rice straw with added lime, superphosphate (SSP), urea or a mixture of selected microorganism species] on nitrogen (N) losses and nutrient concentrations in manure composts. The composts and fresh manure were applied to a three-crop per year sequence (maize–rice–rice) on a degraded soil (Plinthic Acrisol/Plinthaquult) to investigate the effects of manure type on crop yield, N uptake and fertilizer value. Total N losses during composting with SSP were 20% of initial total N, while with other additives they were 30–35%. With SSP as a compost additive, 65–85% of the initial ammonium-N (NH4-N) in the manure remained in the compost compared with 25% for microorganisms and 30% for lime. Nitrogen uptake efficiency (NUE) of fresh manure was lower than that of composted manure when applied to maize (Zea mays L.), but higher when applied to rice (Oriza sativa L.). The NUE of compost with SSP was generally higher than that of compost with straw only and lime. The mineral fertilizer equivalent (MFE) of manure types for maize decreased in the order: manure composted with SSP?>?manure composted with straw only and fresh manure?>?manure composted with lime. For rice, the corresponding order was: fresh manure?>?manure composted with SSP/microorganisms/urea?>?manure composted with lime/with straw alone. The MFE was higher when 5 tons manure ha?1 were applied than when 10 tons manure ha?1 were applied throughout the crop sequence. The residual effect of composted manures (determined in a fourth crop, with no manure applied) was generally 50% higher than that of fresh manure after one year of manure and compost application. Thus, addition of SSP during composting improved the field fertilizer value of composted pig manure the most.  相似文献   

10.
Given high mineralization rates of soil organic matter addition of organic fertilizers such as compost and manure is a particularly important component of soil fertility management under irrigated subtropical conditions as in Oman. However, such applications are often accompanied by high leaching and volatilization losses of N. Two experiments were therefore conducted to quantify the effects of additions of activated charcoal and tannin either to compost in the field or directly to the soil. In the compost experiment, activated charcoal and tannins were added to compost made from goat manure and plant material at a rate of either 0.5 t activated charcoal ha?1, 0.8 t tannin extract ha?1, or 0.6 t activated charcoal and tannin ha?1 in a mixed application. Subsequently, emissions of CO2, N2O, and NH3 volatilization were determined for 69 d of composting. The results were verified in a 20‐d soil incubation experiment in which C and N emissions from a soil amended with goat manure (equivalent to 135 kg N ha?1) and additional amendments of either 3 t activated charcoal ha?1, or 2 t tannin extract ha?1, or the sum of both additives were determined. While activated charcoal failed to affect the measured parameters, both experiments showed that peaks of gaseous CO2 and N emission were reduced and/or occurred at different times when tannin was applied to compost and soil. Application of tannins to compost reduced cumulative gaseous C emissions by 40% and of N by 36% compared with the non‐amended compost. Tannins applied directly to the soil reduced emission of N2O by 17% and volatilization of NH3 by 51% compared to the control. However, emissions of all gases increased in compost amended with activated charcoal, and the organic C concentration of the activated charcoal amended soil increased significantly compared to the control. Based on these results, tannins appear to be a promising amendment to reduce gaseous emissions from composts, particularly under subtropical conditions.  相似文献   

11.
Pot experiments that lasted for 3 y were conducted to investigate the dynamics of nitrogen derived from plant residues (rice root, hull, straw, corn root, and rapeseed pod-wall), and composts (rice straw compost, cattle manure compost, and cattle manure sawdust compost), which were labeled with 15N. The rates of nitrogen uptake by rice (=N efficiency), denitrification, and immobilization derived from the organic materials incorporated before the first year of cultivation were investigated throughout 3 y of cultivation. At the end of the first year of cultivation, relatively high rates of N efficiency were obtained for rapeseed pod-wall (24.6%), rice straw (19.1%), and rice hull (18.6%), while corn root and cattle manure sawdust compost displayed a noticeably high denitrification rate. Corn root, cattle manure sawdust compost, rice hull, and rapeseed pod-wall exhibited remarkably high N mineralization rates ranging from 60 to 75% of the organic materials N applied. Cumulative rates of N efficiencies from the organic materials applied before the first year of cultivation fitted well to a first-order kinetic model and their asymptotes were compared among the organic materials. The asymptotic rates of N efficiency tended to depend on the rates at the end of the first year of cultivation.  相似文献   

