Reducing grey water footprint input and Blue - Green water footprint output of silage maize in biochar applications under irrigation with different water sources

The intensive water consumption in the agricultural sector has aimed to ensure water management by using various water management models. Among these, water footprint (WF) has gained more acceptance as it provides better management with superior-various aspects. However, WF calculations are usually carried out using estimated-data and generally only considering blue and green water consumption. However, no field-study has been found in the literature showing the contribution of grey WF as an input to the reduction of blue and green WF outputs by the use of treated waste water (TWW) in irrigation with biochar application (B). Thus, this fieldstudy investigated the effect of B in irrigating silage maize with different water sources on WF values per unit fresh-dry biomass yields of silage maize by considering real-data instead. It was determined that the blue, green, grey, and total WF values per unit fresh-dry biomass yield decreased with B, and similarly decreased with TWW compared to fresh water (FW) as the grey WF values per unit fresh-dry biomass yield increased. In B and TWW, total WF values per unit fresh-dry biomass yields decreased by 10-12 % and 12-14 % compared to No-B and FW. It has been determined that B and TWW can be recommended considering the WF reduction effect per unit freshdry biomass yield and that the effect of irrigation with TWW in reducing blue, green, and total WF with less grey WF output per unit fresh-dry biomass yield is remarkable and also that field-studies should be carried out with real-data instead of estimated-data for clearer and more accurate results in WF calculations.