Effect of organic amendments on soil salinity and the growth of maize (Zea mays L.)

Soil salinity is a major concern in southwestern part of Bangladesh because almost 30% cultivable lands are currently lying under risk of salinity where 30-50% yields loss is happening. Organic amendments have found to be effective in the amelioration of saline soil by improving soil physical and chemical properties as well as crop selection is another criteria for sustaining viability of crops in saline soil. For ensuring sustainable saline soil management, a comparative pot study was carried out during kharif 1 season in 2015 to observe the effect of organic amendments (solid waste, vermicompost and cow dung) on soil salinity and its influence on the growth of maize. Composite soil was collected at a depth of 0-15 cm from Gozalmari village of Jalma Union in Batiaghata Upazila under Khulna district, Bangladesh that was saline (10.6 dS/m) in nature and the irrigation water sample was collected from beside Kazibacha river (4.28 dS/m) that was also moderately saline. The maize cultivar “Shuvra” was used for cultivation in the study. The experiment comprised of four treatments viz. T0: Control (No organic manure); T1: Solid waste (36g); T2: Vemicompost (72g); T3: Cow dung (33g). Five seeds were sown in each pot. Seeds were treated with Agrosan GN to protect them from seed and soil borne pathogens. Chemical fertilizers were not used in the experiment. Irrigation was done two times before harvesting: at 20 days after sowing (DAS) and at 40 DAS with river water and rain water was irrigated naturally during the season. Findings were that the organic amendments significantly influence the physico-chemical properties of the saline soil. All organic treated soils significantly reduce the soil EC (from 10.6 dS/m to 3.4 dS/m) and pH (from 7.63 to 7.38) compared to control soil (p?0.05). In case of survival parameters (e.g %gemination, rate of survival at 50 DAS) of maize, the treatments were found insignificant (p?0.05). But in terms of growth parameter (plant height and root length), significant differences were found between control and organic amendments treated soil (p?0.05). It may be concluded that organic amendments treated soils showed better results than that of control soil. If proper management can be implemented, this positive results will bring hope to the local poor farmers at least can introduce a new crop in fallow agricultural land during the kharif 1 season.