Soil health and economic evaluations of direct seeded rice through metabolomic and biochemical fingerprinting

The present study was conducted for three consecutive cropping seasons from 2020-2022 in Amritsar of Punjab with the objective to analyze the soil health and economic impact of direct seeded rice (DSR) technology over puddled transplanted rice (PTR). It was recorded high number of average earthworm count in the soil sample of DSR fields (Mean value 124.6) as compared to PTR fields (Mean value 68). The soil health was also improved through DSR technique as various physical parameters i.e. porosity, bulk density & water holding capacity observed better in DSR fields over PTR technique. The soil samples of DSR fields also showed high amount of NPK (N: 219, P: 816, K, 101.4) and mineral content (Mg: 1298, Ca: 1336, Zn: 4.85, Mn: 87.5, Cu: 8.51 & Fe; 9.92) as compared to PTR fields. It was also observed that soil sample of DSR field showed improved carbon composition (HAs, FPA, GRSPs, WSOC, HWSOC, EE) & soil enzymatic activity (DHA, ALK, ACP & PMN) as compared to PTR soil sample. The various reproductive, photosynthetic, and yield parameters of rice crops was observed improved in DSR over the PTR. The HPLC-MS based fingerprinting showed up-regulation of amino acid and phenolics in rice grains grown through DSR technique over the PTR. The cost of field preparation and tillage was reduced by 62.15% in DSR over PTR. The DSR technology resulted into yield improvement by 3.44-18.21% as compared to transplanted rice. A net profit of 13.91-31.62% was calculated in DSR over PTR technique.