Biological and nano fertilizers are alternative and supplements to chemical fertilizers security for the sustainability of agricultural production. The objective of this study was to investigate the effect of biological and nano fertilizers on the quantitative and qualitative yield of cow pea during two crop years (2018-2019 and 2019-2020) in the research farm of the South Agricultural Research and Education Center of Kerman province, Iran. This experiment was carried out factorial in designs of randomized complete blocks with 16 treatments and 3 replications, the studied factors include four levels of biological fertilizers (control, zinc amino chelate, aminoalexin, and bio20) and four levels of nano chelates (control, boron nano chelate, potassium nano chelate and iron nano chelate). The results of the experiment showed that there was no significant difference between the two years of the experiment in terms of all quantitative and qualitative traits. Although the effect of the year on the traits was not significant, the application of biological fertilizers and nano chelate had a significant effect on the quantitative and qualitative traits of cowpea. In other words, the lowest amount of quantitative and qualitative traits related to cowpea was in the absence of biological fertilizers and nano chelate. Based on the obtained results, the application of bio20 biological fertilizer along with iron nano chelate or potassium nano chelate caused a significant increase in quantitative and qualitative traits. In general, and according to the results of the experiment, it was found that the use of biological fertilizers, especially bio20 and aminoalexin, caused a significant improvement in the quality characteristics. The positive effect of bio20 and aminoalexin in improving quality characteristics was significantly higher when used together with nano chelates, especially nano chelates of iron and potassium which is likely due to the positive effect of potassium and iron in various plant metabolic processes. It includes osmotic regulation, increasing chlorophyll, and photosynthesis. Therefore, the interaction of bio fertilizers (Bio20) with nano chelate (iron and potassium) increased seed yield by 50% compared to the control (no fertilizer use).