Elemental analysis of humic acid through FTIR and GCMS method and evaluation of humic acid as bio-stimulant for enhancing the yield and quality of rice

The use of humic substances (HS) as a bio-stimulant emerged as one of the sustainable ways of crop production. The purpose of this study is to analyze the chemical structure of humic acids (HA) through Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS) methods. This study also aimed to assess the effect of applying HA on the paddy (CO-55 rice variety) to improve the yield and quality of the crop. The experiments were laid out in a completely randomized design with three biological replications in July- 2023 and November-2023-24 at wetland farm (11o 0’5.73’’N latitude, 76o55’33.16’’E longitude for Kharif season and 11o0’7.65’’N latitude, 76055’35.64’’E longitude for Rabi season, respectively), Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu. Here, four different concentrations of HA viz. 0.1, 0.2, 0.3 & 0.4% were applied at active tillering and panicle initiation stages of rice along with soil test crop response - integrated plant nutrient system (STCR-IPNS) recommendation-based fertilizers. The application of various treatments showed positive effects in all the parameters of crops viz. growth, yield & quality of rice. Foliar application of HA at 0.3 % recorded the highest grain yield of 5975 and 6245 kg ha-1 which was 5.75 and 6.0 % over control treatment and quality of rice grain viz. protein content (11.9 &13.4 %) and starch (93 & 90 %) in Kharif and Rabi season, respectively.