Integrated use of NPK chemical fertilizers and bio-stimulants improved soil fertility, fruit yield, quality and net returns in pomegranate (Punica granatum L.)

Abstract

Bio-stimulants are gaining importance for elevating the stagnated yield level resulting from continuous use of chemical fertilizers (CF) in many crops, however, their use in pomegranate have not been fully explored. Two years of field experiments were conducted on a 5-years old pomegranate cv. Bhagwa orchard to investigate the effects of different combinations of commercial bio-stimulant products namely, microbial-based product A containing consortium of Rhizophagus spp. (5 kg ha−1), seaweed extract-based granular formulation D (30 kg ha−1) and liquid formulation B (625 and 1250 ml ha−1) through soil application as well as wettable granular formulation, C (1 and 2 g l−1) and liquid formulation, E (1 ml l−1) through foliar sprays along with chemical fertilizers on soil fertility, trees’ nutrition, fruit yield and quality of pomegranate. Results showed that integrated use of CF and bio-stimulants significantly increased the number of bisexual flowers. However, the combination of microbial-based product A (5 kg ha−1), seaweed extract based liquid formulation B (625 ml ha−1) in soil and foliar spary of seaweed extract based wettable granular formulation C (1–2 g l−1) with CF resulted in production of the highest fruit yield (increased by 41.97–51.61%) with 23.08–33.38% increase in the exportable grade fruit and improved quality attributes viz. ascorbic acid, anthocyanin, non-reducing sugar, protein, and mineral content of fruits through enhancement in soil fertility and trees’ micronutrient status compared to only CF. These doses combinations of bio-stimulants along with CF gave rise to the highest benefit–cost ratio of 2.10–2.34:1 and hence can be recommended for sustainable pomegranate cultivation.