Drought and salinity: A comparison of their effects on mineral nutrition of plants

Abstract

The increasing frequency of dry periods in many regions of the world and the problems associated with salinity in irrigated areas frequently result in the consecutive occurrence of drought and salinity on cultivated land. Currently, 50% of all irrigation schemes are affected by salinity. Nutrient disturbances under both drought and salinity reduce plant growth by affecting the availability, transport, and partitioning of nutrients. However, drought and salinity can differentially affect the mineral nutrition of plants. Salinity may cause nutrient deficiencies or imbalances, due to the competition of Na+ and Cl– with nutrients such as K+, Ca2+, and NO$ _3^- $. Drought, on the other hand, can affect nutrient uptake and impair acropetal translocation of some nutrients. Despite contradictory reports on the effects of nutrient supply on plant growth under saline or drought conditions, it is generally accepted that an increased nutrient supply will not improve plant growth when the nutrient is already present in sufficient amounts in the soil and when the drought or salt stress is severe. A better understanding of the role of mineral nutrients in plant resistance to drought and salinity will contribute to an improved fertilizer management in arid and semi‐arid areas and in regions suffering from temporary drought. This paper reviews the current state of knowledge on plant nutrition under drought and salinity conditions. Specific topics include: (1) the effects of drought and salt stress on nutrient availability, uptake, transport, and accumulation in plants, (2) the interactions between nutrient supply and drought‐ or salt‐stress response, and (3) means to increase nutrient availability under drought and salinity by breeding and molecular approaches.

Effect of Salt Stress on Na Accumulation, Antioxidant Enzyme Activities and Activity of Cell Wall Peroxidase of Huckleberry (Solanum scabrum) and Eggplant (Solanum melongena)

“…This lower Na + /K + ratio, as shown for huckleberry in the present study, is important for plants under salinity stress, as K + is the most abundant element in plants, intervening in many biological processes including enzyme activation, transport of sugars, stomatal regulation and osmoregulation (Hu and Schmidhalter, 2005).…”

The effects of selenium and other micronutrients on the antioxidant activities and yield of corn (Zea mays L.) under drought stress

“…Our results are also in agreement with Wang et al (2004) and Rahimizadeh et al (2007) who indicated that application of micronutrients can alleviate the adverse effects of stresses such as salinity and drought on plant growth. Micronutrient presence in the structure of antioxidants (Yu and Rengel 1999;Allen et al 2007), their important effects on the cellular respiration (Tan et al 2010), and their deficiency under drought make their application necessary under different conditions, including stress (Hu and Schmidhalter 2005). At the control level of water stress, addition of Se or micronutrients decreased the antioxidants activities or corn grain yield.…”

Response of Salt-Stressed Wheat ( Triticum aestivum L.) to Potassium Humate Treatment and Potassium Silicate Foliar Application

“…Data represented in Fig. 5 indicate that salinity stress caused a significant reduction in total soluble proteins and carbohydrates of grains where, salinity may cause nutrient deficiencies or imbalances, due to the competition of Na + and Cl -with nutrients such as K + , N, and Ca 2+ (Hu & Schmidhalter, 2005). Nitrogen-deficiency during early reproductive development severely limits crop yield (Dolferus et al, 2011).…”