Phosphorus cycling in wheat pasture rotations .II. The role of the microbial biomass in phosphorus cycling

Soil Research ◽  
1988 ◽  
Vol 26 (2) ◽  
pp. 333 ◽  
Author(s):  
MJ Mclaughlin ◽  
AM Alston ◽  
JK Martin
Keyword(s):  
Microbial Biomass ◽  
Phosphorus Cycling ◽  
Wheat Crop ◽  
Plant Residues ◽  
Double Labelling ◽  
Soil P ◽  
Soil Microbial ◽  
Native Soil ◽  
Wheat Pasture

The incorporation of phosphorus derived from fertilizer and plant residues into the soil microbial biomass was studied under field conditions by using isotopic double labelling. The 33P-labelled medic residues (Medicago truncatula cv. Paraggio) and 32P-labelled fertilizer were added to a solonized brown soil (Calcixerollic xerochrept) before sowing of a wheat crop ( Triticum aestivum cv. Warigal). Amounts of 31P, 32P and 33P in the microbial biomass were determined at 0, 7, 18, 32, 46, 61, 81 and 95 days after sowing of the wheat. Throughout the experiment, amounts of 31P in the microbial biomass were closely related to gravimetric soil water content, with a large and rapid increase in the amount of 3 1 ~ in the microbial biomass being observed in the first 7 days after wetting of the (initially) dry soil. Due to banding of the fertilizer at sowing, little (<5%) of the 32P was recovered in the microbial biomass throughout the experiment. Of the 33P applied in the medic residues, 22-28% was recovered in the microbial biomass. Most of the P taken up by the microbial biomass was derived from native soil P (i.e. not added that season).

Phosphorus cycling in wheat-pasture rotations. III. Organic phosphorus turnover and phosphorus cycling

Soil Research ◽  
1988 ◽  
Vol 26 (2) ◽  
pp. 343 ◽  
Author(s):  
MJ Mclaughlin ◽  
AM Alston ◽  
JK Martin
Keyword(s):  
Organic Phosphorus ◽  
Soil Surface ◽  
P Uptake ◽  
Phosphorus Cycling ◽  
Plant Residue ◽  
Organic P ◽  
Inorganic P ◽  
Soil P ◽  
Wheat Pasture ◽  
P Cycle

The incorporation of 32P and 33P from 33P-labelled fertilizer and 33P-labelled pasture residues into organic and inorganic fractions of soil P was studied in a solonized brown soil (Calcixerollic xerochrept) cropped to wheat (Triticum aestivum). Most of the plant residue 33P was present as inorganic P at the time it was added to the soil, but only 7 days later almost 40% had been incorporated into organic P fractions of the soil. As the fertilizer was banded near the soil surface at sowing, little of the 32P from the 32P-labelled fertilizer was incorporated into organic forms, even after 95 days. From a knowledge of the P uptake by the plants and microorganisms, an integrated P cycle for this soil under wheat-pasture rotations was developed. We propose that fertilization of the pasture phase of the rotation stimulates the build-up of residual inorganic and organic P, while fertilization of the wheat phase predominantly stimulates the accumulation of inorganic forms of P in the soil.

scholarly journals Intracellular Storage Reduces Stoichiometric Imbalances in Soil Microbial Biomass – A Theoretical Exploration

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefano Manzoni ◽  
Yang Ding ◽  
Charles Warren ◽  
Callum C. Banfield ◽  
Michaela A. Dippold ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Nutrient Cycling ◽  
Theoretical Perspective ◽  
Nutrient Retention ◽  
Model Parameters ◽  
Soil C ◽  
Soil Microbial ◽  
Pulse Experiment ◽  
Intracellular Storage

Microbial intracellular storage is key to defining microbial resource use strategies and could contribute to carbon (C) and nutrient cycling. However, little attention has been devoted to the role of intracellular storage in soil processes, in particular from a theoretical perspective. Here we fill this gap by integrating intracellular storage dynamics into a microbially explicit soil C and nutrient cycling model. Two ecologically relevant modes of storage are considered: reserve storage, in which elements are routed to a storage compartment in proportion to their uptake rate, and surplus storage, in which elements in excess of microbial stoichiometric requirements are stored and limiting elements are remobilized from storage to fuel growth and microbial maintenance. Our aim is to explore with this model how these different storage modes affect the retention of C and nutrients in active microbial biomass under idealized conditions mimicking a substrate pulse experiment. As a case study, we describe C and phosphorus (P) dynamics using literature data to estimate model parameters. Both storage modes enhance the retention of elements in microbial biomass, but the surplus storage mode is more effective to selectively store or remobilize C and nutrients according to microbial needs. Enhancement of microbial growth by both storage modes is largest when the substrate C:nutrient ratio is high (causing nutrient limitation after substrate addition) and the amount of added substrate is large. Moreover, storage increases biomass nutrient retention and growth more effectively when resources are supplied in a few large pulses compared to several smaller pulses (mimicking a nearly constant supply), which suggests storage to be particularly relevant in highly dynamic soil microhabitats. Overall, our results indicate that storage dynamics are most important under conditions of strong stoichiometric imbalance and may be of high ecological relevance in soil environments experiencing large variations in C and nutrient supply.

