砂姜黑土区控释尿素与普通尿素掺混对小麦-玉米轮作定位产量及氮肥利用率的影响

在驻马店新坡村进行了小麦-玉米轮作制下的控释尿素与普通尿素掺混比例定位试验研究。结果表明:控释尿素与普通尿素掺混处理的小麦、玉米产量均以70%控释尿素+30%普通尿素处理最好,第1年和第2年的小麦产量分别比100%普通尿素处理增产17.0%和21.1%,玉米产量分别比普通尿素处理增产16.2%和16.2%;氮肥利用率与产量结果一致,均以70%控释尿素+30%普通尿素处理最高,分别为53.9%和54.5%。     

控释尿素与普通尿素掺混对小麦和玉米轮作产量及氮肥利用率的影响研究

对小麦/玉米轮作制下进行了控释尿素与普通尿素掺混比例试验.试验结果表明：控释尿素与普通尿素掺混处理的产量是在小麦、玉米上均以控释尿素70%＋普通尿素30%处理最好;小麦产量分别为8 000和8 150 kg/hm2,比100%控释尿素处理增产6.2%和7.2%,比100%普通尿素处理增产17.0%和16.7%,比对照增产39.9%和34.5%,它们之间的差异达1%显著水平;玉米产量分别为6 780和6 550 kg/hm2,比100%控释尿素处理增产5.1%和5.6%,比100%普通尿素处理增产16.2%和17.8%,比对照增产22.1%和20.8%,它们之间的差异达1%显著水平.     

控释尿素在夏玉米上的施用效果及氮素利用率研究

通过田间试验方法,对比评价控释尿素在夏玉米上的施用效果和方法。根据施用控释尿素对玉米籽粒产量、氮素吸收和利用率的影响,探讨控释尿素在夏玉米上的施用效果。试验结果表明：与普通尿素相比,施用控释尿素后,玉米产量及氮素利用率均明显提高。     

控释尿素和控释BB肥对夏玉米的增产效果研究

采用控释尿素和普通尿素两种氮素肥料及含控释尿素的BB肥进行夏玉米肥效试验研究。试验结果表明：100％控释尿素处理产量最高,为8714kg／hm^2。和8838kg/hm^2,与同等氮素用量的普通尿素相比,分别增产658kg／hm^2和667kg／hm^2,提高8．2％和8．2％,增产效果显著;控释尿素用量在70％～100％时,产量随氮肥用量的增加而增加,普通尿素也呈同样趋势;70％控释尿素处理与100％普通尿素处理相比,产量差异不大,没有达到显著性差异,说明施用控释尿素可以比普通尿素用量减少约1／3的纯氮用量,夏玉米作物产量并不下降。     

控释尿素与普通尿素配合施用对夏玉米的增产效果研究

对控释尿素与普通尿素配合施用进行试验,试验在驻马店市农科所农场进行。夏玉米试验结果表明,控释尿素与普通尿素配合施用的产量均以控释尿素70%+普通尿素30%处理最好。产量为8115kg/hm2,比控释尿素单施(处理1)增产390kg/hm2,提高5.0%;比普通尿素单施(处理5)增产1230kg/hm2,提高17.9%;比处理6(CK)增产2940kg/hm2,提高56.8%;它们之间的差异达1%显著水平。     

砂姜黑土区控释尿素与普通尿素掺混对小麦/玉米轮作的产量及氮肥利用率的影响

试验结果表明:控释尿素与普通尿素掺混处理的产量在小麦玉米轮作上均以控释尿素掺混30%普通尿素处理最好。小麦产量:新坡村与农科所农场的产量分别为8096kg/hm2,8211kg/hm2;比控释尿素单施处理增产5.4%和7.2%,比普通尿素单施处理增产21.0%和22.6%,比对照(CK)增产40.2%和44.2%,它们之间的差异达5%或1%显著水平。小麦氮肥利用率变化趋势与产量变化趋势基本一致,均以控释尿素掺混30%普通尿素处理最高,新坡村与农科所农场小麦氮肥利用率分别为54.5%和52.7%。玉米产量:新坡村与农科所农场的产量分别为8715kg/hm2,9020kg/hm2,比控释尿素单施处理增产6.1%,6.7%,比普通尿素单施处理增产16.2%,16.1%,比对照增产55.7%,56.6%,它们之间的差异达1%显著水平。     

缓释和控释尿素的研究与开发综述

分析了尿素利用率低对环境的影响和尿素在土壤中的释放过程，阐述了各种缓释和控释尿素的产品设计，缓释机理和制备方法以及国内外对缓释和控释尿素尤其是包膜尿素的研发进展，对提高尿素利用率，研究高效控释包膜尿素进行了展望。     