12.
Effects of composting manure on viability of Giardia cysts (GC) and Cryptosporidium cysts (CO) were determined in a two-year study with manure from feedlot cattle bedded on barley straw or woodchips. Each year, manure was deposited in 8 m × 2.5 m × 2 m windrows (one per bedding type) on a sheltered concrete pad. On day 0, porous bags containing 100 g of feces from confirmed Giardia- and Cryptosporidium-positive cattle (9 bags per retrieval day in Year 1; 3 per day in Year 2) were implanted in the windrows. Replicate bags were placed on the concrete pads as uncomposted controls. Windrow temperature and water content were measured and compost was turned mechanically twice each week. Fecal bags were retrieved and subsampled for enumerations of total and viable cysts and cysts after 1, 2, 3, 7, 10, 17, 24 and 31 days in 1998 and after 1, 2, 3, 7, 9, 16, 23, 30, 42, 56, 70 and 98 days in 1999. Windrow temperatures (TEMP) exceeded 55°C during the fourth week of composting, and remained above 50°C for 4 wk thereafter in 1999. Bedding material did not affect overall mean temperature in either year, but TEMP was higher with straw than with woodchip from day 10 to day 17 in 1998 (P < 0.05) and on day 16 and day 42 in 1999 (P < 0.10). In 1998, moisture content decreased from 62.2 to 43.2% during composting of woodchip manure and from 67.3 to 39.3% during composting of straw manure. In 1999, moisture content decreased from 61.0 to 31.8% for woodchip and from 64.5 to 28.6% for straw compost. Percentage of viable CO declined gradually over the 31 days in 1998. The following year revealed a rapid decline in viability of GC and CO once compost temperature exceeded 55°C and viabilities of GC and CO were reduced to zero after 42 days (straw compost) and after 56 days (woodchip compost). Exposure of CO and GC to temperatures > 55°C for a period of 15 days appears to be an effective method of inactivating Giardia cysts and Cryptosporidium cysts in feedlot manure.  相似文献   

13.
The effects of using intermittent aeration during composting on ammonia emissions and dry matter loss were determined during composting of hog manure amended with sawdust. Composting trials lasted three weeks and used pilot-scale 200 liter vessels (four). The experimental design used replication of two treatments, continuous aeration (CA) and intermittent aeration (IA), in two series of experiments (total of eight tests). In the CA sequence, compost temperatures were controlled at 60°C using feedback control on high and low air flow fans while the IA sequence consisted of five minutes of air flow followed by 55 minutes of rest. Mixing ratios of hog manure to sawdust were 1:1.1 and 1:1.7 dry weight basis with resulting C:N ratios of 18.2 ± 1.2 and 23.7 ± 2.2 for the two series of tests. Airflow reduction was 63 percent for IA compared to CA. Percent nitrogen loss between treatments were moderately statistically different (α = 0.14) with average percent nitrogen loss at 29.7 percent for CA and 23.0 percent for IA. Nitrogen loss as ammonia-N was higher for CA than IA (25.9 versus 14.3) but was not statistically different. No significant differences existed in dry solids loss between treatments and the physical and chemical properties of the compost produced from IA were similar to that from CA for each series. Results showed that IA compared to CA may be a practical way to reduce nitrogen loss and ammonia emissions during composting of swine manure with sawdust.  相似文献   

14.
In sub-Saharan Africa, manure and loam soil are popular growing media substrates. However, their poor physiochemical properties limit their use in growing media. Following a survey of farmers, single species sawdust, mixed species sawdust, and rice husk (RH) were selected and composted with poultry manure. Additionally, the RH was charred for use in soilless media. Objectives were to produce feedstock-specific composts and determine appropriate proportion for using them in containerized systems. Three composts produced were amended with soil in ratios of 1:1, 1:2, and 1:3 (v/v) in an initial experiment. In a second experiment (soilless), the single sawdust and RH compost were each amended with RH biochar in ratios of 1:0, 1:1, 1:2 (v/v) and subjected to half or full pot irrigation. RH compost amended soils gave the highest lettuce yield. In the soilless media, 2:1 ratio (v/v) of biochar to sawdust compost gave the highest yield.  相似文献   

