EFFECT OF FERTILIZERS ON THE PRODUCTION POTENTIAL OF DIFFERENT CROP SEQUENCES IN ARID REGIONS

A field experiment aimed at optimizing fertilizer use in different cro p sequences, was conducted during 1991-92 and 1992-93 at Mandor (Jodhp ur). Double-crop sequences recorded higher annual productivity and net return over monocrops. Pearlmillet [Pennisetum glaucum (L.) R. Sr. em end. Stuntz.]-cumin (Cuminum cyminum L.) was found more remunerative b ut less sustainable compared with pearlmillet-Indian mustard [Brassica juncea (L.) Czernj. & Cosson] in view of higher cost and risk involve d in cumin cultivation. Ail the double crop sequences and wheat (Triti cum aestivum L. emend. Fiori & Paol.) grown after fallow responded to 100% of recommended fertilizer level (RFL). Additional manuring with f armyard manure (FYM) @ 5 tonnes/ha in 91 beyond 50% of RFL improved yi eld of double crops for 3 consecutive seasons. Mustard and cumin grown as monocrops required to be fertilized up to 50% of RFL and additiona l fertilization (organic or inorganic) did not bring about improvement in productivity any further.