Abstract:
Chemical nitrogen (N) fertilizers are regarded as one of the environmental contaminants in
addition to the necessity for fossil sources for their production. Conversely, it is impossible to neglect
the supply of nitrogen needed as one of the essential ingredients for plant function. For organic
agriculture, it is crucial to use alternative fertilizer management to reduce the harmful impacts and
production costs of chemical fertilizers. In a one-year pot experiment, nitrate (NO−
3
) leaching and
nitrogen efficiency of wheat were examined in relation to biochar (B) mixed with urea (U), legume
residues (L), and azocompost (A), which represent chemical, green, and biological sources of Nfertilizers, respectively. Control (no biochar, no fertilizer), U (46 kg ha−1
), A (5 t ha−1
), L (5 t ha−1
),
B (10 t ha−1
), UB, AB, and LB were the experimental treatments. Grain yield of wheat was enhanced
by 337% and 312% with UB and UL, respectively. The LB produced the highest grain N yield, with a
rise of 8.8 times over the control. L had the highest N-use efficiency, with an increase of 149% over
the control. The highest N-harvest index and N-recovery efficiency were obtained by using LB, with
values of 91 and 70 %, respectively. Nitrate leaching occurred in the following order: U > Control ≥ A
≥ L > UB > AB ≥ LB > B. Nitrogen is retained for the plant in the extensive specific surface of biochar
when N-fertilizers are used in conjunction with them. This not only improves N-efficiency but also
minimizes nitrogen loss through leaching. Additionally, the soil can benefit from the addition of
leguminous organic fertilizer in a similar way as to urea fertilizer in terms of increasing wheat grain
yield, particularly when combined with biochar.
