Lower Doses of NaCl Promotes Growth in Alfalfa (Medicago Sativa L. cv. Ek Sali) Cultivated on the Soil Amended with Farmyard Manure

Salinity is the key problem for crop cultivation in several regions of India. To study the plant growth and photosynthetic pigments of alfalfa under salinity stress, an experiment was conducted in a factorial design wherein alfalfa seeds were grown in polythene bags in triplicate, containing 3.5 kg sandy-loam soil, poor in NPK amended with 5%, 10%, 15%, 20% and 25% (w/w) Farmyard manure (FYM). NaCl doses of 0, 10, 20, 50, 100, 200 and 500mM were given for one month after the plants attained enough strength. Lower salinity doses of 10, 20 and 50mM with FYM proved to be the growth promoter for the plant. Peaks of shoot height (103.00cm), root depth (24.00cm), shoot dry biomass (8.97g/plant), root dry biomass (2.33g/plant) and leaf area (2467.17cm2/plant) were recorded in plants grown on soil amended with 15% FYM and treated with 50mM NaCl. Plant growth started to decrease at 100mM NaCl and afterwards. Comparatively, better performance of the plant and overall growth recorded in plants raised on soil amended with 15% FYM. Similarly, the highest chlorophyll a (0.71mg/g), chlorophyll b (0.86mg/g), carotenoids (0.48mg/g), chlorophyll a+b (1.57mg/g) were found in plants raised with 20% FYM at 50mM salt stress. Plants failed to survive at 500mM NaCl. The outcomes suggest that the interaction of fertilizer and lower salinity doses prove to be instrumental for the growth of alfalfa.