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猴耳环苗木的结瘤、生物产量和养分化学计量特征对施肥的响应
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作者 黄世能 张迪 +1 位作者 王雪鑫 陈祖旭 《南方林业科学》 2022年第3期37-40,60,共5页
为探明猴耳环苗期的合理施肥措施及编制其人工林栽培的标准操作规程(SOP)提供理论依据,本研究采用L_(9)(3^(3))正交设计开展了N、P、K 3种肥料不同配比的苗期施肥试验,测定了苗木结瘤、生物产量与化学计量特征对施肥的响应,并用N-P-K限... 为探明猴耳环苗期的合理施肥措施及编制其人工林栽培的标准操作规程(SOP)提供理论依据,本研究采用L_(9)(3^(3))正交设计开展了N、P、K 3种肥料不同配比的苗期施肥试验,测定了苗木结瘤、生物产量与化学计量特征对施肥的响应,并用N-P-K限制因子三轴图确定苗木生长的限制因子。结果表明,不同配比施肥对9个月生苗木的结瘤数量和鲜重没有显著影响,但对生物产量影响显著,N∶P∶K=20∶20∶0配比苗木的生物产量显著高于其他配比,增加N肥可显著提高苗木的生物产量。N、P、K化学计量关系分析表明N是猴耳环苗木生长的限制因子,苗期施加适量的N肥对苗木发育有益。 展开更多
关键词 猴耳环 施肥 结瘤 生物产量 养分化学计量
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皖西大别山农耕区表层土壤养分地球化学综合评价及影响因素
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作者 董秋瑶 宋超 +3 位作者 温皓天 向娇 王攀 严明疆 《岩矿测试》 CAS CSCD 北大核心 2024年第2期344-355,共12页
土壤养分是影响农作物产量的重要指标,掌握中国主要农业生产区的土壤养分时空演变特征对合理使用农业土地资源具有重要的意义。本文以中国重要农耕区皖西大别山六安地区为研究区,采集浅层土壤(0~20cm)样品1295组,采用硫碳仪、X射线荧光... 土壤养分是影响农作物产量的重要指标,掌握中国主要农业生产区的土壤养分时空演变特征对合理使用农业土地资源具有重要的意义。本文以中国重要农耕区皖西大别山六安地区为研究区,采集浅层土壤(0~20cm)样品1295组,采用硫碳仪、X射线荧光光谱法、电感耦合等离子体发射光谱法等技术进行测试。应用统计学分析方法,在分析pH值的基础上,对总氮(TN)、总磷(TP)和钾(K)和土壤有机质(SOM)四个地球化学养分指标进行单指标养分等级划分和土壤养分综合等级评价,并探讨了各项指标的影响因素。结果表明:研究区98.88%的土壤为酸性土壤(其中8.03%为强酸性土壤),受地貌类型影响较大;TN分布以中等丰富为主,受土壤类型影响较大;TP以中等含量和缺乏为主,受地貌类型的影响较大;K是最为丰富的元素,其含量在中等及以上的比例达97.81%,主要受地貌类型的影响;SOM以中等和较缺乏为主,受土壤类型、土地利用方式和地貌类型的共同影响,且SOM含量与TN含量呈高度正相关。全区土壤养分等级以中等为主,占全区总面积的60.10%,其次是较缺乏土壤,占25.27%,南部山区养分状况优于北部平原区。整体上,研究区土壤具有养分较差、养分分布不均匀、普遍酸化的特点,部分地区应按需调整肥料的使用平衡土壤养分。可通过农田养分的管理,提高农业产量。 展开更多
关键词 表层土壤 电感耦合等离子体发射光谱法 土壤养分地球化学综合等级评价 土地利用方式 土壤类型 地貌类型
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不同间伐强度对华北落叶松人工林土壤养分-微生物生物量-胞外酶化学计量的影响 被引量:7
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作者 曹芹 邱新彩 +2 位作者 刘欣 彭道黎 程顺 《中南林业科技大学学报》 CAS CSCD 北大核心 2022年第4期83-92,共10页
【目的】探究间伐强度对土壤养分-微生物生物量-胞外酶化学计量特征的影响。【方法】以河北省塞罕坝机械林场华北落叶松人工林为研究对象,设置不同间伐强度(对照、轻度间伐、中度间伐和重度间伐)标准地,采集0~10、10~20和20~30 cm土壤样... 【目的】探究间伐强度对土壤养分-微生物生物量-胞外酶化学计量特征的影响。【方法】以河北省塞罕坝机械林场华北落叶松人工林为研究对象,设置不同间伐强度(对照、轻度间伐、中度间伐和重度间伐)标准地,采集0~10、10~20和20~30 cm土壤样品,测定土壤养分含量、微生物生物量含量和胞外酶活性,分析土壤养分-微生物生物量-胞外酶化学计量比。【结果】1)随间伐强度增大,土壤碳(C)、氮(N)、磷(P)含量先增后降,在中度间伐中观测到最大值;间伐降低了土壤C∶N、C∶P和N∶P。2)间伐提高了土壤微生物生物量碳、氮和磷(MBC,MBN和MBP)含量,尤其是中度间伐;间伐提高了土壤MBC∶MBN而降低了MBN∶MBP,土壤MBC∶MBP在不同间伐强度间无显著差异(P>0.05)。3)土壤β-1,4-葡萄糖苷酶(BG)活性在不同间伐强度间未表现出显著差异(P>0.05),土壤β-1,4-N-乙酰氨基葡萄糖苷酶+亮氨酸氨肽酶(NAG+LAP)活性、酸性磷酸酶(AP)活性和(NAG+LAP)∶AP在中度间伐和重度间伐中显著高于对照和轻度间伐(P<0.05),中度间伐和重度间伐的BG∶(NAG+LAP)显著低于对照和轻度间伐(P<0.05),中度间伐的土壤BG∶AP显著低于对照(P<0.05)。【结论】间伐能够促进养分循环,尤其是中度间伐。研究结果可为不同间伐强度人工林中养分循环、资源限制和生态过程研究提供理论支撑,为该区域华北落叶松人工林的合理经营提供理论依据。 展开更多
关键词 间伐强度 华北落叶松 土壤养分-微生物生物量-胞外酶化学计量 相对资源限制
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中国土壤化学的研究与展望 被引量:21
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作者 徐建明 蒋新 +7 位作者 刘凡 窦森 周立祥 徐仁扣 徐明岗 黄巧云 李航 何艳 《土壤学报》 CAS CSCD 北大核心 2008年第5期817-829,共13页
回顾土壤化学中重要研究领域的研究进展,可为21世纪土壤科学的长远发展提供基础学科分支的理论依据。本文在简短回顾我国土壤化学发展历程的基础上,总结讨论了近年来我国土壤化学的研究特点、现状及部分进展,并据此对该领域的未来研究... 回顾土壤化学中重要研究领域的研究进展,可为21世纪土壤科学的长远发展提供基础学科分支的理论依据。本文在简短回顾我国土壤化学发展历程的基础上,总结讨论了近年来我国土壤化学的研究特点、现状及部分进展,并据此对该领域的未来研究趋势及重点发展方向作了概括性展望。综合分析认为,对土壤进行宏观调控要以土壤微观性质的认识为前提。新近基于分子尺度微观光谱技术对土壤微观性质的原位观测及认识的飞跃是近年来我国土壤化学研究领域迅速发展的基础;近代土壤学、环境科学、生态学、生物地球化学、化学、生物学以及地质医学等多学科的交叉与渗透又进一步拓展了传统土壤化学研究的领域,促进了土壤化学多个分支学科的形成和发展;立足农业生产,同时着眼于人类生存环境转变,建立具有中国特色的可变电荷土壤化学理论与技术体系,完善现代土壤学理论,是今后中国土壤化学研究的重要发展方向。 展开更多
