Comparing the efficiency of chemical fertilizers against bio-solids for P-utilization by maize under alkaline calcareous soil conditions

Abstract

Maize is a widely grown cereal crop that serves multiple purposes regarding food and industrial use. Climatic conditions of Pakistan are arid to semi-arid, and our soils are also phosphorus deficient. To combat this problem, phosphatic fertilizers are applied but low solubilization and high prices of phosphatic fertilizers are the major constraints in use of P fertilizers in large amounts. The common inorganic P sources are very costly, and have low fertilizer use efficiency; therefore, bioavailability of P needs to be enhanced using innovative measures. Keeping in view, a pot study was performed for enhancing maize growth and P bioavailability from treated bio-solid in comparison to conventional P fertilizers. De-watered treated bio-solid was used. Hybrid (PFP209) variety of maize crop was used against various sources of P fertilizers. There were 9 treatments with 3 replications: T1 = Control (ck); T2 = DAP @ 80 kg ha^-1; T3 = Nitrophos @ 130 kg ha^-1; T4 = Fe₂SO₄ Treated Bio-solid-I @ 400 kg ha^-1; T5 = Fe₂SO₄ Treated Bio-solid-I @ 800 kg ha^-1; T6 = Fe₂SO₄ Treated Bio-solid-I @ 1200 kg ha^-1; T7 = KH₂PO₄ Treated Bio-solid-II @ 400 kg ha^-1; T8 = KH₂PO₄ Treated Bio-solid-II @ 800 kg ha^-1 and T9 = KH₂PO₄ Treated Bio-solid-II @ 1200 kg ha^-1. It was noticed that both treated bio-solids when applied at higher rates (1200 kg ha^-1) produced significant beneficial effects on plant biomass. The highest values for most growth parameters were recorded with bio-solid-II treated with KH₂PO₄ @ 1200 kg ha^-1 with plant height (192.17 cm), shoot dry weight (178.5 g), root dry weight (89.33 g), stem diameter (28.5 mm), P content in shoot (0.51 mg g^-1) and root (0.36 mg g^-1) of maize.