Evaluation of different fertilizer types in potato crop under various irrigation regimes

Abstract: India is the second largest producer of potatoes in the world. Shallow root system makes potato crop an inefficient nutrient consumer and sensitive to water stress. Anecdotal evidence hints that many potato growers of northwest India prefer complex NPK fertilizers or compound NP fertilizers over the straight fertilizers because they believe the former to be more efficient on agronomic basis. Thus, this study was aimed at conducting a comparative evaluation of various fertilizer sources across different irrigation and FYM regimes over two years on a loamy sand soil. A field experiment in split-split plot design was used with one additional blocking factor of soil variability. The main plot involved two FYM levels (0 and 50 t ha^-1) and three irrigation water pan evaporation (IWPE) based irrigation regimes (IR1 with IWPE 2.0, IR2 with IWPE 1.4, and IR3 with IWPE 0.8) in sub-plots. Four fertilizer treatments in sub-sub plot involved a check (T0); T1 with N,P, and K respectively from straight fertilizers urea, single superphosphate (SSP), muriate of potash (MOP); T2 with P from DAP, remaining N from urea, and K from MOP; T3 with P from NPK complex (12:32:16) fertilizer and the remaining N from urea and K from MOP. General trends in tuber yield and irrigation water use efficiency (IWUE) during the year 2011 and statistically proven results of various a priori single degree of freedom contrasts showed that NPK complex fertilizer and NP compound fertilizer performed better than straight fertilizers.