Effect of selenium and nano vanadium spraying and NPK fertilizer source on the qualitative traits and active substances in rice grains

Between June 15 and November 26, 2021, field research was carried out in the Al-Tali'a district (41 - Al-Hussainiya, south of Hilla city), Babylon province, Iraq. to evaluate rice plants ("Anber Cultivar 33") response to fertilization with mineral and organic NPK fertilizer and furthermore sprinkling certain active ingredients and quality requirements for rice grains (Anber 33 cultivar) with nano vanadium and nano selenium. The experiments were done using a completely randomized block design (RCBD). A straightforward one-way experiment was used to randomly assign the treatments. The experiment included the addition of mineral NPK fertilizer at two levels (0 and 300 kg ha-1) and with two levels of organic NPK-O fertilizer addition (0 and 1000 kg ha-1). While the two sprays of nano vanadium and nano selenium at a focus of (100 mg L−1) used to represent the treatments of spraying with nanomaterials brought the total number of experimental units to 16 treatments. According to the statistical analysis of Duncan's test, we may conclude that the quadruple combination of nano and ground fertilizers for two fertilizer sources (NPK+NPK-O+Nano Va+Nano Se) gave the highest percentage of nitrogen in grain, (1.440%). The same combination also achieved the highest percentage of protein in cereals, which reached (8.568%), as well as the highest content of vanadium in cereals, reaching (4.2 mg kg−1) and selenium (1.667 mg kg−1). As for the active substances, the (combined nanomaterials) treatment gave the highest percentage of hydrocarbons, which amounted to (33.8%) in the record of the (NPK-O organic fertilizer) treatment, and the highest volatile oils percentage, (35.4%). As for the unsaturated fatty acids, the treatment (NPK-O+Va+Se) gave the highest percentage of oleic acid, (61.8%), while the treatment (NPK+Va+Se) recorded the highest percentage of linoleic acid, (69.3%). While saturated fatty acids recorded the highest level in (NPK-O+Va+Se) treatments, which recorded (22.5%) of palmitic acid. As for saturated acid, the (NPK) treatment recorded the highest percentage, reaching (49.3%).