Investigating nutrient controls over microbial activity in tropical soils

2021 ◽  
Author(s):  
Lucia Fuchslueger
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Microbial Communities ◽  
Microbial Activity ◽  
Microbial Growth ◽  
Tropical Soils ◽  
Phosphorus Availability ◽  
Soil P ◽  
Soil Microbial ◽  
Low Phosphorus

&lt;p&gt;The Amazon rainforest is an important sink for atmospheric CO&lt;sub&gt;2&lt;/sub&gt; counteracting increased emissions from anthropogenic fossil fuel combustion and land use change storing large amounts of carbon in plant biomass and soils. However, large parts of the Amazon Basin are characterized by highly weathered soils (ultisols and oxisols) with low availability of rock-derived phosphorus (and cations), which are mostly occluded in soil or bound in organic matter. Such low phosphorus availability is thought to be (co-)limiting plant productivity. However, much less is known whether low phosphorus availability influences the activity of heterotrophic microbial communities controlling litter and soil organic matter decomposition and thereby long-term carbon sequestration in tropical soils.&lt;/p&gt;&lt;p&gt;In tropical soils high temperature and humid conditions allow overall high microbial activity. Over a larger soil phosphorus fertility gradient across several Amazonian rainforest sites, at low P sites almost 40 % of total P was stored in microbial biomass, highlighting the competitive strength of microorganisms and their importance as P reservoir. Across all sites soil microbial biomass was a significant predictor for soil microbial respiration, but mass-specific respiration rates (normalized by microbial biomass C) rather decreased at higher soil P. Using the incorporation of &lt;sup&gt;18&lt;/sup&gt;O from labelled water into DNA (i.e., a substrate-independent method) to determine microbial growth, we found significantly lower microbial growth rates per unit of microbial biomass at higher soil P. This resulted in a lower microbial carbon use efficiency, at a narrower C:P stoichiometry in soils with higher P levels, and pointed towards a microbial co-limitation of phosphorus and carbon at low soil P levels. Furthermore, data from a multi-year nutrient manipulation experiment in French Guiana and from short-term lab incubations suggest that microbial communities thriving at low P levels are highly efficient in taking up and storing added P, but do not necessarily respond with increased growth.&lt;/p&gt;&lt;p&gt;Soil microbial communities play a crucial role in soil carbon and phosphorus cycling in tropical soils as potent competitors for available P. They also play an important role in storing and buffering P losses from highly weathered tropical soils. The potential non-homoeostatic stoichiometric behavior of microbial communities in P cycling is important to consider in soil and ecosystem models based on stoichiometric relationships.&lt;/p&gt;

The relative contribution of plant residues and fertilizer to the phosphorus nutrition of wheat in a pasture cereal system

Soil Research ◽  
1986 ◽  
Vol 24 (4) ◽  
pp. 517 ◽  
Author(s):  
MJ Mclaughlin ◽  
AM Alston
Keyword(s):  
Microbial Biomass ◽  
Wheat Plant ◽  
Dry Weight ◽  
Plant Residues ◽  
Soil Microbial ◽  
Relative Contribution ◽  
Medicago Trunculata ◽  
Microbial P ◽  
32P Uptake ◽  
Total P

Wheat plants (Triticum aestivum cv. Warigal) here grown in a solonised brown soil (Calcixerollic xerochrept) which had been previously cropped to medic (Medicago trunculata cv. Paraggio). The 33P-labelled medic residues and 32P-labelled monocalcium phosphate were added to the soil in factorial combination. Amounts of 31P, 32P and 33P in the wheat plants and in the soil microbial biomass were determined. Addition of residues depressed wheat dry weight, 31P and 32P uptake, while simultaneously increasing amounts of 31P and 32P incorporated into the microbial biomass. Addition of fertiliser had no effect on the proportion of plant P taken up from the residues, but significantly increased the proportion of microbial P derived from this source. The 31P held in the microbial biomass was significantly increased by both residue and fertiliser P addition, with the former having the larger effect. Of the total P applied to the soil, medic residues contributed approximately one-quarter of that supplied by the fertiliser. Of the total P in the wheat plant, medic residues supplied approximately one-fifth of that supplied by the fertiliser.

scholarly journals Integration of biochar and chemical fertilizer to enhance quality of soil and wheat crop (Triticum aestivum L.)

