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1.
通过海藻酸增效剂对尿素在土壤中的形态转化特征及其氨挥发损失的试验,研究了海藻酸增效剂对氮肥增效的作用机理,为进一步开发利用海藻酸资源、提高氮肥利用率提供科学依据。试验以山东潮土和安徽黄褐土为供试土壤,以海藻酸增效尿素为供试肥料,采用室内培养方法,设置不施肥(CK)、普通尿素(U)和海藻酸增效尿素(AU)3个处理,定期采集土壤样品测定土壤酰胺态氮、铵态氮、硝态氮含量及氨挥发量。结果表明,1)海藻酸增效剂能有效延缓土壤中尿素的水解。2)与普通尿素处理(U)相比,AU处理氨挥发总量降低3.74%～16.10%,在潮土和黄褐土上氨挥发速率分别降低 11.54%～ 21.57%和 18.18%～81.81%。3)AU处理铵态氮的峰值在潮土和黄褐土上分别出现在第 5和 7 d,其峰值提高了 4.86%～ 12.02%。4)海藻酸增效剂抑制了第5～ 7 d内土壤铵态氮向硝态氮的转化。综上所述,海藻酸增效剂可以减缓尿素的水解,降低氨挥发速率和损失量,抑制培养前期铵态氮向硝态氮的转化并且在不同的土壤中对氮素转化的影响效果不同,对黄褐土中氮素转化的抑制作用更明显。 相似文献
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常规灌溉条件下施氮对温室土壤氨挥发的影响 总被引：4，自引：1，他引：4
为明确温室土壤的氨挥发特征,探讨适宜的减量施氮措施对氨挥发损失量及黄瓜产量的影响,在常规灌溉条件下设置了3个施氮（尿素）处理,采用通气法测定了冬春季黄瓜地中的氨挥发速率。结果表明：温室土壤在氮肥基施后7 d出现氨挥发速率峰值,但在氮肥追施后,施肥带与非施肥带的氨挥发速率峰值分别在第1 d与第5 d出现,氨挥发速率的峰值比氮肥基施时下降了8.6%～46.3%,施肥带的累积氨挥发量是非施肥带的0.91～1.54倍。冬春季黄瓜地的氨挥发损失量为16.7～26.6 kg/hm2,其中减施氮25%处理N900（900 kg/hm2）与减施氮50%处理N600（600 kg/hm2）与习惯施氮处理N1200（1 200 kg/hm2）相比,氨挥发损失量分别降低了22.1%和37.2%。而2 a黄瓜产量的平均值以处理N600（600 kg/hm2）最高,比处理N1200（1 200 kg/hm2）增加了6.52%。综合考虑氨挥发损失量、黄瓜产量及施氮量,在河北省的温室冬春季黄瓜生产中,比农民习惯氮用量（1 200 kg/hm2）减少25%～50%的措施是可行的。 相似文献
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不同水氮条件对日光温室冬春茬黄瓜栽培氨挥发的影响 总被引：4，自引：0，他引：4
通过设置不同灌水、施氮处理,采用通气法研究了温室土壤施肥带与非施肥带的氨挥发特征,探讨了节水灌溉、减量施氮处理与传统水氮处理土壤氨挥发的差异及其影响因素。结果表明,冬春季温室黄瓜土壤在氮肥基施7 d后出现氨挥发峰值,减施氮25%处理的氨挥发峰值比传统施氮处理降低18.2%~34.3%;追肥后,施肥带和非施肥带的氨挥发速率峰值分别在第1 d和第5 d出现,减施氮25%处理与传统施氮处理相比,氨挥发速率峰值降低12.3%~37.2%;节水灌溉处理与传统灌水处理相比,氨挥发峰值则提高3.9%~47.0%。土壤中铵态氮含量以及温度的升高可促进土壤的氨挥发,而土壤含水量则与氨挥发速率呈负相关。在黄瓜花期和初瓜期,施肥带的累计氨挥发量显著高于非施肥带,而初瓜期之后,施肥带与非施肥带的氨挥发无显著差异。整个黄瓜生育季的累计氨挥发量为11.4~26.6 kg.hm 2;与传统施氮和灌水处理相比,减施氮25%处理的累计氨挥发量可降低20.8%~22.2%,但节水灌溉处理的累计氨挥发量却有所增加,增加幅度为0~4.51%。适宜减少灌水和氮肥用量不会降低黄瓜产量,且可大幅度提高灌水和氮肥利用效率。 相似文献
