Effects of nitrogen source,rate and application time on boronia (Boronia megastigma Nees) leaf nitrogen and flower production

Nitrogen was supplied from two fast release sources, ammonium sulfate ((NH₄)₂SO₄) and calcium nitrate (Ca(NO₃)₂) and a slow release source, isobutylidene diurea (IBDU) to boronia, a new flower crop native to Australia. At lower rates (25 kg per ha), N availability from different sources, as indicated by the leaf N concentration, did not differ within a month after application but three months after application, N availability was higher from IBDU than from (NH₄)₂SO₄ or Ca(NO₃)₂. At 50 or 100 kg per ha, N availability was higher throughout the year from (NH₄)₂SO₄ or Ca(NO₃)₂ than from IBDU, thereby allowing luxury consumption and causing toxicity. The flower yield increased with increasing N rates. Complete doses of all N rates which were applied early during the vegetative growth gave the highest yields and the same N rates applied in split doses at different phases of plant growth decreased the yields. In addition, high N availability during flowering (caused by a split dose) further decreased the yield. At all application times, IBDU gave the highest yield and the differences in yields with (NH₄)₂SO₄ and Ca(NO₃)₂ were not significant. The leaf N concentration associated with maximum yield declined as the plant advanced towards flowering.     

控释尿素与化肥配施对水稻产量及氮素利用率的影响

通过两地试验研究控释尿素与化肥配施对水稻产量及氮素利用率的影响。结果表明,控释尿素与普通尿素配施处理的产量和氮肥利用率均以控释尿素80%+普通尿素20%处理最好,两点的产量分别为9 989.8、9 995.6 kg/hm~2,较同等氮素用量的普通尿素100%处理分别增产16.2%和16.1%;控释尿素配施普通尿素处理均能提高氮肥利用率,比控释尿素处理提高6.7~1.8个百分点,比普通尿素处理提高12.3~4.1个百分点。     

Effect of instrument response time on heat release rate measurements

A linear hereditary integral technique provides simple analytic solutions for deconvoluting thermopile and oxygen consumption data to remove the effect of instrument response time on peak and integrated heat release rate values. A comparison of corrected and uncorrected thermopile and oxygen sensor data obtained on an Ohio State University (OSU) apparatus for various materials indicates that significant errors in peak and integrated heat release rate can result from delayed instrument response to repidly changing heat flows. However, correcting for temporal effects alone using this procedure does not account for differences between heat release rate values obtained by thermopile and oxygen consumption methods.     

Relationships between ammonia volatilization and nitrogen fertilizer application rate,intake and excretion of herbage nitrogen by cattle on grazed swards

Grazed pastures emit ammonia (NH₃) into the atmosphere; the size of the NH₃ loss appears to be related to nitrogen (N) application rate.The micrometeorological mass balance method was used to measure NH₃ volatilization from rotationally grazed swards on three plots in the autumn of 1989 and throughout the 1990 growing season. The aim of the research was to derive a mathematical relationship between NH₃ volatilization and N application rate, which would vary between soil type and weather conditions. In both years the plots received a total of 250, 400 or 550 kg N ha^–1 as calcium ammonium nitrate (CAN) split over 6 to 8 dressings. The number of grazing cycles ranged from 7 to 9 for the three N plots.In the last two grazing cycles of 1989, NH₃ losses were 3.8, 12.0 and 14.7 kg N ha^–1 for the 250N, 400N and 550N plots, which was equivalent to 5.3%, 13.9% and 14.4% of the amount of N excreted on the sward, respectively. In 1990, NH₃ losses were 9.1, 27.0 and 32.8 kg N ha^–1 for the 250N, 400N and 550N plots, which was equivalent to 3.3%, 6.9% and 6.9% of the N excreted, respectively. Differences in urine composition between the plots were relatively small. Rainfall and sward management affected the size of the NH₃ volatilization rate. Volatilization of NH₃ was related to N excretion and N application rate.A calculation procedure is given to enable the estimation of NH₃ volatilization from N application rate. Adjustments can be made for grazing efficiency, grazing selectivity, N retention in milk and liveweight gain, concentrate N intake and milking duration. Losses of NH₃ increase progressively with an increase in N application rate until herbage yield reaches a maximum at an application rate of about 500 kg N ha^–1 yr^–1.     