2016 ◽  
Author(s):  
Usman Khalid Chaudhry ◽  
Salman Shahzad ◽  
Muhammad Nadir Naqqash ◽  
Abdul Saboor ◽  
Sana Yaqoob ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Microbial Biomass ◽  
Soil Amendments ◽  
Block Design ◽  
Combined Treatment ◽  
Wheat Crop ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial

A wide variety of soil amendments like manures, compost, humic acid and bio-sorbents have been used to make nutrients available to crops as well as to protect them from toxic elements. Among soil amendments, biochar has been known to improve soil crumping, soil nutrients’ availability to plants and ultimately the yield of crops. A field experiment was conducted by using biochar prepared from Dalbergia sissoo Roxb. wood by brick batch process. Two doses of biochar were applied to soil 0 and 12 t ha-1. Fertilizer rates used in the experiments were 25% recommended doses of fertilizers (RDF), 50% RDF, 75% RDF and 100% RDF alone & with biochar applied under two factorial randomized complete block design in natural field conditions (RDF of NPK fertilizer is 120-60-60 kg ha-1) . Soil physico-chemical properties viz., bulk density, particle density, porosity, pH, electrical conductivity, organic matter, soil organic carbon, total nitrogen, available phosphorus, available potassium, soil organic carbon, soil microbial biomass carbon and soil microbial biomass nitrogen were measured from the soil samples collected from 0-30 cm depth. All these parameters varied significantly among the treatments. A combined treatment of biochar and 50% of the recommended dose of NPK was most effective for soil conditioning. Agronomic parameters were also measured by standard methods. Due to chelation of heavy metal ions and availability of nutrients to the soil, yield of the crop may significantly increase due to cumulative treatment of fertilizer and biochar but upto a certain limit.

scholarly journals Integration of biochar and chemical fertilizer to enhance quality of soil and wheat crop (Triticum aestivum L.)

2016 ◽  
Author(s):  
Usman Khalid Chaudhry ◽  
Salman Shahzad ◽  
Muhammad Nadir Naqqash ◽  
Abdul Saboor ◽  
Sana Yaqoob ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Microbial Biomass ◽  
Soil Amendments ◽  
Block Design ◽  
Combined Treatment ◽  
Wheat Crop ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial

A wide variety of soil amendments like manures, compost, humic acid and bio-sorbents have been used to make nutrients available to crops as well as to protect them from toxic elements. Among soil amendments, biochar has been known to improve soil crumping, soil nutrients’ availability to plants and ultimately the yield of crops. A field experiment was conducted by using biochar prepared from Dalbergia sissoo Roxb. wood by brick batch process. Two doses of biochar were applied to soil 0 and 12 t ha-1. Fertilizer rates used in the experiments were 25% recommended doses of fertilizers (RDF), 50% RDF, 75% RDF and 100% RDF alone & with biochar applied under two factorial randomized complete block design in natural field conditions (RDF of NPK fertilizer is 120-60-60 kg ha-1) . Soil physico-chemical properties viz., bulk density, particle density, porosity, pH, electrical conductivity, organic matter, soil organic carbon, total nitrogen, available phosphorus, available potassium, soil organic carbon, soil microbial biomass carbon and soil microbial biomass nitrogen were measured from the soil samples collected from 0-30 cm depth. All these parameters varied significantly among the treatments. A combined treatment of biochar and 50% of the recommended dose of NPK was most effective for soil conditioning. Agronomic parameters were also measured by standard methods. Due to chelation of heavy metal ions and availability of nutrients to the soil, yield of the crop may significantly increase due to cumulative treatment of fertilizer and biochar but upto a certain limit.

Response of soil microbial biomass to 1,2-dichlorobenzene addition in the presence of plant residues

1998 ◽  
Vol 17 (8) ◽  
pp. 1462-1468 ◽  
Author(s):  
Andrew A. Meharg ◽  
Clare L. Wyatt ◽  
Ian P. Thompson ◽  
Mark J. Bailey ◽  
Richard J. Ellis ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Plant Residues ◽  
Soil Microbial
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