The seedlings in rice field were found to have thin lanky growth with reddish leaves and poor root development. This is because the soil lacks

The thin and lanky growth of seedlings in rice field with reddish leaves and poor root development indicates a deficiency in a nutrient in the soil. Among the given options, the nutrient most likely lacking in the soil is phosphorus. This is because phosphorus is essential for root growth, stem strength and the development of healthy leaves. A deficiency in phosphorus can lead to stunted growth and discoloured leaves. Therefore, if the soil lacks phosphorus, the seedlings in the rice field will show the symptoms described.