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Case Studies on Nitrate Leaching in Arable Fields of Organic Farms

 

作者: E. Scheller,   H. Vogtmann,  

 

期刊: Biological Agriculture & Horticulture  (Taylor Available online 1995)
卷期: Volume 11, issue 1-4  

页码: 89-102

 

ISSN:0144-8765

 

年代: 1995

 

DOI:10.1080/01448765.1995.9754696

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

Nitrogen supply of crops on organic farming systems mainly depends on mineralization of soil organic matter nitrogen. Mineralization was studied by taking soil samples from 30 plots in the crop rotation of two organic farms at intervals of 7 to 14 days during the growing season. On fallow plots net-mineralization alternated with net-immobilization three times from April to November. These soil inherent dynamics were modified by cultivation and the growing cycles of the different crops. Several cases could be observed which led to high accumulations of leacheable nitrate in soils: 1. fallow during growing season, 2. fallow during autumn and winter, 3. manuring in autumn, 4. leaching of chopped green manure by rain, 5. low nitrogen uptake of crops because of diseases, 6. transfer of mineralizable nitrogen from spring to autumn. The concept of the soil merely as a storage place for plant nutrients was one of the main factors for mistakes in nitrogen management. Understanding the interactions of plant residues, soil microbial biomass, net- mineralization intensity and the phases of N-uptake of different crops can lead to a practice of organic agriculture with good yield levels and low losses of nitrate-nitrogen to groundwater.

 

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