Nutrient analysis

Dried and crushed 250gm soil samples (dried at 100 °C for 48 h) were passed through 2.0 mm sieve to remove roots and other aggregate matter. The soil chemical analysis was performed at the division of soil science, SKUAST-K Shalimar. pH was determined electrochemically with the help of glass electrode pH meter, as suggested by Jackson 1973. Exchangeable cations were extracted using 1 mol L⁻¹ neutral ammonium acetate solution and quantified using the Kjeldahl method to measure the cation exchange capacity (CEC)³⁷. The organic carbon of the soil samples was determined using the Walkley and Black method as outlined by³⁸. Total nitrogen of the soils was determined using the Kjeldahl’s method following H₂SO₄ acid digestion method as suggested by³⁸. The available K was determined from NH₄OAc. (pH, 7.0) extract as described by³⁸. The extract was analysed for available K by a flame analyzer at 589 nm. The available phosphorus was extracted from the soil with 0.5 M NaHCO₃ (Olsen’s Method) at pH 8.5 and molybdo-phosphoric blue colour method of analysis was used for determination. Calcium and magnesium were estimated using atomic absorption spectrophotometer (AAS 4141) protocol using³⁸. All quantified soil properties are given in Supplementary Table S1.