Optimizing crop quality and yield: Assessing the impact of integrated potassium management on Chinese cabbage (Brassica rapa L. subsp. chinensis)

Potassium, a pivotal macronutrient essential for growth, development, and crop yield, serves as a critical determinant of soil productivity. Its depletion disrupts the equilibrium of soil nutrients, prompting an investigation into integrated potassium management strategies to address this challenge. A field experiment was conducted during the winter season of 2020 using a randomized complete block design, with eight treatments, each replicated three times in Chinese cabbage (<i>Brassica rapa</i> L. subsp. <i>chinensis</i>). These treatments comprised standard (100 %) and reduced (75 % and 50 %) rates of the recommended dose of potassium (RDK) via muriate of potash (MOP). Variations in the inclusion and exclusion of plant growth-promoting rhizobacteria (PGPR), farmyard manure (FYM) as 25 % of the potassium recommendation, and foliar spray of nano potash were systematically implemented. Findings unequivocally demonstrated that the treatmentT₈, involving 100 % RDK +25 % K through FYM + PGPR + nano K fertilizer spray at 25 and 40 DAS, yielded significant improvements in both green fodder (64.0 t ha^-1) and dry fodder (7.87 t ha^-1).Moreover, T₈ exhibited the highest values for total ash (8.75 %), total ash yield (68.9 ± 2.88 kg ha^-1), ether extract (2.85 %), ether extract yield (22.4 ± 0.88 kg ha^-1), crude protein (9.71 %), and total crude protein yield (76.4 ± 3.21 kg ha^-1). Conversely, a marked reduction was observed in various fiber components and carbohydrate fractions upon application of the T₈ treatment. The lowest values of yield, crude protein content, total ash ether extract were recorded in treatment T₁ (control) applied with no potassium. This investigation underscores the inadequacy of the recommended potassium dose in achieving optimal productivity, necessitating a re-evaluation of potassium fertilization levels. The integrated approach involving FYM, PGPR, and nano potash, coupled with the recommended potassium dose through MOP, emerges as a promising avenue for augmenting both yield and quality parameters in Chinese cabbage.