Seed placement accuracy
Table 4 shows that GPS-guided precision sowing substantially improved seed placement accuracy compared to conventional sowing methods. GPS-guided precision sowing produced noticeably more uniform seed placement compared with conventional sowing across the studied legume crops. Field measurements of plant spacing taken within randomly selected quadrats showed that seeds placed using the GPS-enabled precision seeder were distributed more consistently along crop rows.
Seed placement uniformity was calculated as the percentage of plants whose spacing fell within ±20% of the recommended intra-row spacing for each crop. Using this metric, the precision sowing plot achieved an average spacing uniformity of approximately 95%, whereas the conventional sowing plot showed a considerably lower uniformity of about 70%.
The improved uniformity observed under precision sowing indicates that GPS-guided planting systems can significantly reduce irregular seed spacing, which commonly occurs in conventional sowing due to manual seed distribution or uneven planter operation. More consistent spacing contributes to uniform crop establishment and reduces intra-row competition among plants.
Germination rate
Germination performance was evaluated 15 days after sowing using quadrat-based plant counts within each plot (Table 5). Across the three legume crops studied, chickpea, soybean and pigeon pea, germination rates were consistently higher in the precision sowing plot compared with the conventional sowing plot.
The observed germination rate under precision sowing ranged between 85-90%, whereas the conventional sowing plot showed germination rates ranging from 70-80%. These results suggest that improved seed placement and consistent sowing depth provided by GPS-guided planting may enhance seed-to-soil contact and create more favorable conditions for seed germination.
The highest germination rate was observed in soybean under precision sowing, while pigeon pea exhibited the lowest germination under conventional sowing. Overall, the results indicate that improved spatial distribution of seeds contributes to better crop establishment across different legume species.
Plant population density
Table 6 presents the plant population density achieved under precision and conventional sowing methods. Plant population density was measured 30 days after sowing within the same quadrats used for germination assessment. The precision sowing plot consistently showed higher plant population densities across the three crops compared with the conventional sowing plot. Average plant population density in the precision sowing plot ranged from 18 to 22 plants per square meter, while the conventional sowing plot showed lower densities ranging from 15 to 18 plants per square meter.
The higher plant density observed in the precision sowing plot reflects more efficient seed placement and reduced seed loss during sowing. Uniform plant spacing also helps minimize competition for water, nutrients and sunlight during early growth stages.
Yield
Grain yield was measured at crop maturity and converted to kilograms per hectare based on the harvested area (Fig 1). Across the three legume crops evaluated, the precision sowing plot consistently produced higher yields than the conventional sowing plot. Average yields in the precision sowing plot ranged from 1500 to 1600 kg/ha, while the conventional sowing plot produced yields between 1300 and 1400 kg/ha.
Across crops, precision sowing resulted in an approximate 12-15% increase in yield compared with conventional sowing. The yield advantage is likely associated with improved germination, better plant spacing and more consistent crop stands established by the precision planting system.
Resource efficiency
In terms of resource efficiency, the precision sowing plot had only 6% seed wastage, whereas the conventional sowing plot experienced 17% seed wastage (Fig 2). The precision sowing method significantly reduced seed wastage by ensuring that seeds were placed accurately, reducing overlap and underplanting. This not only cuts down on seed costs but also contributes to more sustainable farming by minimizing input waste.
The reduction in seed wastage highlights a key advantage of precision sowing: Enhanced input efficiency. In a country like India, where agricultural input costs are a significant burden on farmers, such savings are critical for improving the economic sustainability of farming operations.
The results of this study indicate that GPS-guided precision sowing may improve several aspects of crop establishment and productivity under the conditions of the present field trial. Notable improvements were observed in seed placement accuracy, germination rate, plant population density, yield and resource efficiency. These findings align with precision agriculture research that highlights the potential benefits of spatial accuracy and optimized input application.
Seed placement accuracy increased from 70% under conventional sowing to 95% with GPS-guided methods. This demonstrates the system’s ability to maintain consistent row spacing and depth. Better placement reduces gaps and seed clustering, which often cause uneven stands in traditional systems. Previous studies confirm that precision seeding improves spatial uniformity, leading to stronger early crop vigor and consistent emergence
(Pareek et al., 2022). Senthilkumar et al., (2025) reported that GPS- and AI-enabled seeding robots enhanced depth by 28.57%, spacing by 33.33% and yield by 30.77%, while reducing water and fertilizer use by 25%. Our results support these findings, showing that precise placement directly affects crop performance and input efficiency.
The germination rate was higher in precision plots (88%) compared to conventional plots (75%). This improvement is due to better seed-to-soil contact and consistent depth placement. Germination is sensitive to micro-environmental conditions, including moisture and soil structure. Irregular depth or spacing can delay or prevent emergence due to crusting, clods, or uneven moisture.
Lamichhane et al., (2019) emphasized that accurate placement reduces these risks, creating uniform conditions for all seeds.
Reed et al., (2022) also found that optimal depth and spacing improved legume emergence. Our results confirm that GPS-guided sowing reduces variability in emergence and supports a more uniform crop stand.
Plant population density reached 20 plants/m² in precision plots, compared to 16 plants/m² in conventional plots. This increase complements the higher germination rate and indicates successful early establishment. Uniform spacing reduces intra-row competition and ensures adequate access to light, nutrients and moisture for each plant. Similar findings in maize and wheat show that optimized spacing enhances canopy development and increases biomass accumulation and yield
(Djaman et al., 2021; Ghimirey et al., 2024). Manu et al., (2024) demonstrated that aerial yield mapping and targeted management of low-yield zones could improve overall production by up to 20%. These results support the importance of stand consistency in maximizing crop potential.
Yield increased by 14.8%, from 1,350 kg/ha in conventional plots to 1,550 kg/ha in precision plots. This gain reflects improvements in early crop establishment, including better placement, higher germination and improved spacing. Precision sowing reduces plant stress and optimizes input use. Similar outcomes have been reported in cereals and legumes, where precision sowing reduced seedling variability and improved productivity
(Feng et al., 2024). Seed wastage decreased from 17% in conventional plots to 6% in precision plots. This highlights a clear advantage in input efficiency. In India, where input costs are high and land is limited, reducing waste while maintaining yield is crucial.
McDonald et al., (2024) also found that precision planting reduces input overuse without affecting crop productivity.
Overall, the observed improvements across measured parameters suggest that GPS-guided precision sowing has the potential to enhance crop establishment and input efficiency under practical farm conditions. However, the present study represents a single-season, single-location comparative field assessment and the lack of replicated experimental plots limits the ability to generalize the findings across diverse cropping systems or agroecological regions. Soil type, climate variability and management practices may influence the magnitude of these effects. Future research should incorporate replicated multi-location and multi-season trials to validate these observations and to better quantify the agronomic and economic benefits of precision sowing technologies. Integration with remote sensing tools
(Manu et al., 2024) and germination prediction models
(Lamichhane et al., 2019) may further support adaptive management and improved decision-making in precision agriculture systems.