Influence of manuring and irrigation scheduling on system productivity, resource use efficiency, nutrient uptake and incidence of early shoot-borer (Chilo infuscatellus) in sugarcane (Saccharum spp. hybrid complex) and garlic (Allium sativum) intercroppin

A field experiment was conducted during the autumn seasons of 201013 at Pusa, Bihar, to identify suitable fertilizer and irrigation requirement in sugarcane (Saccharum spp. hybrid complex) + garlic (Allium sativum L.) in- tercropping system for system productivity, resource-use efficiency, nutrient utilization and early shoot borer (Chilo infuscatellus Snellen) incidence in sugarcane. Sugarcane + garlic (1: 2) with 100% recommended dose of fertilizer (RDF) to sugarcane (150, 37.1, 49.8 kg N, P, K/ha) and garlic (100, 34.9, 66.4 kg N, P, K/ha) showed sig- nificantly higher dry weight of garlic bulb (1.14 t/ha), bulb yield of garlic (3.5 t/ha), cane-equivalent yield (130.3 t/ ha), land-equivalent ratio (1.30), area-time equivalent ratio (1.08), net returns ( 1,96,300/ha) and benefit: cost ra- tio (2.96) than rest of the fertilizer treatments. The total N, P and K uptake by sugarcane and garlic were also found the maximum in this treatment. Fertility levels did not affect available N and K status after harvesting of sug- arcane and garlic but significantly increased organic carbon and available P when analyzed after harvesting of sugarcane and garlic. Intercropping system exhibited significantly lowest incidence of early shoot borer (6.7%) than sole sugarcane (11.4%). Different irrigation schedules significantly influenced growth and yield attributes. Ap- plication of 4 irrigations at 30, 60, 90 and 120 days after sowing (DAS), being at par with 3 irrigations, resulted in higher cane yield (92.4 t/ha), bulb yield of garlic (3.6 t/ha) and land-equivalent ratio (1.36) than the remaining irri- gation levels. With the increase in irrigation from 1 to 4 resulted increase in cane-equivalent yield, area-time equivalent ratio and net returns, maximum being recorded with 4 irrigations at 30, 60, 90 and 120 DAS. However, benefit: cost ratio (3.05) and N, P and K uptake by sugarcane were significantly improved up to 3 irrigations (30, 60 and 90 DAS). There was increasing trend of soil organic carbon and available N, P and K in post-harvest soil with increasing irrigation levels, whereas increasing level of irrigation reduced the incidence of early shoot borer in sugarcane. Sugarcane + garlic with 100% RDF to both the crops in combination with 4 irrigations (30, 60, 90 and 120 DAS) resulted in the highest N (29.1 kg/ha), P (12.5 kg/ha) and K (27.6 kg/ha) uptake by garlic. The interac- tion effects showed that sugarcane + garlic (1: 2) with 100% RDF to both the crops in combination with 3 irriga- tions at 30, 60 and 90 DAS gave at par net returns with that of sugarcane + garlic with 100% RDF to both the crops along with 4 irrigations at 30, 60, 90 and 120 DAS in sugarcane + garlic intercropping system.