मृदा उर्वरता एवं उर्वरक प्रौद्योगिकी

Coated slow-release fertilizers are particularly beneficial in permeable soils where leaching losses of nutrients are high.

• Clay soils dominated: Heavy clay soils have low permeability and high CEC, inherently minimizing leaching losses.
• Drainage is improper: Poor drainage results in waterlogging and gaseous denitrification losses, not leaching.
• Leaching losses are high: Polymeric or sulfur coatings control the dissolution rate of soluble nutrients, preventing massive downward leaching in porous sandy soils and high-rainfall conditions.
• Leaching losses are normal: Standard commercial fertilizers are economically preferred under normal leaching conditions.

• Wheat tolerates high chloride levels and utilizes muriate of potash effectively.
• Chloride-containing fertilizers (such as MOP / KCl) are unsuitable for potato, tobacco, and sugarbeet because excessive chloride accumulation suppresses starch formation, reduces dry matter and specific gravity of tubers, and impairs chipping quality. Potassium sulfate (K2SO4) is recommended.
• Soybean tolerates moderate chloride.
• Sugarcane utilizes chloride fertilizers without significant cane quality detriment.

• 100 kg DAP provides 18 kg N and 46 kg P2O5.
• 150 kg DAP provides 27 kg N and 69 kg P2O5.
• 200 kg DAP provides 36 kg N and 92 kg P2O5.
• Commercial DAP fertilizer contains 18% N and 46% P2O5. To supply 115 kg of P2O5: DAP required = (115 / 46) × 100 = 250 kg. In addition, 250 kg DAP supplies: 250 × 0.18 = 45 kg of Nitrogen, meeting both crop nutrient requirements exactly.