Net Primary Production, Biochemical Composition and Economics of Sugarcane ( Saccharum officinarum ) Cultivation in Saline and Non-saline Soils of South-Western Punjab, India

Sugarcane ( Saccharum officinarum ) is cultivated across the globe with substantial variability in cane productivity and biochemical quality attributes. We studied the performance of seven mid-late maturing sugarcane varieties (MLMSVs) and five early maturing sugarcane varieties (EMSVs) cultivated in saline (E.C. 1:2 = 3.40 dS m −1 ) and non-saline (E.C. 1:2 = 0.774 dS m −1 ) soils for quantitative assessment of biochemical and agronomic attributes, different components of net primary production (NPP) (viz. economic yield; NPP EY , above-ground biomass; NPP AGB , below-ground biomass; NPP BGB , litter; NPP L , rhizodeposition; NPP Rhizo ) and the economic efficiency of different varieties. Significant reduction ( p < 0.05) in plant height with leaves, plant height without leaves, tillers plant −1 , 5-cane weight, length of inter-nodes, inter-nodes stalk −1 , cane diameter at ground surface and breast height by ~ 28.9, 17.3, 22.3, 45.6, 35.0, 10.9, 42.0 and 35.0% respectively was observed as compared to the non-saline soils. Higher productivity (92.1 Mg ha −1 ) of 22.1% was obtained under saline compared to the non-saline soils. Maximum accumulation rate (145.2–224.6 kg cane ha −1 d −1 ) for different sugarcane varieties in saline soils was significantly lower (by ~ 17.6%) than the non-saline soils. The agronomic N efficiency was significantly lower for CoPb-92 (352.4 kg cane kg −1 fertilizer-N) in saline soils, while for Co J-64 (550.3 kg cane kg −1 fertilizer-N) in the non-saline soils. Juice purity was decreased by ~ 18.7% in saline soils, as compared to the non-saline soils which exhibited a significant increase (R 2 = 0.95**, p < 0.01) with increase in sucrose content. These results revealed a linear significant relationship between juice purity and commercial cane sugar (R 2 = 0.97**, p < 0.01). However, salinity increased the total phenols (TP) content by ~ 10.1% over non-saline soils. These results showed that soil salinity significantly decreased the NPP EY , NPP AGB , NPP BGB , NPP L and NPP Rhizo compared with the non-saline soils. The NPP AGB decreased by ~ 19.2–43.5% for EMSVs and ~ 15.9–28.0% for MLMSVs cultivated in saline soils. Amongst the varieties, CoPb-92 has significantly lower NPP EY (by ~ 35.3%) than the CoPb-95 in the saline soils. The average gross returns (AGRs) were significantly lower for CoPb-92, whilst the highest was obtained from CoPb-95 under saline conditions, which resulted in enhanced economic efficiency of 8.7 US$ ha −1 d −1 for CoPb-95 by ~ 55.4% in saline soils and ~ 8.5% in non-saline soils than CoPb-92.