Sustainable Horticulture: Assessing the Efficacy of Organic and Bio-Fertilizers in Supporting Tree Health and Production-Review

Abstract

Chemical fertilizers and pesticides have greatly enhanced agricultural productivity over the last half-century, but their unselective application has been responsible for environmental pollution, soil degradation, pest resistance, and human health issues. Hence, there has been increasing interest in environment-friendly methods like Integrated Pest Management (IPM), biofertilizers, and organic farming. Biofertilizers—consisting of beneficial microorganisms like bacteria, fungi, and algae—increase nutrient availability due to nitrogen fixation and mineral dissolution, and provide a sustainable source of chemicals. Organic farming and organic amendments enhance soil fertility, microbial diversity, and ecosystem services, and sustain or enhance crop quality. Organic systems, in earlier research, were shown to have yields equal to conventional systems under favorable conditions, but it requires more labor and higher input costs. Recent research has highlighted the application of biofertilizers and microbial inoculants in tree crops, namely citrus, apricot, olive, pomegranate, and apple, and has noted improved growth, yield, fruit quality, nutrient uptake, and disease resistance. A combination of synergistic inputs like amino acids, humic substances, PGPR, mycorrhizal fungi, and organic amendments further increases crop productivity and stress tolerance. Emerging technologies such as nanomaterials, microbial endophytes, and controlled environment agriculture hold further promise for sustainable productivity. Long-term experiments reaffirm that mixed and organic fertilization methods equal or surpass the nutritional and yield capacity of inorganic fertilizers, but these have lower environmental effects. It indicates the potential of organic and biological inputs in sustainable horticultural production, especially for perennial tree crops, and stresses their role in addressing future food demand against altered climatic and demographic scenarios.