ANS:A - Ammonium sulphate

The best fertilizer for paddy, or rice cultivation, often depends on various factors including soil conditions, nutrient requirements, and local agricultural practices. However, among the options provided, Ammonium sulfate and Potassium nitrate are commonly used fertilizers for paddy cultivation due to their nutrient content and compatibility with rice plants.

1. Ammonium sulfate: This fertilizer provides a readily available source of nitrogen and sulfur, both of which are essential nutrients for rice plants. Nitrogen promotes vegetative growth and overall plant vigor, while sulfur is important for protein synthesis and enzyme function. Ammonium sulfate is typically applied before planting or as a top-dressing during the growing season to meet the nitrogen and sulfur needs of rice crops.
2. Potassium nitrate: Potassium nitrate is a fertilizer that supplies nitrogen and potassium to plants. Nitrogen from potassium nitrate supports rice plant growth and development, while potassium contributes to overall plant health, stress tolerance, and grain quality. Potassium nitrate is often applied as a basal fertilizer or as a foliar spray to provide a balanced supply of nitrogen and potassium throughout the rice growing season.

Both Ammonium sulfate and Potassium nitrate can be suitable choices for paddy cultivation, but the specific fertilizer recommendation may vary based on soil test results, nutrient deficiencies, and agronomic considerations specific to each rice-growing region. Additionally, it's important to follow recommended application rates and timing to optimize fertilizer efficiency and minimize environmental impacts. Consulting with local agricultural experts or extension services can help determine the best fertilizer strategy for paddy cultivation in a particular area.