Soil nitrogen mineralization in a soil with long-term history of fresh and composted manure containing straw or wood-chip bedding

Long-term effects of fresh (FM) versus composted (CM) beef manure application to barley (Hordeum vulgare L.) on potentially mineralizable nitrogen (N ₀ ), and mineralizable nitrogen (N) pools, were evaluated in a clay loam soil in southern Alberta, Canada. A suite of laboratory-based indices were evaluated for prediction of soil N supply. The treatments were three rates (13, 39, 77 Mg ha^?1 dry wt.) of FM or CM containing either straw or wood-chip bedding, 100 kg N ha^?1 as inorganic fertilizer, and an unfertilized control. Treatments were fall-applied annually for 8 years (1998–2005). Soil samples (top 15 cm) were collected in spring 2006. The medium and high rates of organic amendment resulted in increases in N ₀ , and readily (Pool I) and intermediate (Pool II) mineralizable N pools in ranges of 140–355 % compared with the average of the fertilizer and control treatments. Fertilizer application had no significant effect on mineralizable N pools, but increased the mineralization rate constant (k) compared with the control. Application of FM and use of straw bedding resulted in a greater quantity of readily available and intermediate mineralizable N, and also increased the rate of N turn-over as indicated by greater values of k, compared with CM and wood-chip bedding. Among laboratory-based measures of soil N supply, CaCl₂–NO₃ (r² = 0.84) and NaHCO₃-205 (r ² = 0.79) were strong predictors of plant N uptake (PNU). Increased soil mineralizable N did not translate into greater barley dry-matter yield or PNU. Composted beef manure and use of wood-chip bedding can be recommended as alternatives to FM and use of straw bedding for barley production is Southern Alberta.     

Determination of the mineralization of nitrogen from composted chicken manure as affected by temperature

Incubations at 5, 10 or 20°C of composted chicken manure in a sand, clay or loam soil consistently released nitrogen. A statistical model fitted to the data confirmed that the temperature dependence followed an Arrhenius pattern. The data were used to test the hypothesis that composted manure behaves more like native soil organic matter than fresh residues and this idea is illustrated with the use of a computer simulation model. Extrapolation of the model results in several climates suggests that about 40% of the organic N in composted chicken manure becomes available to crops during the first year and 6–12% during each subsequent year.     

Drivers of soil net nitrogen mineralization in the temperate grasslands in Inner Mongolia,China

Soil net nitrogen mineralization (NNM) of four grasslands across the elevation and precipitation gradients was studied in situ in the upper 0–10 cm soil layer using the resin-core technique in Xilin River basin, Inner Mongolia, China during the growing season of 2006. The primary objectives were to examine variations of NNM among grassland types and the main influencing factors. These grasslands included Stipa baicalensis (SB), Aneulolepidum Chinense (AC), Stipa grandis (SG), and Stipa krylovii (SK) grassland. The results showed that the seasonal variation patterns of NNM were similar among the four grasslands, the rates of NNM and nitrification were highest from June to August, and lowest in September and October during the growing season. The rates of NNM and nitrification were affected significantly by the incubation time, and they were positively correlated with soil organic carbon content, total soil nitrogen (TN) content, soil temperature, and soil water content, but the rates of NNM and nitrification were negatively correlated with available N, and weakly correlated with soil pH and C:N ratio. The sequences of the daily mean rates of NNM and nitrification in the four grasslands during the growing season were AC > SG > SB > SK, and TN content maybe the main affecting factors which can be attributed to the land use type.     

Effect of organic manure and chemical fertilizer on nitrogen uptake and nitrate leaching in a Eum-orthic anthrosols profile

Distribution and accumulation of NO₃-N down to 4 m depth in the soil profile of a long term fertilization experiment with organic manure and N and P chemical fertilizer were studied after 12 years, wheat and corn were planted in each year. The apparent N recovery decreased with increased N and P fertilizer. NO₃-N was mainly accumulated in 0-1.2 m depth of the soil profile with a maximum of 34 mg N kg-¹ for the treatment with 120 kg N and 26 kg P per hectare, a secondary maximum of 7.2 mg N kg-¹ was found at 3.2 m depth in the same treatment. NO₃-N accumulation in the soil profile was minimized in the trials with highest manure application. Nitrogen that was not recovered was leached as NO₃-N deeper than 4 m depth, was immobilized in the profile or was lost by denitrification. This revised version was published online in August 2006 with corrections to the Cover Date.     

