Effect of Soil type and Moisture content on Survival, Mobility, Nodule occupancy of inoculated Rhizobium leguminosarum bv. viciae and Lentil growth

In a green house study, sandy clay loam soil restricted the survival and downward movement of seed inoculated Rhizobium leguminosarum bv. viciae inoculum in lentil maximum upto 6, 8, 10, 12 and 12 cm in comparison to 8, 10, 12, 14 and 16 cm in sandy loam soil at 16, 23, 37, 44 and 51 DAS, respectively, at 50% of water holding capacity (WHC). Soil moisture level of 50% of WHC supported better survival and movement of the inoculum in both the soils than 30% moisture level. Sandy loam soil produced higher nodule number, by 16.6% at 0–10 cm depth, by 30.8% at 10–20 cm depth and, by 47.4% below 20 cm depth than sandy clay loam soil. The effect of soil types was more conspicuous at 30% moisture showing significantly more nodule number, by 15.5%, in sandy loam soil than sandy clay loam soil. Sandy loam soil recorded 8.9 and 18.0% more nodule occupancy than in sandy clay loam soil and 30% moisture gave significantly less nodule occupancy, by 15.1 and 31.3% respectively, than 50% moisture level at 0–10 cm and below 10 cm depths. Nodule and plant dry weights were also significantly more in sandy loam than sandy clay loam soil and 50% than at 30% moisture level. However, the favourable effect of increasing moisture from 30 to 50% of WHC was more evident in sandy clay loam soil showing increase of 49.6% in nodule dry weight and 25.6% in plant dry weight.