EFFECT OF PARTIAL DECOMPOSED ORGANIC MULCH IN REDUCING SALINITY IN RHIZOSPHERE TO IMPROVE OVERALL PLANT GROWTH
The partially decomposed organic mulch, alone or amended with gypsum was investigated in decreasing salinity level of rhizosphere and improvement of overall growth and yield of okra plant under different salinity levels in irrigation water. The okra plants were grown in large clay pots (diameter, 30 cm) and irrigated with water of different salinity levels i.e. non-saline control (C, ECiw = 0.5 dSm-1), 0.15% Sea salt solution (S1, ECiw = 2.0 dSm-1) and 0.3% sea salt solution (S2, ECiw = 4.2 dSm-1). Vegetative growth (shoot height, fresh & dry biomass) and reproductive growth parameters (number of fruits, average fruit length and total fruit weight per plant) were found to be proportionally decreased under increasing salinity in irrigating water without application of mulch or gypsum treatments. The application of mulch either alone or amended with 0.2% gypsum revealed significant improvement in all the above mentioned parameters under control and both the salinity levels. Mulch alone improve total fruit yield 17%, 13% and 31% under control, S1 and S2, whereas more improvement was recorded if mulch amended with gypsum 96.8%, 68% and 53% respectively. The comparative analysis of the mulch treatments summarized as under.
Mulch & Gypsum > Gypsum > Mulch > Non-Mulch
The results suggested that application of partially decomposed organic mulch (with or without gypsum amendments) to the soil surface can increase tolerance level of okra and improve overall growth and yield of the