覆盖作物

They investigated production and application status of agricultural plastics mulching film, development prospect of environment friendly bast fiber film.

考察发现，日本很多作物栽培普遍使用塑料地膜覆盖，使用后的废弃地膜由专门的回收公司进行处理，不污染环境。

BMP production systems will encourage quicker ground cover, more crop residues, greater root growth and more leaf area, all of which will improve N use efficiency and reduce erosion.

最佳管理措施生产体系将有助于迅速覆盖地表，产生较多的作物残留，促进根系生长和增加叶面积，这些都会提高氮素利用率同时降低侵蚀。

As a part of "Outstanding Young Researcher project- Water Erosion Predicting model", the purpose of this study is to do research on the method for estimating Cover and Management Factor in China, to evaluate the effects of crop cover in different stages by estimating soil loss ratio of individual crop stage period, and to compare the effects of different land use patterns by their average annual value of C factor.

本研究作为杰出青年基金项目《土壤水蚀预报模型研究》的一部分，目的在于探讨我国覆盖与管理因子的计算方法，估计不同耕作制度下农地多年平均C值；通过估计不同农作期土壤流失率评价作物发育不同时期对土壤侵蚀的作用；通过估计多年平均覆盖与田间管理因子分析不同土地利用方式的水土保持效益。

The value of roughness is depended on landscape, vegetation cover and crop cultivation direction, the larger the roughness is, the less the wind erosion intensity is.

地表粗糙度反映地表对风速减弱的作用以及对风沙流的影响，其值大小取决于地形、植被覆盖及作物的播种方向，粗糙度越大风蚀强度越小。

Mulch is one of the best things people can do for their plants.

覆盖是人们对作物所能做的最好的事情之一。

In order to study conveniently,suppose that each crop row have the same distance, each crop row has not interleaving and there is no weed in the field. Under these conditions some researches were developed.

本文研究时以菜田作物幼苗为作业对象，且假设作物沿行有规律地种植，呈一株一株间隔生长姿态，彼此两株和两行间没有交叠或覆盖。

As the crop remains in place during3-4 years, various cover crops are intercropped o keep enough residue cover.

免耕种植的紫花苜蓿作物残茬可以在田里保持3－4年，不同作物间作提供了足够的残茬覆盖。

In natural vegetation area, where mainly are forest land, the yearly relative humidity and precipitation of spring are the driving forces to the change of NDVI. In brush and shrub area, the change of NDVI is driven by the precipitation and relative humidity of autumn. In grassland and rare tree bush grassland district, the main driving forces are human factors, and the driving mechanism is that farmland and cropping sown area are negative to the change of NDVI, but society factors are positive.

对于以林地为主的自然植被区植被覆盖变化，主要受到春季降水、春季湿度和年均湿度的正驱动，黄淮海地区的北部主要为干旱、半干旱区，因此春季降水偏多会利于植被生长；灌丛和萌生矮林区，秋季降水和秋季湿度对其植被NDVI变化呈负驱动；草原和稀树灌木草原区植被覆盖的变化，耕地面积、作物播种面积对之为负驱动，而其他社会经济因子则为正驱动。

In low yield region,"life-maintaining water"should be guaranteed and otherconstruction should be enforced.3.NT altered soil surface condition for mulch cover and without tillage.NT improved availablesoil water for summer corn growth.Stronger"source and pool"and sound crop structure werebuilt in NT system.

覆盖免耕减少了土壤蒸发，具有较优越的土壤水分状况，同时增加了作物蒸腾，在一定程度上缓解了因降雨分配不均导致夏玉米需水与土壤供水的矛盾，提高了作物产量和水分利用效率。

Conventional tillage with bare ground, conventional tillage with straw incorporated and no-tillage with straw mulch were studied in the Hexi corridor of Gansu provience. The result showed: on summer fallow NTS stored soil water more than CTB and CTS by 30.62mm and 23.91mm, respectively; the winter storage irrigation quotas should be reduced to 900~1350 m^3/hm^2 on winter fallow; evaporation controlling rate arrived 38.1% and 7.3% at winter storage irrigation quotas 975m^3/hm^2 and 2100m^3/hm^2, respectively; NTS did not reduce ET during the spring wheat growth stage; yields different between treatments was not significant.

对甘肃河西内陆河灌区采用常规耕作、秸秆还田和覆盖免耕技术的农田水分效应进行研究，试验结果表明：在夏季休闲期，覆盖免耕比常规耕作和秸秆还田多贮水30.62mm和23.91mm；冬季休闲期可将大定额的储水灌溉减少到975~1350立方公尺/hm^2；覆盖免耕抑制蒸发率在储水定额为975立方公尺/hm^2时达到最大值38.1%，而在2100立方公尺/hm^2时最小为7.3%；覆盖免耕在作物生育期并没有减少土坡耗水量；各处理产量之间没有显著差异。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。