Impacts of cyanobacteria and Bradyrhizobium inoculation on lupine plants under different nitrogen rates in sandy soil

Abstract EN

A field experiment was conducted in sandy soil at Ismailia Agricultural Research Station, (Ismailia Governorate, Egypt, in two successive winter sea-sons of 2015/2016 and 2016/2017.

The experi-ment aimed to study the response of lupine plants (Lupinus albus L.) variety Giza 2 to cyanobacteria applied with different methods under different ni-trogen fertilizer rates and inoculated with rhizobia.

Results revealed that application of cyanobacteria generally increased the mean values of nodules number, dry weight of nodules and shoot dry weight of lupine plants, nitrogen uptake, biological activity of the soil rhizosphere lupine plants, yield, yield components and seed protein content as compared to those recorded by the control treat-ment without cyanobacteria.

Increasing nitrogen rates decreased the mean values of both nodules number and dry weight of nodules.

On the contra-ry, increasing nitrogen rate up to 100% of the rec-ommended one increased all the other tested pa-rameters.

The highest values of these parameters were recorded when cyanobacteria were applied as dry + soaking combined with 75 % N rate ex-pect for those of number and nodules the dry weight of nodules that gave their highest values when the lupine plants received the treatment of dry + soaking combined with 50 % N rate.

In con-clusion, the use of cyanobacteria along with rhizo-bia as renewable nitrogen source for lupine pro-duction can save 25% N from that required for lu-pine.