Why salinity kills plants

Sprinkle the salt around the base of the plant and allow it to naturally break down in the soil's moisture. For small weeds, such as dandelions, you might only need three or four chunks.

For larger plants, try a handful of the salt. It works relatively quickly, so if you don't notice the plants wilting in about two days, add a bit more rock salt around the plants' bases. Watering the plants soon after adding the rock salt will help it dissolve into the soil.

A major problem with using rock salt even in small concentrations is that is tends to stay in the soil for years until water leaches it out. Plant Cell Environ. Ghassemi F. Salinisation of land and water resources: Human causes, extent, management and case studies.

Greenway H. Mechanisms of salt tolerance in nonhalophytes. Plant Physiol. Munns, R. Munns R. Physiological processes limiting plant growth in saline soil: some dogmas and hypotheses. Munns R Comparative physiology of salt and water stress. Condon A. The significance of a two-phase growth response to salinity in wheat and barley.

Rivelli, A. R James, R. Condon, A. Tony Lindsay, M. Lagudah, E. Schachtman, D. Hare R. Avenues for increasing salt tolerance of crops, and the role of physiologically based selection traits. Plant and Soil Rengasamy P Transient salinity and subsoil constraints to dryland farming in Australian sodic soils: an overview. Impact Mitigation Methods Updates Menu. The Impact of Salinity Stress.

Types and Causes of Salinity Natural or primary salinity Primary salinity results from the accumulation of salts over long periods of time, through natural processes, in the soil or groundwater. Table 2: Concentration of salts in rain and seawater. Measuring soil salinity Soil salinity is measured by its electrical conductivity. Table 4: Units for measuring salinity, and conversion factors. Figure 1. Example of an EM survey taken on a paddock basis at ground level.

Image courtesy of P. The repercussions of salinity The Effect of Salinity on Plants Salts in the soil water may inhibit plant growth for two reasons. Variation in Salt Tolerance between Species The three most important crops in the world are wheat, rice and maize. Figure 2. Biomass production of four diverse and important plant species in a range of salinities.

Wheat is one of the more salt-tolerant crops, and rice is one of the more salt-sensitive crops. Two halophytes: a saltbush species Atriplex amnicola and a grass Diplachne syn.

Leptochloa fusca or Kallar grass. Both halophytes show outstanding salt tolerance with high growth rates and are being used in Australia and Asia for grazing on saline land. Figure 3. Note that the ECe is more applicable to an irrigated than a rainfed field, in the latter the soil moisture content might be time less than in a saturated paste.

Causes of the Growth Reduction under Saline Conditions The effects of a saline soil are two-fold: there are effects of the salt outside the roots, and there are effects of the salt taken up by plants. Figure 4. Two accessions of the diploid wheat progenitor Ae. Circles denote the tolerant accession, triangles the sensitive one. The percentage of transpired water that is retained in the shoot can be calculated from the product of the water use efficiency wue ; mass of shoot produced per mass of H 2 O transpired and the shoot water content wc ; shoot H 2 O per shoot mass : Water use efficiency WUE of plants growing at moderate evaporation demand are usually in the range of mg g -1 , the variation due to extremes of evaporative demand, rather than a peculiarity of the species.

The Relationship between Transpiration and Salt Uptake The fundamental processes governing the relationship between water and ion flow through roots are complex and not well understood.

Figure 5. The relation between ion concentration in the xylem A , ion flux to the shoot B , and transpiration water flow Munns, Mechanisms of Control of Salt Transport Here we look at differences between species in the ability to tolerate the salt-specific component of salinity.

Control at the whole plant level Control of salt transport into and through the plant takes place at five sites in the plant Fig. Figure 6. Control points at which salt transport is regulated. These are: 1. Avoid planting in areas where runoff naturally flows. Leaching soils by watering heavily can help remove salts from well-drained soils.

This is not possible with poorly draining soils. Improve drainage of poorly drained soils by adding organic matter. Protect plants with physical barriers such as burlap, plastic, or wood. Use salt tolerant plants in areas near roads, driveways, and sidewalks. Remember that salt tolerant does not mean injury free. The following is a table of the reported salt tolerance of selected trees and shrubs. Tolerance can also vary depending on method of salt exposure spray vs.

There are conflicting reports for salt tolerance of many species. Soil type and climate variability can result in differences in plant response between areas. The following sources also have lists of reported salt tolerance of some common landscape plants:.

Soluble Salts in Soils and Plant Health. Beckerman, J. Salt Damage in Landscape Plants. Purdue Extension. Factsheet IDW. Gould, Ann. Impact of Road Salt on Adjacent Vegetation. Rutgers Cooperative Extension. New Jersey Agricultural Experiment Station. The Effects of Rain Water on Plants. Osmosis Facts for Kids. Soft Water Disadvantages. How Salt Affects Living Organisms. Facts About Calcium Chloride. Trees That Grow in Saltwater. How to Light a Lightbulb With Saltwater.