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长期有机无机肥配施对冬小麦籽粒产量及氨挥发损失的影响 总被引：13，自引：2，他引：11
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黄淮海平原是我国重要的粮食主产区,针对该区域氮肥利用率低且损失率高等问题,以国家土壤质量新乡观测实验站为研究平台,监测长期不同施肥模式下小麦玉米轮作体系土壤氮素损失规律,探讨减少黄淮海平原土壤氨挥发的科学施肥方式,为提高氮肥利用效率提供理论依据。设置了对照(CK)、单施化肥(NPK)、单施有机肥(M)、秸秆还田配施化肥 (NPK+S)、化肥增施有机肥(NPK+M)5个处理,于小麦季观测潮土氨挥发损失,分析土壤矿质氮含量、pH值对氨挥发的影响。结果表明,长期施肥对小麦产量及氮素吸收有显著影响。各施肥处理小麦产量均显著高于CK处理,且籽粒、秸秆和颖壳产量以NPK+M处理最高,分别达11.6、13.38和3.34 t·hm-2,较NPK处理分别增加15.6%、39.1%和18.4%。各处理的小麦地上部吸氮量以NPK+M处理最大,达306.67 kg·hm-2,较NPK、NPK+S处理分别提高14.3%、44.7%。不同施肥处理对土壤氨挥发有显著影响,小麦季土壤氨挥发速率峰值主要在施肥后1～4 d 内,其中NPK+S处理观测到的峰值高达N 0.40 kg·hm-2·d-1, 相似文献
6.
控释尿素对土壤氨挥发和无机氮含量及玉米氮素利用率的影响 总被引：7，自引：1，他引：7
采用田间试验,通过与普通尿素对比,系统研究了硫膜和树脂膜控释尿素的施用对土壤氨挥发损失、无机氮含量、玉米增产效应及氮素利用率的影响。研究结果表明:硫膜和树脂膜控释尿素的施用能够有效抑制土壤氨挥发速率,土壤氨挥发速率峰值出现时间比施用普通尿素滞后4～6 d,土壤氨挥发累积量和损失率比普通尿素分别减少了24.75%～61.66%,1.95%～4.06%;硫膜和树脂膜控释尿素的控释性能有效地维持了玉米生育期耕层土壤NH4+-N和NO3--N含量,保证了玉米生育期氮素的供应,并能达到"前控后保"的效果;降低土壤氨挥发损失和保持耕层土壤速效氮含量水平是硫膜和树脂膜控释尿素能够显著提高玉米产量、氮素利用率的主要原因。 相似文献
7.
减氮条件下砂壤质潮土区小麦–玉米轮作体系氨挥发特征及排放系数 总被引：1，自引：0，他引：1
8.
不同氮肥缓释化处理对夏玉米田间氨挥发和氮素利用的影响 总被引：27，自引：4，他引：23
9.
为探明生物炭对河南潮土区土壤氨挥发和小麦氮素吸收的影响,本研究设置不施肥(CK)、氮磷钾化肥(NPK)、生物炭(BC)、化肥配施生物炭(BC+NPK)4个处理,测定小麦季土壤氨挥发速率、籽粒产量和氮素吸收量。结果表明,在小麦基肥期,CK和BC处理氨挥发速率相对稳定,平均速率在0.06 kg·hm-2·d-1左右,且无显著差异。而NPK和BC+NPK处理氨挥发速率在基肥施入后2～3 d达到峰值,分别为0.86和1.25 kg·hm-2·d-1,BC+NPK处理较NPK处理显著提高45.35%。在小麦追肥期,NPK和BC+NPK处理土壤氨挥发速率最大值分别为0.96和1.07 kg·hm-2·d-1,且均在追肥后第7天达到最大值。与NPK处理相比,BC+NPK处理导致土壤氨挥发累积量增加9.45%,在基肥期和追肥期分别增加了5.47%和13.44%。整个小麦生育期,BC+NPK处理的土壤铵态氮含量平均值为21.61 mg·kg-1,较NP... 相似文献
10.
