LAUSR

Overuse of nitrogen (N) fertilizer, a crucial productivity factor in world cropping systems, is detrimental to the sustainability of crop production from an economic and environmental perspective. Mean yield, N fertilizer use, partial factor productivity (PFP) of N, N use efficiency (NUE) and N surplus in wheat, cotton and rice production in Pakistan, which account for 75% of total national fertilizer N use, were compared with those for the top producer countries for 2014. Pakistan was among the top four in terms of N use but had low mean yields, with the lowest PFP and NUE and highest N surplus. During 1961–2014 in Pakistan, N fertilizer use and N surplus grew at a much faster pace than mean yields; however, PFP and NUE continued to decline to much lower levels. The great potential for Pakistan to increase NUE lies in agronomic practices other than increasing N fertilization, such as balanced crop nutrition, irrigation management, inclusion of legumes in crop rotations, precision in-season N management and the use of enhanced efficiency fertilizers, as is the case for many other parts of the world. Nitrogen is critical to crop production but its overuse challenges sustainability. This study finds that, despite intense and growing nitrogenous fertilizer use, Pakistan’s crop yields have risen much more slowly than expected.