NUTRIENT BALANCES AS AFFECTED BY INTEGRATED NUTRIENT AND CROP RESIDUE MANAGEMENT IN COTTON-WHEAT SYSTEM IN ARIDISOLS. II. PHOSPHORUS

Abstract

Impact of integrated nutrient and crop residue management on crop productivity, phosphorus (P) uptake and apparent P balances was investigated in a 5-year field experiment on two calcareous soils, i.e., Awagat (coarse loamy) and Shahpur (fine silty) in cotton-wheat sequence. Minimum mean P uptake (kg ha⁻¹) by cotton with Farmers’ Fertilizer Use (FFU) treatment was 8.89 in Awagat and 11.54 in Shahpur soil. Corresponding maximum mean P uptake was 15.30 and 17.01 kg ha⁻¹ with Integrated Nutrient Management (INM), respectively. Nutrient treatments effect on P uptake by wheat was similar to cotton. Phosphorus uptake was further enhanced by crop residue recycling. Phosphorus uptake trend by cotton was negative under FFU without residue recycling and was positive with residue recycling. While P uptake trends were positive under all other treatments. INM yielded positive apparent P balances (kg ha⁻¹) of 56–306 in Awagat and 24–288 in Shahpur soil.

Keywords:

• cotton-wheat
• Aridisols
• apparent P balances
• balanced nutrient management
• integrated nutrient management
• P uptake

ACKNOWLEDGMENTS

Financial support for this field-cum-laboratory investigation was provided by the Ministry of Science & Technology, Government of Pakistan, through the Pak-Kazakh Joint Research Fund Project. The authors are indebted to the Central Cotton Research Institute, Multan and the Pak-German Institute for Cooperative Agriculture, Multan for invaluable support in this challenging field research endeavor. We are also grateful to M. Inayat Khan and M. Asif Ghumman for guidance and support in experimental design and statistical analysis of data and to M. Tauseef Tabassum and Zulfqar Ali for assistance in laboratory analytical work.