Integrated nutrient management in blackgram– potato–wheat sequence

A field experiment was conducted on silty clay loam soil of Gwalior, Madhya Pradesh during 2003–04 to 2005–06 to identify the best nutrient management option for blackgram (Phaseolus mungo) – potato (Solanum tuberosum) – wheat (Triticum aestivum) sequence. There were seven treatment combinations {one control, two sole organic manures (Nadep and FYM @ 15 t/ha), two sole inorganic fertilizers [50% recommended dose of fertilizers (RDF) and 100% RDF] and two organic manure + inorganic fertilizers (50% RDF + 5 t/ha manure)} which were applied to all the three crops. Blackgram yield was not affected by different fertility treatments. Highest potato tuber yield (20.3 t/ha) was recorded when 100% NPK was applied whereas, the highest wheat yield (3.8 t/ha) was recorded when NPK was applied 50% through inorganic + 5 t FYM/ha. Highest production efficiency (128 kg/ha/day) and potato equivalent yield (30.7 t/ha) were recorded with 50% NPK + 5 t Nadep compost/ha but highest sustainable value index (0.80) was recorded with 15 t FYM/ha. The economic parameters viz. benefit-cost ratio (1.57), net returns (36713/ha), return per spent (0.57), production efficiency (kg/ha/day) were higher with 5 t FYM/ha + 50% RDF compared with 100% RDF; however, potato equivalent yield was the same between the two treatments. Since, most of the economic parameters were in favour of the treatment 50% RDF + 5 t FYM/ha, hence it proved to be the best treatment followed by 100% RDF.