Effect of Bio NP Consortium, Iron, and Zinc on the Chemical and Biological Characteristics of Kharif Maize [Zea mays (L.)] Grown in Loamy Sand Soil

Abstract

Excessive use of chemical fertilisers has degraded soil health, highlighting the need for sustainable practices. Biofertilisers and essential micronutrients such as iron and zinc play key roles in improving nutrient availability, soil fertility, and maize productivity in loamy sand soils. A field experiment titled "Influence of Bio-NP Consortium, Iron, and Zinc on the Physico-chemical and Biological Characteristics of Kharif Maize [Zea mays (L.)] Grown in Loamy Sand Soil" was conducted at the Jorapura Farm of the Livestock Research Station, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat, during the kharif seasons of 2019 and 2020. A total of eighteen treatment combinations were evaluated, including two seed inoculation treatments with biofertiliser: without bio-NP consortium (B0) and with bio-NP consortium (B1). Additionally, three levels of iron (4.0, 6.0, and 8.0 kg Fe ha-1) and three levels of zinc (2.0, 4.0, and 6.0 kg Zn ha-1) were assessed using the GAYMH-1 cultivar. The experiment was laid out in a randomised block design with a factorial arrangement and three replications. Results revealed that seed inoculation with the bio-NP consortium did not significantly affect available N, P2O5, K2O, or DTPA-extractable iron and zinc contents in soil after maize harvest during the individual years; however, available N and P2O5 contents in soil improved significantly only in the pooled results. Seed inoculation with the bio-NP consortium significantly influenced Azospirillum and PSB counts and urease enzyme activity in soil after maize harvest during 2019, 2020, and in the pooled results. Different levels of iron and zinc application did not exert any significant influence on EC, pH, available N, P2O5, K2O, DTPA-extractable Zn content, Azospirillum and PSB counts, or urease activity in soil after maize harvest during 2019, 2020, and in the pooled results. However, DTPA-extractable iron and zinc in soil after maize harvest were significantly influenced by the application of iron and zinc.