控释尿素减少双季稻田氨挥发的主要机理和适宜用量 总被引：7，自引：1，他引：6
11.
Suyundukov Ya. T. Suyundukova M. B. Bezuglova O. S. Khabirov I. K. Khasanova R. F. Semenova I. N. Rafikova Yu. S. Ilbulova G. R. 《Eurasian Soil Science》2022,55(1):27-35
Eurasian Soil Science - The results of the study of the properties of urban soils of the city of Sibay located in the mining region of the Republic of Bashkortostan are presented. A specific... 相似文献
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Kholodov V. A. Farkhodov Y. R. Yaroslavtseva N. V. Ziganshina A. R. Maksimovich S. V. 《Eurasian Soil Science》2022,55(7):998-1004
Eurasian Soil Science - Layers were step-by-step removed from macroaggregates (2–1 mm in diameter) of Protocalcic Chernozems via successive abrasion in a revolving rotator during 5, 10, 15,... 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(15-16):1631-1646
Abstract Brazil has approximately 30 million hectares of lowland areas, known locally as “Varzea,”; distributed throughout the country. Soils in these areas have the potential to support agricultural production, but very little is known about their fertility. The current experiment was undertaken to characterize the chemical and physical properties of representative “Varzea”; soils collected at 0–20, 20–40, 40–60, and 60–80 cm depth intervals from 23 sites in Goias State of Brazil. Organic matter contents averaged 42 g/kg in the surface 20 cm of soil and should make a significant contribution to overall nutrient availability. Soil pH increased slightly with depth from a mean value of 5.2 in the surface 20 cm of soil to a mean value of 5.4 in the 60–80 cm depth interval. Several soils had exchangeable Al values ≥ 1.0 cmol Al/kg, but soil Al saturation was generally less than the 60% level frequently associated with Al toxicity. However, cereal and legume production could benefit from lime addition in many of these soils. Although base saturation was fairly low in some soils, exchangeable Ca and Mg levels were, in general, adequate throughout the profile. Extractable P levels were adequate in most surface soil samples. Extractable K levels in these soils were generally low, and the application of K fertilizers should be beneficial, especially in conjunction with lime addition. The high clay content “Varzea”; soils of the Brazilian lowlands have some drainage problems but generally exhibit favorable chemical properties for crop production when compared to soils of the well‐drained Cerrados. 相似文献
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Ye. V. Rogozhina N. V. Kostina L. S. Malyukova 《Moscow University Soil Science Bulletin》2011,66(1):32-35
An estimation of potential nitrogen-fixing activity of various soil types under agrophytocenoses of tea, filbert, peach, and
pawpaw which grow in the area of Greater Sochi is given. High indicators of nitrogen fixation activity in the soil in the
course of vegetation were characteristic of agrocenoses of pawpaw, peach, and filbert. The lowest level of nitrogen fixation
was noted in the soil of a tea plantation. A negative correlation dependence of potential nitrogen-fixing activity on the
acidity of the soil solution was established. A study of the seasonal dynamics of the activity of nitrogen fixation of soils
of agrocenoses of the subtropical zone of Russia made it possible to distinguish a less active winter and more active spring-summer-autumn
periods. 相似文献
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物联网是一个集信息通信、数据交换、传感器技术与软件工程于一体的综合性产业,探讨和分析了物联网的结构体系与发展中遇到的安全问题。 相似文献
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荔枝种子从果实中剥离出来后, 即使在室内条件下, 也极易失水干缩, 潮湿环境中又易发霉而腐烂。扫描电镜观察表明: 种皮上布满纹孔, 水分散失面积很大; 种脐部为疏松的海绵组织, 且营养丰富。据此, 生产上应对种子彻底清洗, 并保存于适当湿度的环境中, 以提高其发芽率。 相似文献
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The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air‐popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first‐order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the internal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements. 相似文献