Effects of the urease inhibitor N-(n-butyl)phosphorothioic triamide in low concentrations on ammonia volatilization and evolution of mineral nitrogen     

L. Vittori Antisari  C. Marzadori  P. Gioacchini  S. Ricci  C. Gessa 《Biology and Fertility of Soils》1996,22(3):196-201

Laboratory incubation experiments were conducted to study the influence of increasing concentrations of N-(n-butyl)phosphorothioic triamide (NBPT) on NH₃ volatilization and rate of urea hydrolysis and evolution of mineral N in Ozzano, Rimini and Carpi soils with different physicochemical characteristics. Low concentrations of NBPT reduced NH₃ losses due to volatilization after urea fertilization and the effectiveness of the inhibitor was related to the soil characteristics (e.g. high concentrations of organic C and sand). After 15 days of incubation, no significant reductions of losses were found for any of the NBPT concentrations employed in Rimini soil. The application of NBPT led to a considerable reduction of the formation of nitrite. This process was completely annulled with the highest dose of NBPT (0.5% w/w_urea) in the Carpi soil after 15 days. In Rimini soil, however, the use of NBPT was less effective in influencing nitrite formation. The use of NBPT favoured accumulation of nitrate proportional to the NBPT concentration employed while it had no influence on the NH _inf4 ^sup+ fixation by 2:1 layer silicates. The data obtained support previous evidence that NBPT is effective in reducing the problems encountered in using urea as fertilizer. However, environmental conditions and soil physicochemical characteristics may have an important influence on the effectiveness of NBPT.  相似文献   

无水氨、尿素氨化秸秆饲喂肉牛的效果   总被引：2，自引：0，他引：2  

杜增昱  张思温 《中国畜牧杂志》1992,28(1):7-10

为了评价无水氨、尿素氨化麦秸、玉米秸饲喂肉牛的效果,用42头肉用生长母牛及阉牛进行了80天饲养试验。试验开始牛平均体重为135公斤,按随机区组设计分为7组,占干物质3％的无水氨氨化麦秸组(WA)、占干物质5.4％的尿素加大豆粉氨化麦秸组(WUS)、麦秸组(W);占干物质3％的无水氨氨化玉米秸组(CA)、占干物质5.4％的尿素加大豆粉氨化玉米秸组(CUS)、占干物质5.4％的尿素氨化玉米秸组(CU)、玉米秸组(C).各组牛秸秆自由采食,混合精料按体重的1％喂给。为了平衡日粮粗蛋白质水平,W组及C组每日每头分别加喂32克和37克尿素。试验结果表明:秸秆经氨化处理后含氮量提高88-151％,肉牛采食每公斤秸秆干物质的时间显著缩短。WA组、WUS组、W组、CA组CUS组、CU组和C组的日增重分别为0.66、0.54、0.52、0.57、0.63、0.56、0.48公斤(P<0.01)。添加大豆脲酶对尿素氨化玉米秸的效果无明显影响。  相似文献   

Comparison of measurements of canine plasma creatinine, glucose, proteins, urea, alanine aminotransferase, and alkaline phosphatase obtained with Spotchem SP 4430 and Vitros 250 analyzers     

Trumel C  Diquélou A  Germain C  Palanché F  Braun JP 《Research in veterinary science》2005,79(3):183-189

The suitability of the Spotchem 4430 benchtop biochemistry analyzer for canine blood samples was tested for creatinine, glucose, proteins, urea, alkaline phosphatases and alanine aminotransferase. Results obtained from whole blood and corresponding heparin plasma were identical except for proteins which were higher in plasma (n=10). Between series imprecision (n=10) was <5% for substrates and <10% for enzymes. Comparison of results from 100 Li-heparin samples with those measured with a Vitros 250 analyzer showed good correlation (r>0.93). The slopes of the Passing-Bablock's regression ranged from 0.90 to 1.20 and intercepts were low. The mean biases were low, except for creatinine for which the results obtained by Spotchem (Jaffe reaction) were about 20 micromol/L higher than with the Vitros (enzymatic reaction). The results of this study show that the Spotchem analyzer is suitable for use in canine whole blood or plasma when small numbers of tests are to be performed and large analyzers are not available.  相似文献   

