Abstract:
Phosphorus is a critical nutrient for rice Oryza sativa (L.) cultivation, and phosphorus
fertilizer (P) application is essential for achieving optimal yields. In Sri Lanka, rice
farmers primarily rely on Triple Super Phosphate (TSP) as a P source. However, local
alternatives like Single Super Phosphate (SSP), derived from Eppawala Rock
Phosphate, could offer a sustainable option. This study aimed to assess the
effectiveness of SSP as a substitute for TSP in rice farming. A field experiment was
conducted at the Rice Research Station, Sammanthurai, Ampara district, during the
Yala season using the Bg 352 rice variety, which is known for its favorable response
to P fertilization. The experiment included five treatments with varying ratios of TSP
and SSP: 100% TSP (T1), 75% TSP with 25% SSP (T2), 50% TSP with 50% SSP
(T3), 25% TSP with 75% SSP (T4), and 100% SSP (T5). The experiment followed a
randomized complete block design with four replicates. Observations focused on
vegetative growth, yield characteristics, and soil properties, including pH, electrical
conductivity, and available P. Statistical analysis was conducted using analysis of
variance (ANOVA), at a 95% confidence interval. Mean separation was performed
using the LSD method. Among the treatments, T2 demonstrated notable
improvements, showing an increase in both the number of tillers and panicles, which
are crucial factors in maximizing yield. The soil data revealed that T2 maintained a
pH of 4.79±0.02, an electrical conductivity of 22±0.07 µS cm-1, and an available P
level of 3.14±0.02 mg kg-1, indicating favorable conditions for plant growth.
Furthermore, the final yield for T2 was 4.29±0.24 kg plot-1, significantly higher than
other treatments. This result suggests that a blend of 75% TSP and 25% SSP could
effectively improve rice fields' productivity. The study's findings indicate that
combining TSP with SSP supports phosphorus availability and improves plant
performance and soil health, making this combination a viable and sustainable
approach for Sri Lankan rice farming.
