Impact of gypsum, organic manure and nitrogen levels to produce BT. cotton crop from partially reclaimed coastal salt affected soils

A field experiment was conducted at Coastal Soil Salinity Research Station, NAU, Danti-Umbharat, Gujarat during kharif season (2019-20 to 2021-22) to study the effect of gypsum, organic manure and nitrogen levels to produce Bt. cotton crop under partially reclaimed coastal salt affected soils. Experiment consisted of total twelve treatments combinations that were repeated three times using a factorial randomized block design. These combinations included two gypsum levels (G1: 25% GR and G2: 50% GR), two organic manure levels (O1: FYM 10 t/ha and O2: Biocompost 10 t/ha) and three levels of nitrogen (N1: 50% RDN, N2: 75% RDN and N3: 100% RDN, 240 kg N/ha). The results revealed that the application of gypsum @ 50% GR (G2) recorded significantly highest growth, yield parameters and seed cotton yield viz., number of sympodia per plant (21.2), boll weight (3.37 g), number of bolls per plant (28.6) and seed cotton yield (1639 kg/ha) in pooled results. Among organic sources, application of biocompost @ 10 t/ha (O2) resulted in significantly highest boll weight (3.33 g), number of bolls per plant (28.7) and seed cotton yield (1636 kg/ha) in pooled results. In case of nitrogen levels, application of 100% RDN (240 kg N/ha) (N3) yielded significantly higher boll weight (3.35 g), number of bolls per plant (29.6) and seed cotton yield (1699 kg/ha) over treatments N1 and N2 but in boll weight treatments N2 was at par with treatment N3 in pooled results. Interaction effect of gypsum @ 50% GR along with biocompost @ 10 t/ha (G2O2) recorded highest seed cotton yield (1750 kg/ha) as compared to rest of the treatments combinations. Further, gross income and net income realized was higher in G2O2 (Rs.122500/ha and Rs.51363/ha) and N3 (Rs.118930/ha and Rs.48983/ha) as compared to other treatments. From the results it could be concluded that application of gypsum @ 50% GR along with biocompost @ 10 t/ha and 100% RDN (240 kg N/ha) enhance yield of Bt. Cotton with improvement in partially reclaimed coastal salt affected soils.