Soil conditioners as candidates to mitigate salt/water stress effects on sorghum growth and soil properties

Abstract

In arid and semiarid regions the use of saline water is common in agricultural irrigation, due to the scarcity of high-quality irrigation water. Thus, agriculture faces a challenge in developing strategies to grow crops under such adverse conditions in these regions. The objectives of this research are to study soil chemical properties and sorghum growth response to saline irrigation levels and application of soil conditioners. A greenhouse experiment (4x5) was carried out using a Cambisol cultivated with sorghum and irrigated with five saline water levels: 100%, 80%, 60%, 40% and 20% of soil field capacity (FC). Soils were treated with no soil conditioner (control), organic matter, elemental sulfur (S0) + organic matter and gypsum + organic matter, applied to the soils 30 days before sorghum planting. At 60 days after plant emergence, measurements were recorded for: leaf water potential, plant dry weight, soil P availability, and soil chemical properties. Increasing saline water levels reduced exchangeable and soluble cations and saline variables. Organic matter + elemental sulfur promoted the highest levels of P in the soil and soil saturation extract. This mixture and the saline irrigation of 60% of field capacity promoted the greatest plant growth. However the organic matter + gypsum mixture promoted higher leaf water potential in relation to the other conditioners tested. The saline irrigation level equivalent to 60% of field capacity and the incorporation of organic matter + S0 were sufficient to reduce soil salinity and sodicity, maintaining P and soluble/exchangeable cations contents to a level that best promoted sorghum growth