土壤施用有机物料后重组有机质变化规律的探讨Ⅰ.对有机无机复合及腐殖质结合形态的影响   总被引：1，自引：0，他引：1  

姜岩  窦森 《土壤学报》1987,24(2):98-104

通过在粉壤质黑钙土和粘壤质轻度盐化草甸土上进行田间、盆栽及培养试验,研究了施用各种有机物料后两年来重组有机质的变化状况.施用有机物料可以提高土壤有机质和重组有机质的含量,可以提高有机无机复合量,降低原土复合度.各种有机物料的效果并不一样,追加复合量和追加复合度均随玉米秸秆施用量的增加而提高,但复合系数却因用量的增加而降低.施用有机物料后重组有机质中各种结合形态的腐殖质在绝对含量上都明显提高,但以松结合态的增加较多,松/稳、松/紧比值提高.这种作用主要表现在施用的第一年.  相似文献   

Recovery of 15N Labelled Urea as Affected by Fixation of Ammonium by Clay Minerals     

Huating Dou  Diedrich Steffens 《植物养料与土壤学杂志》1995,158(4):351-354

A greenhouse experiment was conducted with Lolium perenne to determine whether ammonium (NH₄⁺-N) fixation by clay minerals can increase the recovery of nitrogen following application of ¹⁵N labelled urea. A silty loam subsoil, B_t horizon from an Alfisol derived from loess, pH (CaCl₂) 7.9, was chosen for the experiment. The NH₄⁺-N fixation capacity was altered by varying the distribution of potassium (K) in the upper and lower soil layer. In the K₀ treatment (control), the upper soil layer fertilized with urea was not supplied with K, whereas the lower soil layer was fertilized with 300 mg K kg^?1 soil. In the K₁^?, K₂^? and K₃ treatment the upper soil was supplied with 100-, 200- and 300 mg K kg^?1 soil, respectively. The soil in the lower layer of the K₃ treatment was not supplied with K. The recovery of ¹⁵N from applied urea (¹⁵N uptake of Lolium perenne plus residual soil ¹⁵N_t) was 86.1% in the K₀ treatment and 75.2%, 69.1% and 69.6% in K_1-, K_2- and K₃ treatments, respectively, showing that ¹⁵N losses were smallest in the K₀ treatment. Two weeks after applying ¹⁵N labelled urea the amounts of nonexchangeable ¹⁵NH₄⁺-N in the upper soil layer were significantly higher in the K₀ treatment than in the treatments with K application. Apparently, NH₄⁺-N fixation by clay minerals can reduce NH₃ volatilization after urea fertilization, if the amount of exchangeable K is low.  相似文献   

糖心菠萝的鲜切加工工艺及贮藏保鲜技术的优化研究     

孟祥春  窦同心  张爱玉  刘岩 《农产品加工．学刊》2011,(4):8-11

以广东省增城的糖心菠萝为原料,研究了果实的成熟度、切分后紫外线杀菌及抗坏血酸和柠檬酸处理对鲜切菠萝贮藏保鲜期及品质的影响。结果表明,选择适宜成熟度的整果,切分后用质量分数为1%柠檬酸或1%VC+1%柠檬酸浸泡处理,并将切块用紫外线照射杀菌,最后用托盘+保鲜膜包装,可延长鲜切菠萝的贮藏期至6d,较好地保持了糖心菠萝的新鲜品质和风味。  相似文献   

陇中黄土高原旱地覆盖耕作效应的初步研究   总被引：2，自引：1，他引：2  

窦学诚 《甘肃农业大学学报》1994,29(1):56-60

试验结果表明：小麦生育期秸秆覆盖能平抑土温变化和改善土壤水分环境，由于多因素关联作用，所以增产效果以适量覆盖最佳。另外，麦收后休闲期覆盖耕作均有利于改善下茬物的底墒条件，但对其它土壤性状影响不大。  相似文献   

苏格兰型留兰香优质高产栽培技术研究     

窦宏涛 《勤云标准版测试》2006,(1)

为了探索苏格兰型留兰香的优质高产栽培技术,对影响其产量和品质的主要农艺措施(如播期、密度、配方施肥、最佳收获期等)进行综合研究。结果表明苏格兰型留兰香精油产量≥82.5kg/hm2且品质优的农艺措施的优化方案为:播期11月7日—11月22日(即立冬至小雪),密度25.1￣36.2万苗/hm2,施肥量纯N169.2￣214.5kg/hm2、P2O591.8￣134.0kg/hm2,最佳收获期为主茎10%左右的花蕾开花期。  相似文献   

超数排卵对奶牛产奶量及繁殖能力的影响   总被引：5，自引：0，他引：5  

高志敏  窦忠英  王新庄 《西北农林科技大学学报(自然科学版)》1993,21(Z2):62-64

用FSH+PGF_(2)对16头黑白花奶牛进行超数排卵处理。超排前4d和超排1～10d日均产奶量差异不显著(P>0.05)。超排采胚后1头因年老淘汰,1头冲胚时发现患有慢性卡他性脓性子宫内膜炎进行治疗未配,其余14头冲胚后发情正常,人工授精后均妊娠,和正常牛发情配种妊娠率无差异。超数排卵对奶牛产奶量及繁殖能力无影响。  相似文献   

