Phosphorus flow analysis in maize cultivation: a case study in Thailand

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Phosphorus (P) is crucial for plant growth, with increasing demand for agricultural products driving intensive farming systems.
• Maize is a key crop for animal feed production in Thailand, making its nutrient dynamics important for the agricultural sector.

Purpose of the Study:

• To investigate phosphorus (P) flows in maize cultivation systems in Thailand.
• To identify major P inputs, outputs, and losses using a mass-balanced approach.
• To compare P flow patterns between rainy and dry seasons.

Main Methods:

• Conducted a field survey of 131 maize plantation plots.
• Applied the conservation of mass-balanced concept to quantify P flows.
• Analyzed P input via chemical fertilizers and output in grain products.

Main Results:

• Total P input was 27.76 kg P/ha (rainy season) and 34.96 kg P/ha (dry season), primarily from chemical fertilizers (approx. 97%).
• P output in grain was 31.7-37.3% of total input. Soil retained 41.3-43.9% of applied P.
• P loss via runoff was higher in the rainy season (6.0%) than the dry season (4.5%).

Conclusions:

• Seasonal and geographical factors significantly influence P flow patterns in maize cultivation.
• P accumulation in soils and P loss to the hydrosphere are greater during the rainy season.
• Optimizing P flows through enhanced nutrient management is essential to reduce P loss in Thai maize production.