Soil physico-chemical properties as affected by integrated use of blended fertilizer, cattle manure, vermicompost and mineral nitrogen and phosphorus in potato (Solanum tubersoum) in acidic soil of south-western Ethiopia

A field experiment was conducted in Belg (February to May) and Meher (June to October) seasons of 2020 at Abelo kebele in Masha district of Ehiopia, to determine the effects of blended mineral NPSB fertilizer, cattle manure (CM), vermicompost (VC) and mineral NP on soil physico-chemical properties with a view to generate new data and extend community service to farmers. The fertilizer treatments consisted of 7.5 t CM/ha combined with 75% and 50% of recommended dose of NP fertilizers (RDF), 7.5 t VC/ha combined with 75, 50 and 25% of NP, 5 t VC/ha combined with 75% NP, 100 kg NPSB/ha + 61.5 kg P/ha + 146 kg N/ha, 150 kg NPSB + 53.7 kg P/ha + 138 kg N/ha, 200 kg NPSB + 46 kg P/ha + 128 kg N/ha, 100% of NP (165 kg N/ha+60 kg P/ha) and no-fertilizer treatment (control), making a total of 11 treatments. The experiment was laid out in a randomized complete-block design with 3 replications. Results indicated that the application of 75% of NP (124 kg/ha + 45 kg P/ha) combined with 7.5 t/ha VC significantly increased the soil pH (6 and 7.29%), organic carbon (62.3 and 119%), total N (85 and 135%), available P (64.72 and 62.66%), cation-exchange capacity (CEC) (16.5 and 31.92%), exchangeable Ca+² (16.3 and 18.25%), exchangeable Mg+² (19.8 and 141.42%), exchangeable K+ (7.14 and 18.33%) and reduced the bulk density (7.87 and 9.52%), exchangeable acidity (368 and 455%), exchangeable aluminum (377 and 249%) in Belg and Meher seasons, respectively. Thus, the use of 7.5 t VC/ha combined with 75% of mineral nitrogen (124 kg N/ha + 45 kg P/ha) could significantly enhance the soil physico-chemical properties of acidic soil over sole application of either 200% mineral NPSB or 150% mineral NPSB or 100% NP or control treatment.