山羊骨髓间充质干细胞生物学性能鉴定及诱导分化为心肌细胞的研究     

庞全海张慧茹  华进联马勇江 窦忠英 《勤云标准版测试》2005,(5)

 研究了关中奶山羊骨髓间充质干细胞的分离、培养和生物学特性，并在体外诱导分化为心肌细胞表型。结果表明，山羊MSCs具有很好增殖能力；能够耐受反复冷冻和解冻；表达细胞表面标志CD44、CD105、CD166，弱表达CD34、CD106，而不表达CD14、CD45。该类细胞用5-氮胞苷诱导分化后，能够表达心肌α-actin，并呈PAS染色阳性。  相似文献   

Cellular immune responses of BALB/c mice induced by intramuscular injection of PRRSV-ORF5 DNA vaccine with different doses   总被引：1，自引：0，他引：1  

Anchun Cheng  Mingshu Wang  Xiwen Chen  Nigen Xini  Wenbo Dou  Xuemei Li  Wumei Liu  Gang Wang  Pingying Zhang 《Frontiers of Agriculture in China》2007,1(1):105-110

BALB/c mice were immunized with 50 μg, 100 μg, 200 μg of pcDNA-PRRSV-ORF5 DNA vaccine respectively by intramuscular injection, with PBS and pcDNA3.1(+) as controls. Fluorescence activated cell Sorter (FACS) was used to detect the number of CD₄ ⁺ and CD₈ ⁺ T-lymphocytes. T-lymphocyte proliferation test was used to detect proliferation of the T-lymphocyte cells in peripheral blood lymphocytes of mice vaccinated with pcDNA-PRRSV-ORF5 DNA vaccine. The results showed that the difference in ConA response to T-lymphocytes in blood was highly significant between all experimental groups and the control group (P < 0.01). The number of CD₄ ⁺ T-lymphocytes in experimental groups was significantly higher than that of the control group 7 d after vaccination. The number of CD₈ ⁺ T-lymphocytes in the experimental groups was higher than that of the control group 28 d after vaccination. Mice immunized with a higher dose (200 μg) of DNA vaccine demonstrated higher cellular immune response than those immunized with a lower dose (100 μg, 50 μg) of DNA vaccine. The results demonstrated that pcDNA-PRRSV-ORF5 DNA vaccine could induce a good cellular immune response which may be dose-dependent. __________ Translated from China J Vet Sci Mar, 2006, 26(2): 111–114 [译自: 中国兽医学报] The first three authors contribute equally to this work.  相似文献   

大豆根瘤菌(Bradyrhizobium japonicuum)在黑龙江省接种效果与接种有效性的研究     

窦新田  李树藩  李晓鸣  李新民  程恒昌  吴尔其  桑秀香  潘绍英 《中国农业科学》1989,(5)

据1983-1985年在黑龙江省45个县,(市)792个试验点,6种土壤和14个大豆品种的小区试验和大面积试验证明:大豆接种根瘤菌比不接种平均增产11.2%,每公顷增收大豆241.5公斤。5年(1983-1987)累计应用面积已达31.5万公顷。由于大豆接种根瘤菌增加了大豆的结瘤数和根瘤重、植株鲜重和干重、植株含氮量和根瘤固氮酶活性,从而提高大豆产量和籽实蛋白质含量。本文研究了大豆接种根瘤菌的有效性与土著根瘤菌生态分布(以大豆自然结瘤性状C值、接种回收率为指标),大豆品种对根瘤菌的选择性,土壤化学因子(N.P.K.DH.有机质)的相关关系以及与化学肥料(磷酸二铵)、微量元素肥料(钼酸铵),VA菌根真菌的联合增产效应。  相似文献   

光肩星天牛幼虫空间分布型的研究   总被引：3，自引：0，他引：3  

张树怀  赵建兴  夏秀清  窦玉珍 《内蒙古农业大学学报(自然科学版)》1996,(4)

本文采用扩散系数Ｃ法、扩散指数Ｉ０法、Ｃａｓｓｉｃ指标ＣＡ法，种群群集均数入法，Ｔａｙｌｏ指数ｂ法和Ｉｗａｏ的平均拥挤度ｍ与平均数ｘ的回归分析法，测定了杨树上光肩星天牛幼虫的空间分布属于聚集分布，符合负二项分布模型。同时探讨了空间分布型在序贯抽样中的应用。行道树和防护林中理论取样数（Ｎ）与单株虫口平均密度（ｘ－）的关系分别为：Ｎ＝８．００利用有虫株率（Ｐ）简易估计虫口密度的关系式分别为：ｘ＝７．２６２０［－／ｎ（１一Ｐ）］￣０．６００３和ｘ＝３．６９２５［－１ｎ（１－Ｐ）］￣．３９１０１。  相似文献