基施尿素对片麻岩新成土旱地谷子生长及土壤硝态氮时空分布的影响     

李向文  王红  张爱军  张瑞芳  周大迈 《干旱地区农业研究》2012,30(5):128-132

本试验在片麻岩新成山地土壤上,设置0(CK)、N 120kg/hm2(N120)、N 225 kg/hm2(N225)、N 300kg/hm2(N300)4个施氮水平,布置田间微区试验,小区面积为10m2,研究了尿素不同施用量对旱地谷子生长及土壤硝态氮时空分布的影响。定位试验第二年的结果表明:在该试验条件下,N120处理谷子产量达到最高为4.76 kg/10m2,之后提高施肥量N225和N300处理的谷子产量并没有显著增加;从0~60 cm土壤剖面中硝态氮时空分布的差异可以看出:在施肥20 d后,N120、N225和N300处理NO3--N含量在0~40 cm土层显著增加,其中N225和N300处理NO3--N已经下移到40~60 cm土层。施肥80 d后,各施肥处理的硝态氮有一部分已经移出60 cm土层。到施肥96 d(谷子收获),N120、N225和N300处理比CK处理土壤剖面中NO3--N含量显著增加,且氮肥用量越高,土壤中NO3--N含量越高。  相似文献   

几类干草防腐剂简介     

陈卢亮 《中国奶牛》2012,(11):16-18

对牧草进行打捆储藏可以有效降低牧草营养损失,但储藏过程中因微生物的作用会导致牧草发热甚至腐败从而降低其饲用价值。因此,在干草调制过程中,应添加干草防腐剂以抑制微生物的生长和繁殖。本文对几种常用干草防腐剂进行介绍,以供同行调制干草时参考。  相似文献   

施氮模式对玉-麦周年轮作系统产量和氮吸收利用的影响   总被引：3，自引：0，他引：3  

李岚涛  任丽  尹焕丽  郭娅  王海标  张倩  王宜伦 《中国生态农业学报》2019,27(11):1682-1694

为明确适宜豫北平原夏玉米-冬小麦一体化种植的高效施氮管理模式,2016—2017年分别在豫北典型高产田区河南省鹤壁市和中产田区河南省原阳县开展了夏玉米-冬小麦周年轮作不同施氮模式对夏玉米与冬小麦产量、氮素吸收和利用效率影响的田间试验。共设5种处理:不施氮肥(T1)、普通尿素按210 kg(N)?hm?2一次性基施(T2)、普通尿素分次施用且总施氮量同T2(T3)、控释尿素与普通尿素配比氮素减量施用(T4)和控释尿素与普通尿素配比氮素足量施用(T5)。分别于夏玉米和冬小麦关键生育期测试叶片SPAD值、植株与籽粒氮含量及生物量等氮营养指标,并于成熟期测定产量和产量构成因子,分析计算植株氮积累量与吸收利用特征。结果表明,处理间,高、中产区夏玉米与冬小麦产量、产量构成因子及氮素营养指标整体变化趋势均为T5T4T3T2T1。产区间,各处理夏玉米和冬小麦产量性状及氮营养指标均表现为高产区显著优于中产区。综合各处理平均值,高产区夏玉米产量、植株氮含量和氮素积累量相比于中产区分别平均提高58.0%、19.2%和47.1%,冬小麦增幅则分别为34.7%、33.3%和85.9%。氮利用效率方面,高、中产田在氮肥表观利用率、氮肥农学效率和100kg籽粒需氮量变化趋势均表现为T5T4T3T2T1,处理间差异显著;氮素收获指数则与此相反。豫北平原夏玉米-冬小麦周年轮作制在作物稳产甚至增产条件下,采用尿素与缓释氮肥掺混配施的氮肥优化施用模式不仅可有效减少肥料用量,还能显著提升肥料利用率,降低氮肥损失。  相似文献   

