C:N:P stoichiometry and nutrient limitation of the soil microbial biomass in a grazed grassland site under experimental P limitation or excess
TLDR
In this article, the availability of essential nutrients, such as nitrogen (N) and phosphorus (P), can feedback on soil carbon (C) and the soil microbial biomass, and the results confirm that C:N:P ratios within the microbial biomass were constrained (i.e. homeostatic) under near optimum soil conditions.Abstract:
The availability of essential nutrients, such as nitrogen (N) and phosphorus (P), can feedback on soil carbon (C) and the soil microbial biomass. Natural cycles can be supplemented by agricultural fertiliser addition, and we determined whether the stoichiometry and nutrient limitation of the microbial biomass could be affected by an unbalanced nutrient supply. Samples were taken from a long-term trial (in effect since 1968) with annual applications of 0, 15 and 30 kg P ha−1 with constant N and potassium. Soil and microbial biomass CNP contents were measured and nutrient limitation assessed by substrate-induced respiration. Linear regression and discriminant analyses were used to identify the variables explaining nutrient limitation. Soil and biomass CNP increased with increasing P fertiliser, and there was a significant, positive, correlation between microbial biomass P and biomass C, apart from at the highest level of P fertilisation when the microbial biomass was over-saturated with P. The molar ratios of C:N:P in the microbial biomass remained constant (homeostatic) despite large changes in the soil nutrient ratios. Microbial growth was generally limited by C and N, except in soil with no added P when C and P were the main limiting nutrients. C, N and P, however, did not explain all the growth limitation on the soils with no added P. Increased soil C and N were probably due to increased net primary production. Our results confirm that C:N:P ratios within the microbial biomass were constrained (i.e. homeostatic) under near optimum soil conditions. Soils with no added P were characterised by strong microbial P limitation and soils under high P by over-saturation of microorganisms with P. Relative changes in biomass C:P can be indicative of nutrient limitation within a site.read more
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Long-term phosphorus fertilisation increased the diversity of the total bacterial community and the phoD phosphorus mineraliser group in pasture soils
Hao Tan,Matthieu Barret,Marlies J. Mooij,Olivia Rice,John P. Morrissey,Alan D. W. Dobson,Bryan S. Griffiths,Fergal O'Gara +7 more
TL;DR: It is shown that P fertilisation affects the microbial diversity of soil ecosystems, which might potentially modulate the soil biogeochemical cycle.
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Ecological importance of soil bacterivores for ecosystem functions
TL;DR: A new theoretical framework based on ecological stoichiometry stressing the role of C:N:P ratios in soil, microbial and plant biomass as important parameters driving bacterivore-effects on soil N and P availability for plants, immobilization of N andP in the bacterial biomass, and plant responses in nutrition and growth is proposed.
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Linkages of C:N:P stoichiometry and bacterial community in soil following afforestation of former farmland
Chengjie Ren,Fazhu Zhao,Di Kang,Gaihe Yang,Xinhui Han,Xiaogang Tong,Yongzhong Feng,Guangxin Ren +7 more
TL;DR: C, N, and P levels in soil and microbial biomass increased following afforestation, with a significant correlation observed, especially for the N:P ratio, and a rise in 〈alpha〉- and 〉beta-diversity of soil bacteria was observed in response to afforstation, and was linked to soil C:P andN:P ratios.
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Effects of nitrogen and phosphorus addition on soil microbial community in a secondary tropical forest of China
Jian Li,Zhian Li,Faming Wang,Bi Zou,Yao Chen,Jie Zhao,Qifeng Mo,Yingwen Li,Xiaobo Li,Hanping Xia +9 more
TL;DR: In this article, the impacts of nitrogen (N) addition, phosphorus (P) addition and N×P interaction on soil microbial biomass and microbial community composition in tropical forests were explored, and it was shown that N addition usually did not affect microbial biomass, which was increased by P addition over 3 years of fertilization.
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Differential responses of soil bacterial communities to long-term N and P inputs in a semi-arid steppe
TL;DR: The results suggest that the below-ground bacterial communities are more sensitive to N inputs, but P inputs can also play an important role in bacterial niche differentiation in pots with higher N or P input.
References
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Standard Methods for the Examination of Water and Wastewater seventh edition
TL;DR: Standard Methods for the Examination of Water and Wastewater seventh edition, Standard methods for the examination of water and wastewater seventh edition , کتابخانه دیجیتال جندی اهواز.
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An extraction method for measuring soil microbial biomass c
TL;DR: In this paper, the effects of fumigation on organic C extractable by 0.5 m K2SO4 were examined in a contrasting range of soils and it was shown that both ATP and organic C rendered decomposable by CHCl3 came from the soil microbial biomass.
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Chloroform fumigation and the release of soil nitrogen: A rapid direct extraction method to measure microbial biomass nitrogen in soil
TL;DR: In this paper, a direct extraction method for measuring soil microbial biomass nitrogen (biomass N) is described, which is based on CHC13 fumigation, followed by immediate extraction with 0.5 M K2SO4 and measurement of total N released by CHC 13 in the soil extracts.
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A physiological method for the quantitative measurement of microbial biomass in soils
TL;DR: The respiratory method provides reproducible estimates of biomass size within 1–3 h after soil amendment, and can be combined without difficulty with a selective inhibition method for determination of bacterial and fungal contributions to soil metabolism.