In Fig. 2a, the amount of fertilizer applied to plants is usually large; in Fig. 2b, the part of the applied fertilizer taken up by plants is usually small, ranging between 10% to 40% depending on soil type, fertilizer type, and plant; and in Fig. 2c, the part of the applied fertilizer that is lost could be in the range of 60% to 90% of the original amount of fertilizer or manure applied (Hardy and Eaglesham 1995; Rowarth 1997; Hood et al. 1999; Gyneshwar et al. 2002; Barlog and Grzebisz 2004; Kleinman et al. 2005).