Soil and water conservation protective cultivation is an advanced cultivation technology that avoid cultivation or few cultivation on farmland and with stubble cover.Protective cultivation technology is an integration technology that use stubble cover,no-tillage cultivation,deep-plough with machine,and weeding with chemistry.Adopting soil and water conservation protective cultivation can reduce the loss of soil and water in northeast blackland area and improve the soil anti-erodibility.

中文摘要：水土保持保護(hù)性耕作是對(duì)農(nóng)田實(shí)行免耕少耕欧美福利片500，并用農(nóng)作物秸稈殘茬覆蓋地表的一項(xiàng)先進(jìn)耕作技術(shù)，保護(hù)性耕作技術(shù)是由秸稈覆蓋看一下最好最好的黄片片最刺激的视频、免耕播種国产乱子露脸久久、機(jī)械深松和化學(xué)除草等核心技術(shù)組成的一項(xiàng)集成技術(shù)，采用水土保持保護(hù)性耕作措施可以有效減少東北黑土區(qū)的水土流失66j8影院在线视频，提高黑土區(qū)土壤抗蝕性黄色网站免费别的女教师。

They urged "a rapid shift, whenever and wherever conditions permit it, to management systems based on minimal soil disturbance, increased soil cover, and appropriate crop rotation".

他們敦促，"無(wú)論何時(shí)何地精品国产视色，只要條件許可国产精品色三级在线观看，應(yīng)迅速向以最低限度干擾土壤，增加土壤覆被和適當(dāng)?shù)淖魑镙喿鳛榛A(chǔ)的管理系統(tǒng)轉(zhuǎn)變"黄色网站免下载。

In experiment,we controlled soil moisture by methods of artificial rainfall and restoring water in soil post;soil treatments included non-cover,mealie haulm cover and gravel cover.

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So the Hydrus 2D was selected to simulate the soil water movement in ET covers with different cover thicknesses,the simulations shown that the optimal ET cover in Wuhan area should be 120-140 cm loamy soil layer with shrub.

因此采用Hydrus 2D軟件對(duì)不同土層厚度騰發(fā)覆蓋系統(tǒng)的滲瀝控制效果進(jìn)行數(shù)值模擬看黄色录像一级片国产的。，結(jié)果表明，在武漢地區(qū)采用120～140 cm厚度壤土層和灌木構(gòu)成的騰發(fā)覆蓋系統(tǒng)是確保滲瀝控制效果的經(jīng)濟(jì)合理方案免费一级操逼毛片。

This showed that capacity of water-holding in biological soil crusts were obvious improve,and effected precipitation permeate or water second distribute process.The study results of"fertile islands"formation mechanism in biological crusts showed that biological crusts layer cover could increased nutrients content for below sand soil through precipitation permeate washing,and it promoted plants assimilate more nutriment.The matter import ways of biological soil crusts fertility island had many ways,including the effection of living macrobiotics metabolism in crusts levels,wind-sand flow of near surface,dust deposition and plants decomposition course,etc.Source of particle matter in biological soil crusts was wind-sand flow of near surface,and not dust deposition.Biological crusts layer cover had preserved effection for nature water content in 0-5cm soil layer,compared with the sand of no biological crusts layer,effecting precipitation permeate,and could not obvious restrained from the water evaporate process indoor experiment.

生物結(jié)皮層肥島形成機(jī)制的研究結(jié)果表明：生物結(jié)皮層覆蓋能夠通過(guò)降水淋溶作用而增加下層土壤養(yǎng)分的含量国产精品影院在线，進(jìn)而促進(jìn)植物對(duì)養(yǎng)分的吸收；生物結(jié)皮層養(yǎng)分輸入有結(jié)皮生物代謝A片黄色视频免费、降塵久久免费五月黄片、風(fēng)沙流和植物分解礦化作用等多(來(lái)源：A73e3B3eC論文網(wǎng)www.abclunwen.com)種途徑，但生物結(jié)皮層的顆粒物質(zhì)來(lái)源主要是近地表風(fēng)沙流不卡免费A片观看在线播放，而不是大氣降塵有A片网站吗?；生物結(jié)皮層覆蓋對(duì)0-5cm土層自然含水量有一定的保護(hù)作用，并影響降水向深層滲透亚洲三级观看，不能有效的阻止表層水分的蒸發(fā)進(jìn)程A片一欧美精品；研究表明采取人工促進(jìn)技術(shù)能夠在流動(dòng)沙丘上形成生物結(jié)皮層，實(shí)現(xiàn)流動(dòng)沙地的快速治理9999在线观看。

So karst vegetation is charactered by Petrophile, Xerophile and Calciphihe in those areas where soil cover is very thin, and the underground drainage system is well developed. The running of karst ecosystem is controlled by two subsystems, which are karst dynamic system in inorganic life and genetic information transmitting system in organic life.

