Knowledge Network Node

Non-Point Pollution from Crop Production: Global, Regional and National IssuesEnglish Full Text

D. NORSE Department of Geography, University College London, 4 Taviton Street, London WC1H 0BT (UK).

Abstract: China is now the world’s largest producer and user of industrial fertilizers and manures. Consequently China plays a substantial role in global N cycle dynamics and in man’s disruption of the nitrogen cycle though there are still significant uncertainties about the size and importance of emission and leaching rates. A major cause of China’s global role is the overuse of nitrogen fertilizers, which is most serious with intensive vegetable production where application rates can be up to 50% greater than crop needs, but is also a problem with wheat, rice and maize. China’s overuse of nitrogen fertiliser over the past 10-20 years has resulted in non-point source (NPS) pollution from crop production becoming a major cause of water pollution, and the situation is projected to get worse. In contrast, water pollution from point sources such as intensive livestock production and urban or industrial development is being brought more under control. The consequences for air pollution are equally serious. Emissions of nitrous oxide from fertilizers and manures may be so large that China could be responsible for 25-30% of global emissions of this damaging greenhouse gas and of the global warming resulting from it. The main national and local issues relate particularly to low fertilizer use efficiency and the losses of ammonia and NOx that lead to acid precipitation, and leaching and run-off losses that result in high nitrate levels in groundwater and eutrophication of rivers and lakes. The reasons why farmers overuse nitrogen fertilizer are complex and not fully understood. They involve agro-climate differences between provinces and counties, farming systems and farm income structures. Although there is a wide range of institutional and technological improvements that can greatly reduce this overuse rapid progress in reducing NPS is unlikely.
  • Series:

    (B) Chemistry/ Metallurgy/ Environment/ Mine Industry; (D) Agriculture

  • Subject:

    Environment Science and Resources Utilization; Fundamental Science of Agriculture

  • Classification Code:

    X592

  • Mobile Reading
    Read on your phone instantly
    Step 1

    Scan QR Codes

    "Mobile CNKI-CNKI Express" App

    Step 2

    Open“CNKI Express”

    and click the scan icon in the upper left corner of the homepage.

    Step 3

    Scan QR Codes

    Read this article on your phone.

  • HTML
  • CAJ Download
  • PDF Download

Download the mobile appuse the app to scan this coderead the article.

Tips: Please download CAJViewer to view CAJ format full text.

Download: 103 Page: 499-508 Pagecount: 10 Size: 224K

Related Literature
  • Similar Article
  • Reader Recommendation
  • Associated Author