Rice straw amendment ameliorates harmful effect of salinity and increases nitrogen availability in a saline paddy soil

摘要

High concentrations of salt (NaCl) in soils reduce plant growth and have enormous influence on nitrogen dynamics in the soil solution. However, addition of rice straw is expected to mitigate the effect of salinity on nitrogen cycling, therefore positively influencing plant growth. This study describes how rice seedling emergence and early growth in a saline paddy soil can be improved by adding rice straw to the soil and incubating the soil/straw mixtures for two months. I conducted a short-term laboratory incubation and a plant growth experiment to evaluate the benefit of rice straw addition to a saline paddy soil with respect to nitrogen availability and the associated growth response of saline tolerant (BRRI Dhan47) and saline sensitive (BRRI Dhan28) rice seedlings. A naturally saline paddy soil was collected from the coastal area of Bangladesh. The soil was then incubated with rice straw (0%, 25%, 50%, 100%, and 200% of the straw yield) for two months. After that, BRRI Dhan47 and BRRI Dhan28 rice varieties were sown in these incubated soils. Rice seedlings were harvested after 14 days of sowing. My results indicated that raw rice straw addition to saline paddy soil decreased the bio-availability of salt. Furthermore, BRRI Dhan28 responded better than the BRRI Dhan47 to increased addition of rice straw to soil. Bulk soil pH declined and nitrogen availability increased with increasing rice straw in addition to saline paddy soil. This study concluded that rice straw can be a meaningful soil amendment to decrease harmful effect of salt and increase nitrogen availability in a saline paddy soil.