Statement I : Growth of plants is smooth with a complete fertilizer. Statement I : A complete fertilizer always contains N, P, K.

Statement I is true as fertilizers are synthetic or natural substances applied to soil to supply essential nutrients that enhance plant growth and fertility [3]. While plants can grow without them, many species like vegetables and flowers require fertilizers to reach their full potential and maintain health. Statement II is also true and provides the correct explanation for Statement I. In the fertilizer industry, a "complete" fertilizer is specifically defined as a product containing all three primary macronutrients: nitrogen (N), phosphorus (P), and potassium (K) [1]. These three elements are critical limiting factors for plant development [4]. Because a complete fertilizer provides this full spectrum of primary nutrients, it ensures the smooth and balanced growth of plants by addressing their most significant nutritional requirements simultaneously [2].

Sources

1. [1] Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 9: Agriculture > FERTILISERS > p. 302
2. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 25: Agriculture > Fertilizers > p. 363
3. [4] https://pmc.ncbi.nlm.nih.gov/articles/PMC4468412/
4. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > 3) Agricultural sources: > p. 74