Alternate cropping systems to rice (Oryza sativa)-wheat (Triticum aestivum) for Punjab

A field experiment was conducted from 2006–07 to 2008–09 at Punjab Agriculture University, Ludhiana, centre of AICRP on Cropping Systems to evaluate the effect of 10 crop sequences on productivity, profitability, weed population and soil fertility. Maximum rice (Oryza sativa L.) equivalent yield was recorded by maize (Zea mays L.)-potato (Solanum tuberosum L.)-onion (Allium cepa L.) (32.0 t/ha) followed by summer groundnut (Arachis hypogaea L.)-potato-bajra (Pennisetum glaucum L.) (fodder), and maize-potato-summer moongbean (Vigna ra-diata L. Wilczek) cropping systems. These cropping systems produced an additional rice equivalent yield of 10.0 to 19.1 t/ha and saved 75.6 to 122.3 cm irrigation water over the rice-wheat system. The highest energy production was with maize-wheat (Triticum aestivum (L.) Fiori & Paol]-moonngbean (43.7 x 10⁶ K.cal) whereas the production efficiency (98.8 kg/day/ha) and net returns (1.65 x 10⁵) were highest in maize-potato-onion cropping system. The population of Phalaris minor was lower in all the cropping systems when compared with the rice-wheat system. The maize based cropping system showed positive influx of N, P and K over initial values.