Optimum growth duration of Sesbania aculeata genotypes for green manuring in so die soils: Fibrefoliage relationship 65

Sesbania is a very useful green-manuring crop during reclamation and management of sodic soils. However, proper time of green manure application in such soils is crucial. Though its high foliage yield is preferred, higher fibre content becomes undesirable because of impaired decomposition of lignified and woody tissues. In the present study, conducted in the more controlled sodic soil environments of lysimeters, suitable growth duration of Sesbania for green manuring in high sodic versus moderate sodic soils is suggested, based on the optimum balance of foliage and fibre contents. All the genotypes involved in the study exhibited strong positive association of foliage production and fibre contents from 40 to 60 days based on correlation and regression analyses in both sodic soil environments. With the increasing growth duration, foliage and fibre contents increased more under moderate sodicity than under higher stress. Based on these two parameters, it is concluded that a 50-days-old crop could be incorporated in normal and reclaimed sodic soils (pH2 9.2), whereas up to 55 days of growth should be allowed for ploughing into severe sodic soils (pH2 9.6).