Economic-viability of sequential cropping systems under non-saline calcareous soil of Bihar

An experiment was conducted at the CTRI Research Station, Pusa, Bihar, during 1994–95, 1996–97 and 1997–98 on sandy loam (alluvial), non-saline calcareous soil (pH 8.2) under irrigated condition. Treatments consisted of 12 tobacco (Nicotiana tabacum L.)-based cropping sequences involving legumes (pulses and oilseeds), cereals and non-legumes in the system in randomized block design with 4 replications. Total cured leaf yield, first grade outturn (high-value marketable produce) and physical leaf quality parameters in base crop of tobacco were significantly influenced due to different sequential cropping systems. The maximum total cured leaf yield of 2,384 kg/ha and first-grade outturn of 1,508 kg/ha were recorded in sequence of sunnhemp (Crotalaria juncea L.) (GM)-tobacco-fallow (summer ploughing), followed by rice (Oryza sativa L.) -tobacco-cowpea [Vigna unguiculata (L.) Walp.] (2,301 and 1,495 kg/ha), sunflower (Helianihus annuus L.)-tobacco-blackgram (Phaseolus mungo L.) (2,236 and 1,425 kg/ha) and groundnut (Arachis hypogaea L)-tobacco-greengram (P. radiatus L.) (2,218 and 1,420 kg/ha) total cured and first-grade leaf yields respectively). The minimum Orobanche (a total root parasite) incidence in base crop tobacco was observed when tobacco was preceded or succeeded by sesame (Sesamum indicum L). Leaf-area index (LAI) and physical leaf quality parameters such as spangling. puckering and maturity in tobacco followed almost similar trend to that of tobacco leaf yields. The maximum net return (Rs 65,832/ha) was recorded in sequence sunflower-tobacco-blackgram, followed by groundnut-to-bacco-greengram (Rs 64,893/ha), soybean-tobacco-sunflower (Rs 63,702/ha) and blackgram-tobacco-sor-ghum [Sorghum bicolor (L.) Moench] + moth (Rs 63,505/ha) sequences. The minimum net return (Rs 53,523/ha) was recorded in maize (Zea mays L.) tobacco-maize.