Eggshell powder as calcium source on growth and yield of groundnut (Arachis hypogaea L.)

ABSTRACTThe use of eggshells as an alternative source of calcium carbonate for groundnut can reduce the impact on the natural reserves of limestone, a non-renewable natural source. This study aimed to investigate the effects of eggshell powder application on the growth and yield of groundnut. The calcium treatments were lime application (A0) at 500 kg ha−1 and four rates of eggshell powder application including A1 (200 kg ha−1), A2 (300 kg ha−1), A3 (400 kg ha−1), and A4 (500 kg ha−1). Two application times, T1 (applying 5-days before sowing) and T2 (applying 5-days after flowering) were employed. The result showed that eggshell powder could be a useful alternative source to supply Ca for groundnut. Application of eggshell powder before sowing resulted in significantly higher pod yield and total calcium uptake with better growth parameters than after flowering. Increasing eggshell powder application rates also increased soil pH and calcium contents, and plant calcium uptake. The application rate of eggshell powder before sowing at the rate of 300 kg ha−1 produced the highest pod yield and was suggested to be optimum