The effect of urea pellet size and rate of application on ammonia volatilization and soil nitrogen dynamics

In a field experiment on deep, yellow, sandy soil near Badgingarra, Western Australia, the residual value of superphosphate applied one and two years previously was measured relative to freshly-applied superphosphate using yields of narrow-leafed lupin (Lupinus angustifolius), barley and wheat. In addition, soil samples were collected for measurement of bicarbonate-extractable soil P. This was also used to estimate the residual value of the superphosphate.For lupins and wheat, and for bicarbonate-extractable soil P, the residual value decreased with increasing level of application. For barley grain, the residual value was not significantly affected by the level of application.The decrease in residual value of superphosphate with increasing level of application is attributed to increased leaching of applied phosphorus (P) down the profile of the sandy soils as the level of application increases. This may reduce subsequent plant yields due to the delay in seedling roots reaching the P in the soil during the crucial early stages of plant growth.For lupins, the relationship between yield and the level of superphosphate applied was markedly sigmoidal. The relationship for wheat and barley was exponential. Consequently, at suboptimal levels of P application, lupins required about two to three times more P than wheat or barley to produce the same yield. However, lupins required less P to achieve near-maximum yield.     

Effect of level,timing and method of nitrogen application on spring-planted sugarcane

A field experiment conducted at the Indian Agricultural Research Institute, New Delhi during the years 1976–79 involving two planted cane crops and two ratoons showed that nitrogen application to planted cane increased the millable cane and sugar yields of the planted cane and had a significant residual effect on the ratoon. Taking together the yields of planted cane and ratoon, an application of 150 kg N ha^–1 increased the yield of millable cane by 33.3t ha^–1 and that of sugar by 3.9t ha^–1. The results suggested that with 75 kg N ha^–1 three-quarters should be applied at planting, while with 150 kg N ha^–1 only half should be applied at planting. The remaining dose of nitrogen should be applied at earthing up. Foliar application of part of the nitrogen indicated some advantage in the case of millable canes in the planted cane, but this did not show up in the sugar yield.     

Growth response,yield and yield components of upland cotton (Gossypium hirsutum L) as affected by rates and time of nitrogen application in the Nigerian savannah

Effects of rate and time of nitrogen fertilization on growth, yield and yield components of upland cotton (Gossypium hirsutum L) were studied in two years (1975–76). Four rates of nitrogen application (0, 26, 52 and 78 kg ha^–1) timed at 3 or 8 weeks after sowing were compared. Seed cotton yield components increased significantly with increased N application at least up to 52 kg N ha^–1, with yield increases between 49% and 73%. Seed cotton yield was influenced by treatments mainly through boll number. Both crop growth rate and fruiting were enhanced by nitrogen fertilization. Applying N at 8 weeks (flowering) favoured yield only slightly over that at 3 weeks (thinning), but improved crop growth and fruiting by about 64% and 24%, respectively. There were significant N rate × time interactions in favour of fertilization at flowering. Applying 52 kg N ha^–1 at 8 weeks seems best for cotton in the Nigerian savannah.     

