Effect of wastewaters on plant growth and soil properties

Abstract

Abstract Effects of wastewaters on plant growth and soil properties were studied in a pot experiment. Mean biomass ranged from 159 to 210 g per pot for maize and from 165 to 212 g per pot for sorghum in different water salinity treatments. Mean dry matter yield ranged between 28.9 to 38.3 and 34.9 to 50.4 g per pot in different water salinity treatments for maize and sorghum crops, respectively. The crop yield showed significant increase with increase in water salinity. This was presumably due to the nutrients present in wastewaters, especially the nitrogen. Plant yield decreased slightly at water salinity level of 2330 mg L‐1 (TDS), indicating that high water salinity can neutralize the beneficial effects of nutrients in wastewaters. Soil salinity and sodicity increased significantly with corresponding increase in water salinity and sodicity (r values of 0.98 (maize) and 0.98 (sorghum) for soil salinity, and 0.96 (maize) and 0.95 (sorghum) for SAR of soils). The interaction between crop and water treatments was significant for soil salinity (an LSD of 0.48 at p = 0.05) and SAR of soil (an LSD of 2.55 at p = 0.05). Overall, the soil salinity and sodicity was significantly more in sorghum than maize. The results showed that wastewaters can successfully be used to grow corn and sorghum as forage crops, provided 15 to 20% excess water is applied to meet leaching requirements to maintain soil salinity within acceptable limits for optimal agricultural production. Key words: wastewatermaizesorghumsoil salinitysodicity