Smart fertigation effects on groundnut (Arachis hypogaea L.) yield, nutrient uptake and soil health

Precise application of water and nutrients is crucial for sustainable groundnut cultivation. Field experiments were conducted to evaluate the performance of smart fertigation systems on groundnut yield, nutrient uptake, soil microbial population and soil enzyme activities. The experiments were conducted at two locations. Location I was at a farmer's field in Kanjipatti village, Kalaiyarkoil block, Sivagangai district, Tamil Nadu (rabi 2023) and Location II was at the Central Farm of the Agricultural College and Research Institute, Madurai district, Tamil Nadu (summer2024). Field trials were laid out in a split-plot design with three replications. The treatments comprised three drip irrigation methods in the main plots, namely; conventional drip irrigation (M1), time-based automated drip irrigation (M2) and sensor-based automated drip irrigation (M3) and five drip fertigation methods in the subplots, viz., drip fertigation of 75% RDF (F1), drip fertigation of 100% RDF (F2), STCR-based drip fertigation (F3), sensor-based fertigation at 75% NPK level (F4) and sensor-based fertigation at 100% NPK level (F5). The results revealed that pod yield, total NPK uptake, pod uptake, haulm uptake, microbial population and enzyme activities were significantly higher with the combination of sensor-based automated drip irrigation and sensor-based fertigation at 100% NPK level (M3F5). The M3F5 treatment increased crop yield by 44-45%, dehydrogenase activity by 44-64% and phosphatase activity by 57-65% across both seasons compared to M1F1. However, the post-harvest available nutrient status was recorded higher with conventional drip irrigation combined with drip fertigation of 100% RDF (M1F2). Based on the experimental results, it can be concluded that sensor-based automated drip irrigation combined with sensor-based fertigation at 100% NPK level (M3F5) enhanced groundnut yield, nutrient uptake, microbial population and enzyme activities.