Influence of pH,time and rate of application on phosphate rock dissolution and availability to pastures

Soil Samples were collected from a field experiment conducted to evaluate the agronomic effectiveness of a reactive phosphate rock (PR), Sechura sand, relative to that of monocalcium phosphate (MCP) at different soil pHs and rates of application. The samples were analysed for P soluble in the soil solution and bicarbonate extractable P. The rate of dissolution of PR was calculated from the data on the fractionation of inorganic P. In MCP plots P in the soil solution decreased sharply with time especially at low pHs and high rates of fertiliser application. In PR plots the concentration remained with time at the same as or a slightly higher level than that was found one month after application. Solution concentration of P was lower at very high rates of PR application than at intermediate rates. In both MCP and PR plots bicarbonate extractable P decreased with increasing pH. Bicarbonate extractable P was linearly related to MCP but not to PR applied. The rate of dissolution and the proportion of PR dissolved decreased with increasing rates of PR application but the amount dissolved increased. Phosphate dissolved at high level of PR application did not seem to enhance proportionately either the concentration of P in soil solution or bicarbonate extractable P.     

Influence of pH,time and rate of application on phosphate rock dissolution and availability to pastures

The agronomic effectiveness of an unground reactive phosphate rock from Sechura, Peru, was compared with that of monocalcium phosphate in a severely P deficient and highly P retentive soil (vitrandept) over a period of three years. Soil pHs were adjusted to pH 5.1, 5.3, 5.6 and 6.4. The sward consisted mostly of ryegrass (Lolium perenne) and white clover (Trifolium repens). Fertilisers were applied at six rates at pH 5.3 and three rates at other pHs in the first year. For two of the rates fertilisers were reapplied in the second year. Dry matter yields, P uptake and ground cover of clover were determined during the experimental period. In phosphate rock treated plots a negative linear relationship was obtained between soil pH and the logarithm of yield. The agronomic effectiveness of phosphate rock relative to monocalcium phosphate increased with time at all pHs. Calculated at fertiliser rates which produced near maximum yields, relative agronomic effectiveness at soil pHs 5.1, 5.3, 5.6 and 6.4 were respectively 58, 60, 18, and 5 in year one; 118, 125, 77 and 38 in year three. At pH 5.3, as the rate of application increased the relative agronomic effectiveness of the phosphate rock generally decreased in year one but was enhanced in the intermediate rates in years two and three. The data for ground cover of clover gave a similar trend to that for herbage yield and P uptake.     

连续流中氮负荷对好氧颗粒污泥的稳定性影响

研究了连续流反应器中好氧颗粒污泥（AGS）处理无机高氨氮废水的脱氮性能及稳定性。接种成熟AGS启动反应器,前55天内进水氮负荷由1.0 kgm-3d-1逐步提升至4.0 kgm-3d-1,56~125天内氮负荷逐步减小至1.4 kgm-3d-1,126~145天氮负荷再次升高至2.0 kgm-3d-1。前75天内观察到明显的颗粒破碎及污泥流失,且颗粒平均粒径不断减小。虽然多次补充接种AGS以维持系统稳定性,但前90天内颗粒的污泥容积指数（SVI）、胞外聚合物（EPS）及比耗氧速率（SOUR）剧烈波动。受疫情影响,91~109天反应器原位闲置。重新运行后AGS的理化指标逐渐趋于稳定。前45天内氨氮去除率逐渐增大至98%以上,在46~75天内迅速减少至50%左右,此后再次回升至99%以上。总无机氮去除率大部分时间处在35%~45%之间。通过污泥截留试验探索了反应器对污泥的选择性筛分效果。当沉淀池中挡板深度为27 cm时,反应器对污泥的截留率在98%以上,出水污泥粒径多为0~0.30 mm污泥。利用高通量测序分析污泥菌群组成变化。与接种AGS相比,145天时AGS中的硝化细菌属（Nitrosomonas）相对丰度明显增大,而反硝化细菌属（unclassified_Flavobacteriaceae、unclassified_Xanthomonadaceae、Thauera等）的相对丰度略有降低。     

