اثر مواد آلي، گچ و آبشويي بر ويژگي‌هاي فيزيكي و شيميايي يك خاك سديمي

The Effects of Organic Matter, Gypsum and Leaching on Physico-chemical Properties of a Sodic Soil

به منظور بررسي تاثير سطوح مختلف گچ (صفر، 50 و 100 درصد نياز گچي) و مواد آلي از بقاياي گياه يونجه، ذرت، ضايعات خرما و خاك اره (5/1 و 3 درصد كربن آلي) بر ويژگي‌هاي فيزيكي و شيميايي يك خاك سديمي يك آزمايش فاكتوريل در قالب طرح كاملا تصادفي با سه تكرار در گلخانه به اجرا درآمد. نتايج نشان داد كه مصرف گچ سبب بهبود ويژگي­هاي خاك سديمي قبل و پس از آبشويي شد. مصرف مواد آلي قبل از آبشويي نسبت جذب سديم، درصد سديم تبادلي و درصد رس قابل انتشار را به صورت ناچيزي افزايش داد ولي پس از آبشويي خاك مقدار اين ويژگي ها در مقايسه با شاهد بطور معني­داري كاهش يافت. اثربخشي مصرف گچ به همراه مواد آلي براي اصلاح ويژگي­هاي خاك سديمي به ويژه در تركيب با ضايعات خرما به ميزان 3 درصد كربن آلي بيشتر از مصرف جداگانه آن­ها پس از آبشويي بود.

In order to investigate the effects of different levels of gypsum (0, 50 and 100% gypsum requirement), organic matter (1.5 and 3% w/w organic carbon) from different sources (alfalfa residue, corn residue, date waste and saw dust) and leaching on the physico-chemical properties of a sodic soil, a factorial experiment was conducted in a greenhouse using a completely randomized design with three replicates. The results showed that the application of gypsum improved the sodic soil properties, before and after the leaching. However, the application of organic matter slightly increased sodium adsorption ratio, exchangeable sodium percentage and the percentage of dispersible clay measured before leaching. But after leaching, these characteristics were decreased significantly as compared to the control. The application of organic matter together with gypsum, especially the application of 3% date waste with gypsum, improved the properties of the sodic soil after the leaching more effectively than the application of gypsum and organic matter separately.