TY - JOUR
T1 - Three residual benefits of applying phosphate fertilizer
AU - Barrow, N. J.
AU - Barman, Prashanta
AU - Debnath, Abhijit
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Fertilizer P provides three benefits to subsequent crops. The first is that P not lost in produce or leachate remains in soil. However, its effectiveness usually decreases with time because the P slowly diffuses into the adsorbing particle. The second benefit stems from the resulting increased negative charge and decreased buffering capacity. We test whether this decreases the P required for a given yield. The third benefit occurs because, given enough P, the penetration reaction stops. We test whether it is then sufficient to only supply P needed by the plants. We incubated for 35 d at 60°C samples of a P-deficient soil to which we had added five levels of P. At the end of this incubation period, we measured P sorption and desorption on one set of samples of the soil. On another set, we added several different levels of P and measured plant response. On a third set, we similarly added several different levels of P but incubated soil plus the extra P for a further 3 d at 60°C before measuring plant response. Incubating the soil with P decreased the P buffering capacity and increased the effectiveness of P applications. The effects were nonlinear with greatest effect occurring at low levels of application. The incubation with P also virtually eliminated sorption-desorption hysteresis. With increasing levels of incubated P, the difference in plant response between the once-incubated and the twice-incubated treatments decreased linearly. All of the observations are consistent with slow penetration of the adsorbed P.
AB - Fertilizer P provides three benefits to subsequent crops. The first is that P not lost in produce or leachate remains in soil. However, its effectiveness usually decreases with time because the P slowly diffuses into the adsorbing particle. The second benefit stems from the resulting increased negative charge and decreased buffering capacity. We test whether this decreases the P required for a given yield. The third benefit occurs because, given enough P, the penetration reaction stops. We test whether it is then sufficient to only supply P needed by the plants. We incubated for 35 d at 60°C samples of a P-deficient soil to which we had added five levels of P. At the end of this incubation period, we measured P sorption and desorption on one set of samples of the soil. On another set, we added several different levels of P and measured plant response. On a third set, we similarly added several different levels of P but incubated soil plus the extra P for a further 3 d at 60°C before measuring plant response. Incubating the soil with P decreased the P buffering capacity and increased the effectiveness of P applications. The effects were nonlinear with greatest effect occurring at low levels of application. The incubation with P also virtually eliminated sorption-desorption hysteresis. With increasing levels of incubated P, the difference in plant response between the once-incubated and the twice-incubated treatments decreased linearly. All of the observations are consistent with slow penetration of the adsorbed P.
UR - http://www.scopus.com/inward/record.url?scp=85054790133&partnerID=8YFLogxK
U2 - 10.2136/sssaj2018.03.0115
DO - 10.2136/sssaj2018.03.0115
M3 - Article
AN - SCOPUS:85054790133
VL - 82
SP - 1168
EP - 1176
JO - Soil Science Society of America Journal
JF - Soil Science Society of America Journal
SN - 0361-5995
IS - 5
ER -