جستجوی مقالات مرتبط با کلیدواژه "اصلاح خاک" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

Nowadays, the addition of bio-charcoal to soils, as a way for carbon sequestration in the soil, reducing the concentration of carbon dioxide in the air, improving soil fertility, and reducing wind erosion, has attracted much attention. The aim of this study was to investigate the effect of biochar application on yield and components of Haloxylon species in a randomized complete block design with soil additive factors including mycorrhizal fungi at two levels (consumption of 50 g of mycorrhiza and non-consumption of mycorrhiza), natural charcoal, and biochar produced from municipal waste compost at four levels (0, 50, 150 and 250 g / kg soil of dry soil), in the greenhouse of the Agriculture and Natural Resources, University of Tehran for nine months. The results showed that the addition of biochar had no significant effect on any of the morphological characteristics of Haloxylon persicum except root surface. The results also indicated that the average collar diameter, height, root area, fresh and dry weight of Haloxylon aerial parts in mycorrhiza-free treatments increased 31.9%, 35.7%, 15.5%, 56.9%, and 32.6%, respectively, and in mycorrhiza treatments, these characteristics increased by 4.7, 16.1, 11.1, 33.4, and 6.7%, respectively, as compared to the control treatment. Among the treatments studied, treatment nine (soil + 150 g natural charcoal + 250 g municipal waste compost) had the most positive effect on the morphological characteristics of Haloxylon.

Biochar, as a soil reclamation material, has received attention by researchers during recent decades. In this study, a greenhouse experiment was conducted in a randomized complete block design (RCBD) in factorial arrangement in order to investigate the effect of natural and municipal waste compost biochars on the chemical properties of sandy soils from Kashan's sand dunes. The experimental treatments consisted of natural and municipal waste compost biochar each with four levels (0, 1, 3 and 5%) with the total of 16 culture media. Chemical analysis was performed for soil, biochar, and for 16 culture media resulting from these combinations in three replications. The results of analysis of variance and comparing means of measured characteristics (EC, pH, Ca, Mg, K, and OM) showed that these characteristics were significantly affected by the different levels of natural biochars. Soil pH decreased in some treatments and treatment No 5 had the most pH reduction. Both biochar treatments increased soil EC, pH, Ca, Mg, and OM by 5.5, 3.9, 2.4, 1.9, and 3.7 times, respectively. In general, treatment No 13 (soil + 5% natural biochar + 5% municipal waste compost biochar) had the highest influence on soil characteristics. As a practical application, the use of studied biochars as sources of Ca, Mg, K, and OM can be considered in soil reclamation projects and fertilizer management.

Sulfur is an essential element for plant growth since its presence in betamine, biotein, aminoacid, and sulfulipid compoundsplaysa key role in activating many enzymes, synthesizingproteins, and counteractingthe toxicity of heavy metals in plants. In addition to its nutrirional value, sulfur is known as a soil amendment for improving thephysico-chemical propertiesofcalcareous, sodic, and saline-sodic soils. Agriculture inKhorassan Razavi Province,as one of the greatest and most important producers across the nation,plays animportant role in providing the essential needs,producing food, supplyingindustrial raw materials, and creating employmentfor the population in the province.Due to the inadequate physico-chemical conditions, however,the soils in thisprovinceare not able to provide (horticultural and farm crop) plants with all their nutritional requirements, especially phosphorous and micronutrients. Although nutrient requirements might be met in the short term through continueduse of chemical fertilizers,it will in the long term lead to soil and water pollution. Study has shown that proper use of sulfur in soil can not only improve soil chemical and physical properties but alsocontribute tobetter nutrient uptake by plants and preventthe associated environmental problems. Based on these results, application of sulfur, organic matter, and Thiobacillus by 2% the sulfur weight may be recommended for improving both plantyieldand soil physico-chemical properties.

Soil salinity and sodicity are escalating problems worldwide، especially in arid and semi-arid regions. This study investigates the effect of some mineral and organic amendments on reclaiming a saline- sodic soil based on distribution of soluble cations. The soil amendments consist of control، cattle manure، pistachio residue، gypsum، manure + gypsum and pistachio residue + gypsum; water treatments with and without sulfuric acid with three replicates were performed. At the end of experiments soluble cations were measured at different depths. The results indicated that monovalent cations and also the EC and SAR showed the lowest values near the soil surface، while bivalent cations had no significant variation with depth. This finding shows that monovalent cations would be more mobile than the bivalents. Also، it was found that in comparison with gypsum، sulfuric acid had more efficiency in the SAR decreasing. However، in calcareous soils، this aim would be achieved by only irrigation. Pistachio residue and cattle manure had the highest and the lost efficiencies in decreasing of the EC and SAR. The findings of this research reveal the relative importance and efficiency of pistachio residue in reclaiming of the sodium affected soil.

Reclamation is needed on about 130 thousand hectares of saline-sodic soils in the Golestan province. This field experiment was conducted on a saline-sodic soil to compare changes in chemical properties after various treatments. Treatments were: (i) gypsum، (ii) sulphuric acid، (iii) sulphur and (iv) a control. Also، 60 cm of water added to all treatments for leaching. Electrical conductivity (EC)، pH، exchangeable Na+، Na+، Ca+2 and Mg+2 of the soil in the saturated paste extract under each treatments were measured in the 30 cm and 60 cm soil depths after 40 days. All statistical analysis were performed using the SAS software package. Desalinization and desodification processes were observed in all the treatments. Gypsum and sulphuric acid application increased the soluble Ca+2 Mg+2 and decreased the soluble Na+ in the top 60 cm of soil. Therefore، gypsum and sulphuric acid application significantly decreased SAR، EC and pH in the top 60 cm of soil. Sulphur decreased SAR، EC and pH when compared to control in the top 60 cm of soil. But non-significantly decreased these same parameters. In general، for surface soil improvement، gypsum and sulphuric acid application was the most effective of the treatments used.