Dynamics of Zinc Fractions in Soil as Affected by Zinc Fertilization in a Maize-maize Cropping Sequence in Upper Brahmaputra Valley Zone of Assam, India

Zinc is considered as an important micronutrient for maize which a promising emerging cash crop the state of Assam, India. A field experiment was conducted at experimental farm Krishi Vigyan Kendra, Jorhat, Assam Agricultural University during 2018-19 and 2019-20 to study dynamics zinc fractions in soil maize-maize cropping sequence affected by fertilization. The laid down randomized block design (RBD) with twelve treatments combinations basal foliar application through sulphate oxide nanoparticles (ZnO NPs). results revealed that fertilization significantlyinfluenced studied both years under investigation. distribution different soils harvest found following order: water soluble plus exchangeable-Zn < complexed-Zn crystalline sesquioxide bound-Zn amorphous residual-Zn. Among treatment combinations, Zn @ 3.75 kg ha-1 combination 500 ppm ZnO NPs exhibited highest concentration content (1.10 ppm) soil. (2.95 ppm), sesquioxide-bound-Zn (4.11 mg kg-1), (3.76 residual-Zn (125.65 total-Zn (137.33 were recorded receiving 7.5 ha-1. studied, percent contribution lowest while fraction contributed total pool. Furthermore, path coefficient analysis had towards plant available DTPA extractable-Zn Moreover, all be significantly positively correlated each other indicating existence dynamic equilibrium