Application of nano iron and iron nitrate in wheat and pea intercropping: An approach to sustainable agriculture

Nano-fertilizers due to the small amount of used fertilizer and the accuracy of plant acquisition are considered as a strategy to reduce inputs and achieve sustainability in agriculture production. In this experiment, the effects of nano iron and iron nitrate on the growth characteristics of wheat in different wheat and chickpea intercropping systems were investigated. The experiment was performed as split-split plot in randomized complete plot design with three replications in the research field of Campus of Agriculture and Natural Resources, University of Tehran, Karaj, Iran, in 2019. The main plots included five planting patterns (wheat monoculture, pea monoculture and three intercroppings of wheat:pea with 50:50, 70:50 and 90:50 ratio), sub-plots included three fertilizer treatments (control, nano-iron and iron nitrate) and sub-sub-plots included two fertilizer concentrations (1500 and 750 mg/L). The results showed that the 50:70 intercropping and concentration of 750 nano-iron had the highest iron use efficiency of wheat and in total, the iron use efficiency of wheat in 50:70 intercropping was higher than the other planting patterns. In contrast, the highest iron use efficiency of pea was observed in 50:90 intercropping and 750 concentration of iron nitrate. In all intercropping treatments, the fertilizer use efficiency by wheat and pea in nano-iron was higher than iron-nitrate. The highest wheat biomass and grain yield was obtained in monoculture + nano-iron (16371 and 5042 kg/ha, respectively) and monoculture + iron-nitrate (16062 and 5554, respectively), and the lowest wheat biomass and grain yield was related to 90:50 intercropping and iron-nitrate, but the highest pea biomass and grain yield in most fertilizer treatments at the concentrations of 750 and 1500 mg/L was related to iron-nitrate and nano-iron, respectively. The results of this experiment showed that in most of the planting pattern treatments and in all studied traits, the concentration of 750 mg/L iron nano-fertilizer was similar or even higher than the concentration of 1500 mg/L and therefore, a lower concentration of nano-fertilizer can be used and the consumption of fertilizer can be reduced.