The study looked at how adding sulphur and phosphorus to pigeonpea plants affected their growth and soil quality. They found that using 20 kg of sulphur and 50 kg of phosphorus per hectare led to a significant increase in grain and straw yield. This combination also improved the soil's fertility and did not affect phosphorus availability. To keep the soil fertile for pigeonpea crops, it's important to use both sulphur and phosphorus together.