Optimizing Maize Growth and Phosphorus Use Efficiency through Integrated P Application and Irrigation Strategies

Abstract

Phosphorus (P) is crucial for plant functions like root growth, energy transfer, photosynthesis, and cell division. Yet, its soil efficiency is hindered by high fixation, low solubility, and immobility. Besides, its increased availability and subsequent plant uptake requires availability of sufficient moisture, as increased soil moisture contents higher dissolution of P occurs leading to increased root development, which, ultimately, increase nutrient uptake by plants. We performed a field experiment to check the effect of different P application levels along with different irrigation schemes in improving P uptake efficiency of maize and its related growth and yield attributes. In different treatments, irrigation was provided at recommended levels, skipped at milking and flowering stages to check the impacts of moisture contents on soil P availability. We observed that among different P levels, application of P at 90 kg ha-1 along with recommended irrigation level enhanced different maize traits, such as shoot length (13.4%), root length (51%), shoot fresh and dry weights (35 and 25%), root fresh and dry weights (37 and 42%), SPAD value (17%), chlorophyll ‘a and b’ (16 and 7%), P use efficiency (255%), harvest index (43%) and carotenoid contents (26%), as compared to control followed by P at 120 kg ha-1. Furthermore, in terms of soil nutrient attributes, P at 90 kg ha-1 along with recommended irrigation level enhanced soil organic matter (17%), active carbon (22%), available P (122%) and extractable potassium (36%), as compared to control. A consecutive decline in all the measured attributes was pragmatic under skipped irrigation systems under all the P application levels. We concluded that P application at 90 kg ha-1 combined with recommended irrigation levels can significantly increase P use efficiency of maize along with increased soil P availability and related growth and yield attributes.