Effect of conjoint use of fertilizers and soil amendments on soil fertility and yield of groundnut (Arachis hypogaea L.)

The field experiment was conducted during 2017-18 and 2018-19 at Oilseeds Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (Maharashtra) to study the effect of fertilizer and soil amendment on soil fertility and yield groundnut (Arachis hypogaea L.). The experiment was laid out in randomized block design with three replications and nine treatments. The pooled data revealed that the application of gypsum and phosphogypsum did not influence significantly the soil pH, EC, organic carbon and calcium carbonate content. However, the fertility status of soil in terms of available nitrogen, phosphorus, potassium and sulfur as well as exchangeable calcium, magnesium was found significantly higher with the application of RDF-sulfur free + 400 kg phosphogypsum ha-1. The available nitrogen, phosphorus, potassium, sulfur, exchangeable calcium and magnesium contents were increased by 10, 23, 7, 122, 42, and 14% with RDF-sulphur free + 400 kg phosphogypsum ha-1 as compared to control, respectively. Significantly higher pod (2.0 t ha-1) and haulm yield (2.5 t ha-1) of groundnut was observed with RDF-sulphur free + 400 kg phosphogypsum ha-1. Similarly, the oil and protein contents were also increased with phosphogypsum level and maximum oil (51%) and protein (29.4%) contents were observed with RDF-sulphur free + 400 kg phosphogypsum ha-1 treatment. This treatment was statistically at par in terms of soil fertility, yield, oil and protein content of groundnut with RDF-sulphur free + 300 kg phosphogypsum ha-1.