a long-term field experiment was conducted for 7 years to evaluate the effect of different amendments to mitigate the adverse effect of saline-sodic water in a calcareous soil under cotton-wheat cropping system. the pooled results over 7 years revealed that the application of saline-sodic water decreased the mean cotton-seed yield by 20.7% as compared to good quality canal water. however, wheat...

The effect of gypsum on the physical and chemical characteristics of sodic soils is nonlinear and controlled by multiple factors. The support vector machine (SVM) is able to solve practical problems such as small samples, nonlinearity, high dimensions, and local minima points. This paper reports the use of the SVM regression method to predict changes in the chemical properties of sodic soils un...

Soil salinity is a major abiotic stress adversely affecting plant growth and crop production worldwide. Increased salinization of arable land is expected to have destructive universal effects, resulting in 30 % land loss within the next 25 years and up to 50 % by the middle of twenty-first century (Porcel et al. 2012; Kapoor et al. 2013; Abdel Latef and Chaoxing 2014). The term ‘‘salinity’’ ref...

Assessing the ability of soil microorganisms to dissolute poorly soluble native calcite to supply Ca2+ is a new area to be explored in reclaiming sodic soils by supplying adequate Ca2+ and reducing the recurrent sodicity. Hence, the present study aimed to isolate a calcite dissolving bacteria (CDB) from calcareous sodic soils and to understand the mechanism of calcite dissolution. Of the 33 CDB...

rganic matter and clay miner0 als in soils have negatively charged surfaces that act much like cation exchange resins. When more than 15% of the exchange sites are neutralized by Na+ and the final ionic strength of the aqueous extract is less than about 0.04 M, the clays and organic matter are dispersed. Under these conditions, the solution pH is usually greater than 8.4, and carbonate (COi-) a...

A field experiment was carried out to study the changes of soil bacteria, fungi and actinomycetes in saline-sodic soils for different numbers of cultivated years under drip irrigation. The drip irrigation had substantial effects on levels of bacteria, fungi and actinomycetes. With increased number of cultivated years under drip irrigation, the soil biological properties were greatly improved. A...

Our aim in this work is (1) to characterize mineralogically and geochemically the brown amphibole and other minerals filling millimetric veins in the Cóbdar metabasalts of the Betic ophiolites in southern Spain, and (2) to deduce their genetic conditions, mainly with the aid of the optical microscopy and analytical electron-microprobe analysis, complemented by transmission and analytical electr...

soil samples from the jakara irrigation project site were evaluated with respect to possible degradation caused by irrigation. most of the soils were neutral to alkaline with ph values ranging between 6.58 + 0.04 and 10.45 + 0.03. the electrical conductivity ranged from 0.3 + 0.01 to 75.2 + 0.06 dsm-1 which implies low to very high salinity. the concentrations of the exchangeable cations in the...