Application of liquid cattle manure and inorganic fertilizers affect dry matter,nitrogen accumulation,and partitioning in maize

Efficient use of N applied in the form of organic and inorganic fertilizers is important in maize (Zea mays L.) production to maximize producer’s economic returns and maintain soil and water quality. A field study was conducted for three consecutive years (2003–2005) in Thessaloniki, Greece to investigate whether liquid cattle manure can be used to replace inorganic fertilizers and also whether inorganic fertilizer can be applied preplant or as a combination of preplant and sidedress and can affect maize growth, development and N use efficiency. The treatments were control (unfertilized), liquid dairy cattle manure (Manure), application of 260 kg N ha⁻¹ year⁻¹ as basal dressing (N-single), application of 130 kg ha⁻¹ year⁻¹ N as basal dressing before sowing and 130 kg N ha⁻¹ when plants were at the eight-leaf stage (V8) (N-split). In 2 out of the 3 years of the study there was a significant positive effect of fertilizer application on maize growth, development, N uptake, and partitioning compared with the control. Dry matter production was increased by an average of 39% during the 2 years in plots fertilized either with manure or inorganic fertilizers than the control plots. Also from the yield components kernel weight per ear and number of kernels per ear were increased by an average of 35% and 32%, respectively in the fertilized plots compared with the control plots. Chlorophyll level was affected as it was increased by an average of 18%, 14%, and 18% at the ten-leaf stage (V10), silking and milk stage, respectively in the fertilization treatments compared with the control. Similar trend was observed in the other parameters that were studied. No differences were found between the manure and the different times of N application which indicates that manure can be used to replace inorganic fertilizer. Applying N either preplant in a single application or in split application (half of N preplant and half as sidedress) did not have any effect on any characteristics that were studied indicating that preplant application can be used as it is more cost effective. The present study indicates that liquid cattle manure can be used to replace inorganic fertilizers and also that there was no difference between preplant and sidedress application of N.     

Nitrogen balance and accumulation pattern in three contrasting prairie soils receiving repeated applications of liquid swine and solid cattle manure

The expansion of intensive livestock operations in western Canada has increased concerns about overloading of nutrients in manured lands. The magnitude of nutrient accumulation and its distribution in the soil profile varies with soil-climatic conditions. The objective of this study was to determine loading and distribution of manure-derived nitrogen (N) in the soil profile as influenced by repeated manure applications. Four field experiments were conducted at three sites (Dixon, Melfort and Plenty) in Saskatchewan under longer-term manure management. The four field experiments provide contrasts in soil type, climatic conditions, manure type, application and cropping history to enable the effect of these factors to be evaluated. Liquid hog manure (LHM—Experiment 1) and solid cattle manure (SCM—Experiment 2) treatments were applied annually over 8 years at Dixon (Black Chernozemic loam soil—Udic Boroll in sub-humid climate), while only LHM was applied at Plenty (Dark Brown Chernozemic heavy clay soil—Typic Boroll in semi-arid climate) over 6 years (Experiment 3), and at Melfort (Dark Gray Luvisol silty clay loam soil—Mollic Cryoboralf in humid climate) over 5 years (Experiment 4). Soil samples were collected in the spring and autumn of 2003 and 2004, and were analyzed for organic N, ammonium-N (NH₄⁺-N) and nitrate-N (NO₃⁻-N) concentrations. Plant samples were collected to determine the impact of manure application rate on plant N uptake and crop N removal. The annual application of LHM (37,000 L ha⁻¹ yr⁻¹) and SCM (7.6 Mg ha⁻¹ yr⁻¹) at agronomic rates at Dixon (added N balances crop demand for that year), or larger rates of LHM (111,000 L ha⁻¹) applied once every 3 years (Melfort) did not significantly elevate NO₃⁻-N in soil compared to the unfertilized control. Lower crop removal and reduced leaching of NO₃⁻-N due to drier conditions as occurred at the Plenty site contributed to greater accumulation of nitrate in the top 60 cm at equivalent rates compared to the other two sites. At large manure rates, excess N from the balance estimates could not be accounted for in soil organic N and was assumed to be lost from the soil-plant system. At the Dixon LHM site, deep leaching of NO₃⁻-N was observed at the excessive rate (148,000 L ha⁻¹ yr⁻¹) up to the 150 cm depth, compared to the control. At Dixon, the large annual application rate of SCM (30.4 Mg ha⁻¹ yr⁻¹) did not significantly increase NO₃⁻-N in the 0–60 cm soil compared to the control, which was attributed to lower mineralization of organic N from the SCM. Over the short and medium term, LHM application at large rates every year poses a greater risk for loading and deep migration of NO₃⁻-N in soil than large rates of SCM. Larger single applications made once every 3 years were not associated with accumulation or deep leaching. To prevent loading, rates of applied manure nitrogen should be reduced when crop N removal potential is diminished by high frequency of drought.     

