Quantifying the contribution of microbial inoculation and zinc fertilization to growth, yield and economics of wheat (Triticum aestivum) in different methods of cultivation

Abstract

A field experiment was conducted at research farm of ICAR-Indian Agricultural Research Institute, New Delhi in winter (rabi) season of 2013-14 and 2014-15 with the aim to quantity the contribution of two microbial inoculations and zinc (Zn) fertilization to growth, yield and economics of wheat (Triticum aestivum L.). Experiment was conducted in split-plot design (variety HD 2967) involving three different methods of cultivation, viz. conventional wheat (CW), system of wheat intensification (SWI) and zero tillage (ZT) as main plot and nine nutrient management options as subplot in each method of cultivation involving recommended dose (N120P25.8), 75% recommended dose (N90P19.35), 75% recommended dose + Anabaena sp (CR1) + Providencia sp (PR3) and 75% recommended dose + Anabaena- Pseudomonas (An-Ps) biofilmed formulation with and without Zn which make total eight options along with one absolute control (N0P0Zn0). Zinc was applied to soil @ 5 kg Zn/ha through zinc sulphate heptahydrate. Results of two years study revealed that, contribution of CR1 + PR3 consortia and An-Ps biofilmed formulation to yield improvement is 360 and 370 kg/ha with Zn and 190 and 230 kg/ha without Zn fertilization; while increase in net return was Rs 5 370 and Rs 5 520/ha respectively with Zn and Rs 3 080 and Rs 3 650/ha without Zn, respectively. Soil microbial biomass carbon (MBC) is more in all inoculated treatments than uninoculated treatment with highest in 75% recommended dose (N90P19.35) + An-Ps biofilmed formulation + Zn (372 μg/g soil) at 90 days after sowing. Total nitrogen uptake was increased by 37.5 and 39.8 kg/ha due to application of CR1 + PR3 consortia and An-Ps biofilmed formulation along with Zn, respectively. Zinc fertilization increased grain yield and net returns by 180 kg/ha and Rs 2 340/ha, respectively with treatment containing recommended dose (N120P25.8). Total uptake of Zn at harvest was significantly higher in treatment containing recommended dose (N120P25.8) with Zn (327.7 g/ha) than same treatment without zinc application (289.2 g/ha). Zero tillage wheat recorded significantly higher yield (4.56 tonnes/ha) than both conventional (4.33 tonnes/ha) and SWI (4.31 tonnes/ha) methods of cultivation which leads to higher net return in ZT wheat (Rs 53.86 × 103/ha) than other methods of cultivation. Uptake of nitrogen, phosphorus, zinc and soil MBC was significantly higher in zero tillage wheat. In nutshell, application of any one inoculation along with 75% recommended dose (N90P19.35) + Zn fertilization was promising nutrient management option by considering their quantifiable contribution and among cultivation methods ZT method found superior than CW and SWI method.