Characterization of Diverse Agro-Climatic Zones

The present study was carried out at four sites i.e. farmer’s field in Multan (29°.959593 N, 71°.343759 E), Faisalabad (31°.7053030 N, 73°.0215580 E), Sahiwal (30°.533018 N, 72°.758652 E) and Lahore (31°.748680 N, 74°.103364 E) regions. Two-year experiments were conducted on rice (2019 and 2020) and wheat (2019–20 and 2020–21) separately at each site. Pre-sowing soil samples (0–15, 15–30 cm) were analyzed for pH, electrical conductivity (EC), phosphorus (P), potassium (K), zinc (Zn), boron (B), and texture. The pH, EC, B, and texture were measured by following the methods described by [46 , 47 ]. Soil organic matter was determined following Walkley and Black method [48 ]. The soil of each site was classified according to the manual of the Soil Science Division Staff [49 ]. Soil-saturated paste was prepared for pHs, extract of paste was taken for ECe and both were determined using Jenway EC and pH meter model 671P. The P and K were determined using methods of [50 , 51 ] respectively. The concentrations of AB-DTPA extractable Zn were determined following [52 ] method. Briefly, an extractant solution (AB-DTPA) was prepared by dissolving specified quantities of NH₄HCO₃ and DTPA in 1.0 L of distilled water. Soil (10 g) was taken in a calibrated plastic centrifuge tube, and a newly prepared extractant solution (20 mL) was added. The suspension was then shaken for 2 h and the solution was filtered and analyzed for Zn contents using an atomic absorption spectrophotometer (Solar S-100, Thermo Electron, USA). These soil properties are presented in Table 1.
Multan is the southern part of Punjab, and the climate is arid subtropical with extreme summer temperature. Mean winter and summer temperature ranges from 7–26°C and 29–51°C respectively. The climate of Faisalabad is semiarid subtropical with a mean temperature of 6–21°C in winter and 27–39°C in summer. Sahiwal has a semiarid subtropical climate with average winter and summer temperature of 7–25°C and 28–49°C respectively. The climate of Lahore is semiarid subtropical, and temperature may range from 4–21°C in winter and 25–39°C in summer.