Effect of long-term nutrient management practices on soil physical properties under rice-wheat cropping system

Studies on soil test crop response (STCR) based integrated nutrient management (INM) practices were conducted after rabi season of 2018-19 to assess the impact of long-term nutrient management and soil depth on soil physical properties. The experiment was on a vertisol in central India under an ongoing experiment of AICRP on STCR initiated in kharif 2008 at a research farm of JNKVV, Jabalpur (23010' N latitude, 79057' E longitudes and at elevation 393.0 m above mean sea level (MSL). The study was framed in split plot design with four main treatments of nutrient manage- ment (T - control, T - GRD, T - soil test based NPK application for yield of 6.0 t ha-1 for 1 2 3 each crop, and T -T + 10 t ha-1 yr-1 FYM) and four sub-treatments of soil depth (0-15, 4 3 15-30, 30-45 and 45-60 cm) replicated three times. The data on soil physical properties revealed a significant effect of nutrient management and soil depth, viz., large macroaggregates (>2 mm) and small macro-aggregate (2-0.25 mm), MWD and penetration resistance (PR), WHC and bulk density (BD) of soil. The combination of soil test - based NPK and FYM @10.0 t ha-1yr-1 for a targeted yield of 6.0 t ha-1 improved macroaggregates, MWD (1.52 mm), PR (342.6 MPa), water holding capacity (WHC) (40.2%) and BD (1.33 Mg m-3) of soil. INM had no influence on soil texture, moisture content or particle density. The soil depths were found to influence the proportion of sand (40.2 %), clay (43.5%) and moisture content (35.2%) with maximum percentages at 0-15 cm and 45-60 cm, respectively. The interaction effects of INM and soil depths were found to have no impact on soil physical properties.