15.
Three windrows were constructed from a mixture of horse manure and soiled bedding collected from four equestrian centres in the Fraser Valley, British Columbia, where stables were bedded with hemlock, spruce, and fir wood shavings. Composting was accomplished by turning the windrows twice a week during the first four weeks and once a week for eight additional weeks. At the end of 12- week composting period, windrows were combined and allowed to cure for three months. The cured compost was tested for the ability to promote cucumber (cv Enigma) seedling growth, supply micronutrients, and suppress mycelial growth of plant pathogen Fusarium oxysporum f.sp. radicis cucumerinum (FORC). The heights and dry weights of cucumber seedlings grown in 20% compost in sawdust were significantly greater than those grown in sawdust alone. When fed with nutrient solutions lacking micronutrients, seedling grown in 20% compost gave significantly greater height, dry weight, and chlorophyll concentrations compared to seedlings grown in sawdust alone. The analysis of extractable micronutrients indicated that manganese, followed by zinc and boron, were the predominant micronutrients in horse manure compost. Both iron and molybdenum concentrations were present in less than one ppm and copper was present just above one ppm. There was a significant correlation (r2 = 0.83) between in vivo chlorophyll measurements by SPAD-502 chlorophyll meter and the in vitro chlorophyll measurement by spectrophotometer. Thus in vivo measurements of SPAD-502 chlorophyll meter can be used to assess nutrient availability from compost to cucumber seedlings. Horse manure compost also contained bacteria that suppressed mycelial growth of FORC.  相似文献   

16.
This work is aimed at characterizing compost maturity and, organic matter transformation during this process, by the use of nondestructive spectroscopic and thermal techniques, together with some chemical analysis. Composting was conducted in a laboratory over a period of one year using the organic fraction of domestic wastes, fresh farmyard manure, spent coffee and sawdust as the raw materials. Samples were retired after different periods of composting and were analyzed by differential scanning calorimetry (DSC) and fourier transform infrared (FTIR) spectroscopy as well as by routine chemical parameters including temperature, pH, C/N, ash content and humic-like substances content. Results showed that in case of domestic wastes, spent coffee and farmyard manure, the C/N ratios, ash and humic acid content showed a typical high rate of change during the first 197 days of composting and tended to stabilize thereafter, probably as a result of the maturity of the produced composts. In contrast, sawdust underwent only a very limited transformation even after one year of composting. Thermoanalytical and spectroscopic data confirms these finding and gives useful and complementary information with respect to the structure, the heterogeneity and the relative stability of the compost products. In particular, as the decomposition proceeded, there was an increase in aromatic to aliphatic structure ratio and a decrease in the importance of peptide structures of composts. Besides, both the spectroscopic and the thermal behavior of compost samples, retired beyond 197 days of composting, tended to be regular, less dependent on the raw material and close to that characterizing mature composts, with the exception of sawdust samples. We concluded that the spectroscopic and thermal techniques used are complementary to one another and to chemical tests and could be a powerful and fast approach for the study of compost maturity.  相似文献   

17.
用鸡粪与小麦秸秆为堆肥原料进行高温好氧堆肥试验,研究添加鸡粪对小麦秸秆高温好氧堆肥过程中堆体温度、pH值、碳氮比和养分等理化指标的影响,寻求鸡粪与小麦秸秆高温堆肥的最佳配比,为农作物秸秆快速资源化利用提供科学依据和技术指导。结果表明,鸡粪与小麦秸秆在C/N=25时堆体达到的温度最高,为62℃,达到最高温度所需的时间最短,为2 d。堆肥过程中各处理pH值变化基本一致,都是先上升后下降的过程。堆肥结束时A2处理C/N=14.4,NH4＋-N含量比最高时降低了76.2%,腐殖质比初始增加了50.2%,胡敏酸相对于最低点升高了160%,富里酸与堆肥前相比降低57.1%。堆肥结束时,全氮含量除A1处理有所降低外,其余处理均有所增加。各处理堆肥全磷、全钾、速效磷和速效钾含量在堆肥结束时比堆肥初始均有所增加。综合判断,鸡粪与小麦秸秆C/N=25进行堆肥较为适宜。  相似文献   

