Soil water salinity is dependent on soil type, climate, water use and irrigation routines. Reduce Soil Salinity. Naturally, the Australian soil contains salt components which have build up over an extended period of time. of soil salinity, namely primar y (natura l) and secondary (due to human activity, i.e., dry lan d and irr igated land salinity). The primary effect of excess salinity is that it renders less water available to plants although some … Salinity is often associated with prolonged wetness and lack of surface cover and therefore increases the vulnerability of soils to erosion. Sodic soils are alkaline, rich in sodium carbonates, with an exchange complex dominated by sodium ions. The cause of this process is the accumulation of salts in soil capillaries leading to a sharp decrease in plant fertility. As the water evaporates, salts dissolved from the soil deposit and accumulate at the soil surface. Irrigation of soils is directly proportional to decrease in soil salinity (Cetin and Kirda, 2003). In this Topic. Water table fluctuations and the resulting salt deposits into soils are a natural phenomenon, referred to as ‘primary salinity’. The primary effect of excess salinity is that it renders less water available to plants although some is still present in the root zone. Salinization is the increase of salt concentration in soil and is, in most cases, caused by dissolved salts in the water supply. Cropping with Saline Irrigation Water Irrigation guidelines for cropping with saline water. Soil salinity also occurs due to human-made process such as irrigation making it … How does secondary salinity occur? In the situation of a dugout or seeping irrigation canal, lining the canal or dugout to prevent the loss of water is the first step. primary source of salts in soil is from rock weathering. Salinity is a concern in most states, but especially in the south-west of Western Australia. You do not currently have access to this article, Access to the full content requires a subscription. Soil salinization is a key regulator of plant/soil nitrogen pools and, by altering soil electric conductivity and affecting the functioning of soil microorganisms, it impacts nutrient cycling and global fluxes. Cause of soil salinity. Solving the Problem; References ; Causes. Causes of soil salinity. Soil Quality Testing. Sodium bicarbonate is also common. Microbes involved in organic matter mineralization and thus the carbon, nitrogen, and sulfur biogeochemical cycles are also implicated. In other situations, referred to as secondary salinity causes by agricultural activities, excess water causes the salinity, if the causes can be determined such as summerfallow practices or a seeping irrigation canal, the solution is to reduce or stop the source of excess water entering into the groundwater. Nitrogen in agricultural systems may be fixed from the atmosphere by legumes, decomposed from soil organic matter (the dead remains of plants and animals) by soil organisms, or … Solid Earth, 7(1), 177. Soil salinity changes the fertile land to unproductive land, which ultimately results in economical loss (Grieve et al., 1986). 3.1.2 Salinity and plant growth. The presence of salts and alkaline conditions, together with the occurrence of drought and seasonal waterlogging, creates some of the most extreme soil environments where only specially adapted organisms are able to survive. High salts concentration results in high osmotic potential of the soil solution, so the plant has to use more energy to absorb water. In contrast, irrigation water with higher salinity than the soil tends to cause particles to stay together, maintaining soil structure. Irrigation salinity occurs due to increased rates of leakage and groundwater recharge causing the watertable to rise. In the study conducted by; Y. Ali, Z. Aslam, M. Y. Ashraf and G. R. Tahir they concluded that there is a reduction in chlorophyll content due to the inhibitory effect caused by various salts. Areas near Dumbleyung Lake have become unsuitable for grazing due to increased salinity. plants, animals, aquatic ecosystems, water supplies, agriculture and infrastructure). By definition, a saline soil contains excess soluble salts that reduce the growth of most crops or ornamental plants. In dryland areas, if the source of excess water is the result of summerfallowed fields, farmers would need to adopt different cropping practices. Causes of Soil Salinisation How does secondary salinity occur? Oxford Research Encyclopedia of Environmental Science, Commonwealth Scientific and Industrial Research Organisation, Land and Water, Framing Concepts in Environmental Science, Sign in to an additional subscriber account, Cation Exchange and Solution Interface Chemistry, Formation of Soil Carbonates and Alkalinity, Case Study: Mt Lofty Ranges, South Australia—A Mediterranean Climatic Region (>600 mm Rain per Annum, Winter Rainfall Maximum)/Koppen Climate Class: Grassland, Warm, Summer Drought, https://doi.org/10.1093/acrefore/9780199389414.013.264. Thus a concentration of 3 grams per litre will be about the same as 4.5 millimhos/cm. Another term to know is “salinization.” That’s the process of soluble salts (for example, sodium) building up in soil over time. Salinity can affect plant growth in several ways, directly and indirectly: Direct soil salinity damages: Decreased water uptake. Routine soil testing can identify your soil’s salinity . Soil salinity comes from salt spray and foam blown inland, and the amount of salt usually correlates well with the distance inland or degree of protection from the wind. Evaluation of promising technologies for soil salinity amelioration in Timpaki (Crete): a participatory approach. 2006: This Australian publication talks about the causes of soil salinity under dryland agriculture and its effects on agriculture production. Poor land management can also lead to anthropogenically induced secondary salinity. This is a diagram showing the method in which salinisation occurs: Figure 1.1 Australia's natural salinity has been worsened by changes in land use since European settlement. “However, if the soil is severely saline, a salt tolerant grass mixture should be seeded and established. Eventually, when the salt concentration is very high, a white salt crust forms on the soil surface. Dryland Salinity: Soil Processes and Management: Annals of Arid Zone: Peer-reviewed publication. 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