【摘 要】
:
A field experiment, involving lime N (calcium cyanamide, CaCN2) fertilization as a control measure, was conducted to study environmental problems induced by lon
【机 构】
:
Center for Environmental Science in Saitama,Jinenjou-no-kai,State Key Laboratory of Soil and Sustain
【基金项目】
:
中国科学院知识创新工程项目;国家自然科学基金
论文部分内容阅读
A field experiment, involving lime N (calcium cyanamide, CaCN2) fertilization as a control measure, was conducted to study environmental problems induced by long-term heavy N application in Japanese tea fields. Long-term tea cultivation caused serious soil acidification. Seventy-seven percent of the 70 tea fields investigated had soil pH values below 4.0, and9% below 3.0, with the lowest value of 2.7. Moreover, excess N application in tea fields put a threat to plant growth,induced serious nitrate contamination to local water, and caused high nitrous oxide loss. Compared with the conventional high N application treatment (1 100 kg N ha-1) without lime N, the low N application (400 kg N ha-1) with calcium cyanamide effectively stopped soil acidification as well as achieved the same or slightly higher levels in tea yield and in total N and amino acid contents of tea shoots. The application of calcium cyanamide could be a suitable fertilization for the prevention of environmental problems in tea cultivation.
其他文献
为探索麝香草酚复合物、中草药和合生素替代抗生素饲养肉鸭的可行性,选择2 400只健康雏鸭,随机分为4组,每组3个重复,每重复200只鸭进行试验.对照组饲喂基础日粮+5 mg/kg黄霉
在大田试验条件下于灌浆期对两种株型的高产玉米品种丰禾1(平展型)及郑单958(紧凑型)的冠层结构特征进行研究,并对灌浆期冠层结构与产量及其构成因素进行相关分析。结果表明:
以无公害落叶浆果类果品标准为评价标准,对浙江省猕猴桃主产区180个猕猴桃样品中农药残留情况进行了分析与评价.结果表明:浙江省猕猴桃农药品种检出率71.4%,样品农药检出率52.
[目的]对烯肟菌酯异构体进行分离以及4个异构体的杀菌活性进行研究。[方法]柱层析法分离异构体,质谱和核磁进行结构鉴定。[结果]确定了烯肟菌酯4个异构体的空间构型,对黄瓜霜
Six novel thiosemicarbazones containing sugar and thiosemicarbazide moieties were synthesized by a five-step procedure using D-galactose and D-xylose as the sta
The adsorption characteristics of heavy metals: Cu(Ⅱ), Pb(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ) ions on tourmaline were studied. Adsorption equilibrium was established. The a
A short sequential extraction procedure(SSEP) was applied to the determination of more readily available metal fractions of Zn, Cu, and Cd in the riverbed sludg
Heavy metal contamination in soils has been of wide concern in China in the last several decades. The heavy metal contamination was caused by sewage irrigation,
AIM: Platelet-activating factor (PAF) is a pro-inflammatory and angiogenic lipid mediator. Here we aimed to investigate levels of PAF, lyso-PAF (the PAF precurs
The DNA-damaging effects of the combined pollution of heavy metal and organic contamination on earthworms were evaluated by single cell gel electrophoresis (SCG