Optimising sugarcane biochar and nutrient management on growth and productivity of spring maize under trans-Gangetic plains of Punjab
A field experiment was conducted during the spring season of 2024–25 at the Agricultural Research Farm, Lovely Professional University, Punjab, to evaluate the optimisation of sugarcane straw biochar rate and nutrient management on spring maize (Zea mays L.). The trial was laid out in a split-plot design (SPD) with 3 replications. The main plot received three different treatment levels of sugarcane biochar rate which included 5 t ha-1 (M1) and 10 t ha-1 (M2) and 15 t ha-1 (M3). Similarly, 4 treatments were selected for the subplot section, consisting of S1 for absolute control, S2 for 100 % recommended dose of nitrogen and phosphorus (RDNP), S3 for 50 % RDNP with nano di-ammonium phosphate (nano DAP) and S4 for 50 % RDNP with liquid nutrient foliar sprays. Results revealed that, M3 achieved the significantly highest plant height of 221.46 cm during harvest while also reaching the highest dry matter accumulation (DMA) of 230.06 g plant-1 and soil plant analysis development (SPAD) index of 45.53 which resulted in a 31.8 % grain yield increase compared to M1. The evaluation of different nutrient conditions showed that S2 and S3 performed equally well for all measured characteristics when compared to S1. Under the S2 treatment, both plant height and grain yield increased by 28.1 %, while yield attributes also showed improvement. The interaction showed distinct patterns because M3S2 achieved significantly highest growth and yield of spring maize. The maximum chlorophyll index (46.80), grain yield (57.03 q ha-1) and straw yield (75.03 q ha-1) were found in M3S2 which are statistically at par with M3S3 and M3S4. The combination of reduced fertiliser application with foliar treatment produced better crop results when biochar usage reached its peak level. Therefore, integrating sugarcane biochar with optimised nutrient level offers a pragmatic pathway for improving growth and productivity of spring maize in Punjab.