Influence of Organic Liquid Formulations on Growth and Nutrient Status in a Juvenile Plum Orchard

Formulations prepared from natural products tend to stimulate plant growth by providing essential mineral nutrients and plant hormones as well as improving the soil microbial biomass. The study was conducted during 2019 and 2020 to evaluate the effect of applying liquid formulations derived from natural products on plant growth and soil health of a newly established ‘Black Amber’ plum orchard in the North-Western Himalayan region. Results showed that application of the recommended dose of fertilizers (F) recorded the maximum annual shoot growth, plant spread, leaf area and chlorophyll content, which was followed by biogas slurry (3 L plant⁻¹). Leaf macronutrient content was highest in inorganic fertilizer (F) treatment. Biogas slurry (3 L plant⁻¹) application recorded high leaf micronutrient content, while also stimulating the best results in macronutrient content among the organic formulations. Jeevamrit (3 L plant⁻¹) improved leaf area, leaf K, leaf Cu and leaf Zn content and induced improvement in the soil microbial population, while soil organic carbon was highest under biogas slurry (3 L plant⁻¹). Inorganic fertilizers (F) recorded the maximum soil nutrient content; however, organic formulations of jeevamrit (3 L plant⁻¹), biogas slurry (3 L plant⁻¹) and plant growth promoting rhizobacteria (PGPR) (1.5 L plant⁻¹) showed significant improvement in soil nutrient status. The results indicate the potential of liquid formulations made from natural products in creating a sustainable crop production system and reducing dependence on inorganic fertilizers.