Soil physicochemical and chemical properties effected by long-term fertilizers and manures under rice-rice cropping system in Inceptisols

Abstract

A long-term field experiment, initiated in the 2000-01 cropping season under the AICRP on LTFE, was conducted at the Regional Agriculture Research Station of Professor Jayashankar Telangana Agricultural University in Jagtial. Its primary objective was to investigate the long-term alterations in soil physico-chemical and chemical properties induced by continuous fertilization practices within a rice-rice cropping system on Inceptisols. The study employed a Randomized Block Design comprising seven distinct organic and inorganic nutrient treatment combinations, each replicated thrice. Soil samples were systematically collected, processed and subjected to comprehensive analysis during the kharif 2024. Evaluations encompassed critical soil parameters such as pH, electrical conductivity (EC), organic carbon (OC) and available macronutrients (N, P and K). After 24 years of sustained amendment application, the results revealed no statistically significant alterations in pH and EC across treatments; however, pronounced variations were observed in organic carbon and available macronutrients concentrations. At the surface layer (0-15 cm), pH ranged from 7.95 to 8.06, EC from 0.48 to 0.53dS m-1 and organic carbon from 0.42 to 1.02%. The available macronutrients levels at this depth spanned: available nitrogen 94-191 kg ha-1, phosphorus 11.8 to 47.4 kg ha-1 and potassium 312 to 497 kg ha-1. In the subsurface layer (15-30 cm), pH varied from 8.00 to 8.40, EC from 0.42 to 0.48dS m-1 and organic carbon from 0.26 to 0.60%. Subsurface macronutrients ranges were nitrogen 86-156 kg ha-1, phosphorus 5.8 to 34.6 kg ha-1 and potassium 295 to 452 kg ha-1. A discernible trend indicated an increase in pH with increasing soil depth, concurrently with a decline in EC, organic carbon and available macronutrient levels. These findings offer crucial insights into the sustainable management of soil health under intensive agricultural systems.