关键词 土壤化学 胶体化学 界面化学 有机质化学 养分化学 污染化学
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西藏墨脱县优选耕地土壤养分地球化学特征
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作者 索朗次仁 多吉卫色 +2 位作者 次仁旺堆 洛桑旺堆 尼玛次仁 《现代盐化工》 2022年第5期98-100,共3页
对墨脱县优选耕地区进行土壤养分地球化学特征分析,查明墨脱县调查区土地质量状况,为调查区所在地方政府履行土地资源管理、农业结构调整、土壤环境保护、脱贫攻坚等管理职能提供科学依据。通过对185件样品进行有机质、N、P、K、B、Mn... 对墨脱县优选耕地区进行土壤养分地球化学特征分析,查明墨脱县调查区土地质量状况,为调查区所在地方政府履行土地资源管理、农业结构调整、土壤环境保护、脱贫攻坚等管理职能提供科学依据。通过对185件样品进行有机质、N、P、K、B、Mn、Zn、Cu、Se、Mo、碱解N、速效P、速效K、pH、As、Cd、Cr、Hg、Pb、Ni、Co、V、F、I、Ge等25项元素指标的分析测试发现,墨脱县调查区的土壤以酸性土壤为主,而调查区表层土壤有机质含量以较丰富、丰富为主,两者合计面积达到22.02 km2,占调查区总面积的86.71%。调查区土壤全氮、碱解N、全磷、有机质含量相当丰富,全钾、速效P含量以中等为主,速效K以较缺乏为主。根据土壤养分综合等级划分,调查区土壤养分综合评价等级丰富的地块面积占4.90%,较丰富的地块面积占78.83%,中等的地块面积占15.41%,较缺乏地块面积占0.86%,无缺乏地块。 展开更多
关键词 土壤养分地球化学特征 元素组合及分布规律 墨脱县
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不同种植年限对贺兰山东麓葡萄园土壤养分特性的影响
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作者 孙浩然 董琼 +3 位作者 李惠霞 周静 马瑞 李晓慧 《中国农学通报》 2024年第30期75-83,共9页
贺兰山东麓地区具有独特的地理环境和良好生态条件,是中国优质的葡萄酒产区,土壤营养条件与葡萄酒的品质紧密相关。本研究旨在探究贺兰山东麓不同种植年限葡萄园土壤化学性质及养分状况,以期对该地区特色产业结构调整提供依据。通过方... 贺兰山东麓地区具有独特的地理环境和良好生态条件,是中国优质的葡萄酒产区,土壤营养条件与葡萄酒的品质紧密相关。本研究旨在探究贺兰山东麓不同种植年限葡萄园土壤化学性质及养分状况,以期对该地区特色产业结构调整提供依据。通过方差分析和Pearson相关性分析,对树龄小于5 a、5~10 a、超过10 a的3种不同种植年限葡萄园样地土壤进行了评估。结果显示,当种植年限在5~10 a之间时,土壤pH呈现下降趋势;而当种植年限超过10 a时,pH开始上升。在树龄为5~10 a的土壤中,有效磷和速效钾含量表现出明显的波动,但当树龄超过10 a时,这些含量开始恢复。不同深度层土壤中的有机质、碱解氮、全磷和全钾含量受树龄的影响较小,存在一定范围的波动。养分因子之间的相关性分析发现,当种植年限超过10 a后,养分因子之间的相关性显著降低。这些结果表明,随着种植年限的增加,土壤养分因子以及养分因子之间的关系会发生变化,这为优化贺兰山东麓地区葡萄园土壤管理和改良提供了依据。 展开更多
关键词 贺兰山东麓 葡萄园 土壤 化学性质 养分特征 种植年限
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不同放牧干扰对滇西北高原泥炭沼泽土壤生态化学计量特征的影响 被引量:10
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作者 方昕 郭雪莲 +1 位作者 郑荣波 付倩 《水土保持研究》 CSCD 北大核心 2020年第2期9-14,共6页
为了阐明放牧过程对泥炭沼泽土壤化学计量特征的影响及机制,为放牧对湿地生态系统干扰及泥炭沼泽养分循环研究提供理论基础。以滇西北高原泥炭沼泽为研究对象,分析了土壤含水率、pH值、总有机碳(TOC)、总氮(TN)、总磷(TP)、铵态氮(NH+4... 为了阐明放牧过程对泥炭沼泽土壤化学计量特征的影响及机制,为放牧对湿地生态系统干扰及泥炭沼泽养分循环研究提供理论基础。以滇西北高原泥炭沼泽为研究对象,分析了土壤含水率、pH值、总有机碳(TOC)、总氮(TN)、总磷(TP)、铵态氮(NH+4-N)、硝态氮(NO-3-N)及土壤碳(C)、氮(N)、磷(P)生态化学计量特征,从而研究了放牧过程中藏猪翻拱(ZG)和牦牛践踏(JT)对泥炭沼泽土壤化学计量特征的影响。结果表明:放牧降低了土壤含水率、pH值、TN、TOC含量,增加了TP含量;ZG显著增加了NO-3-N含量。放牧降低了土壤养分化学计量,其中ZG和JT的C/P存在显著差异(p<0.05);放牧降低了微生物生物量碳氮比(MBC/MBN)及微生物生物量碳磷比(MBC/MBP),却提高了微生物生物量氮磷比(MBN/MBP),其中ZG对微生物生态化学计量的影响显著高于JT;放牧增加了生态酶化学计量。冗余分析显示TP、含水率、容重、NO-3-N、TOC是主要影响化学计量的环境因子。MBC/MBN,MBN/MBP均与对应的生态酶化学计量呈正相关,然而MBC/MBP呈相反趋势。C/N,C/P均与对应的生态酶化学计量呈正相关,然而N/P与对应的生态酶活性呈负相关。土壤养分化学计量变化影响了微生物生态化学计量以及生态酶化学计量。 展开更多
关键词 放牧干扰 土壤养分化学计量 生态酶化学计量 泥炭沼泽
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菌根真菌调控灌木铁线莲根际土壤生态化学计量特征对氮沉降的应激响应 被引量:4
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作者 郝龙飞 刘婷岩 +2 位作者 何永琴 张盛晰 赵媛 《林业科学》 EI CAS CSCD 北大核心 2022年第6期151-160,共10页
