查询词典 infertile soil

The study of the long-term dynamic change of soil organic matter and its affecting factors of geoponic practices were important for a comprehensive management on soil fertility. In this paper, based on the soil fertilizer monitoring data in 1980 and 1999 at county level, household survey and statistics data, the dynamic change of soil organic matter content and its affecting factors by relevant agricultural practices in the past twenty years were analyzed comprehensively.

本文以河北省曲周县为例，採用1980年和1999年两次全县的土壤肥力监测以及农户调查数据和统计数据，系统分析了过去20年中土壤有机质的动態及其与之相关的农作管理方式的变化。

Root-derived organic carbon is composed of three compartments: root detritus, root eaudates and root symbionts, which represents a large important and potential C sink in forest ecosystems, The known responses of root derived organic carbon and heterotrophic microbes to elevated CO2 were reviewed. Overall, increases in root biomass, productivity, and exudation indicate an augmentation of C inputs into the soil via roots, although changes in root lifespan are still unclear and may modify this flux positively or negatively, Altogether, changes in root chemistry and morphology that may augment soil C storage under elevated CO2 include decreased N concentration and wider root diameter, Alternately, a shift in rooting depth upwards in the soil profile may increase average turnover rates of root detritus. Effects of CO2 concentration on C qualities of root exudates and root symbionts are the least understood components discussed here, Changes of soil heterotropic microbial activity and community under elevated CO2 still remained large uncertainties.

林木根源有机C包括根东通过根枯落物、根系分泌物和根共生菌周转3条途径向土壤输入的有机C，它是森林生态系统中一个重要的、潜在的C汇，综述了根源有机C与其微生物对CO2浓度升高的响应，虽然对根系寿命的变化尚不清楚，但CO2浓度升高将导致根系生物量、生产量、死亡量和分泌物的增加；同时，CO2升高亦促使根共生菌生物量的增加而增加了共生菌的C归还潜力，表明CO2升高使根源有机C的输入增加了，CO2农度升高情况下，根系化学性质和形态特征的这些变化均有利于增加土壤C的吸存；而根分布深度的降低则对土壤C吸存不利；CO2浓度升高对根分泌物和根共生菌质量的影响研究则极少，CO2浓度升高下土壤微生物活性和群落组成的变化存在较大的不确定性，目前CO2浓度升高下林木根源有机C对森林长期C吸存的贡献仍很不清楚。

Microbial biomass in soil profile showed negative relation with soil pH value and bulk density, while positive correlation with contents of soil organic carbon, light fraction and particulate organic carbon and fine root biomass were found. There were no significant difference between soil microbial biomass and DOC, total N, total P, hydrolyzable N and available P.

土壤微生物生物量垂直分布与土壤pH和容重呈负相关，与土壤的有机碳、轻组有机碳和颗粒有机碳含量及细根生物量呈显著的正相关，但与土壤可溶性有机C和全N、全P、水解性N和速效P含量的相关性不显著。

Based on the results of long term and position research,the dynamic change of soil water content in Taihang Mountain-piedmont Plain with the condition of aeration zone incrassation was studied.Some results are as follows: Soil water content changes with precipitation in different year;Season dynamic can be divided into three stages: accumulating,consuming and stable;Soil water content increases with the increase of soil depth.

本研究利用连续多年的土壤水分观测数据，分析了太行山前包气带土壤水分动态变化特征，结果表明：土壤含水量受丰水年枯水年影响存在年际差异，根据不同季节土壤水分的动态特点，可将其划分为三个时期，即土壤水分消耗期土壤水分累积期和土壤水分相对稳定期。

Based on equipotential models of some scholars, according to a practicable fact which large substation grounding grids are not equipotential any longer, in inequipotential model, the paper analyzes the influence of the soil resistivity and the grounding grid area on the optimum arrangement in the uniform soil; the paper analyzes the reflective coefficient of double-layer soil, the top-layer soil thickness and the grounding grid area on the optimum arrangement.