水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响

采用自主设计的悬浮载体生物膜/颗粒污泥耦合装置,利用硝化菌载体生物膜和反硝化聚磷菌颗粒污泥,研究水力停留时间对生物膜/颗粒污泥耦合工艺脱氮除磷的影响,得出最佳工艺参数。试验考查水力停留时间分别为6 h、7 h、8.5 h和10.5 h,结果表明,当水力停留时间为8.5 h时,系统的COD去除率为91.26%,氨氮和总氮的去除率分别为80.68%和70.58%,厌氧释磷速率也较稳定,为0.47 mg P·（g SS）^-1·h^-1,厌氧释磷速率最高,其碳源利用率最大,反硝化除磷效率最稳定,PO₄^3--P去除率为76.50%,反硝化除磷效率为1.04 mg P·（mg NO₃^--N）^-1,所以当水力停留时间为8.5 h时,系统具有较高的脱氮除磷效率。当水力停留时间过短时,氮磷的去除不完全,过长时,系统不稳定,系统的最优水力停留时间为8.5 h。     

Effect of retention time and organic loading rate on anaerobic acidification and biogasification of dairy manure

Vast amounts of animal manure produced from concentrated animal feeding operations have the potential to be converted into economic gain if the proper processing technology is employed. Anaerobic digestion (AD) is an effective way to convert organic wastes including animal manure into profitable by‐products as well as to reduce the pollution of water, air, and soil caused by these wastes. Two‐phase AD of manure offers several advantages over conventional one‐phase AD. Solids reduction through hydrolysis/acidification might be very significant for animal manure which contains high amounts of solids. However, to date, studies of two‐phase AD of animal manure have been limited to screened manure. Therefore, this study investigated the two‐phase AD of dairy manure with particular emphasis on the effects of retention time and organic loading rate (OLR) on anaerobic acidification and biogasification of unscreened dairy manure. The results indicated that pre‐acidification of dairy manure in daily‐fed continuously‐mixed reactors with no recycle led to significantly high reduction efficiencies of volatile solids and, thus, biogas production in the subsequent methanogenic reactor especially at OLRs of 4–10 g VS dm^?3 day^?1. However, the extent of the stimulation in the biogas production relative to corresponding feed samples was quite variable (between 6.9 and 64.7%) for different solids retention times and OLR combinations. A relatively lower performance was observed for the high OLRs (20–30 g VS dm^?3 day^?1) used which was attributed to the possible wash‐out of the acidifiers at the considerably low retention times (1.25–4 days) used. Copyright © 2004 Society of Chemical Industry     

The influence of rate and time of nitrate supply on nitrogen fixation and yield in pea (Pisum sativum L.)

The influence of nitrate N supply on dry matter production, N content and symbiotic nitrogen fixation in soil-grown pea (Pisum sativum L.) was studied in a pot experiment by means of¹⁵N fertilizer dilution. In pea receiving no fertilizer N symbiotic nitrogen fixation, soil and seed-borne N contributed with 82, 13 and 5% of total plant N, respectively. The supply of low rates of nitrate fertilizer at sowing (starter N) increased the vegetative dry matter production, but not the seed yield significantly. Nitrogen fixation was not significantly decreased by the lower rates of nitrate but higher rates supplied at sowing reduced the nitrogen fixation considerably. Applying nitrate N at the flat pod growth stage increased the yield of seed dry matter and N about 30% compared to pea receiving no nitrate fertilizer. Symbiotic nitrogen fixation was reduced only about 11%, compared with unfertilized pea, by the lowest rate of nitrate at this application time. The pea very efficiently took up and assimilated the nitrate N supplied. The average fertilizer N recovery was 82%. The later the N was supplied the more efficiently it was recovered. When nitrate was supplied at the flat pod growth stage 88% was recovered, and 90% of this N was located in the seeds.     

