Spinach Under Stress Effects of Salinity and Nutrient Deficiency on Growth and Nutritional Properties

Abstract

Salty and nutrient-poor soils are big problems for growing crops, especially vegetables. This study looked at how salt and a lack of key nutrients affect spinach (Spinacia oleracea L.) in greenhouse conditions using sand culture. Plants were watered daily with a nutrient solution missing either nitrogen (N), phosphorus (P), or potassium (K) to create nutrient deficiency. Some plants also received salt (sodium chloride and calcium chloride) to study its effects. Salt reduced plant growth, leaf water content, and leaf size but increased chlorophyll and certain photosynthesis measures. Lack of nitrogen reduced plant growth and photosynthesis, while phosphorus and potassium deficiencies reduced growth but increased chlorophyll when no salt was present. Salt stress and nutrient deficiency also changed spinach nutritional value. Salt increased some beneficial compounds like carotenoids and flavonoids but reduced others. Nutrient deficiencies also changed antioxidant levels and plant compounds differently depending on salt presence. These findings suggest spinach nutrition can be improved with slight salt stress or low fertilizer use, though yields might decrease a little.