Physiological Growth Indices of Maize Under Semi-Arid Irrigated Conditions as Influenced by Subsoil Compaction and Nitrogen Fertilization

The study was initiated to access the effect of subsoil compaction and nitrogen fertilization on various growth indices of maize, at research farm, Department of Soil Science, Punjab Agricultural University, Ludhiana. The split plot design was employed with three levels of subsoil compaction (main plot), three levels of N fertilization (subplot) and three replications. The dry matter accumulation, leaf area (LA) and growth indices were significantly lower under higher level of subsoil compaction. The crop growth rate (CGR) was significantly higher under C0 treatment at 30 DAS, 60 DAS and at harvest than that in C1 and C2 treatment. Higher root mass density was observed in the surface soil under C2 treatment, while a reverse trend was recorded at 15–30 and 30–60 cm soil depth, where higher root mass density was observed under C0 treatment than that in C1 and C2 treatment. Application of higher dose of N resulted in higher dry matter, LA index and growth indices than that in lower N application. A positive exponential relationship was observed between grain yield-CGR and biomass yield-CGR. The total N uptake was lower under C2 subsoil compaction level, while higher N rates improved N uptake. The N fertilization resulted in favourable nutrient regime and thereby improved maize growth, development and yield formation under higher subsoil compaction levels. Further studies could be done to access the environmental and soil health risks associated with higher N application under compacted subsoil conditions. © 2015, The National Academy of Sciences, India.