首页   按字顺浏览 期刊浏览 卷期浏览 Quantification of the soil-water balance under different veld condition classes in a se...
Quantification of the soil-water balance under different veld condition classes in a semi-arid climate

 

作者: H.A. Snyman,  

 

期刊: African Journal of Range & Forage Science  (Taylor Available online 1999)
卷期: Volume 16, issue 2-3  

页码: 108-117

 

ISSN:1022-0119

 

年代: 1999

 

DOI:10.2989/10220119909485725

 

出版商: Taylor & Francis Group

 

关键词: EVAPOTRANSPIRATION;SOIL EROSION;SOIL-WATER CONTENT;SURFACE RUNOFF;WATER-USE EFFICIENCY

 

数据来源: Taylor

 

摘要:

The monthly herbage production, water-use efficiency (WUE: above-ground phytomass production per unit of evapotranspiration), surface runoff and soil loss were determined on grassland in three different ecological conditions, viz. poor, moderate and good, over a four year (1995/1996 to 1998/1999) period. In addition the same measurements were also made on an undisturbed bare soil surface and a soil cultivated twice per annum, only for the last four years. Herbage production and water-use efficiency decreased (P<0.01) when plant cover was reduced or grassland and soil condition declined. The effect of rainfall on productivity is enhanced as plant composition improves from poor through moderate to good. The highest seasonal WUE of 4.76 kg ha−1mm−1occurred in grassland in good condition. The dense plant cover of grassland in good condition provides a situation in which surface runoff and soil loss are lower (P<0.01) than that from grassland in poor condition. Direct evaporation from the bare uncultivated soil surface was on average 69% of the rainfall. These monthly production and water-use efficiency results are of the few, if not the only, data available for the semi-arid climates of southern Africa and can be used with great success in future fodder flow planning.

 

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