The effect of soil amendments and fertilizers on soil electrical conductivity

Abstract

Soil amendments are used either as fertilisers or as soil conditioner. Fertilisers are added to improve the soil's fertility status over a short period of time during the growing season and amendments such as lime and sulphur are used to adjust the soil pH. This practice however might have an impact on the soil's electrical conductivity and salinity, and if soils are over fertilised, the increase in conductivity might be detrimental to production. In this study the effect of certain soil amendments on the conductivity and salinity of soils from Malta was investigated. Two fertilisers commonly used and two soil pH conditioners were added to different soils from Malta and changes in conductivity were monitored. Conductivity was also measured after the addition of water that simulated irrigation, and after flooding. This study has shown that the addition of fertiliser increases soil salinity especially in the case of over fertilisation. In most cases, when fertilisers that instantly produce ions in the soil solution were used, the addition of water resulted in a decrease in salinity. This pattern was observed in most soil types. The increase of salinity after the addition of sulphur was low; however salinity did not increase with the addition of water.