Evaluating the Interactive Impact of Nitrogen Levels and Cultivars on Yield Traits, Nitrogen use Efficiency, Water use Efficiency and Benefit Cost Ratio of Ratoon Rice in Punjab, Pakistan

Abstract

Ratooning of rice (Oryza sativa L.) is process of obtaining grain from tillers that grow from crop stubbles that have already been harvested. Ratooning has gained attention since it has a potential for obtaining yield with conventional techniques. Field experiment was conducted during 2021–2022 at the research farm, Institute of Agronomy, Bahauddin Zakariya University Multan, Punjab, Pakistan. The response of various nitrogen (N) levels (0, 25, 50, 75, and 100 kg ha− 1) was studied on the growth and yield of three rice cultivars (Guard Lp-02, Guard Lp-18, and Super Fine) grown as ratoon rice. In cultivars, Guard Lp-02 and Guard Lp-18 were hybrid but Super Fine was a non-hybrid cultivar. The hybrid cultivars showed a significant response to N levels. The cultivar Guard Lp-18 with higher level of N 100 kg ha− 1 resulted in more plant height, total tillers, fertile tiller, panicle length, and biological yield while the higher number of branches and grains per panicle, 1000-grain weight, and grain yield was achieved by Guard Lp-18 with the application of 75 kg N ha− 1. Maximum agronomic nitrogen use efficiency (ANUE) and economic nitrogen use efficiency (ENUE) was observed at cultivar Guard Lp-18 with N level of 50 kg ha− 1. Likewise, water use efficiency (WUE) was recorded maximum at cultivar Guard Lp-18 with N level 75 kg ha− 1. The highest gross income, net income, and benefit cost ratio (BCR) were noted at 75 kg N ha− 1 among all cultivars but Guard Lp-18 with 75 kg N ha− 1 respond better in ratoon rice. Among rice cultivars, hybrid rice performed better and out yielded non-hybrid cultivars in ratoon rice. The findings of this study revealed that growing ratoon rice will be helpful for increasing farm income; enhancing resources use efficiency and ensuring food security under prevailing agro-climatic conditions of Punjab, Pakistan.