Latest Research News on Soil Salinity: Dec – 2019

Soil Electrical Conductivity and Soil Salinity: New Formulations and Calibrations

A new model describing the relation between bulk soil electrical conductivity (ECa), volumetric content (θw) and electrical conductivity of soil water (ECw) is given along side supporting evidence for its validity. The new model distinguishes between the water and salt present within the soil within the “immobile” (fine pores) and “mobile” (large pores) phases. It provides a possible physical aiming to the transmission coefficient (T) previously utilized in an earlier model and eliminates a limitation of that model which existed under conditions of low salinity. New empirical relations are provided to estimate the parameters needed within the new and old models so as to utilize them for diagnosing soil salinity, in terms of the electrical conductivity of the extract of saturated soil pastes (ECe). [1]

Remote sensing of soil salinity: potentials and constraints

Soil salinity caused by natural or human-induced processes may be a major environmental hazard. the worldwide extent of primary salt-affected soils is about 955 M ha, while secondary salinization affects some 77 M ha, with 58% of those in irrigated areas. Nearly 20% of all irrigated land is salt-affected, and this proportion tends to extend in spite of considerable efforts dedicated to land reclamation. this needs careful monitoring of the soil salinity status and variation to curb degradation trends, and secure sustainable land use and management. Multitemporal optical and microwave remote sensing can significantly contribute to detecting temporal changes of salt-related surface features. Airborne geophysics and ground-based electromagnetic induction meters, combined with ground data, have shown potential for mapping depth of salinity occurrence. [2]

Vesicular-arbuscular mycorrhizas and soil salinity

This review discusses the expansion and activity of vesicular-arbuscular (VA) mycorrhizal fungi in saline conditions. The review includes examination of the consequences of high concentrations of salts on the occurrence of VA mycorrhizal fungi in field soils, and on spore germination, growth of hyphae, establishment of the symbiosis and production of spores in controlled conditions. Information on the expansion and reproduction of VA mycorrhizal fungi under saline conditions is scarce and is usually circumstantial. there’s clear evidence that germination of spores and subsequent hyphal growth of some VA mycorrhizal fungi are reduced by increasing concentration of salts. [3]

Soil salinity and matric potential interaction on water use, water use efficiency and yield response factor of bean and wheat

We studied the consequences of soil matric potential and salinity on the water use (WU), water use efficiency (WUE) and yield response factor (Ky), for wheat (Triticum aestivum cv. Mahdavi) and bean (Phaseoulus vulgaris cv. COS16) in sandy loam and clay loam soils under greenhouse conditions. Results showed that aeration porosity is that the predominant factor controlling WU, WUE, Ky and shoot biomass (Bs) at high soil water potentials. As matric potential was decreased, soil aeration improved, with Bs, WU and Ky reaching maximum value at −6 to −10 kPa, under all salinities. [4]

On Improving Seed Germination and Seedling Growth in Rice under Minimal Soil Salinity

Aims: it had been assumed that two- way approach i.e. nutrient-priming with potassium salt of the seeds and afterward ammonium sulphate application could also be binary beneficial for growth of rice besides evidencing genetic variability under salt stress

Study Design: The experiment was laid call at Complete Randomized Design with three replications.

Place and Duration of Study: The study was conducted in laboratory and glass house of Soil Salinity Research Programme of natural resource Research Institute at National Agricultural research Centre, Islamabad, Pakistan during the amount from May to August, 2016. [5]

Reference

[1] Rhoades, J.D., Manteghi, N.A., Shouse, P.J. and Alves, W.J., 1989. Soil electrical conductivity and soil salinity: New formulations and calibrations. Soil Science Society of America Journal, 53(2), (Web Link)

[2] Metternicht, G.I. and Zinck, J.A., 2003. Remote sensing of soil salinity: potentials and constraints. Remote sensing of Environment, 85(1), (Web Link)

[3] Juniper, S. and Abbott, L., 1993. Vesicular-arbuscular mycorrhizas and soil salinity. Mycorrhiza, 4(2), (Web Link)

[4] Soil salinity and matric potential interaction on water use, water use efficiency and yield response factor of bean and wheat
Mahnaz Khataar, Mohammad Hossien Mohammadi & Farzin Shabani
Scientific Reports volume 8, (Web Link)

[5] uz-Zaman, B.-, Ali, A., Ali Mahmood, I., Suhaib, M., Arshad Ullah, M. and Ishaq, M. (2017) “On Improving Seed Germination and Seedling Growth in Rice under Minimal Soil Salinity”, Asian Research Journal of Agriculture, 4(1), (Web Link)