Changes in some chemical properties of saline-sodic soils over time as affected by organic residues: An incubation study

Mohsen Jalali,Maryam Saeedi Lotf,Faranak Ranjbar

doi:10.17951/pjss.2020.53.1.1

Mohsen Jalali, Maryam Saeedi Lotf + Show 1 more

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https://doi.org/10.17951/pjss.2020.53.1.1

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Abstract

<p>Salinization and sodification of agricultural lands in arid and semi-arid regions of the world are two limiting factors in the crop production. This study was conducted to evaluate the effect of readily available agricultural residues on changing some chemical properties of saline-sodic soils. Wheat, potato, sunflower, and canola residues were separately added into three saline-sodic soils at a rate of 2% by weight and thoroughly mixed with soils. Control and treated soils were incubated for 168 days at a constant moisture and temperature. The pH, electrical conductivity (EC), soluble cations, available nitrate (NO3-) and phosphorous (P), cation exchange capacity (CEC), and exchangeable sodium percentage (ESP) were measured during the incubation. The EC increased in the response to the incorporation of plant residues, whereas the pH was reduced. The application of organic components in soils increased CEC and decreased ESP. The results showed that the maximum reduction in ESP was observed in the potato treatment because of the highest Ca2+ concentration. The average reduction in ESP of treated soil samples at the end of incubation followed this order: 16.1% (potato residue-treated soil) &gt;12.7% (canola residue-treated soil) &gt;11.1% (wheat residue-treated soil) &gt;9.6% (sunflwer residue-treated soil). The potato residue was the most effective amendment in changing the chemical properties of saline-sodic soils in comparison with other organic residues. The results indicated that the application of organic residues had a positive impact on reducing the soil sodicity and improving the soil fertility depending on their chemical composition.</p>

Highlights

Salinity and sodicity are two of soil destructive factors (Qureshi et al 2008) seriously increasing due to the improper use of soil and water resources
Only the trend of changes in control and treated soil samples 1 was shown in figures, ANOVA and comparison of means were completely given in tables
The values of pH, electrical conductivity (EC), cation exchange capacity (CEC), and exchangeable sodium percentage (ESP) of saline-sodic soil samples were significantly affected by application of organic amendments under controlled laboratory conditions

Summary

Introduction

Salinity and sodicity are two of soil destructive factors (Qureshi et al 2008) seriously increasing due to the improper use of soil and water resources. Population growth and the subsequent increase in the demand for more food and fiber have led to the cultivation in saline and sodic soils. The excessive accumulation of salts in the rhizosphere results in decreasing available water and increasing osmotic pressure and toxicity of some elements for plants. In contrast to saline soils, sodic soils have excessive levels of sodium (Na+) adsorbed onto cation exchange sites. Soil sodicity causes the degradation of soil structure due to the clay dispersion. A poor physical structure leads to the difficulty of soil tillage and seed germination and plant growth restriction. The remediation of saline-sodic soils is essential prior to cultivation

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