Intensive synthetic agricultural systems reliant on NPK — Nitrogen, Phosphorous, Potassium — inputs have precipitated global soil degradation over recent decades. Synthetic fertilisers have driven considerable growth in agricultural productivity, but declining farmer margins and rising input costs have renewed interest in traditional alternatives like jeevamrut, fermented mixture of cow dung, cow urine, jaggery, and pulse flour used within India’s Zero Budget Natural Farming (ZBNF) movement pioneered by Subhash Palekar. This paper reports an original comparative growth and soil-nutrient study of jeevamrut compared with a chemical fertiliser control conducted using traditional preparation materials and expert-validated laboratory soil analysis. The experiment and empirical results are consistent with the wider ZBNF literature that shows that jeevamrut narrows the growth gap with chemical fertiliser over successive weeks and builds measurable soil organic carbon. However, the study also foregrounds a pattern that is rarely discussed in the literature: the raw growth data shows jeevamrut-treated plants trailed the chemical-fertiliser control throughout the observation period, with the proportional gap narrowing over successive weeks rather than closing entirely. This paper argues that this “lag” plausibly engages and interacts with well-documented barriers to sustainable-technology among smallholder farmers, including present bias, loss aversion, and social proof effects, to help explain why a fertiliser that is cost-effective and environmentally friendly is relatively under-adopted. By merging a hands-on agronomic case study with a review of behavioral and development economics literature on sustainable technology adoption, this paper offers an account of why proof is insufficient to drive adoption of practices and proposes many behaviorally-informed strategies to close that gap.