Results 31 to 40 of about 2,765 (167)
Shuitu Baochi Xuebao, 2007 对轮作及大豆、玉米、小麦长期连作白浆土中氮含量及有机态氮组分变化进行研究。结果表明，在不施肥情况下，小麦连作区土壤由全氮、碱解氮降幅最大，酸解总氮、氨基酸态氮和氨基糖态氮降幅最小。在施有机肥情况下，土壤全氮、碱解氮及酸解总氮则以小麦连作区增幅最小，玉米连作区增幅最大；氨基酸态氮和氨基糖态氮在轮作区增幅最大。其他组分氮在轮作与连作小区间变化无规律。
田秀平, 薛菁芳, 韩晓日
doaj +2 more sources
Shuitu Baochi Xuebao, 2005 于西藏中部生态条件下,就麦类作物轮作、麦油轮作对土壤化学和生物性质的影响以及农田养分平衡等进行了初步研究。结果表明,不同轮作方式对土壤化学和生物学过程具有显著不同的影响。轮作周期内春青稞→春油菜、春小麦→春油菜轮作对以细菌为主导的土壤微生物的生长与繁殖具有显著的促进作用,耕层土壤有机质、全氮、全磷的绝对增长量分别达3.05~3.06g/kg,0.06~0.07g/kg,0.01~0.26g/kg。麦类作物间,春小麦→春青稞轮作对土壤肥力亦具明显的恢复作用;春小麦→春小麦连作、春青稞 ...
钱成 蔡晓布 张永青
doaj
Effects of Cross-slope Tillage and Increasing Organic Fertilizer on Soil Nitrogen and Phosphorus Loss Characteristics and Soil Fertility on Gentle Slope [PDF]
, 2023 [Objective] Nitrogen and phosphorus loss characteristics and soil fertility changes on a gentle slope of cultivated land were analyzed under optimal fertilization and cross-slope tillage in order to provide a basis for reducing nitrogen and phosphorus ...
Chen Jianjun +4 more
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Functional Ecology, Volume 38, Issue 12, Page 2709-2719, December 2024.Read the free Plain Language Summary for this article on the Journal blog. Abstract Resilience to drought represents an important focus for trees during climate change, with the aim of predicting the resistance and recovery of species worldwide. Previous studies mainly linked tree growth resilience to plant functional traits that are related to ...
Xijin Zhang +7 more
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Shuitu Baochi Xuebao, 2018 通过田间试验研究了不同作物轮作模式中生物质、粗蛋白生产潜力和氨排放，以探讨粮改饲进程中较优的种植模式。以冬小麦—夏玉米（W-SuM）轮作为基准，探讨了华北地区黑麦草—夏玉米（R-SuM）、黑麦草—春玉米（R-SpM）、黑麦草—双季玉米（R-DM）和双季玉米(DM) 4种轮作体系的干物质、粗蛋白的生产潜力和氨气排放。结果表明：黑麦草—双玉米轮作模式较好，干物质年产量和粗蛋白含量分别达到31 012，2 529 kg/hm2，比常规冬小麦—夏玉米体系分别增加了14.3%，8.2 ...
杨 羚 +5 more
doaj
OPEN MIND: Shake Up Taboo by Design! [PDF]
, 2015 Gamman has contributed a 1,000-word article and a transcript of her keynote from the Open Design Forum 2014, Hong Kong Design ...
Davis, Sevra +3 more
core
Ultrasound in Obstetrics &Gynecology, Volume 64, Issue 5, Page 635-650, November 2024.ABSTRACT Objectives To reach an international expert consensus on the diagnosis, prognosis and management of fetal lower urinary tract obstruction (LUTO) by means of a Delphi procedure, and to use this to define a core outcome set (COS). Methods A three‐round Delphi procedure was conducted among an international panel of experts in fetal LUTO.
H. J. Mustafa +90 more
wiley +1 more source
Shuitu Baochi Xuebao, 2008 2003-2005年在宁南旱区将10年生苜蓿耕翻后进行了9种轮作方式的试验,研究不同轮作方式中前茬对第三年春小麦产量、土壤养分、pH值和酶活性的影响。结果表明,不同轮作方式下的第三年春小麦产量及土壤养分、pH值、酶活性各指标间差异性达到显著水平。0-60 cm土层有机质、全氮、碱解氮和速效钾平均含量均下降,降幅分别为0.05~2.24 g/kg,0.019~0.325 g/kg,0.118~12.280 mg/kg和8.87~166.88 mg/kg,pH值下降0.03~0.31 ...
刘沛松 +5 more
doaj
Research Progress of Nitrogen Leaching in Farmland Soil [PDF]
, 2014 对农田土壤氮素淋失的相关研究进行综述和总结是研究农业面源氮素污染的一个至关重要的前提。本文从土壤氮素渗漏淋失形态和迁移机理、氮素渗漏淋失的研究方法和影响土壤氮素渗漏淋失的因素三方面进行了详细的分析介绍,概述了近年来国内外农田氮素渗漏淋失的研究进展和研究成果,并在此基础上展望了未来氮素淋失研究工作的重点。研究结论对农田土壤的水肥管理措施及浅层地下水硝氮污染的减缓有一定的理论和借鉴意义Reviewing and summarizing the related research of farmland ...
朱木兰, 李青松, 王吉苹
core
Ultrasound in Obstetrics &Gynecology, Volume 64, Issue 5, Page 661-668, November 2024.ABSTRACT Objective To determine the diagnostic accuracy of virtual autopsy using whole‐body postmortem ultra‐high field magnetic resonance imaging (MRI) at 7 Tesla (T), using a short T2‐weighted imaging (T2‐WI) protocol, compared with classical autopsy, for detecting structural abnormalities in small second‐trimester fetuses. Methods Thirty consecutive
A. Staicu +11 more
wiley +1 more source