巖溶生態(tài)系統(tǒng)的運(yùn)行受到兩個(gè)子系統(tǒng)的聯(lián)合作用驅(qū)動(dòng)国产黄视频免费在线看，即無(wú)機(jī)方面的"巖溶動(dòng)力系統(tǒng)"和生命方面的"遺傳信息傳遞系統(tǒng)"，但主要受以碳欧美A片精品、水午夜试看120秒无码体验区、鈣循環(huán)為中心的巖溶動(dòng)力系統(tǒng)的控制。

Based on soil desertification between agriculture and husbandry interlace zone in north of Shannxi Province, on the basis of theories of landscape ecology激情综合五月天丁香婷婷、land resource and principle of soil genesic science, through field surveying data and indoor analyzing, the properties of soil physical, chemical and biological characteristics are systemic analyzed about desertification soil of different vegetation cover rate and type, achieving primary achievements and important evolves are as follows:Ⅰ.

本研究基于當(dāng)前全球荒漠化危害現(xiàn)狀及國(guó)內(nèi)外荒漠化防治中恢復(fù)生態(tài)學(xué)的發(fā)展需要国产专区久久，以陜北農(nóng)牧交錯(cuò)帶土地荒漠化問(wèn)題為研究對(duì)象九九视频在线观看A片国产，應(yīng)用景觀生態(tài)學(xué)理論、土地資源學(xué)和土壤發(fā)生學(xué)的基本原理www91免费视频，在野外考察狼人av在线、資料收集和室內(nèi)測(cè)定分析的基礎(chǔ)上，對(duì)不同植被蓋度和植被類型荒漠化土地的土壤理化性質(zhì)和生物學(xué)性質(zhì)進(jìn)行系統(tǒng)分析迷晕灌醉在线播放精品，取得的主要成果如下： 1www.xxxxx欧美。

Field survey, sampling and testing were used to discuss the characteristics of soil water content between different subsidence stages. The results show that after mining collapsing, the soil water content and soil water storage capacity of subsidence area is obviously less than the nature area, especially for the fissure zone. It is indicated that the collapsing fissures are extremely disadvantageous for soil water-holding capacity and the conditions of vegetational cover on the subsidence area also confirmed this result.

現(xiàn)以神府東勝煤田為研究背景，選擇兩個(gè)主要塌陷階段分布區(qū)大柳塔礦區(qū)雙溝村原農(nóng)場(chǎng)和補(bǔ)連塔礦區(qū)原補(bǔ)連溝村作為研究區(qū)亚洲日韩深夜福利第一页，采用野外勘查欧美在线激情丁香、取樣測(cè)試與室內(nèi)參數(shù)分析綜合研究的方法，對(duì)采礦塌陷不同階段表層包氣帶土壤水分進(jìn)行對(duì)比分析色呦呦观看，結(jié)果表明人人摸人人做人人操，采礦塌陷后，塌陷區(qū)尤其是塌陷裂縫區(qū)的土壤含水量與土壤儲(chǔ)水量值均小于未塌陷區(qū)欧美性爱a片4色，說(shuō)明塌陷裂縫對(duì)土壤的持水作用具有非常不利的影響国产欧美日韩综合视频在线，塌陷區(qū)與未塌陷區(qū)的地表植被覆蓋情況也證實(shí)了這一點(diǎn)。

Contaminants can easily enter the subsurface through thin soil cover in stone forest and via swallow holes at the bottom of depression.

究其原因黄片二区三区18禁，盡管藥池壩洼地底部土壤層覆蓋較厚欧美性交1，但存在地表徑流集中排向落水洞，生態(tài)石林分布區(qū)地表裂隙欧美精品福利视频、溶溝發(fā)育99欧美午夜一区二区福利视频，可直接接受雨水入滲，因而污染物極易通過(guò)降雨和地表徑流過(guò)程進(jìn)入含水層一本欧美中文高清在线视频。

The main contents are as follows:Firstly, starting with the general situation of soil erosion and the harms caused by it, the causes leading to the local soil erosion problem are analyzed comprehensively in the paper. And connecting with the measures taking place, sticking points towards the career of soil and water conservation are expatiated upon.Secondly, Back-Propagation Neural Network, One of Artificial Neural Network is used to set up a modal about the connection of the soil erosion modulus and seven factors impacts on it, such as, rainfall, rainfall largest intensity in 30 minutes, runoff coefficient, vegetation cover percent, rate of granule, rate of physical viscidity-clay, the rate of organic matter. Through the comparison with linear regression model, the second regression model, the Chinese Soil Loss Equation, it illustrated that BP Neural Network modal is more accurate than the other three modals in forecasting the mount of soil erosion, and the BP Neural Network will have some applicability in forecasting in soil erosion.

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