金正大包膜尿素与普通尿素不同掺混比例对玉米肥效试验的研究初报

从金正大包膜尿素与普通尿素不同掺混比例对玉米肥效的试验结果看:70%包膜尿素 30%普通尿素掺混比例处理产量最高,667m2为586 kg,比包膜尿素处理增产5%,比普通尿素处理增产22%;从作物经济性状产量构成因素看,主要在穗粒数表现差异较大。     

控释尿素对小麦增产效果与提高氮肥利用率的研究

采用控释尿素和普通尿素两种氮素肥料进行优质小麦郑麦366肥效试验研究。两地试验结果表明：100％控释尿素处理产量最高,为7980kg／hm^2和8290kg／hm^2,与同等氮素用量的普通尿素相比增产12．0％、14．0％;产量随氮肥用量的增加而增加;用量70％控释尿素处理与用量100％普通尿素处理之间相比,产量差异不大,没有达到显著性差异,说明施用控释尿素可以比普通尿素减少1／3的纯氮用量。     

包膜控释尿素在湖北中稻上合理施用量的研究

在湖北省中稻上开展了控释尿素不同施用量的田间试验。研究结果表明,施用控释尿素不仅可以提高中稻产量,而且可以提高氮肥的农学效率及表观利用率,控释尿素70%的用量与普通尿素100%的用量效果相当,并随着控释尿素施用年限的增加,控释尿素施用效果越显著,控释尿素至少可以减少氮肥用量30%。     

A comparative study of urea hydrolysis rate and ammonia volatilization from urea and urea calcium nitrate

A comparing of urea hydrolysis and NH₃ volatilization from urea supergranules and urea calcium nitrate (UCN, a new fertilizer produced by Norsk Hydro A/S, Norway) was made on two different flooded soil types, a high-CEC clay loam (Ås) and an intermediate-CEC clay loam (Kinn).Nitrogen loss by ammonia volatilization was reduced from 17% by surface application of urea supergranules (USG) on flooded Ås soil to 3% and 6% by UCN briquettes at either the same urea or nitrogen concentration as USG. A significant reduction was even found with the surface application of prilled UCN, 12% and 18% N-loss for prilled UCN and urea, respectively. The floodwater pH and NH ₄ ⁺ content was lower with UCN than urea, which reduced the potential for ammonia volatilization.NH₃-loss (5%) was significantly less when USG was surface applied on Kinn soil, while NH₃-loss from UCN briquettes was independent of soil type. The reduction in NH₃-loss from USG on Kinn soil was due to a decrease in the pH and NH ₄ ⁺ content of the floodwater caused by a reduced rate of urea hydrolysis.The rate of urea hydrolysis was lower with UCN than USG in both soils, but the difference between UCN and USG was greater in the Ås soil than in the Kinn soil. Three days after deep placement (10 cm), 18% of UCN urea and 52% of USG urea were hydrolyzed in Ås soil, while only 12% UCN and 17% USG were hydrolyzed in the Kinn soil.The surface application of USG on flooded soil reduced the rate of urea hydrolysis as compared to deep placement. 30% and 17% of USG urea was hydrolyzed after four days on Ås and Kinn soil, respectively. During the first few days the rate of hydrolysis of UCN was more affected by the soil type than the application method. Four days after surface application 32% and 13% UCN urea was hydrolyzed on Ås and Kinn soil, respectively. The rate of urea hydrolysis exhibited a zero-order reaction when USG and UCN-briquettes were point placed in flooded soils.     

脲醛树脂包膜尿素的制备研究

介绍了脲醛树脂包膜尿素的制备方法,研究了脲醛树脂及植物油用量对脲醛树脂包膜尿素氮初期溶出率的影响。结果表明,包膜量越多,包膜尿素氮的溶出率越低,但使用脲醛树脂直接包膜尿素的方法并不理想;先使用植物油在尿素颗粒的表面包一层油膜,再使用脲醛树脂包膜,可大幅度降低包膜尿素氮的溶出率,在使用1.0%的植物油后,树脂包膜量为15%时,氮的初期溶出率即可低于40%,大大降低包膜材料的使用量。     

Solubility of metallic-salt in acid nutrients in acid fertilizer solutions of urea phosphate,urea sulfate and urea nitrate

Solubilities of individual metallic-salt micronutrients were determined at 0°C in saturated acid fertilizer solutions of urea phosphate, urea sulfate, and urea nitrate. By using the acid pH mechanism, less expensive metallic salts can be used with drip irrigation applications to supply specific micronutrient needs to crops.Solubility of the sulfates of Cu, Fe, Mn, and Zn varied with each acid solution. Solubility of the above sources in the urea sulfate solutions also varied with the amount of sulfate in solution. The solubility of molybdenum decreased with the acidic conditions of the urea nitrate acid solution but appeared to increase for the urea phosphate and urea sulfate acid solutions. Boron was only slightly soluble in all the acid solutions.     

