Responses of total, reactive and dissolved phosphorus pools and crop yields to long-term fertilization

Maintaining an appropriate soil phosphorus level is key to ensure sustainable phosphorus management for crop production and to minimise phosphorus losses to water bodies. However, the effects of long-term fertilization on different soil phosphorus pools, crop yields and phosphorus loss risk remain unclear. This requires insights into the responses of soil phosphorus pools, crop phosphorus uptake with related crop yields and phosphorus loss to long-term phosphorus inputs. Changes in four soil phosphorus pools (PCACL2, POLSEN, POX and PTOTAL, respectively) and crop yield responses to various fertilization rates were examined in a 29-year long-term phosphorus fertilization experiment in China. Results showed that the increase in the four soil phosphorus pools was proportional to the accumulated phosphorus surplus, i.e., the input minus uptake. POLSEN and POX increased linearly with continuous phosphorus application and peaked at a phosphorus accumulation near 3200 kg P ha−1. Beyond this threshold, continuous phosphorus application caused a gradual increase in PTOTAL and a linear increase in PCACL2, which implies an increasing risk for leaching. The POX pool accounted for 87% of the accumulated phosphorus surplus until soil phosphorus saturation occurred. The crop yields of wheat and maize responded clearly to changes in PTOTAL, POX, POLSEN and PCACL2, with POX explaining most of the yield variation. Furthermore, POX was highly correlated with PCACL2, being a risk indicator for phosphorus leaching. Given that POX explains best how much of phosphorus surplus accumulates in soil, the variation in crop yield, and the risk for P leaching, it can be used as a valuable and reliable indicator to manage phosphorus sustainably.

Bibliographic Details

Main Authors:	Gu, Yu, Ros, Gerard H., Zhu, Qichao, Zheng, Dongfang, Shen, Jianbo, Cai, Zejiang, Xu, Minggang, de Vries, Wim
Format:	Article/Letter to editor biblioteca
Language:	English
Subjects:	Fertilization, Long-term experiment, Phosphorus, Phosphorus surplus, Saturation, Soil phosphorus pool,
Online Access:	https://research.wur.nl/en/publications/responses-of-total-reactive-and-dissolved-phosphorus-pools-and-cr
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