Effect of cyanobacterial inoculation and fertilizers on rice seedlings andpostharvest soil structure

The effect of soil inoculation with urea, Nostoc muscorum, and Tolypothrix tenuis on rice seedlings, nutrient contents, and structure of postharvest s oil was studied. Tolypothrix tenuis and T. tenuis + urea produced the highe st increase in oxidizable C (54.60% both) which resulted 7.63% higher than urea. Tolypothrix tenuis also produced the highest increase in soluble C (2 41.14%). Regarding nitrogen (N) soil content all treatments produced a posi tive difference. No treatment exerted any effect on soil available phosphor us (P). The percentage of aggregates >50 (m increased with all treatments f rom 6 to 12%, except N. muscorum. Tolypothrix tenuis produce the highest ef fect, with 50% more of these aggregates than urea. Seedling dry weight and shoot length were higher than control for all treatments. Shoots were longe st with N. muscorum + urea being this treatment more effective than each Cy anobacteria alone. There was no effect on the number of leaves. Except for N. muscorum, all treatments increased the seedling N content. Postharvest s oil showed a better quality when inoculated with T. tenuis or T. tenuis + u rea compared to urea. Cyanobacterial fertilizers are a promising alternativ e to avoid soil pollution caused by agrochemicals and recover the nutrient content and structure lost after harvest as they bring to soil combined N ( some of them are N fixers), exopolysaccharide that improve soil structure a nd bioactive substances that enhance seedlings growth.