【目的】对比1年生灌木铁线莲菌根苗与非菌根苗根际土壤生态化学计量特征对氮沉降的响应规律,分析菌根生物技术对苗木根际土壤微生态环境的调控机制,为探究全球气候变化背景下生态系统稳定性提供理论参考。【方法】以1年生盆栽灌木铁线... 【目的】对比1年生灌木铁线莲菌根苗与非菌根苗根际土壤生态化学计量特征对氮沉降的响应规律,分析菌根生物技术对苗木根际土壤微生态环境的调控机制,为探究全球气候变化背景下生态系统稳定性提供理论参考。【方法】以1年生盆栽灌木铁线莲菌根苗(3种丛枝菌根真菌接种处理:根内根孢囊霉、摩西斗管囊霉单一接种和2种AMF菌剂等质量1∶1混合接种)和非菌根苗(未接菌处理)为研究对象,设置4个氮沉降处理,即不施氮(0N,0 g·m^(-2)a^(-1))、低氮(LN,3 g·m^(-2)a^(-1))、中氮(MN,6 g·m^(-2)a^(-1))和高氮(HN,9 g·m^(-2)a^(-1)),分析1年生灌木铁线莲根际土壤有效养分生态化学计量比、微生物生物量化学计量比、酶化学计量比和微生物养分限制(向量长度表示微生物碳相对限制程度;向量角表示微生物氮或磷相对限制程度)等指标,探究接菌和氮沉降处理对根际土壤微生物代谢的调控机制。【结果】各氮沉降处理中,3种接菌处理苗木根际土壤可溶性有机碳与有效氮的比值和可溶性有机碳与有效磷的比值均高于未接菌处理。3种接菌处理中,HN处理根际土壤有效氮与有效磷的比值最大,显著(P<0.05)高于LN处理;而未接菌处理根际土壤有效氮与有效磷的比值则在MN处理最大,显著(P<0.05)高于LN处理。0N处理下,未接菌处理微生物生物量氮与微生物生物量磷的比值显著(P<0.05)高于其他3种接菌处理,而MN和HN处理下,未接菌处理微生物生物量氮与微生物生物量磷的比值显著(P<0.05)低于其他3种接菌处理。LN处理下,接种摩西斗管囊霉处理微生物生物量碳与微生物生物量氮的比值分别较未接菌处理、接种根内根孢囊霉处理和混合接菌处理显著(P<0.05)增加208.5%、109.2%和209.4%。0N处理下,3种接菌处理中与碳和氮转化相关酶的化学计量比、与碳和磷转化相关酶的化学计量比、向量长度和向量角均显著(P<0.05)高于未接菌处理;而HN处理下,不同接菌处理的向量长度间无显著差异。接菌处理对微生物碳限制和磷限制的总效应系数大于氮沉降处理,且接菌处理导致微生物碳限制和磷限制增加。【结论】接种菌根真菌可有效调控根际土壤生态化学计量特征对低氮沉降的响应,其中摩西斗管囊霉的调控能力最强;接菌处理对根际土壤微生物碳限制和磷限制的调控作用大于氮沉降处理。 展开更多
关键词 丛枝菌根真菌 氮沉降 有效养分化学计量比 微生物生物量化学计量比 化学计量比 微生物养分限制
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杉木×观光木异龄复层混交对林木生长及土壤理化性质的影响 被引量:20
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作者 刘涛 王家妍 +2 位作者 李万年 莫雅芳 杨梅 《西北林学院学报》 CSCD 北大核心 2022年第1期125-130,共6页
为探究杉木纯林引入观光木转化为异龄复层林后土壤理化性质和土壤养分含量的变化特征,以及驱动土壤肥力变化的主要影响因子,以观光木纯林、杉木纯林和杉木林下套种观光木形成的杉木×观光木异龄复层林为对象,测定了3种林型下林分生... 为探究杉木纯林引入观光木转化为异龄复层林后土壤理化性质和土壤养分含量的变化特征,以及驱动土壤肥力变化的主要影响因子,以观光木纯林、杉木纯林和杉木林下套种观光木形成的杉木×观光木异龄复层林为对象,测定了3种林型下林分生长、林地土壤理化性质和养分含量及其化学计量比等指标,分析杉木×观光木异龄复层林林分结构、林木生长和土壤肥力质量特点。结果表明:1)异龄复层林中观光木和杉木的树高、胸径分别为5.3 m、2.52 cm和18.56 m、20.19 cm,显著高于纯林;2)3种林型间土壤物理性质差异显著。异龄复层林相比较纯林,土壤密度降低4.84%~11.94%,土壤孔隙度分别增加10.29%~22.27%,持水量增加8.62%~34.54%,有效改善了土壤孔隙结构和持水状况。3)各层土壤有机质、全N、全P、全K及速效养分与观光木、杉木纯林均差异显著,土壤养分含量随着土层加深而递减。各养分含量分别比杉木、观光木纯林高出7.87%~41.31%、14.32%~53.57%,各层土壤有机质和养分含量由大到小呈现为:异龄复层林、杉木纯林、观光木纯林。4)异龄复层林中C∶N、C∶P平均值分别为16.62、61.46,均低于杉木和观光木纯林,促进了土壤中N、P的有效释放。因此,在异龄复层林中观光木获得更适宜其生长的良好的遮阴环境,2个树种间形成生态位互补,提高了空间和自然资源的利用率,促进了树木生长。异龄复层林能显著提高土壤有机碳和养分含量,且明显高于纯林,在杉木林中套种观光木能加快土壤微生物的转化和矿化作用。 展开更多
关键词 异龄复层混交林 林分改造 观光木混交 土壤理化性质 土壤养分化学计量比
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Application of N: P Stoichiometry to Ecology Studies 被引量:88
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作者 张丽霞 白永飞 韩兴国 《Acta Botanica Sinica》 CSCD 2003年第9期1009-1018,共10页
Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study e... Stoichiometry has long been addressed in the studies of ecosystem ecology, but it was almost ignored for a long time. Until recently, ecologists have become aware that stoichiometry could provide a new tool to study ecology from genes to the biosphere. Among this trend, N:P stoichiometry is used actively in ecological interactions since nitrogen (N) and phosphorus (P) are the two most important elements in most ecosystems. This article reviews the application of N:P stoichiometry to the studies of ecological problems at different levels, including ecosystem, community and species. Meanwhile, we also provide the cellular basis of N:P stoichiometry, identify the shortages in the use of N:P stoichiometry theory, and put forward some perspectives for future research to be conducted. 展开更多
关键词 trophic interaction trophic dynamics ecological interactions nutrient limitation
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Chemical Constituents of the Suspension Cell Cultures of Maytenus hookeri 被引量:7
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作者 鲁春华 张建新 +1 位作者 甘烦远 沈月毛 《Acta Botanica Sinica》 CSCD 2002年第5期603-610,共8页
