Long-term trends of chemical fertilizer consumption and productivity in cultivating five major crops in Iran

Material indicators are important in sustainable production to decrease resource use and environmental impacts and increase economic productivity. The present research aims to calculate material indicators of chemical fertilizers in crop production systems in Iran. Material intensity and productivity for nitrogen, phosphor, and potassium were calculated from 1980 to 2016. Cereal, pulse, oilseed, tuber, and fiber were the studied crops. The mean production value in all systems was 4.40 ton.ha⁻¹, which had an increasing trend from 1980 to 2016. The mean of material intensity for the fertilizers in all production systems were 2.19, 1.04, and 0.16 kg.ton⁻¹, respectively while the mean values of the material productivity were 0.52, 1.16, 13.39 ton.kg⁻¹, respectively. The productivity of all studied fertilizers had an increasing trend while it had a decreasing trend for phosphor and potassium in recent years. The results of the present research can be used to optimize fertilizer consumption and consequently decrease production costs and environmental impacts.