Indigenous knowledge systems available to conserve soil and water and their effects on physico-chemical properties on selected smallholder farms of KwaZulu-Natal.

Abstract

Most of rural South Africa is semi- arid, experiencing a variable climate with extreme events such as droughts, floods or thunderstorms. In spite of this, communal farmers develop indigenous strategies to cope with these extremes in order to sustain agricultural production. The aim of the study was to document indigenous strategies that smallholder farmers in Bergville and uMsinga, in KwaZulu Natal use to predict weather, conserve soil and water in an effort to improve crop yields. Data was gathered through a baseline survey, which was supplemented with laboratory analyses to evaluate the physio-chemical properties of soil under different conservation practices in both areas. The baseline survey was carried out in sixteen villages, (eight villages each from uMsinga and Bergville). Information was gathered through 5 key informant interviews, 8 focus group discussions and 200 household questionnaires in each area. Soil characterisation was also done in the same sixteen villages by sampling from six conservation techniques namely zero and minimum tillage, intercropping, contour ploughing, fallowing and ridge/furrow planting, which were compared with conventional tillage. Soil samples were collected at 0-20, 20-40 and 40- 60 cm depth, then analysed for total C, N, P, pH, bases, EC, organic C, exchangeable Al and particle size distribution using standard laboratory techniques. Aggregate stability and bulk density were determined at 0-20 cm depth only by collecting aggregates and soil cores respectively. Results showed that Bergville and uMsinga farmers rely on crop and livestock farming, home industries, poultry farming, salaries and social grants for income. Farmers also believe that the climate has been changing over the years through temperature rises and more erratic rain. They use indigenous indicators such as wind and cloud patterns, animal and bird behaviour, shape of the moon and position of the sun to predict weather. To cope with extreme weather, farmers rely on rainmakers and traditional healers in drought years, open drainage pathways to drain excess water during floods, burn incense to quell thunderstorms and lightning, then use the aloe plant, ashes and cow dung to control pests and diseases. Farmers also use drought tolerant crops (sorghum / millet), varieties (yellow maize) to cope with dry spells; and practices such as intercropping and crop rotation to sustain soil productivity. To conserve soil and water, farmers use raised beds, mulching, early maturing crops, furrows & ridges, earth dams and animal manure in the gardens; while contour farming, zero tillage, fallowing, terraces and animal manure are used in the fields. Techniques such as zero tillage, terraces, furrow/ridge, raised bed and mulching were adopted from science. Whereas fallowing, contour ploughing, manure addition, earth dams and rainwater harvesting are IKS. In uMsinga most farmers still prefer their indigenous methods. Whereas in Bergville, farmers prefer scientific methods. Zero, minimum and conventional tillage treatments improved soil properties (bases, P, OC and aggregate stability) at Bergville whereas at uMsinga intercropping, contour ploughing and furrow / ridge performed better. The clay fraction did not have much influence on the performance of the techniques. In uMsinga, silt had more impact since it enhanced soil pH, Ca and K availability. High soil pH enhanced availability of bases (Ca, Mg and Na) particularly at Bergville, but negatively correlated with Al. Soil moisture enhanced availability of Mg, Na, P and C: N at but had a negative correlation with K. Whereas in Bergville, soil moisture positively correlated with OC but was negatively correlated with Na. Correlation results showed that there was no relationship between the different particle size fractions and tillage techniques. As a result, the higher performing techniques do not have their performance influenced by textural fraction. It was recommended that farmers in Bergville adopt zero and minimum tillage since they improved soil properties in the field. In uMsinga, intercropping and contour ploughing would be better soil quality enhancers than conventional tillage in the field, while the furrow/ridge is of more benefit in the gardens.