Suspension cell cultures of Maytenus hookeri Loos. (Celastraceae) in SH media were established from the calli induced from the leaves and young steins of M. hookeri on MS media with the supplement of 2 mg/L 2,4-D and ... Suspension cell cultures of Maytenus hookeri Loos. (Celastraceae) in SH media were established from the calli induced from the leaves and young steins of M. hookeri on MS media with the supplement of 2 mg/L 2,4-D and 0.1 mg/L KIN (kinetin). Ethyl acetate extract of the cultures showed inhibitory activities against Penicillium avellaneum UC-4376 which was sensitive to maytansinoids. Exhaustive isolation of natural products from a large scale of suspension cell cultures did not yield maytansine instead of affording nine compounds including one novel triterpenoid, named 2, 3-diacetoxyl maytenusone (1), and eight known ones including squalene (2), beta-sitosterol (3), 2', 3', 4-triacetyl-sitoindoside I (4), salaspermic acid (5), maytenonic acid (6), 2alpha-hydroxy-maytenonic acid (7), 6, 11,12-trihydroxy-8, 11, 13-abietrien-7-one (8) and 11, 12-dihydroxy-8, 11, 13-abietatrien-7-one (9) elucidated on the basis of 1D and 2D NMR data. The H-1-NMR and C-13-NMR assignments were made for 1, 5, 6 and 7, while the C-13-NMR assignments for 5 and 6 were revised. The chemical results suggested that the suspension cell cultures of M. hookeri did not produce maytansinoids under the reported experiment conditions. 展开更多
关键词 Maytenus hookeri CELASTRACEAE suspension cell cultures maytansine 2 3-diacetoxyl maytenusone
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亚热带森林公园土壤微生物量碳分布的影响因素研究
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作者 钟言钰 罗协 李思悦 《环境保护前沿》 2023年第6期1237-1246,共10页
研究以武汉市八分山、青龙山、马鞍山、磨山和九峰山森林公园为对象,研究土壤微生物量碳的分布特征及其土壤环境影响因子。在每座山选择8种主要树种,共设置120个采样点,于2021年9月至11月进行土壤样品采集,采用抖落法采集根际土壤样品... 研究以武汉市八分山、青龙山、马鞍山、磨山和九峰山森林公园为对象,研究土壤微生物量碳的分布特征及其土壤环境影响因子。在每座山选择8种主要树种,共设置120个采样点,于2021年9月至11月进行土壤样品采集,采用抖落法采集根际土壤样品。结果显示:(1) 八分山(57.42~502.22 mg∙kg−1)、青龙山(148.59~563.78 mg∙kg−1)、马鞍山(270.76~908.44 mg∙kg−1)和磨山(137.45 ~ 654.81 mg∙kg−1)不同植物群落土壤微生物量碳间差异显著,九峰山(224.18~595.56 mg∙kg−1)不同植物土壤微生物量碳间无显著差异。(2) 青龙山土壤微生物量碳与铵态氮(r = 0.462, p < 0.05)呈显著正相关;马鞍山土壤微生物量碳与有机碳(r = 0.648, p < 0.01)、硝态氮(r = 0.434, p < 0.05)、铵态氮(r = 0.474, p < 0.05)、无机氮(r = 0.532, p < 0.01)、C:P (r = 0.560, p < 0.01)和N:P (r = 0.420, p < 0.05)呈显著正相关;九峰山土壤微生物量碳与铵态氮(r = 0.578, p < 0.01)、无机氮(r = 0.573, p < 0.01)、C:P (r = 0.551, p < 0.01)和N:P (r = 0.465, p < 0.05)呈显著正相关;八分山和磨山土壤微生物量碳均与环境因子无显著差异。(3) 五座森林公园的土壤微生物量熵碳范围在1%~4%。层次分割法表明土壤微生物量碳的关键驱动因子为有机碳。 展开更多
关键词 土壤碳库 森林土壤 城市森林公园 养分化学计量比 驱动因素
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江苏淮安地区耕地质量现状分析 被引量:5
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作者 张玉萍 姜井军 陈凤英 《江苏农业科学》 CSCD 北大核心 2002年第4期73-74,共2页
关键词 江苏 淮安地区 耕地质量 现状 化学养分 污染程度
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Effects of Tobacco-rice Continuous Cropping Years on Soil Physicochemical Properties and Tobacco Yield and Quality
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作者 向鹏华 郭维 +3 位作者 单雪华 黄银章 陈山 龙世平 《Agricultural Science & Technology》 CAS 2016年第11期2668-2671,2676,共5页
