Investigation of soil quality (health) in commercial production of rooibos tea (Aspalathus linearis) in the Western Cape, South Africa

[摘要] ENGLISH ABSTRACT: The global demand for rooibos tea (Aspalathus linearis) has steadily increased over the past five years thanks to the increased awareness of its health benefits, while rooibos tea production has decreased. If this trend continues, rooibos producers will be unable to meet the world demand. What makes rooibos a particularly challenging crop to grow is the fact that it is a sensitive fynbos species, adapted to low soil nutrient conditions, which can only be cultivated in a niche area of the Western and Northern Cape regions of South Africa. The farmers are under great pressure due to increasing production costs and environmental laws which restrict the establishment of new rooibos fields in fynbos areas. The only way for farmers to meet the demand will have to be by increasing their tea yields and quality while using the same area of land. To date, very little research has been conducted to help the producers. Rooibos farmers report that yields decline dramatically over time since the clearing of the natural fynbos vegetation. It was hypothesized that this decrease in production is most likely related to changes in soil quality (health) and ecology. Thus, the aim of this study was to examine soil (chemical, physical and microbiological properties) and plant quality parameters in cultivated rooibos fields of various ages and adjacent, rooibos stands in pristine fynbos. The results will be used to diagnose the decline in rooibos production and suggest amendment strategies to improve commercial rooibos production.Experimental sites were selected in the Clanwilliam district, at the two oldest (Nardouwsberg and Seekoeivlei) of the six main rooibos producing areas. Virgin fynbos, young rooibos fields (2 years) and older rooibos fields (20-60 years) were selected as sampling sites.

[发布机构] Stellenbosch University