Effects of phosphorus application rate in controlled release formula fertilizer on yield and phosphorus use efficiency of banana in phosphorus-rich soil

Objective  To explore the necessity and importance of phosphorus fertilization in phosphorus-rich soil, clarify the effects of phosphorus application rate in controlled release formula fertilizer on banana yield, phosphorus accumulation and use efficiency of phosphorus fertilizer, and provide a theoretical basis for determining fertilizer formula and rational application of phosphorus fertilizer in phosphorus-rich soil.

Method  The field experiment of phosphorus gradient was carried out to study the effects of phosphorus application rate in the controlled release formula fertilizer on banana shooting and harvest time, yield, phosphorus accumulation and phosphorus fertilizer use efficiency.

Result  In phosphorus-rich soil with Bray-P of 158 mg·kg⁻¹, the supply levels of nitrogen (200 g N per plant) and potassium (400 g K₂O per plant) were fixed. When the phosphorus application rate was 80 g P₂O₅ per plant, the effect of promoting bud emerging and harvest time of banana was most obvious, and the harvest rate at the same period increased by 5.3 to 31.1 percentage points than other treatments. The banana yield and phosphorus fertilizer use efficiency both increased first and then decreased with the increase of the phosphorus application rate. When the phosphorus application rate was 80 g P₂O₅ per plant, the banana yield and apparent P recovery efficiency in the current season were the highest reaching 27.7 kg·plant⁻¹ and 16.0%, respectively.

Conclusion  In phosphorus-rich soil, phosphorus application can increase the banana yield and economic benefit. The ratio of nitrogen (N), phosphorus (P₂O₅), and potassium (K₂O) in the controlled release formula fertilizer was recommended to be 1.0∶0.4∶2.0, and the recommended fertilization application rates were 200 g N, 80 g P₂O₅ and 400 g K₂O per banana plant, of which controlled release N accounted for 20% of total nitrogen.