To investigate the effects of long term tobacco-rice continuous cropping on soil nutrients and flue-cured tobacco leaf yield and quality, the soils of different con- tinuous cropping years were selected in tobacco-ric... To investigate the effects of long term tobacco-rice continuous cropping on soil nutrients and flue-cured tobacco leaf yield and quality, the soils of different con- tinuous cropping years were selected in tobacco-rice multiple system of Hengyang. Some important indexes, including pH, contents of organic matter and available nu- trients of N P K, contents of medium trace elements of soil samples, and contents of main chemical components of flue-cured tobacco samples were detected for fur- ther analyzing. The results showed that pH value of moderate continuous cropping soil(≤7 years) was more coordinated, in addition, leaf yield and quality of flue-cured tobacco were contained, and the sugar-nicotine ratio and potassium-chlorine ratio were proper. However, under long-term continuous cropping (≥10 years) condition, the soil became acidification, and yield and output value of flue-cured tobacco de- clined. It was suggested that improving soil quality by planting green manure or keeping fallow after continuous cropping 7 years in tobacco-rice system. 展开更多
关键词 Tobacco-rice continuous cropping Continuous cropping years Soil nutrients Leaf yield Chemical component
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Exopolysaccharides from Marine Bacteria 被引量:7
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作者 CHIZhenming FANGYan 《Journal of Ocean University of China》 SCIE CAS 2005年第1期67-74,共8页
Microbial polysaccharides represent a class of important products of growing interest for many sectors of indus- try. In recent years, there has been a growing interest in isolating new exopolysaccharides (EPSs)-produ... Microbial polysaccharides represent a class of important products of growing interest for many sectors of indus- try. In recent years, there has been a growing interest in isolating new exopolysaccharides (EPSs)-producing bacteria from marine environments, particularly from various extreme marine environments. Many new marine microbial EPSs with novel chemical compositions, properties and structures have been found to have potential applications in fields such as adhesives, textiles, Pharmaceuticals and medicine for anti-cancer, food additives, oil recovery and metal removal in mining and indus- trial waste treatments, etc This paper gives a brief summary of the information about the EPSs produced by marine bacteria, including their chemical compositions, properties and structures, together with their potential applications in industry. 展开更多
关键词 marine bacteria exopolysaccharides (EPSs) chemical composition potentialapplication
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Science Letters:Nutritional composition of Pakistani wheat varieties
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作者 IKHTIAR Khan ALAM Ze 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第8期555-559,共5页
