PRODUCTIVITY AND NITROGEN REQUIREMENT OF POTATO (SOLANUM-TUBEROSUM)-BASED SEQUENTIAL AND RELAY CROPPING SYSTEMS

A field experiment conducted at New Delhi showed that maize (Zea mays L.)-potato (Solanum tuberosum L.) + wheat (Triticum aestivum L. emend. Fiori & Paol.) + greengram (Phaseolus radiatus L.) double relay cropping gave 40% higher productivity than maize-potato-wheat-greengram sequential cropping. At 240 kg N/ha/year the total productivity of sequential cropping was the highest when 60 kg N/ha was applied to each maize and potato and 120 kg N/ha to wheat; potato yield in this system was 15.8 tonnes/ha. In relay cropping with 28.7 tonnes/ha of potato yield, the productivity was the highest when 120 kg N/ha was applied to potato and the remaining 120 kg N/ha was shared equally by maize and wheat.