Assessment of Fertigation on Growth and Biomass Accumulation of Ginger (Zingiber officinale Rosc.) Varieties

Abstract

Integration of inorganic fertilizers with organic sources such as farmyard manure (FYM) and neem cake is also known to improve soil physical, chemical and biological properties. Organic amendments enhance soil microbial activity, improve soil structure and increase nutrient availability, thereby supporting better plant growth and productivity. A field experiment was conducted during the kharif season of 2021 at the Department of Horticulture, Gandhi Krishi Vignana Kendra (GKVK), University of Agricultural Sciences, Bengaluru, Karnataka, to assess the effect of fertigation levels integrated with organic amendments on vegetative growth and biomass accumulation in two ginger (Zingiber officinale Rosc.) cultivars Rio-de-Janeiro and Himachal. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications, comprising eleven treatments involving different fertigation levels in combination with farmyard manure (FYM @ 30 t ha⁻¹) and neem cake (@ 2 t ha⁻¹). The soil of the experimental site was red sandy loam with pH 6.4, low organic carbon (0.35%), low available nitrogen (201.14 kg ha⁻¹), and medium phosphorus (34.00 kg ha⁻¹) and potassium (152 kg ha⁻¹). Recommended fertilizers were applied through urea, single superphosphate and muriate of potash, with fertigation schedules based on treatment specifications. Observations on growth parameters such as number of leaves, number of tillers, leaf (petiole) length and breadth were recorded at different growth stages (60, 120 and 180 DAP), while biomass partitioning was assessed in terms of fresh and dry weight contribution of aerial parts, roots and rhizomes. The data were analyzed using ANOVA at 5% level of significance. Fertigation treatments significantly influenced growth and biomass accumulation in both cultivars. Among the treatments, T₂ [200% RDF (200:100:100 kg N: P₂O₅: K₂O ha⁻¹) through fertigation + FYM 30 t ha⁻¹ + neem cake 2 t ha⁻¹] recorded superior performance throughout the crop period. T₂ resulted in the highest number of leaves per plant (up to 115.86 in Rio-de-Janeiro and 112.40 in Himachal at 180 DAP) and maximum tillers per plant (10.26 and 9.66, respectively). Leaf growth was also enhanced under T₂, with maximum leaf length (19.10 cm in Rio-de-Janeiro and 19.53 cm in Himachal) and leaf breadth (1.79 cm in Rio-de-Janeiro). Biomass allocation was significantly affected by fertigation treatments. T₂ recorded the highest contribution of rhizomes along with increased allocation to aerial parts and roots in both cultivars on both fresh and dry weight basis. Rhizome contribution under T₂ exceeded 87% on a fresh weight basis and remained dominant on a dry weight basis, indicating efficient partitioning towards the economic yield. The improved performance under T₂ may be attributed to the combined effect of continuous nutrient supply through fertigation and the addition of organic amendments, which enhanced soil fertility, nutrient availability, and nutrient use efficiency. The results demonstrate that integrated nutrient management through fertigation significantly improves vegetative growth and biomass distribution in ginger, with T₂ emerging as the most effective treatment for maximizing growth and rhizome yield.