Effect of different fertigation levels and microbial consortia on yield and water use efficiency of broccoli (Brassica oleracea L. var. italica) under drip irrigation

Abstract

The experiment entitled “Response of broccoli (Brassica oleracea L. var. italica) to different fertigation levels and microbial consortia under drip irrigation” was conducted during the rabi season of 2023-24 at the Interfaculty Department of Irrigation Water Management, Post Graduate Institute, Mahatma Phule Krishi Vidyapeeth, Rahuri, Ahmednagar (Maharashtra). The study aimed to evaluate the effect of fertigation levels and microbial consortia on the growth and yield of broccoli. The experimental field had well-drained clay loam soil (45 cm depth) with low available nitrogen (258.4 kg ha⁻¹), medium phosphorus (19.80 kg ha⁻¹), and very high potassium (395.1 kg ha⁻¹), slightly alkaline in reaction (pH 7.91) and electrical conductivity of 0.38 dS m⁻¹. The experiment was laid out in a split-plot design with three replications. The main plots comprised three fertigation levels: 50% RDF (F₁), 75% RDF (F₂), and 100% RDF (F₃). Five microbial consortia were allotted to subplots: control (C₀), MPKV consortium (C₁), VNMKV Biomix (C₂), Arka microbial consortium (C₃), and IFFCO NPK liquid biofertilizer consortium (C₄). Biofertigation was applied at transplanting and at 15, 30, and 45 days after transplanting. The application of 100% RDF fertigation resulted in the highest curd yields across all harvesting intervals that is 19.47 q ha-1 (first harvest), 20.88 q ha-1 (second), 22.21 q ha-1 (third) and 20.39 q ha-1 (fourth), culminating in the maximum total curd yield of 82.95 q ha-1. This was at par with the 75% RDF fertigation level, which yielded 79.05 q ha-1. The application of 100% RDF through fertigation demonstrated the highest water use efficiency (32.82 kg ha⁻¹ mm⁻¹), outperforming the other fertigation levels. However, it was statistically at par with the 75% RDF fertigation level, indicating that both treatments were similarly effective in optimizing water utilization for yield production. Biofertigation schedule involving the MPKV Consortium demonstrated a significant positive effect on curd yield of broccoli across all harvest intervals: first harvest (25.00 q ha⁻¹), second harvest (24.30 q ha⁻¹), third harvest (30.07 q ha⁻¹), fourth harvest (24.70 t ha⁻¹) and a total curd yield of 104.07 t ha⁻¹. The combination of 100% RDF fertigation with biofertigation using the MPKV Consortium resulted in the highest water use efficiency (41.19 kg ha⁻¹ mm⁻¹) also the combination of 75% RDF and MPKV Consortium (37.76 kg ha⁻¹ mm⁻¹) was found at par with superior treatment.