耕地

NS had higher respiratory quotient at 10~20cm, thus younger microbiology, and CN had younger microbiology at 0~10cm. This was good to sustain soil qualified characters and sustainable potentiality. This showed that mechanic tillage and biological tillage were of the same importance in some degree. It was important for reducing energy cost to enhance the effect of microbiology in soil nutrtient transferring.

免覆在10~20cm土层呼吸商较高，微生物年轻化，常无在0~10cm土层微生物年轻化，对维持土壤的优良性状和可持续利用潜力有益，这在一定程度上说明机械耕地和生物耕地的同等重要性，充分提高土壤微生物在养分转化中的作用对于降低农业生产中的能耗有重要意义。

Determined by the specific geological background of Longhetun, the characteristics of the soil resources show abundant calcium and leaning to alkaline. Monomial indexes to evaluate the revisal coefficient of soil adapted to karst mountains areas were screened out combined with the function of karst dynamics system and analysis of characters of each factor about fertility in soil. Predigestion model to soil revisal coefficient monomial assessment was established by successful importation of the content of nutrition elements in plant body, latent efficient elements in soil and available thickness of soil in the cranny of epikarst according to the characters that three carriers of soil, soil water and karst water supply nutrition to plants and two layers of foundation consist of surface soil and soil in epikarst cranny, and several types of soil revisal coefficient and weather-soil productive potentiality were calculated, the results show that the soil revisal coefficient was even more practical after modification than before, which make up of innovation of this study.

龙何屯特殊的地质背景条件决定了耕地土壤资源的富钙偏碱的特点，结合岩溶动力系统的作用，系统分析土壤中各肥力因子的特点，筛选出适宜岩溶石山区特点的土壤订正系数评价单项指标，针对研究区存在土壤、土壤水、岩溶水三种载体提供植物营养和表层土、土下表层岩溶带裂隙土两层空间基质的特点，成功引入植物体内营养元素含量、土壤元素隐性有效态含量及土下表层岩溶带裂隙土有效厚度等新参数指标，探讨建立了土壤订正系数单项指标评价简化模型，计算出龙何屯各耕地类型土壤订正系数和气候-土地生产潜力，结果显示修正后的土壤订正系数比修正前更符合实际，成为本研究的创新点。

The area of semiarid land has above 75 percent of all cultivated land in Inner Mongolia Autonomous.

1 旱作农业在内蒙古的重要地位内蒙古自治区746－3万hm2耕地中，水浇地仅184－7万hm2，旱地占耕地总面积的75％以上。

Some scholars argued that the cultivated land was not substitutable at all and others on the contrary because of different theoretical backgrounds or perspectives.

耕地面临着巨大的环境压力与需求压力。环境和需求约束下的耕地可替代性问题由此凸现。

To enclose tideland for cultivation can not only solve some problems of tidelands but also make use of the advantages of reclamation to develop cultivated land and aquatic bree...

滩涂围垦既可解决目前一些滩涂存在的问题，又可利用围垦开发耕地和发展水产养殖业等，保证耕地面积动态平衡目标的实现。

To enclose tideland for cultivation can not only solve some problems of tidelands but also make use of the advantages of reclamation to develop cultivated land and aquatic breeding, andto realize dynamic equilibrium of cultivated land area.

滩涂围垦既可解决目前一些滩涂存在的问题，又可利用围垦开发耕地和发展水产养殖业等，保证耕地面积动态平衡目标的实现。

To enclose tideland forcultivation can not only solve some problems of tidelands but also make use of the advantages of reclamation to develop cultivated land and aquatic breeding , andto realize dynamic equilibrium of cultivated land area .

滩涂围垦既可解决目前一些滩涂存在的问题，又可利用围垦开发耕地和发展水产养殖业等，保证耕地面积动态平衡目标的实现。

With the development of civilization, peoples demand became more and more , land, as an important product stuff ,the intensity of landuse became higher and higher ,as the result: the quantity of farmland decreasing ; average area of tilth deducing ; urban expanding ; in land structure table ,built-up land ascending ,farmland and non-used land declining .

经济的发展，人类社会的进步，人的需求不断的得到满足，土地作为一项重要的生产要素，其利用结构也随之发生着变化：耕地总量的减少，人均耕地面积的下降，城市的扩张，土地利用结构表中，建设用地比例的上升，农用地和未利用地比例的下降等等。

The result indicated that suitable thickness of paddy soil is about 15cm,and for dry arable land it should not be lower than 20cm;The alluvial rivers parent material is the best one to influent the output,the rice fields is the worst with the parent material of slate ground,while the dry and plough land is the worst for its purple sand shale parent material;The paddy rice is best with the acid soil,and the dry crop is the best with the neutral soil;The obstacles horizon exist in 35.2%of the rice fields in research region,and many for middle or top digit obstacles.

结果表明，水稻土的适宜耕层厚度为15 cm左右，旱耕地适宜耕层厚度应不低于20cm；成土母质对产量的影响以河湖沉积物母质最好，稻田以板页岩母质最差，旱耕地以紫色砂页岩母质最差；水稻以酸性土最好，旱作以中性土最好；研究区稻田有35.2%的存在障碍层，且多为中、高位障碍，是影响水稻产量整体提高的主要因素；水稻和旱作都以壤土为最好，其中，稻作怕砂，旱作怕粘；水稻土适宜的容重为1.00—1.29 g/cm~3。

Using agriculture production fuction,this paper comes to the conclusion: assuming the same for all the other factors,the more efficiently the farmers work,the more land they want to rent,vice verse.

本文利用同样家庭板块数据的农业生产函数证明，假如其他因素完全一样，务农效率最高的农户租种更多的耕地，而效率较低的农户会出租更多的耕地。

Objective To investigate the effects of interleukin-1 β converting enzyme gene on the biologic characteristics of ovarian cancer cells.

目的 探讨白细胞介素-1 β转换酶的表达，对卵巢癌细胞生物学特性的影响。

Campylobacter: This illness is the most commonly identified cause of diarrheal illness in the world.

弯曲：这种病是最常见的原因查明腹泻病，在世界上。