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91.
Guifeng, Yiyang County, belongs to a seriously degraded red soil region. In 1991, Pinus elliottii and Lespedaza spp. were the species selected for the establishment of a mixed forest in the area. The results of an investigation of the
soil system in a 12-year-old forest indicated the following: (1) Organic matter and total nitrogen of the forest soil to a
depth of 40 cm were 88.0 and 36.0% higher, respectively, than those of a control plot; total phosphorus and available phosphorus
were 40.9 and 22.3% higher than those of the control; available potassium contents were 8.13% lower than those of the control.
(2) Soil aeration and the soil air regime improved. (3) Proteinase, catalase, and urease in the forest soil to a depth of
40 cm were usually higher than those in the control plot and decreased with soil depth.
Translated from Acta Agriculturae Universitatis Jiangxiensis, 2005, 27(1) (in Chinese) 相似文献
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1991 ̄1995年试验结果表明,在江西分宜花岗岩残积物发育的黄红壤上,杉木幼林施N、P、K及配合处理,使树高、胸径、蓄积总生长量指标分别达到5.67 ̄6.59m、8.35 ̄9.28cm、67.922 ̄96.41m^3/hm^2,较对照增长5.6% ̄20.2%、7.4% ̄17.5%、21.6% ̄56.2%。在各种施肥处理中,以50kg/hm^2P2O5的效果最佳,其连年生长量效应显著持续到第5年; 相似文献
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Dormancy induction in container-grown Abies seedlings: Effects of environmental cues and seedling age 总被引:1,自引:0,他引:1
Twelve-week-old container-grown seedlings of noble fir (Abies procera Rehd.) and Shasta red fir (A. magnifica A. Murr. var. shastensis Lemm.), both high-elevation species, were grown under controlled environments in a study of induction of terminal-bud dormancy. Eight treatment combinations of long (15 h) or short (11 h) photoperiods, warm (25°/20°C) or cool (18°/12°C) thermoperiods, and dry (–1.2 MPa) or wet (–0.6 MPa) moisture regimes were imposed upon seedlings for 12 weeks. Treatment factors significantly affecting the induction of dormancy in terminal buds of seedlings were identified over time. The results suggest that seedlings responded dynamically to dormancy cues. The warm/dry and cool/wet combinations induced dormancy in the first 2 weeks in noble fir and in the first week in Shasta red fir. Short-day/warm and long-day/cool combinations enhanced dormancy induction in weeks 3 to 4 in noble fir and in weeks 1 to 7 in Shasta red fir. Short days and cool thermoperiods independently hastened dormancy induction in noble fir in weeks 5 through 12. 相似文献
98.
Anthony S. Davis Douglass F. Jacobs Kevyn E. Wightman Zonda K. D. Birge 《New Forests》2006,31(2):293-303
Bareroot hardwood seedling production involves intensive soil management. To increase soil organic matter (OM), nurseries
commonly grow a cover crop for 1 year after every 1–2 year of seedling production. Raising soil OM levels can also be achieved
through addition of soil amendments. We studied the influence of chicken manure (CM) and composted leaf, tree, and lawn trimmings
(Cp) on soil properties and morphology of green ash (Fraxinus pennsylvanica Marsh.) and northern red oak (Quercus rubra L.) seedlings. CM was applied at 725, 1450, or 2900 kg ha−1 (CM725, CM1450, and CM2900, respectively) and Cp was applied at 200 m3 ha−1. Addition of CM and Cp significantly raised soil OM levels and altered soil chemical properties compared to the control (Ctrl).
Root-collar diameter increased with addition of CM1450, CM2900, or Cp compared to CM725 or Ctrl plots for northern red oak,
but was largest in soils amended with CM2900 for green ash. Conversely, height was greatest with addition of CM725 for northern
red oak, but green ash seedlings were shorter in Ctrl plots than in all amendments except for CM725. Root volume of green
ash and northern red oak seedlings was positively influenced by addition of CM or Cp. Seedling responses to nursery soil amendments
vary with different forms and amounts of OM. Benefits to seedling growth through application of appropriate materials in the
proper balance can improve seedling morphological quality and positively influence soil chemical properties. 相似文献
99.
本试验旨在研究不同断母乳日龄对犊牛营养物质消化和血清生化指标影响。试验选用新生红安格斯与西门塔尔杂交肉犊牛60头,根据日龄和体重随机分成5个处理,每个处理12头犊牛,公母各占1/2,试验组分别在28、42、56和70日龄进行断母乳(分别为28A、42B、56C、70D组),随后人工哺乳代乳品至90日龄;对照组( CK组)随母哺乳至150日龄。试验时间为出生至150日龄,期间测定体重(0、70、90、150日龄)和血清生化指标(70、90、150日龄)的变化。每个处理选取6头犊牛分别在断奶前(85~90日龄)和断奶后(145~150日龄)进行2期消化代谢试验。每期6 d,其中2 d预试期,4 d正试期。结果显示:1)试验全期体重各组间无显著差异(P>0.05)。2)断奶前各组犊牛营养物质消化率差异不显著(P>0.05),断奶后28A、42B组犊牛干物质消化率显著高于56C、70D组( P<0.05),有机物消化率显著高于70D组( P<0.05),其中42B组消化率略高。3)150日龄试验结束时,28A和42B组血清葡萄糖、总蛋白、甘油三酯、尿素氮、胆固醇、结合珠蛋白、白细胞介素-2、胰岛素样生长因子-1、免疫球蛋白M含量与CK组相比差异不显著( P>0.05),血清免疫球蛋白G、免疫球蛋白A含量分别显著低于、高于CK组( P<0.05),其中42B组略高。由此可见,红安格斯与西门塔尔杂交肉犊牛的断母乳时间以42日龄较为适宜。 相似文献
100.
Patrizia CASAGRANDE PROIETTI Valentina STEFANETTI Doreene Rose HYATT Maria Luisa MARENZONI Stefano CAPOMACCIO Mauro COLETTI Annalisa BIETTA Maria Pia FRANCIOSINI Fabrizio PASSAMONTI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(8):945-951
Biofilm-forming ability is increasingly being recognized as an important virulence factor in several Staphylococcus species. This study evaluated the biofilm-forming ability of sixty canine derived clinical isolates of S. pseudintermedius, using three phenotypic methods, microtiter plate test (MtP), Congo red agar method (CRA) and tube adherence test, and the presence and impact of biofilm-associated genes (icaA and icaD). The results showed that icaA and icaD genes were detected concomitantly in 55 (91.7%) of 60 isolates. A majority (88.3%) of the strains screened had matching results by the tube adherence test, MtP and PCR analysis. Better agreement (95%) was found between the PCR-based analysis and the CRA. Results of the icaA and icaD gene PCRs showed good agreement with CRA results, with a kappa of 0.7. Comparing the phenotypic methods,
the statistical analysis showed that the agreement among the phenotypical tests using categorical data was generally good. Considering two classes (biofilm producer and biofilm non-producer), the percentage of matching results between the CRA method and the tube adherence test and between the CRA method and the MtP was 93.3%. A concordance of 100% was revealed between the MtP and the tube adherence test. The results indicate a high prevalence of the ica genes within S. pseudintermedius isolates, and their presence is associated with in vitro formation of a biofilm. A combination of phenotypic and genotypic tests is recommended for investigating biofilm formation in S. pseudintermedius. 相似文献