Pakistani wheat varieties are grown over a wide agro-climatic range and as such are anticipated to exhibit yield and quality differences. It is therefore necessary to investigate the nutritional status of wheat variet... Pakistani wheat varieties are grown over a wide agro-climatic range and as such are anticipated to exhibit yield and quality differences. It is therefore necessary to investigate the nutritional status of wheat varieties in terms of biochemical and physiochemical characteristics available for food and nutritional purposes in Pakistan. The result shows that wheat grains of different varieties contain a net protein level of 9.15%~10.27%, 2.15%~2.55% total fats, 1.72%~1.85% dietary fibers, 77.65×10-6~84.25×10-6 of potassium and 7.70×10-6~35.90×10-6 of sodium ions concentration, 0.24×10-6~0.84×10-6 of phosphorus, 1.44%~2.10% ash, 31.108~43.602 g of thousand grain mass (TGM) and 8.38%~9.67% moisture contents. This study is significant in providing an opportunity to explore the available wheat varieties and to further improve their nutritional excellence and also essential for setting nutritional regulations for domestic and export purposes. 展开更多
关键词 Wheat varieties Chemical composition Physiochemical characteristics
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Soil Organic Carbon and Nutrients along an Alpine Grassland Transect across Northern Tibet 被引量:9
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作者 CAO Ying-zi WANG Xiao-dan +2 位作者 LU Xu-yang YAN Yan FAN Ji-hui 《Journal of Mountain Science》 SCIE CSCD 2013年第4期564-573,共10页
Soil carbon and nutrient contents and their importance in advancing our understanding of biogeochemical cycling in terrestrial ecosystem, has motivated ecologists to find their spatial patterns in various geographical... Soil carbon and nutrient contents and their importance in advancing our understanding of biogeochemical cycling in terrestrial ecosystem, has motivated ecologists to find their spatial patterns in various geographical area. Few studies have focused on changes in the physical and chemical properties of soils at high altitudes. Our aim was to identify the spatial distribution of soil physical and chemical properties in cold and arid climatic region. We also tried to explore relationship between soil organic carbon (SOC) and total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), soil particle size distribution (PSD). Samples were collected at 44 sites along a 300 km transect across the alpine grassland of northern Tibet. The study results showed that grassland type was the main factor influencing SOC, TN and TP distribution along the Gangdise Mountain-Shenzha-Shuanghu Transect. SOC, TN and TP contents were significantly higher in alpine meadow than alpine steppe ecosystems. SOC, TN, TP and AN contents in two soil layers (0-15 cm and 15-3o cm) showed no significant differences, while AP content in top soft (0-15 cm) was significantly higher than that in sub-top soil (15-30cm). SOC content was correlated positively with TN and TP content (r = 0.901and 0.510, respectively). No correlations were detected for clay content and fractal dimension of particle size distribution (D). Our study results indicated the effects of vegetation on soil C, N and P seem to be more important than that of rocks itself along latitude gradient on the northern Tibetan Plateau. However, we did not found similar impacts of vegetation on soil properties in depth. Inaddition, this study also provided an interesting contribution to the global data pool on soil carbon stocks. 展开更多