磷酸盐阻燃液的制备及阻燃棉布的应用

室内常用装饰材料大多是由棉、木材等易燃物质制成,易引发火灾、造成人员伤亡和财产损失。因此,对室内常用装饰材料的燃烧性能进行研究是非常必要的。磷酸盐阻燃剂作为一种添加型阻燃剂,采用喷涂或浸渍等方式使棉布、木材等室内常用装饰材料获得较好的阻燃性能。本文采用磷酸氢二铵和磷酸二氢铵作为原料,分别按9:1、8:2、7:3、6:4、5:5、4:6、3:7、2:8、1:9共9种不同的质量比例混合配制磷酸盐阻燃液,并应用于棉布进行浸泡阻燃处理,然后对样品进行阻燃性能表征。实验结果表明,2:8比例的阻燃处理棉布点燃时间和达到峰值时间最长,阻燃效果最佳,目前的研究对于后续改进磷酸盐阻燃液的阻燃性能并分析影响其性能的因素具有重要意义。     

Influence of source, time and method of application, and simulated rainfall on recovery of nitrogen fertilizers applied to bromegrass

Four field experiments were conducted in central Alberta to determine influence of the N source, time and method of application and simulated rainfall on the recovery of¹⁵N-labelled fertilizers applied to meadow bromegrass (Bromus biebersteinii Roem and Shultz. cv. Regar) in plants (topgrowth plus roots) and in soil. The first experiment compared two N sources (urea and ammonium nitrate (A.N.)) and six times of application (early fall, late fall, early winter, early spring, late spring and spring-summer split) where N fertilizers were surface-broadcast. Urea gave lower N recovery than A.N., regardless of time of application (on the average by 16.4% in plants and by 18.3% in plants plus soil). For urea, early spring application gave higher N recovery than the other times of application, especially at the Eckville site. For A.N., spring applications gave higher N recovery than fall or early winter applications but N recovery was only slightly greater with early spring than late spring application. The second experiment evaluated methods of N placement (surface-broadcasting and banding). The N recovery in plants increased with subsurface band placement over surface-broadcast by 20.2% for fall application and by 15.5% for spring application. The other two experiments investigated the effect of amount (0, 5, 10, 20 and 40 mm) of simulated rainfall and interval (0, 1, 2, 4, 8, and 16 d) between surface urea application and simulated rainfall on N recovery. Simulated rainfall of 10 mm immediately after surface urea application on moist soil increased the N recovery in plants by 8.1–10.7% compared to no simulated rainfall. Delaying simulated rainfall (20 mm) by 4 d after surface urea application decreased the N recovery in plants by 8.7–15.2%. In conclusion, the N recovery improved greatly when urea was placed below the soil surface or with simulated rainfall immediately after surface urea application.     

Effect of the timing and rate of nitrogen fertilization on the growth and recovery of fertilizer nitrogen within the potato (Solanum tuberosum L.) crop

The effect of the timing of N fertilizer application on the uptake and partitioning of N within the crop and the yield of tubers has been studied in two experiments. In 1985 either none, 8 or 12 g N m^–2 was applied and in 1986 none, 12 or 18 g N m^–2. Fertilizer N was applied either at planting, around the time of tuber initiation or half at planting and the remainder in four foliar sprays of urea during tuber bulking.¹⁵N-labelled fertilizer was applied to measure the recovery of fertilizer N in the crops.There was an apparent pre-emergence loss of nitrate from the soil when N was applied at planting in 1986, thereby reducing the efficiency of fertilizer use. Applying the N at tuber initiation delayed and reduced the accumulation of N in the canopy compared with crops receiving all their fertilizer at planting. Foliar sprays of urea slightly increased both tuber yields and tuber N contents when compared to a single application at planting. The proportion of the fertilizer N recovered in the crop was little affected by the rate of N application, but a greater proportion of foliar-applied N was recovered than N broadcast at planting, due partly to pre-emergence losses of nitrate in 1986. It is suggested that late applications of N was foliar sprays can be of benefit to crops with a long growing season and reduce environmental losses of N.     

