土壤覆盖

The testing results indicate there is a visible regulating effect in soil temperature with crop residue cover.

试验结果表明，残茬覆盖对土壤温度有明显的调节作用，5、10、15、20 cm各层有覆盖相对于无覆盖分别增温1.5~2.1℃、0.9~1.2℃、0.2~0.9、0.4~0.8℃，随着土壤层的加深，覆盖对土壤温度的调节作用越来越小。4月20日至6月15日前后，随着覆盖量的增加，土壤温度开始升高，但覆盖量增加到一定程度后，土壤温度将下降，在6月20日以后，随着覆盖量的增加，土壤温度逐渐降低，其中30%覆盖相对于无覆盖，降低1.1~1.5℃，50%~80%覆盖降低2~3.6℃，而表土层降低幅度最大，沿深度方向幅度越来越小。

Afterwards, make use of the whole year MODIS-NDVI data of 2004 of Leimeng grassland, Hainan evergreen broad-leaved forests and Qinghai's west hungriness, test the ability of the model of NDVI based on MODIS in monitoring vegetation. The result shows that the MODIS-NDVI can reflect the differences of variety of vegetation and the changes of growth of the same vegetation.

接下来利用2004 年内蒙草原，海南省东部常绿阔叶林和青海省西部荒漠一年中的MODIS-NDVI 数据，对MODIS-NDVI 监测不同植被和土壤覆盖类型的特性进行了研究，结果说明基于时间序列的MODIS-NDVI 对植被种类的生长变化进行了很好的描述。

Mulching can apparently enhance availability ofsoil water,lengthen the duration of available water,enhance redistribution of soil water from covered soil massto adjacent bare soil mass,increase soil moisture in the adjacent bare soil mass,which can lighten threat ofcontinuous drought to survival and growth of youngling.

覆盖能显著提高土壤水分对植物的有效性、延长有效水的持续期、增强覆盖区与相邻非覆盖区下层土壤液态水的运移与再分布，提高相邻非覆盖区下层土壤的水分状况，减轻了持续干旱对造林成活和幼树生长的威胁。

This process varies with the site and circumstances, but in its archetypical form fast-growing annual weeds cover the soil first, playing the role of what ecologists classify as pioneer plants.

这一过程的长短因不同的地点和环境而异。起初，生长迅速的年生草先把土壤覆盖住，起到一种生态学家称之为&先驱植物&的作用。

Sum up under the same condition, NT has more advantages than CT onthose indexes of hydrolyzable nitrogen ,available phosphorus and potassiumin 0-20cm soil layer while there are no evidently difference underneath 20cmsoil layer.2.2 In NT fertilization zone and mantle zone, contents of organic matter in0-40cm soil layer are higher than that in CT.

和常规处理相比，免耕施肥区处理 N3T和覆盖区处理 N3TC 在 0-20cm 土层显著提高了有机质含量，其中覆盖区增加效果显著。2.3 和常规耕翻处理相比，成熟后免耕处理在 0-20cm 土层土壤显著降低了土壤容重和增加了毛管孔隙度和非毛管孔隙度，显著提高了土壤总孔隙度。3 免耕对土壤中不同形态氮素以及土壤水分含量变化的影响3.1 土壤铵态氮拔节期至成熟期是免耕处理和常规处理铵态氮显著差异的形成时期。

However, the soil moisture content at soil depths of 45 cm and 60 cm in the areas with microbiotic crusts is much lower than that in the areas without microbiotic crusts (LSD-test, p.05), which reveals that the microbiotic crusts have high capability of maintaining topsoil moisture.

结皮覆盖区距地表5cm和10cm处的土壤含水量显著高于无结皮覆盖区（LSD检验，P.05）；而45cm和60cm处的土壤含水量则表现为结皮覆盖区极显著低于无结皮区（LSD检验，p.05），说明生物结皮具有较强的保持土壤表层水分的能力。

It was found that all the coloured polyethylene films herein used as plastic mulches increased significantly the soil temperature and conserved soil moisture.

杭州早春，各色地膜覆盖的土壤温度，比对照高1—4℃。地膜覆盖的土壤O_2含量正常，雨后测定，各色地膜覆盖处理的在19.6—19.8％之间，对照为18.8％。各色地膜覆盖的土壤容重都比对照的小，平均为1.08，对照为1.21。

The straw mulching and plastic film mulching with seeding in furrow can improve water use efficiency, in this sense, mulching is water saving.

秸秆覆盖和地膜覆盖垄沟种植春玉米产量大幅度提高，地膜覆盖垄背种植在一定程度上保蓄土壤水分，但由于垄背较高，土壤水分供应不足，较不覆盖减产显著。

Writings on these tablets describe the possible use of something similar to an Archimedes' screw as a process of raising the water to the required height.

花园的土壤覆盖在顶部，树木所需的水分从下方的河流经由隐藏的装置供给等说法，这些细节在后文有更详尽的叙述。

Experiments were conducted in 1955—1957 to determine the merits of the use of gravel as a soil mulch material instead of a mixture of sand and gravel widely used in Kansu.

为了改进这种缺点，我们提出用直径5毫米以上的砾石来代替砂石混合物作为土壤覆盖层。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。