Background: Different methods of fertilization including chemical (chemical fertilizer
such as urea), biological (microbial inoculums) and nano (nutritional elements at the nano level)
fertilization are used for providing plants with their essential nutrients under different conditions
including stress. With respect to the properties of nutrients at the nano level, the method of nano
fertilization, which is a new era in the research, can be used as an efficient method of fertilization for
plant growth and yield production.
Methods: Accordingly, we have suggested a new type of fertilization in this research work by using
a mixture of useful soil microbes with nano nutrients, namely nano biologic. The use of biological
and chemical nano fertilization on the yield of pinto bean (Phaseolus vulgaris L.) was investigated
under drought stress (water deficit) conditions. The experiment was a split plot in which the drought
treatments (different levels of irrigation, according to the water loss from the evaporation pan, class
A), at control (60 mm), medium (90 mm) and high (120 mm) level of stress were used as the main
plots and fertilization treatments including: 1) control (0), 2) Nano Biologic, 3) Nano Biologic with
75 kg pure N (urea, surface braodcast), 4) 150 kg pure N (urea), 5) 75 kg pure N with nano ZnFeMn
(foliarly applied), and 6) 75 kg pure N with ZnFeMn (foliarly applied) were used as the subplots.
Yield and yield components of pinto beans were determined.
Results: The results indicated that although drought adversely affected bean growth and yield production,
nano fertilization types including 3 and 5 resulted in the highest rate of yield and yield components
under water sufficient and deficient conditions.
Conclusion: Accordingly, the importance of this research work is by introducing and selecting the
most appropriate type of fertilization (Nano Biologic and nano ZnFeMn) for bean growth and yield
production under drought stress. Such type of fertilizations can gradually provide the plant with its
essential nutrients and can be of environmental and economical significance compared with the
chemical type of fertilization.