Role of composted organic material in reducing hazardous effect of salinity stress on biological nitrogen fixation and plant growth in salt affected soils of arid region
Agriculture Research, Ministry of Science and Technology, Baghdad, Iraq.
Research Article
Open Access Research Journal of Science and Technology, 2022, 05(02), 001–008.
Article DOI: 10.53022/oarjst.2022.5.2.0047
Publication history:
Received on 19 May 2022; revised on 20 June 2022; accepted on 22 June 2022
Abstract:
Application of organic matter (OM) has shown positive effects on growth and yield of crop grown under soil salinity stress. The present study was conducted to estimate effectiveness of OM in enhancing Biological Nitrogen Fixation (BNF) in soil and in return improving growth and yield of cowpea. Therefore, role of (OM) in alleviating impact of salinity stress on (BNF) in soils of arid region was evaluated in medium textured soils of different content of salts content. Experiment was conducted in pots under greenhouse conditions. Salinity range studied was 3.5, 8.2 and 12.4 dSm-1 in J1, J2, and J3 soil respectively. Compost as OM was added at 15, 25 and 50 g Kg-1 soil. Cowpea local variety was used as a test crop. Total nitrogen in soils without the addition of organic matter after harvesting was the least at the highest salinity level and the highest was in the soil of the least salinity level. Number of root nodules reduced by 27.0% and 49.0% when soil salinity increased to 8.2 and 12.4 dSm-1, respectively, compared to that in soil of 3.5 dSm-1. Total N in Cowpea plant linearly increase with the increase of level of (OM) addition. Rate of Increase in total N was the highest at the lowest salinity level soil and was the least at the highest salinity level soil. Weight of root nodules decreased by 45% when soil salinity increased by 42%. Addition of OM at a rate of 25 g OM Kg-1 soil to J1 soil of (3.5 dSm-1) and soil J3 of 12.4 dSm-1 weight of root nodules increased by 47.0%. and 21.7%, respectively. Dry weight of Cowpea plant grown in the three soils received different levels of OM decreased with the increase of soil salinity irrespective of level of OM addition. Addition of OM at a rate of 15, 25, and 50 g kg-1 soil of 3.5 dSm-1 seed yield increased by 65%,130%, and 136% respectively. These results had confirmed the role of OM in alleviating salinity stress on BNF process in soil.
Keywords:
Rhizobia Bacteria; Nodule; Nitrogen Percentage in Soil; Cowpea
Full text article in PDF:
Copyright information:
Copyright © 2022 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0