Very high applications of nitrogen fertilizer on grassland and residual effects in the following season

At very high nitrogen applications (480 and more kg N ha^–1 yr^–1) in field trials on all-grass swards the amount of N applied exceeded the amount of N harvested. In the humid temperate climate of the Netherlands in the subsequent spring approximately 25, 40, and 50% of this excess nitrogen was recovered as accumulated mineral nitrogen in the 0–100 cm layer of sandy, clay and heavy clay soil, respectively. The effect of this excess nitrogen on growth during the subsequent season was measured through the increase in DM and N yield over a reference treatment. In this season all treatments received a uniform application (40 kg N ha^–1 cut^–1). Residual effects were absent on sandy soil but distinct on the clay soils. On the clay soils each accumulated kg soil mineral nitrogen produced 15 kg DM. Assuming a relatively small contribution of residual nitrogen carried over in stubble, roots and organic matter, the accumulated soil mineral nitrogen would seem to be as effective as applied fertilizer nitrogen.     

The effect of fertilizer placement on nitrogen uptake and yield of wheat and maize in Chinese loess soils

Field trials were carried out to study the fate of¹⁵N-labelled urea applied to summer maize and winter wheat in loess soils in Shaanxi Province, north-west China. In the maize experiment, nitrogen was applied at rates of 0 or 210 kg N ha^–1, either as a surface application, mixed uniformly with the top 0.15 m of soil, or placed in holes 0.1 m deep adjacent to each plant and then covered with soil. In the wheat experiment, nitrogen was applied at rates of 0, 75 or 150 kg N ha^–1, either to the surface, or incorporated by mixing with the top 0.15 m, or placed in a band at 0.15 m depth. Measurements were made of crop N uptake, residual fertilizer N and soil mineral N. The total above-ground dry matter yield of maize varied between 7.6 and 11.9 t ha^–1. The crop recovery of fertilizer N following point placement was 25% of that applied, which was higher than that from the surface application (18%) or incorporation by mixing (18%). The total grain yield of wheat varied between 4.3 and 4.7 t ha^–1. In the surface applications, the recovery of fertilizer-derived nitrogen (25%) was considerably lower than that from the mixing treatments and banded placements (33 and 36%). The fertilizer N application rate had a significant effect on grain and total dry matter yield, as well as on total N uptake and grain N contents. The main mechanism for loss of N appeared to be by ammonia volatilization, rather than leaching. High mineral N concentrations remained in the soil at harvest, following both crops, demonstrating a potential for significant reductions in N application rates without associated loss in yield.     

Degumming and refining practices in the U.S.

The “state of the art” of degumming and refining crude vegetable oils in the U.S. is discussed with reference to (a) production volumes and significant quality characteristics of oils processed; (b) processes and equipment for degumming, refining, and waterwashing the oils, illustrated by diagrams and flow charts; and (c) key process controls and analytical testing requirements for each unit operation.     