免疫后时间及流行强度对1剂次水痘疫苗效力的影响

目的探讨免疫后时间及流行强度对接种1剂水痘疫苗效力的影响。方法对广州市天河区2011年1⁶月发病的16月发病的1¹5岁水痘病例,采用1︰1配对的病例对照研究方法,对不同年龄、处在不同流行强度时的1剂次水痘疫苗效力(vaccine effectiveness)进行分析,并评价两者对疫苗效力的影响。结果调查601病例/对照对子,总的疫苗效力为70.33%(95%CI:60.42%15岁水痘病例,采用1︰1配对的病例对照研究方法,对不同年龄、处在不同流行强度时的1剂次水痘疫苗效力(vaccine effectiveness)进行分析,并评价两者对疫苗效力的影响。结果调查601病例/对照对子,总的疫苗效力为70.33%(95%CI:60.42%⁷7.76%,P<0.01),1岁组疫苗效力为90%(95%CI:65.27%77.76%,P<0.01),1岁组疫苗效力为90%(95%CI:65.27%⁹7.12%,P<0.01),随年龄增长,疫苗效力呈下降趋势(χ2趋势=12.68,P<0.01),≥10岁组病例与对照暴露率差异无统计学意义(P>0.05),疫苗基本失去保护效力。集体单位297.12%,P<0.01),随年龄增长,疫苗效力呈下降趋势(χ2趋势=12.68,P<0.01),≥10岁组病例与对照暴露率差异无统计学意义(P>0.05),疫苗基本失去保护效力。集体单位2¹5岁病例511对子疫苗效力为66.67%(95%CI:54.52%15岁病例511对子疫苗效力为66.67%(95%CI:54.52%⁷5.57%,P<0.01),水痘罹患率越高,疫苗效力越低,罹患率在15%以上时,疫苗效力差异无统计学意义(P>0.05),疫苗基本失去保护效力。结论接种1剂水痘疫苗约10%初次免疫失败;免疫后时间及流行强度对疫苗效力均有明显影响,后者影响更大。若将1剂免疫程序改为2剂免疫程序,对控制儿童水痘暴发将具有重要意义。     

Extraction,characterization, and application of seaweed nanoparticles on cotton fabrics

The seaweed Turbinaria conoides was collected from the east seashore of the south India. The dried seaweeds were converted into fine powder, mixed with acetone, and their antibacterial substance was extracted. The extracted substance was characterized by the use of Fourier transform infrared spectroscopy and ultraviolet–visible spectroscopy for functional group identification. The presence of bromine, amine, and phenolic groups was confirmed. Nanosized particles were confirmed by transmission electron microscopy studies. The extract was applied on the enzyme scoured and dyed cotton fabric for bioantibacterial finish. The antibacterial activity of extract on the finished fabric was confirmed by the test results. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of short thermal treatment on cotton degradation

Cotton fabric was subjected to thermal treatment for durations ranging from 0.5 to 5 min at a temperature range of 160°C. In comparison with the untreated cotton, the copper number (measure of the aldehyde content) decreased after heating cotton for up to 3 min at 160°, 180°, and 190°C but increased when heating was prolonged to 5 min. Thermal treatment at 200°C or above caused an appreciable increase in the copper number. The carboxyl content increased with time of heating, attained a maximum, and then fell down to reach values which in some cases were lower than that of untreated cotton. Thermal treatment at 180°C caused a substantial reduction in the D. P.; this reduction increased with time of treatment. At the other temperatures there was no significant decrease in D. P. when cotton was heated up to 3 min. The D. P. decreased in these cases only when the thermal treatment was conducted for 5 min. The tensile strength remained practically unimpaired after thermal treatment of the cotton for up to 2 min, regardless of the temperature used within the range studied. A loss in tensile strength of ca. 9% and 13% was observed with fabrics treated for 5 min at 160° and 180°C, respectively. This contrasts with a loss of ca. 4% at 190°C, 7% at 200°C, and 8% at 220°C. The highest dye exhaustion was obtained on cotton which was thermally treated at 180°C prior to dyeing, while the lowest dye exhaustion was obtained on cotton heated at 220°C. Thermal treatment at 160°C left the susceptibility of cotton toward the dyestuff practically unaltered.