Organic farming in the improvement of soil health and productivity of tea cultivation: A pilot study

Abstract

AbstractThe sub‐mountainous tea gardens of the Dooars region of West Bengal, which contribute approximately 25% of the national tea yield, are constantly fighting with diminishing soil fertility. Inorganic alternatives like chemical fertilizers can provide easier yet short‐term solutions, as their prolonged and indiscriminate usage leaches the soil, devouring its productivity, increasing the soil's heavy metal contents, and subsequently accumulating those heavy metals in leaves. A plausible substitution in this scenario could be the use of organic alternatives like composting or biofertilizer. Although references to such alternative means are found in the literature, a holistic approach targeting plant growth promotion along with mitigating soil metal toxicity is lacking. Keeping this background in mind, this pilot study was designed to optimize the dosage of novel biofertilizers (using resident and alien flora) that can reduce heavy metal loads and residual toxicity in soil, thereby improving overall soil health and tea production. Two potential metallophilic plant growth‐promoting strains of Bacillus sp. (previously reported) were selected and applied to potted tea plants of two different varieties of tea: TV9 and TV25. Among the two modes of treatment tested: solid treatment (compost amended with bacterial culture) and liquid treatment (cell pellets mixed in water suspension), the water suspension‐based direct application of resident soil bacteria showed the highest physiological growth with reduced metal toxicity. Based on physiological data and physico‐chemical data collected, it was observed that direct application of bacteria showed better results in both plant and soil health improvement in comparison to regular compost amended with beneficial microflora. Therefore, this small‐scale pilot study aimed to optimize the dosage and mode of application of novel biofertilizers for improved soil and plant health.