Growth dynamics and yield of cotton-wheat in relation to nutrient use and irrigation regimes under sub-surface drip irrigation system

The present study was conducted to evaluate growth dynamics and yield of cotton-wheat cropping system under sub-surface drip irrigation at Punjab Agricultural University, Ludhiana during 2019-2020 and 2020-2021. The experiment was conducted with the combination of 3 irrigation regimes (60 80,100% ET_c), 2 fertility levels (80% recommended dose of nitrogen (RDN),100 % RDN) and 3 methods of application of nutrients (M_foliar i.e. foliar application of nutrients, M_soil i.e. soil application of nutrients). These 12 combinations were compared with further three controls; control1: surface drip + 100% RDN + M_foliar; control 2: surface drip + 100% RDN+ M_soil; control 3: Flood irrigation + soil RDN + M_foliar. The highest growth, seed cotton, grain yield were recorded at 100% ET_c which was at par with 80% ET_c but significantly higher than 60% ET_c. Among N levels, 100% RDN remained at par with 80% RDN in both the crops. Further, M_foliar resulted in higher growth and yield in cotton over M_soil, however, residual effect of M_soil was more in wheat. Both The control 1 and 2 were better over control 3, in terms of growthand yield. Therefore, foreseeing the impeding water resources, sub-surface drip at 80% ET_c, 80% RDN and M_foliar seems to be a better preposition in terms of water and fertilizer saving than conventional practice of cultivation.