Analyzing potato response to irrigation and nitrogen regimes in a sub-tropical environment using SUBSTOR-Potato model

Increasing water scarcity and rising fertilizer cost warrant their judicious use in the world agriculture. It implies that management interventions should synchronize crop needs with soil supplies of these resources in the root zone to reduce probability of water and nutrient stresses and yield loss. This study examines the applicability of SUBSTOR-Potato model in analyzing potato response to irrigation and nitrogen regimes in a semi-arid sub-tropical environment of Punjab. In order to evaluate the model, database was generated by establishing a field experiment on potato (cv. Kufri Badshah) planted in mid-October on a sandy loam soil. Combinations of three irrigation regimes viz., irrigation water (IW) to pan evaporation (Ep) ratios of 0.8, 1.4 and 2.0 and four N rates viz., 0, 135, 180 and 225 kg ha−1 were randomized in a split-plot design with three replications. Half dose of N for a given rate was applied at planting and the rest half with a common irrigation 4 weeks after planting. The crop was managed for pest control by adopting local recommendations and harvested in end-January.