Observing Changes in Riparian Buffer Strip Soil Properties Related to Land Use Activities in the River Njoro Watershed, Kenya

Autor: William A. Shivoga, Irena F. Creed, E. M. Enanga, C. Maina-Gichaba
Rok vydání: 2010
Předmět:
Zdroj: Water, Air, & Soil Pollution. 218:587-601
ISSN: 1573-2932
0049-6979
Popis: Riparian buffer strip guidelines are under scrutiny in the River Njoro Watershed in Kenya. This study investigated soil properties (bulk density, carbon, nitrogen, and phosphorus) in different land use types (small scale agriculture in recent settlements, mixed agriculture in established peri-urban settlements, large- scale commercial agriculture, and the gazetted forest reference condition) and their adjacent buffer strips. Bulk density, carbon, nitrogen, and phosphorus within 30-m riparian buffer strips adjacent to recent settlement landuseareasweresimilar tothoseofthegazettedforest reference condition, but only bulk density of the buffer strips adjacent to peri-urban and commercial agriculture land use areas were similar to the gazetted forest reference condition. Phosphorus is a sensitive indicator of the impacts of human activity, as increased concen- trations were observed with increasing scale of land use activity. For riparian buffers adjacent to recent settle- ments, soil phosphorus was significantly higher in buffers narrower than 30 m (5.01 mg P kg −1 )t han gazetted forest (3.40 mg P kg −1 )b ut not significantly different for riparian buffers wider than 30 m (3.81 mg P kg −1 ) compared to gazetted forest. Based on the research, it is recommended that policies governing riparian buffer strips become (1) stricter, with the current "maximum" of 30 m considered a minimum; and (2) adaptive, with 30 m used in small- scale agricultural areas, and wider riparian buffer strips used in medium- and large-scale agricultural areas.
Databáze: OpenAIRE
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