关键词 Soil organic carbon Total nitrogen Total phosphorus Particle size distribution Alpinegrassland TIBET
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Comparative Utilization of Different Fibre Feedstuffs by Weaning/Growing Pigs in the Tropics 被引量:2
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作者 Emmanuel Oluropo Akinfala Omotola Macaulay Samuel Temitope Ogundeji 《Journal of Agricultural Science and Technology(A)》 2014年第2期149-154,共6页
This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel... This study was conducted to investigate the effect of feeding different fibre feedstuffs on the performance, nutrient utilization and economics of production of weaning/growing pigs. Five fibre feedstuffs--palm kernel cake (PKC), wheat offal (WO), corn bran (CB), rice bran (RB) and brewers' dried grain (BDG) were used at 25% in each of the five experimental diets that were formulated in this study. Twenty weaner pigs (12.75 ± 0.6 kg) were used for the growth study while 15 pigs (14.95 ± 0.57 kg) were used for the digestibility study. The design of the experiment was completely randomized. The results of the study showed that the performance of the experimental animals were significantly influenced (P 〈 0.05) by the dietary treatments. The apparent digestibility of the crude protein, crude fiber and ether extract showed significant differences (P 〈 0.05) while there was no significant difference (P 〉 0.05) in the apparent digestibility of their dry matter, ash and nitrogen free extract. The diet that contained WO had the best growth response and apparent nutrient digestibility. Results of economics of production also showed that diet with WO gave the best (P 〈 0.05) value in feed cost/'kg gain and net profit/animal. It can be concluded from this study that although all the animals fed the different fibre feedstuffs performed satisfactorily on all the parameters monitored, but for optimum growth, apparent nutrients digestibility and economics of production. WO should be used as a fibre feedstuff in the diets of weaning/growing pigs in the tropics. 展开更多
关键词 PIGS performance DIGESTIBILITY economics of production DIETS
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Effect of Nutrient Type on Chemical Composition and Dry Matter Partitioning of Cassava (Manihot esculenta Crantz)
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作者 V. D. Taffouo E. Tsoata +3 位作者 M. Kenne R. J. Priso T. Fonkou A. Akoa 《Journal of Agricultural Science and Technology》 2010年第4期96-102,共7页
