After analyzing natural factors and human activities, the paper considers the following as main reasons for soil degradation of the source regions of the Yellow River: a natural conditions, climate arid, precipitation decrease, bad soil condition and rich sand source; b human factors, overgrazing, destructive felling, irrational grazing system, wild animals battue, and so on.

在綜合分析自然因素和人為活動(dòng)后毛片-A片免费强奸，本文認(rèn)為氣候干旱在线黑人黄色网站、降水減少538在线视频观看、土壤條件差华人永久免费在线视频、沙源豐富等自然條件和超載放牧www热色com、亂挖濫采日本人人干、放牧制度不合理、大量捕殺野生動(dòng)物等人為因素是造成黃河河源區(qū)土地退化的主要原因欧美大黑屄。

My Office is located in Zhejiang Province Tianmushan University, has rich forest resources, particularly resources are particularly rich pecan, pecan is a kind of epicarp environmental protection, low-cost coverage of a new type of garden materials, and its contains a biochemical factor that can effective in the soil to kill pests; and can increase the green color, rich green texture, landscaping, green landscape and green land; to prevent dust and soil erosion, improve air quality, so that a more pleasant environment; reduce transpiration, especially in summer, be conducive to maintaining soil moisture, prevent soil knot board, to maintain temperature, saving water, at the same time to effectively control weeds.

我處位于浙江省的天目山系黄色A片视频，有豐富的森林資源大黑吊性爱，特別是山核桃資源尤為豐富，山核桃的外果皮是一種環(huán)保A片网站导航、價(jià)廉的新型園林覆蓋資材av日韩免费网址，其含有一種生物化學(xué)因子，能有效的殺死土壤中的害蟲(chóng)全国精品第一区黄片；并且能增加綠地色彩手机黄网欧美高清，豐富綠地質(zhì)感，美化久久免费视频免费看、綠化園林綠地国产热情网站；防止揚(yáng)塵和水土流失，提高空氣質(zhì)量av免费在线观看网站大全，使環(huán)境更優(yōu)美久久国产精品免费一区二区三；減少蒸騰，特別是夏天欧美永久视频免费，有利于保持土壤水份www.玖玖爱免费视频，防止土壤結(jié)板，保持溫度欧美性爱三，節(jié)約水源china农村野外妇女BBw，同時(shí)能有效的控制雜草生長(zhǎng)。

When the green manure crop up pressure to the soil, soil rich in organic matter.

當(dāng)綠肥作物翻壓到土壤中免费一级黄片视频，可以使土壤中的有機(jī)質(zhì)豐富国产无套推油按摩女视频推油。

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 .

研究結(jié)果表明：四種綠肥中草木樨的生物量最高；四種綠肥翻壓后對(duì)土壤有機(jī)質(zhì)和速效養(yǎng)分含量均有一定的影響国产二区视频在线观看，其中草木樨在在线黄色视频、大豆翻壓后土壤有機(jī)質(zhì)分別提高了8.58%，1.01%免费无码一级黄色视频；四種綠肥翻壓后土壤速效氮提高了0.30%-5.96%肏屄视频网站，除大豆外，其它三個(gè)處理的土壤速效鉀含量平均是對(duì)照的1.08倍国产一级在线播放；研究發(fā)現(xiàn)油菜黄片com.、油葵的富鉀作用較為突出。

The silk threads of all colors, the multi-patterned satins and brocades, the cultural environment of learned scholars and the Wu School of Painting, provided rich soil for Suzhou embroidery to mature as early as 500 years ago with the artistic characteristics of being "exquisite, superfine, elegant, and neat".

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It is hence concluded that properly controlled soil Na2SeO3 application in Typic Dark Brown Forest Soil would be an effective way to cultivate Se-rich forest vegetables and to exploit Se-rich vegetable resources under the quasi-natural conditions of the forest region, except heavily perturbed coarse-textured soil.

初步得出久久精品房事视频，典型暗棕壤控制施硒是在近自然條件下培育富硒森林蔬菜并獲取高富硒生物資源的有效途徑；不過(guò)午夜三级免费视频，強(qiáng)烈攪動(dòng)的砂礫質(zhì)暗棕壤卻不利于硒肥保持和植物吸收，不適于富硒森林蔬菜栽培国产精品日韩。

The new born advanced thoughts like rich soil and lucid spring, they comfort people's heart, and nourish the tree of spirit to full growth and blossom.

新生的進(jìn)步的思想就成為撫慰靈魂的沃土和清泉jizz在线视频，必然使人的精神世界的大樹(shù)長(zhǎng)得枝繁葉茂，并開(kāi)出絢麗的花黄色视频观看免费的黄色网站。

The project is sited in the flood plain of the Russian River, with deep, rich soil ideally suited for agriculture.

此工作室坐落在俄羅斯河流的洪泛區(qū)精品一级黄色，地域富饒，土壤肥沃欧美激情亚洲熟妇，非常適合農(nóng)業(yè)生產(chǎn)黄色视频在线观看看网站。

Tall annual marsh elder common in moist rich soil is central North America that can cause ''.

一種一年生的、高大的沼生接骨木台湾亚洲综合色区，它常見(jiàn)于北美中部的潮濕沃土上2020国产高清成年视频，造成''。

Tall annual marsh elder common in moist rich soil is central North America that can cause contact dermatitis; produces much pollen that is a major cause of hay fever .

一種一年生的欧美视频天、高大的沼生接骨木精品视频网站，它常見(jiàn)于北美中部的潮濕沃土上，造成接觸性皮炎黄色网站上视频；產(chǎn)生許多花粉一级精品在线，是引起花粉熱的主要原因。