18.
Compost has been suggested as a nonchemical alternative to methyl bromide (MeBr) for control of root diseases. Its widespread availability and soil improvement properties are appealing to growers, but they need information on its use and effectiveness relative to the control of economically important root diseases in specific crops. Here, we report results from controlled-environment pot studies on the effects of manure composts on two major soilborne diseases of strawberry: red stele (RS) caused by Phythophthora fragariae, and black root rot (BRR), caused by a complex of fungi. Commercially available, on-farm-produced composts, based on either poultry/steer or dairy manure, were incorporated into two different, naturally infested soils at 5, 10, and 20% rates (v/v). Results show that significant control (36-79%) of RS in susceptible cultivar ‘Chandler’ occurred at all rates and with both types of compost in comparison with the unamended soil. Low rates (5%) of poultry/steer manure compost produced more disease control than equivalent or greater rates (10% and 20%) of dairy manure compost. However, the 20% rate had significantly greater soluble salts content than all other rates. At this 20% rate, root/shoot biomass accumulation and shoot health ratings were relatively low and equivalent to those from unamended soil, despite the improved content of soil organic matter, cation exchange capacity, and soil micronutrient content. The 5% amendment rate of poultry/steer manure compost provided more control than the 10% or 20% rates and more than the 5-20% rates of dairy manure compost. Soluble salts content in amended soils was significantly greater than in unamended soils, especially at 20% rates of poultry/steer compost. Leaf N from all treatments was deficient despite additional weekly supplemental fertilization. This deficiency coupled with increased soluble salt content at 20% poultry/steer compost amendments likely contributed to reduced root/shoot biomass accumulation and overall reduced plant vigor, thus increasing plant susceptibility to disease. In contrast to RS, BRR in all compost treatments was moderate in intensity and equivalent to the unamended soil, with slight but insignificant control at 5 and 10% rates of poultry/steer compost. Overall effects of the two manure compost amendments on BRR were inconclusive because no treatments, including the soil only, exhibited roots with extensive disease symptoms, despite cultural evidence of BRR pathogen colonization, especially by Rhizoctonia fragariae, during the course of this pot study. Effects of compost on appearance of BRR in strawberry should be pursued over a significantly longer time period than used here, possibly in field plots located on naturally infested soils subject to environmental stressors and seasonally realistic fertilization rates, because major BRR symptoms do not appear in the short-term even when fungal pathogens are present in the root.  相似文献   

19.
Abstract

The effect of organic amendment with sewage sludge composts of varying heavy metal content on the organic matter content and enzymatic activity of an agricultural soil supporting barley (Hordeum vulgare L.) or lettuce (Lactuca sativa L.) crops was studied. The organic amendments did not improved lettuce growth, the contaminated composts having a negative effect on yield. However, all organic amendments improved barley straw yields although they did not affect grain yields. The addition of the organic materials increased the total carbohydrate content of the soil although this content decreased with cultivation. There was a clearly observed effect of crop type and the degree of heavy metal contamination of the amendment on the most labile carbon (C) fractions (water‐soluble C, carbohydrates, and polyphenolics). In general, soil enzymatic activities were stimulated by addition of sewage sludge compost with low heavy metal content. The compost containing high level of cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn) inhibited protease‐BAA activity with respect to the other composts. After cultivation, urease activity increased in soil amended with the high dose of composts, regardless their degree of metallic contamination. Both crop type and metallic contamination contained in the organic materials added influenced phosphatase and ß‐glucosidase activity.  相似文献   

20.
The application of animal manure as a source of plant nutrients requires the determination of the amount and pattern of nutrient mineralization from manure.A laboratory incubation study was conducted to investigate the influence of lignite amendment and lignite type on carbon(C) and nitrogen(N)mineralization in raw(feedstock) and composted cattle manure following application to soil at 30 and 60 t ha-1.The mineralization of C and N was determined by measuring changes in CO2 evolution ...  相似文献   

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