Impact of salinity and sodicity on biomass, total nitrogen, nitrate reductase activity, leaf area, and chlorophyll contents in maize (Zea mays L.)

摘要

Salinity and sodicity are major constraint in increasing crop production at global level. Millions of the hectares of the land are too saline to produce economic yield. In Ethiopia, 11 million ha of land is salt affected, about half of these soils are saline and remaining half are saline - sodic and sodic soil. As most of the arable land and quality water resources have already been exploited, the use of saline or urban/industrial waste water may be a viable alternative for further agro production. In view of such perspectives, an investigation was conducted to examine the effect of salinity (NaCl) and sodicity (Na2CO3) on biomass, total nitrogen, nitrate reductase activity, leaf area, and chlorophyll contents in Maize (Zea mays L.) plants. The appropriate amount of NaCl and Na2CO3 was dissolved in distilled water for appraisal of artificial salinity and sodicity levels (0, 4, 8, and 12 and mScm~(-1)) in soil medium. Plants were also supplied with potassium (0 and 5mM KNO3) as remedial treatment. Maize plants were analyzed for germination, early growth, biomass, total nitrogen, Nitrate reductase activity, Leaf area, and chlorophyll contents as grown under different ECe levels of salinity and sodicity. The extent of salinity and sodicity effects was compared on the basis of different parameters. It was observed that plants showed substantial reduction in all parameters due to imposition of salinity and sodicity in root medium and it was more so due to sodicity. However, the use of additional potassium brought about an enhancement in these parameters. It is suggested that plants may be raised in saline soil and saline water however; the extent of success depends upon salinity and sodicity levels, remedial treatments and plant species. The outcome of the present work may contribute towards viable utilization of saline soil and water for enhancing agro production of suitable crops, a desired goal to achieve food security.