为了使地表面的电位均匀分布，进一步降低接触电压和跨步电压，更好地保障人身和设备的安全，本文提出了接地网的优化设计方法。

So the higher temˉ perature resistance for the three soil types was in the sequence o f dry red soil, lateritic red soil and lateritic soil.

综合3种配方在高温期间的生理指标变化情况，其耐高温能力由强到弱依次为：燥红壤、赤红壤、砖红壤。

Carbon storages of the upper horizon in lessive dark brown forest soil, brown coniferous forest soil and mountain tundra soil were 10959 gC m-2 (0-20 cm), 4199 gC irf2 (0-10 cm) and 6171 gC m~2 (0-32 cm) respectively, occupy 60%,50% and 77% of total carbon storage. This showed that the upper horizon was accumulating soil organic carbon.

显然，低海拔地带土壤发育程度比高海拔带土壤发育程度要好，这是由于高海拔带土壤受火山喷发、气候、温度等自然因素的影响较大，从而致使土壤有机质的发育过程缓慢。

The results showed that: biomass in the Melilotus suaveolens is the highest in four green manure; after pressed four green manure in the Green the cotton fields, soil organic matter,nutrients are available certain influence; after Melilotus suaveolens and soybean pressed in the soil,organic matter increased by 8.58% and 1.01%;four green manure pressed in the soil available nitrogen increased by0.30%-5.96%,except soybean, the soil available potassium of the other three dealt is 1.08 times that of the control; the role of rich potassium in Rape and Oil sun flowers are even more significant .

研究结果表明：四种绿肥中草木樨的生物量最高；四种绿肥翻压后对土壤有机质和速效养分含量均有一定的影响，其中草木樨、大豆翻压后土壤有机质分别提高了8.58%，1.01%；四种绿肥翻压后土壤速效氮提高了0.30%-5.96%，除大豆外，其它三个处理的土壤速效钾含量平均是对照的1.08倍；研究发现油菜、油葵的富钾作用较为突出。

In summary, MNL and TNL could be used as indices for potential mineralizable N, which are not only suitable for the first season crop but also suitable in evaluating soil N-supplying capacity for two successive season crops; while SON, total soil N and soil microbe N were not good indices for soil potential mineralizable N in short-term.

总体上看，可溶性有机氮和土壤全氮、土壤微生物氮不能作为反映短期可矿化氮的指标；间隙淋洗通气培养淋洗液中淋洗矿质氮、淋洗总氮是评价可矿化氮的较好指标，不仅适宜于第一季作物，而且也适用于对连续两季作物土壤供氮能力的评价。

The results indicated that when initial NO3--N was not leached, soil initial NO3--N and mineral N extracted by CaCl2 before aerobic incubation were closely related with raygrass nitrogen uptake, the correlation coefficients were 0.856 and 0.862, respectively, both reached at 1% significant level. When initial NO3--N was leached, it was no good relationship between mineralizable N extracted by aerobic incubation, soil initial mineral N and mineralizable N extracted by aerobic incubation, N0 and soil initial mineral N and N0 with raygrass nitrogrn uptake, the correlation coefficients were 0.410, 0.553, 0.492 and 0.419, respectively, indicating that the poor effects of mineralizable N on reflecting soil N capacity were influenced and disturbed by initial nitrate.

以包括土壤起始NO3--N盆栽试验植物吸氮量为参比，通气培养前CaCl2所淋洗起始NO3--N和起始矿质氮与5期黑麦草地上部氮素累积量密切相关，相关系数分别为0.856和0.862，达1%显著水平；与此相反，通气培养30周所矿化氮素、土壤起始矿质氮+通气培养30周矿化氮素、氮素矿化势(N0)及N0+起始矿质氮与5期黑麦草地上部氮素累积量间无显著相关关系，相关系数分别仅为0.410、0.553、0.492和0.419。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48