Amelioration strategies for sodic soils: a review

Abstract

Sodic soils are characterized by the occurrence of excess sodium (Na ) to levels that can adversely affect soil structure and disturb availability of some nutrients to plants. Such changes ultimately affect crop growth and yield. There are large areas of the world that exist under sodic soils and need attention for ef®cient, inexpensive and environmentally feasible amelioration. Sodic soil amelioration involves increase in calcium (Ca 2 ) on the cation exchange sites at the expense of Na . The replaced Na together with excess soluble salts, if present, is removed from the root zone through in®ltrating water as a result of excessive irrigations. Record nearly a century old reveal the use of water, crop, chemical amendment, electric current, and tillage as amelioration tools for such soils. Among the amelioration strategies, chemical amendments have an extensive usage. Owing to gradual increases in amendment cost in some parts of the world during the last two decades, this amelioration strategy has become cost-intensive, particularly for the subsistence farmers in developing countries. In the meantime, phytoremediation with low initial investment has emerged as a potential substitute of chemical amelioration. Phytoremediation works through plant root action that helps dissolve native soil calcite (CaCO 3 ) of low solubility to supply adequate levels of Ca 2 for an effective Na À Ca 2 exchange without the application of an amendment. Although signi®cant progress has been achieved in improving amelioration methods, a great deal of work remains to analyse the economics of such methods with focus on (1) the long-term sustainability of the amelioration projects and (2) the consequences of amelioration for the farmer himself, other growers and society as a whole. Computer modelling may help assess economic viability of different soil amelioration methods to extend results broadly to other similar locations. In addition, computer modelling to stimulate movement and reactions of salts in sodic soils has been a potentially useful complement to experimental data. However, such models need evaluation under ®eld conditions.

Ameliorative Effect of CaCl₂ on Growth, Membrane Permeability and Nutrient Uptake in <i>Oryza</i> <i>sativa</i> Grown at High NaCl Salinity

“…K + concentrations reduced by salinity, can be restored to adequate levels by an additional supply of calcium, as it protects cell membranes from adverse effect of Na + and minimizes the leakage of cytosolic potassium. Calcium plays a vital role in the regulation of ionic relations in plants and in improving the soil physical conditions (Qadir et al, 2001).…”

Management of Sodic Waters for Sustainable Crop Productivity of Rice- Wheat Cropping System

“…The menace of unfit ground water can be reduced by using management practices along with amendments either inorganic like gypsum, H2SO4 etc or organic like manures FYM, poultry manure, press mud etc. (Qadir et al, 2001;Saifullah et al, 2002;Yaduvanshi and Swarup, 2006). Present investigation falls under the preview of second aspect mentioned above and effort has been made to utilize sodic underground water for irrigation with suitable amendment techniques to boost crop production under sodic soil condition.…”

Varied Patterns of Sprouting and Nutrient Status of Sugarcane Sprouts in Simulated and Natural Saline/Sodic Soils Across two Growing Seasons

“…Considering the graveness of the matter, the reclamation of saline/sodic lands and their profitable exploitation has been the subject of interest (Qadir et al, 2001;Arshadullah et al, 2012). Sugarcane is amongst the crops planted in two seasons and show differential growth behaviors.…”