In saline soil, plants cannot take up enough water to meet their evaporative demands because of the low osmotic potential of the soil water. Consequently, higher transpiration induces water loss from the plant leaves. This reduction induces stomatal closure, which prevents the transport of water vapor and CO2, and thus photosynthesis and transpiration decrease.
Some nutrients, such as potassium and nitrate, have already proven to significantly boost the efficiency of water use in plants. This type of nutrient is a strategic ally where water supply is restricted. But even in areas where there is adequate water supply, the use of potassium and nitrate will increase the yield per acre, or alternatively, allow any surplus water to be targeted for other additional crops.
Plants that are under water stress combined with potassium deficiency, sweat more, and therefore, need to absorb more water to stay healthy. Research showed that plants adequately supplied with K, showed greater WUE when fed with nitrate compared to ammonium as the nitrogen source. And so, potassium nitrate is essential to the efficient use of water.
SQM's potassium nitrate contributes to a more efficient use of water. High supply of nitrates in the nutrient solution reduces the absorption of chloride, avoiding the use of additional irrigation to remove salinity from the soil, regulates the opening and closing of stomata, resulting in less need for water per kg of plant biomass.