从脂肪酸的尿素包合法固相物中回收尿素的工艺

比较5种回收尿素包合法固相物中的脂肪酸和尿素的方法,其中,甲醇和甲苯的混合溶剂法的回收效果最好。当尿包固相物∶甲醇∶甲苯(g∶mL∶mL)用量比为1∶3∶3时,脂肪酸和尿素的回收率分别为99.12%、99.46%。对回收脂肪酸进行FT-IR、GPC和GC-MS分析:回收的脂肪酸中含有饱和脂肪酸和不饱和脂肪酸(Unsaturated Fatty Acids,UFAs)结构;回收脂肪酸相对分子质量为443,含量93.92%;UFAs含量为93.96%。回收尿素的EMS微观结构分析:回收尿素为针状透明晶体结构和良好的结晶度。考察了回收尿素多次分离多不饱和脂肪酸的效果,重复回收和利用的结果显示:回收尿素6次分离得到的产品中PUFAs含量在81%～89%、UFAs含量为100%、收率在60%～72%。     

新型尿素产品的开发

介绍了国内外新型尿素产品（大颗粒尿素、涂层尿素、包膜尿素、长效尿素）的生产工艺和产品特点。     

Effect of amounts and sequence of additions of urea and water on hydrolysis of surface-applied granular urea in unsaturated soils

The hydrolysis of surface-applied granular urea ( 15 mg of urea/particle) in 14 unsaturated soils as influenced by the amounts and the sequence of additions of urea and water and studied using open and covered soil column systems was in the following order: well-mixed surface-applied surface-applied surface-applied urea, granular urea, granular urea, granular urea, water added > water added > water added water added before, after, before, before, no drying no drying no drying drying The retarded hydrolysis' of surface-applied granular urea is attributed to retarded soil urease activity. Under the nondrying and drying conditions, the positive effect of increasing amounts of added water on the hydrolysis was less apparent when water was added 24–48 hours before than when it was added immediately after surface application of granular urea. When an increasing number of urea granules were evenly placed on a finite surface of unsaturated soil, the rate of urea application (quantity factor) increased but the percentage of urea hydrolyzed remained practically unchanged. These results suggest that it is necessary to consider effective urea concentration and effective urease activity for adequate understanding of in situ hydrolysis of broadcast fertilizer urea in unsaturated soil.     

Effect of prilled urea and modified urea materials on yield and quality of geranium (Pelargonium graveolens L. Her.)

Two field experiments were conducted to study the effect of prilled urea, neem cake coated urea, dicyandiamide treated urea and urea supergranules applied to a perennial aromatic herb, geranium (Pelargonium graveolens L. Her'.) grown on a sandy loam soil. Application of nitrogen increased the biomass and essential oil yields. Neem cake coated urea significantly increased the yields over prilled urea. There was no residual effect of N levels and N carriers. The concentration and quality of essential oil were not influenced either by levels or carriers of N.     

Determining permeability of coatings of polymer-coated urea

Permeability of polymer coatings on urea varies greatly with the type of polymer. A conventional test of measuring the effectiveness of coating involves a 7d static dissolution rate of coated urea into concentrated urea solution, but the results are only qualitative. Our approach was, instead, to make quantitative measurements of permeability, and so make more accurate predictions of release rate of urea across a membrane. A simple device, consisting of a container attached to vertical pipes at the bottom, was constructed to determine permeability of coats on urea granules. A turbulent flow of water ran over a 2 cm pack of coated-urea granules so urea did not accumulate at the outer surface of the coated granules. Separate determinations with two thicknesses of coats (8.8 and 14.7µm) were conducted with water at 12 or 31°C. Permeability and activation energy of permeability were calculated. A comparison was also made between release rate of urea calculated from permeability and that determined by 7d dissolution rate method at 23°C. Nearly 100 h were required for 100% release with the thick coating, but only 20% urea was released after 168 h with the 7d dissolution rate method.     

尿素熔融槽的技改

在尿素熔融喷浆造粒生产复合肥过程中,尿素熔融槽的结构对保证尿素在槽中均匀、快速被加热熔融,防止温度超标和缩二腺的生成非常重要。介绍对尿素熔融槽结构技改的内容和效果,达到了长期无故障生产。