红壤不同含水量对尿素氨挥发的影响   总被引：8，自引：1，他引：7  

周静  崔键  王霞 《土壤》2008,40(6):930-933

根据第四纪红壤水分特征设计160、200、240、280、320、360g/kg6个土壤含水量处理,通过温室模拟,研究了红壤不同含水量对尿素氨挥发的影响。结果表明,等量尿素施入红壤后,氨挥发通量与土壤含水量之间无显著相关性,而高含水量(280、320、360g/kg)处理氨挥发通量峰值较低含水量(160、200g/kg)处理提前10天。氨挥发过程可分为快速-慢速2个阶段,氨累积挥发量(y)与对应时间(t)符合Elovish动力学方程(y=a blnt)。第1～10天,氨挥发累积量随红壤含水量的增加而递增;第11天后,以含水量为240g/kg处理的氨挥发累积N量最低。试验期间,氨挥发累积总N量,以含水量240g/kg时最低(0.90gN),含水量320g/kg时最高(1.16gN),分别占尿素施入N量的9.0%和11.6%。  相似文献   

不同处理方法改善桉木渗透性研究     

覃引鸾  卢翠香  李建章  莫引优 《林产工业》2020,57(4):10-13,24

采用3种方法处理尾叶桉,对尾叶桉木材气体渗透性进行了测定,探讨不同处理方法对木材渗透性影响及其作用机理。结果表明:尾叶桉木材因含有侵填体/树胶、导管壁上筛状纹孔影响木材渗透性,木材纵向渗透性大于横向渗透性。经真空、苯-乙醇、尿素处理后,木材渗透性均得到改善;但真空、苯-乙醇处理改善效果不明显,渗透性比未处理材提高幅度均未超过10%;尿素处理可显著改善尾叶桉木材渗透性,渗透性提高了18.91%~41.41%。  相似文献   

反刍动物雪尿分析：3个指数在评价营养样状态中的比较及应用     

张玮琪  张明海  姜广顺 《野生动物》2008,29(6)

基于以往的综述和研究性文章,本文对通过尿液分析评价反刍动物营养状态的3个指数进行了讨论和比较:相对于A:C比值而言,U:C比值不能够反映不同年份动物的营养限制情况,A:C比值和U:C比值均会因随机抽样的原因导致对动物营养状态的过高或过低估计,在一些物种中A:C比值不如PD:C灵敏。并对这些指数在今后研究中的应用进行了初步探讨。  相似文献   

Azotemia in cats with feline hypertrophic cardiomyopathy: Prevalence and relationships with echocardiographic variables     

Vassiliki Gouni DVM  Valrie Chetboul DVM  PhD  Jean-Louis Pouchelon DVM  PhD  Carolina Carlos Sampedrano DVM  MS  Christelle Maurey DVM  PhD  Herv P. Lefebvre DVM  PhD 《Journal of Veterinary Cardiology》2008,10(2):117-123

ObjectivesThe prevalence of renal azotemia in cats with acquired heart disease is not well documented. The aims of this study were therefore (1) to determine the prevalence of azotemia within a hospital population of cats with hypertrophic cardiomyopathy (HCM), and (2) to evaluate the relationship between echocardiographic variables and plasma urea and creatinine.Animals, materials and methods134 client-owned cats were retrospectively studied including 102 cats with HCM and 32 control cats. A complete physical examination, electrocardiography, systolic arterial blood pressure measurement, thoracic radiographs, and echocardiography were performed. Plasma creatinine and urea were determined in all cats. The animal was considered azotemic if plasma creatinine was >1.8 mg/dL and/or urea >65 mg/dL (i.e. BUN> 30 mg/dL).ResultsThe prevalence of azotemia was lower in control cats (25.0%) than in cats with HCM (58.8%) (P = 0.003). No significant differences in plasma urea and creatinine were observed between the HCM and control cats. There was no effect of plasma creatinine and urea on conventional echocardiographic variables in cats with HCM.ConclusionsAzotemia is a frequent finding in cats with HCM but is not dependent on echocardiographic variables.  相似文献