Biomass productivity and nutrient availability of Cynodon dactylon (L.) Pers. growing on soils of different sodicity stress

Biomass productivity and nutrient availability for Cynodon dactylon were studied in two types of soils (sandy-clay-loam, loamy-sand) of Gangetic alluvial plain, where degraded land (uncultivated sodic wasteland) was developed under cultivated system. The study was performed in three districts of Uttar Pradesh state to assess the site variations. Frequency, density, abundance and IVI increased significantly when the uncultivated sodic land was managed for crop production. Biomass of the species increased significantly from 90 ± 12 to 1349 ± 176 g m−2 with decrease in sodicity stress from 88.4 ± 2.6 to 8.0 ± 0.8 ESP of the soil. The ratio of increase in standing biomass was observed as 1:8:16 in uncultivated sodic land (USL), semi-reclaimed crop field (SCF) and non-sodic crop fields (NCF) considered as a reference site, respectively. Macronutrient concentrations in soil viz. N, K, Ca, and Mg increased from USL to SCF and NCF, whereas Na concentration decreased inversely. In the plants K concentration ranged from 0.47 to 1.8%, whereas, Ca (0.36–0.72%) and Mg (0.24–0.36) concentrations varied to lesser extent. These variations differed significantly among the soil sites. Sodium concentration decreased significantly in plant samples of semi-reclaimed site from the sodic soil site. Micronutrients in plant tissues showed a decreasing pattern from USL to NCF for Zn, Fe, and Mn, whereas, Cu increased correspondingly. Thus the low, modest, and high growth of C. dactylon corresponding to decrease in sodicity stress (ESP and pH) could be used as bio-indicator to assess the degree of reclamation.