Zincated Nanoclay Polymer Composite (ZNCPC): Effect on DTPA-Zn, Olsen-P and Soil Enzymatic Activities in Rice Rhizosphere

Abstract

ABSTRACT Zinc (Zn) is the most deficient micronutrient globally resulting in malnutrition and requires improved mode of delivery for increased nutrient use efficiency. An innovative fertilizer formulation, Zincated nanoclay polymer composite (ZNCPC), containing a total 6.59% Zn was evaluated in a pot experiment in comparison with ZnSO4 using rice (Oryza Sativa L.) (PRH 10 variety) as a test crop. The ZNCPC was applied in two doses [5.0 mg Zn kg−1 (T1) and 2.5 mg Zn kg−1 (T2)] whereas ZnSO4. 7 H2O was applied at single dose (5.0 mg Zn kg−1) (T3) in Zn deficient soil along with a control (without application of Zn) (T4). Effects of two modes of Zn application were evaluated under maximum tillering (MT) (55 days after transplanting) and panicle initiation stage (PI) (70 days after transplanting) on DTPA Zn, Zn uptake, Olsen-P, P uptake and soil enzymatic activities in rhizosphere and non-rhizosphere soil. Treatment T1 increased DTPA-extractable Zn content in rhizosphere soil to 157% in PI stage in comparison with T3. Stimulation of soil enzymes activity namely, dehydrogenase, acid and alkaline phosphatase was recorded in rhizosphere soil. Our study demonstrates that ZNCPC could potentially to be novel and innovative fertilizer formulation to increase Zn uptake in rice.