Indian Journal of Agricultural Sciences 82 (2): 117–21, February 2012 Influence of irrigation methods and fertilizer levels on productivity of potato (Solanum tuberosum) VIPIN SHARMA 1 , I P SHARMA 2 , R S SPEHIA 3 and PARDEEP KUMAR 4 Dr YS Parmar University of Horticulture and Forestry, Nauni, Himachal Pradesh 173 230 Received: 3 December 2010; Revised accepted: 17 June 2011 ABSTRACT A experiment was laid in split-plot design and the treatments comprised sprinkler, drip and furrow irrigation as main plot along with three doses of fertilizers, viz F 1 (NPK @ 150:150:125 kg/ha), F 2 (NPK @ 125:125:100 kg/ha) and F 3 (NPK @ 100:100:75 kg/ha) as sub-plot treatments. Results of the study indicated that irrigation methods manipulated the hydrothermal regimes of the soil comprehensively and mean maximum monthly temperature was lowered by about 1.2 o C under sprinkler irrigation. Under drip irrigation, moisture was near to the field capacity throughout the growth period, whereas, in conventional furrow irrigation, the moisture status curve traveled from above field capacity to 50% moisture depletion conditions. The yield of tubers was appreciably higher under sprinkler and drip, compared to furrow irrigation method. F 1 and F 2 exhibited non significant differences among themselves, in respect of tuber yield, but were significantly higher than F 3 . Economic analysis indicated that sprinkler irrigation and F 2 resulted in optimum benefit: cost ratio. Key words: Benefit : cost ratio, Drip, Field capacity, Hydrothermal regimes, Split-plot design, Sprinkler Potato (Solanum tuberosum L.) ranks fourth among major food crops of the world, occupying an area of 19.26 million ha with annual production and productivity of 320.71 milliontonnes and 16.64 tonnes/ha, respectively (http:// www.fao.org). Asia and Europe are the world’s major potato producing regions, accounting for more than 80% of world production. India ranks third with an annual production of 26.28 million tonnes. Irrigation and fertilization are two important inputs in potato production and increased production depends upon efficient use of irrigation water and fertilizers throughout the growth period. In the present day context, the effective and economic utilization of water and fertilizers is very essential to reduce the cost of cultivation and can best be achieved through the use of improved irrigation techniques, viz drip and sprinkler and supplying balanced and adequate doses of fertilizers. Use of drip and sprinkler irrigation can increase the yield up to 20–40% along with water saving up to 39% in potato crop (Pawar et al. 2002). However, their adoption is restricted mainly due to huge investment needed for installation during the initial period. Therefore, the economic feasibility of these techniques is needed to be assessed for a short-duration crop like potato. The response of applied fertilizers is also expected to vary with different methods of irrigation as frequency of water application is different in sprinkler, drip and conventional furrow irrigation system. Further, it has been reported that soil temperature causes large fluctuations in potato yield and can be manipulated to some degree by adjusting the soil moisture. Therefore, the present studies were conducted to evaluate variable fertilizer doses under different irrigation methods and assess the economic feasibility of these techniques. MATERIALS AND METHODS The studies were carried out at the Experimental Farm, Department of Soil Science and Water Management, Dr Y S Parmar University of Horticulture and Forestry, Nauni, Himachal Pradesh. The farm is located at an elevation of 1 150 m above mean sea level and lies at 30 o 50’30" N latitude and 77 o 08’30"E longitude. Field trials were conducted on potato cv. Kufri Jyoti during spring season (February to May) of 2006 and 2007. The soils were Typic Entrocrept at subgroup level as per Soil Taxonomy of USDA and exhibited nearly neutral reaction, low salt concentration, medium organic carbon, available phosphorus and potassium and low available nitrogen status (Table 1). The experiments were laid out in split-plot design with three main plot and three sub-plot treatments replicated four times as per details given below: Main plot treatments (irrigation methods) = 3 1 Research Scholar (email: drvipin_81@rediffmail.com) 2 Professor (Retired)(email:ipsharma828@yahoomail.com) 3 Assistant Professor, 4 Assistant Extension Specialist 25