Effect of the integrated use of legume residue,poultry manure and inorganic fertilizers on maize yield,nutrient uptake and soil properties

Identification of a sustainable integrated soil fertility management option in the tropics will not only salvage the degraded soils but also enhances the attainment of the goal of food security. This study was conducted in 2004 and 2005 on a degraded tropical Alfisol in south western Nigeria to evaluate the effect of legume residue, poultry manure and inorganic fertilizers on maize yield, nutrient uptake and soil properties. The treatments consisted of two rates of poultry manure (0 and 5 t ha⁻¹), three rates of N fertilizer (0, 50 and 100 kg N ha⁻¹ applied as urea), three rates of P fertilizer (0, 30 and 60 kg P ha⁻¹ applied as single super phosphate) and two soybean treatments (with or without incorporation of legume residue) in various combinations as a factorial experiment in Randomized Complete Block design with three replicates. Results showed that poultry manure alone led to significant increase in maize yield (60%) and soil organic matter (45%). In contrast, legume residue incorporation gave significantly lower increase in yield (7%) and soil organic matter (11%). However, the combined application of poultry manure and legume incorporation led to 72% increase in maize yield as opposed to 63 and 10% increase recorded when manure alone or legume alone were incorporated, respectively. Optimal maize yield was achieved when manure application was integrated with P fertilizer application. The interaction of P fertilizer and legume incorporation indicated that soil phosphorus and maize P concentration were significantly increased with the application of the P fertilizer and legume incorporation. Hence, the application of P fertilizer alone is most likely to be economical compared with its integration with legume incorporation.     

Influence of cultivars and nitrogen rates on the residual effects of potassium applications to preceding cotton on maize

The long-term residual effects of K application rates and cultivars for preceding cotton (Gossypium hirsutum L.) on subsequent maize (Zea mays L.) and the influence of N rates applied to preceding cotton and to maize on the residual K effects were examined on maize under no-tillage in the United States. Two field experiments were conducted on a no-till Loring silt loam at Jackson, TN during 1995–2008 with N rates (90 and 179 kg ha^?1) × K rates (28, 56, and 84 kg ha^?1) and cotton cultivars (determinate and indeterminate) × K rates (56 and 112 kg ha^?1) as the treatments, respectively, in the preceding cotton seasons. Maize was planted under no-tillage on the preceding cotton experiments without any K application during 2009 through 2011. The residual effects of K rates applied to preceding cotton on soil K levels were significantly influenced by the N rates applied to preceding cotton and to maize when the data were combined from 2008 to 2011. Relative to the standard N management practices of 168 kg N ha^?1 for maize and 90 kg N ha^?1 for preceding cotton, the higher N application rate 269 kg N ha^?1 to maize and 179 kg N ha^?1 to preceding cotton reduced the residual effects of K rates on soil K. However, cultivar for preceding cotton did not affect the residual effects of K fertilizer on soil K fertility, leaf K nutrition, plant growth, or grain yield of subsequent maize on a high K field.     

Finished oil handling and storage in the U.S.

Various techniques are practiced in the U.S. to prevent deterioration of vegetable oils following the final stage of processing through deodorization. Because oxidation; free fatty acid development, or adulteration by impurities are the primary concerns, the general practice is to keep oils in closed vessels in an atmosphere that excludes oxygen and moisture and where temperatures are controlled at minimum levels. The technology of sparging and blanketing finished oils with nitrogen during storage and transfer from vessel to vessel is shown. Also, a typical blanketing system for a series of vessels, pressure controllers, and techniques to avoid vacuum conditions is described.     

2005年美国能源政策法案分析

2005年8月美国参、众两院通过了美国能源政策法案,该法案鼓励国内石油和天然气的生产,鼓励石油、天然气、煤气和电力企业等采取节能、洁能措施,该法案虽然在近期内不能减轻美国对进口原油的依赖,但会对美国未来一段时间的能源供需产生深远影响。对美国石油需求变化的因素进行了分析:主要由于汽油需求的增长、柴油需求的增长、高的税收和燃料价格的变化。     

美国汽油生产及进口来源分析

根据美国能源信息署公布的资料,从美国汽油生产和进口来源两方面入手,分析了目前及未来5年美国汽油的供应形势以及未来美国汽油供应的潜在危机。     

Authorizations and restrictions on soy protein in foods in the U.S.

The Food and Drug Administration makes the basic decisions on what materials will be permitted in U.S. foods. The U.S. Department of Agriculture then selects those items which it will allow in meats and poultry products. The Food and Drug Administration is in the process of developing definitions for soy products and issuing the regulatory controls over their uses. Care is being taken not to impose burdensome regulatory restrictions on a technology that is in a rapid state of development.     

前苏联黄磷及其加工产品生产评述

本文简述了前苏联黄磷及其衍生物生产的现状、特点。前苏联磷化工总体技术水平比美国低。并提出了我国发展黄磷工业应注意的问题。