Differentiated response of plant and microbial C: N: P stoichiometries to phosphorus application in phosphorus-limited paddy soil
2019
Yuan, Hongzhao | Liu, Shoulong | Razavi, Bahar S. | Zhran, Mostafa | Wang, Jiurong | Zhu, Zhenke | Wu, Jinshui | Ge, Tida
Phosphorus (P) application is an indispensable practice in agricultural crop production. However, the effect of P on crop and microbial biomass stoichiometries as well as its role in soil nutrient dynamics, remain poorly understood, thereby limiting our ability to predict the ecological consequences of agricultural practices. Herein, we conducted a P application experiment in a subtropical P-limited paddy soil to examine the effect of P addition on soil nutrient availability as well as on rice and the microbial C:N:P stoichiometries. The results showed that soil dissolved organic carbon (DOC) and available P content were simultaneously affected by P application and rice growth stage. Further, addition of P served to increase rice C and N content while decreasing the C: P and N: P stoichiometric ratios, indicating that P input contributed to rice growth and N absorption. Marked increases in soil microbial biomass carbon (MBC) and phosphorus (MBP) were also observed in soil treated with P. Moreover, the microbial C:N:P stoichiometry increased with rice growth stage, suggesting that changes in microbial and plant nutrient demand throughout the rice plant growth cycle causes competition between microorganisms and plants for N and P. Pearson's correlation and redundancy analyses revealed that available nutrients of soil were intercorrelated and regulated the patterns of rice and microbial C:N:P stoichiometries. In conclusions, P enrichment altered soil nutrient composition, microbial nutrient mining strategies, and rice C:N:P stoichiometry, thereby contributing to rice growth and improving crop yield.
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