Nature-Based Plant Nutrition to Sustain Soil Health and Chemical-Free Prosomillet Farming in Semi-Arid Tropics

In order to preserve soil health and, consequently, crop yields, ancient India embraced a number of indigenous practices. A facet of this is “Vrikshayurveda.” Recent farming methods, however, have compromised soil health while increasing crop yields. It’s time to assess traditional organic methods for producing chemical-free food. Nearly 30% of people worldwide are fed millets, that are rich in nutrients and adaptable to a variety of climates, including tropical and temperate zones. Owing to the paucity of information on such methods in millets, this study investigates different ways to meet the nutritional needs of plants at different growth stages using only leaves of tropical trees. Two consecutive field trials were laid out during Summer and monsoon seasons of 2020–2021 at an experimental farm, Tamil Nadu Agricultural University, India. It was set-up in a split-plot design and replicated twice. Main plots included leaf biomass (LBM), i.e. incorporation of fresh tree leaves of five tropical legume trees as a nutrient source (Nitrogen (N)-equivalence basis), subplots included Leaf extract foliar spray <i>i.e</i>. fresh five tree leaf extracts. Twenty-five treatment combinations were involved. We found a positive and significant influence on the growth, physiology, and yield of prosomillet. Incorporation of fresh leaf biomass as a basal nutrient supplier into soil, six weeks before sowing, increased soil organic carbon (SOC) to 5.4 g kg⁻¹ from 4.0 g kg⁻¹ at the end of the first crop, which was 10% more than conventional practice and 6.7 g kg⁻¹ at the end of the second crop, which was 19.6% more. From the study it is concluded that this novel technology ensures better productivity and economics, and improves SOC. Results revealed that incorporation of tree leaf biomass, viz. <i>Albizia lebbek</i> (L.) Benth. or <i>Gliricidia sepium</i> (Jacq.) Kunth ex Walp. on N-equivalence basis and seed fortification before sowing, and foliar spraying with leaf tea extracts, <i>viz</i>. <i>Mangifera indica</i> (L.) or <i>Moringa oleifera</i> Lam. 5% concentration during critical crop growth stages would certainly produce as good as yield compared to standard crop cultivation