Work

Soil test crop response based fertilizer calibration and soil nutrient forecasting for aerobic rice on Alfisols of Southern India

Year: 2026

Type: article

Abstract: The Soil Test Crop Response (STCR) approach integrates indigenous soil nutrient supply with crop requirements for site-specific fertilization. While vital for water-efficient aerobic rice, STCR-based precision frameworks for Alfisols in Southern India remain under-researched, representing a significant knowledge gap. In this context, Field experiments were conducted to develop and validate targeted yield and post-harvest soil test value (PHSTV) prediction equations. The results revealed that to produce one quintal of grain, 1.85, 1.14, and 2.70 kg of N, P 2 O 5 , and K 2 O were required under NPK alone, whereas 1.77, 1.09, and 2.88 kg were required under the integrated approach with poultry manure. Validation trials demonstrated that STCR-based recommendations for a 65 q ha −1 target achieved grain yields up to 68.85 q ha −1 , representing a 29.3% increase over the general recommended dose (53.25 q ha −1 ) and 41.2% over the soil test laboratory approach (48.76 q ha −1 ). Furthermore, the STCR approach recorded a superior Benefit–Cost Ratio of 1.61 compared to 1.09 for the general dose. PHSTV prediction equations showed high reliability (R 2 up to 0.96 for P 2 O 5 ), enabling accurate nutrient estimation without constant testing. This study establishes STCR as a precise, economically superior strategy for sustainable aerobic rice production

Source: Scientific Reports

DOI: 10.1038/s41598-026-48172-4