The objective of our study was to determine the effects of four types of fertilisers enrichments (manure potassic (K), phosphatic (P), phosphatic and potassic (PK) and nitrogenized, phosphated and potassic (NP... The objective of our study was to determine the effects of four types of fertilisers enrichments (manure potassic (K), phosphatic (P), phosphatic and potassic (PK) and nitrogenized, phosphated and potassic (NPK)) on chemical composition and dry matter in cassava (Manihot esculenta) organs (clone 1171) during harvest period. The pots experiment was laid out in randomised complete bloc design with five treatments and four replications. Water, nitrogen, potassium, phosphorus, sodium, total proteins and total lipids contents of the leaves, shoots and tubers were determined. After 9 months growing period, results showed that fertilizer types enriched with K, PK and NPK significantly increased the organic compounds contents of the leaves (P〈0.05). Furthermore, fertilizers with high phosphorus content significantly increased the lipid contents of the leaves (25%). Fertilizers enriched with NPK positively influenced the biomass partitioning in Manihot esculenta. Application of fertilizers enriched with NPK led to higher levels of total proteins in the leaves and tubers (70 mg g DM^-1 and 30 mg g DM^-1 respectively) compared to control (17 mg g DM^-1 and 9 mg g DM^-1 respectively). These results help to demonstrate the value of these fertilizers enrichment to improve the chemical composition and dry matter partitioning of cassava. 展开更多
关键词 CASSAVA nutrient type chemical composition partitioning dry weight
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Fruit Nutritional Value of Cornelian Cherry Genotypes (Comus mas L.) Selected in the Vojvodina Province
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作者 S. Bijelie B. Golosin J. Ninie Todorovie S. Cerovie 《Journal of Agricultural Science and Technology》 2011年第3期310-317,共8页
This paper reviews results of some morphometric properties and chemical analyses of natural populations of the Cornelian cherry collected in the Vojvodina Province in 2008. Purpose of this study was the selection of t... This paper reviews results of some morphometric properties and chemical analyses of natural populations of the Cornelian cherry collected in the Vojvodina Province in 2008. Purpose of this study was the selection of the best genotypes for future breeding program until the final goal and that is standardizing Cornelian cherry cultivars. Chemical content has been found to depend on the genotype. Total sugar content in fruits ranged from 11.77% (CPC16) to 41.62% (BPC7), vitamin C from 17.15 mg/100 g (APC8) to 42.30 rag/100 g of fresh fruit (APC2), Ca pectat from 0.17% (APC6) to 2.52% (KC 1 ) and anthocyanin from 22.65 mg/100 g (APC4)to 96.30 rag/100 g of fresh fruit (BPC1). Cornelian cherry fruits have an especially high content of minerals compared with other fruit species: the potassium content (in ppm) ranges from 2330 (APC6) to 11487 (APC4), the calcium content from 33.80 (APC6) to 1307.70 (BPC1), the sodium content from 22.82 (BPC8) to 273.48 (APC8), the magnesium content from 10.20 (APC6) to 372.80 (APC8) and the iron content from 2.38 (KC2) to 14.40 (APCS). The balanced content of nutrients, a wide range of food products made from the Cornelian cherry and an extremely high nutritional value make this fruit species a highly recommendable food item, especially if it comes from organic production. 展开更多
关键词 Cornelian cherry SELECTIONS chemical properties nutritional value
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