Options for increasing the biological cycling of phosphorus in low-input and organic agricultural systems

2009 ◽  
Vol 60 (2) ◽  
pp. 116 ◽  
Author(s):  
C. N. Guppy ◽  
M. J. McLaughlin
Keyword(s):  
Organic Matter ◽  
Enzyme Activation ◽  
Available P ◽  
Competitive Sorption ◽  
Organic P ◽  
Agricultural Systems ◽  
Ph Change ◽  
Research Issues ◽  
Low Input ◽  
P Sources

In all systems, phosphorus (P), particularly phosphate, is inexorably drawn to sorption surfaces or precipitated, and is removed from the readily plant-available P pools. Mobilising this less-available P is a significant challenge in organic and low-input agro-ecosystems where readily available P sources may not be applied regularly. Although good-quality inputs, with low C : P ratio, and rotations may be effective in managing organic P cycles in pasture and forestry systems, extensive cropping systems will remain problematic. Two conceptual models are proposed to use organic matter additions to transfer this recalcitrant P into the biocycle, one involving highly labile organic matter and the other involving less-labile organic additions. Current literature provides some evidence for the efficacy of both models, but further work is necessary to clarify which is optimal for agro-ecosystems relying on either low inputs of P or forms of P that are allowed in organic agricultural systems, such as manures or rock phosphate. The microbial biomass is integral to P biocycling in organic systems, but further work is necessary to clarify the role of fungal and bacterial decomposers in decomposition processes. Identifying P-efficient cultivars with low translocation from roots to shoots to provide an ‘organic’ P source for following crops, essentially optimal rotation sequences for mobilising P using plants, is an avenue of promising research potential. Enzyme activation of recalcitrant organic P sources is unlikely to be effective if applied to bulk soils; however, further research on enzyme activities in the rhizosphere holds promise. We strongly recommend that further research be directed toward understanding and limiting reactions of inorganic P with soil colloids and minerals, either through chemical means (pH change, competitive sorption) or introduction and manipulation of organic materials. The research issues identified above overlap considerably with conventional agricultural concerns and benefits will accrue to both conventional and organic producers where further research is promoted.

Modifying DSSAT Crop Models for Low‐Input Agricultural Systems Using a Soil Organic Matter–Residue Module from CENTURY

2002 ◽  
Vol 94 (3) ◽  
pp. 462-474 ◽  
Author(s):  
Arjan J. Gijsman ◽  
Gerrit Hoogenboom ◽  
William J. Parton ◽  
Peter C. Kerridge
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Agricultural Systems ◽  
Low Input ◽  
Crop Models

Modifying DSSAT Crop Models for Low-Input Agricultural Systems Using a Soil Organic Matter–Residue Module from CENTURY

2002 ◽  
Vol 94 (3) ◽  
pp. 462 ◽  
Author(s):  
Arjan J. Gijsman ◽  
Gerrit Hoogenboom ◽  
William J. Parton ◽  
Peter C. Kerridge
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Agricultural Systems ◽  
Low Input ◽  
Crop Models

scholarly journals Syngenetic rapid growth of ellipsoidal silica concretions with bitumen cores

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hidekazu Yoshida ◽  
Ryusei Kuma ◽  
Hitoshi Hasegawa ◽  
Nagayoshi Katsuta ◽  
Sin-iti Sirono ◽  
...  
Keyword(s):  
Organic Matter ◽  
Early Diagenesis ◽  
Ph Change ◽  
Carbon Preference Index ◽  
Diffusion Growth ◽  
Silica Precipitation ◽  
Precipitated Silica ◽  
Preference Index ◽  
Decomposition Of Organic Matter ◽  
Growth Diagram

AbstractIsolated silica concretions in calcareous sediments have unique shapes and distinct sharp boundaries and are considered to form by diagenesis of biogenic siliceous grains. However, the details and rates of syngenetic formation of these spherical concretions are still not fully clear. Here we present a model for concretion growth by diffusion, with chemical buffering involving decomposition of organic matter leading to a pH change in the pore-water and preservation of residual bitumen cores in the concretions. The model is compatible with some pervasive silica precipitation. Based on the observed elemental distributions, C, N, S, bulk carbon isotope and carbon preference index (CPI) measurements of the silica-enriched concretions, bitumen cores and surrounding calcareous rocks, the rate of diffusive concretion growth during early diagenesis is shown using a diffusion-growth diagram. This approach reveals that ellipsoidal SiO2 concretions with a diameter of a few cm formed rapidly and the precipitated silica preserved the bitumen cores. Our work provides a generalized chemical buffering model involving organic matter that can explain the rapid syngenetic growth of other types of silica accumulation in calcareous sediments.

scholarly journals Phosphorus extracted by ion exchange resins and mehlich-1 from oxisols (latosols) treated with different phosphorus rates and sources for varied soil-source contact periods

2013 ◽  
Vol 37 (3) ◽  
pp. 667-677 ◽  
Author(s):  
Irio Fernando de Freitas ◽  
Roberto Ferreira Novais ◽  
Ecila Mercês de Albuquerque Villani ◽  
Sarah Vieira Novais
Keyword(s):  
Sandy Loam ◽  
Extraction Methods ◽  
Available P ◽  
Molar Ratio ◽  
P Availability ◽  
Triple Superphosphate ◽  
Experimental Conditions ◽  
Reactive Phosphate ◽  
Exchange Resins ◽  
P Sources

Despite the large number of studies addressing the quantification of phosphorus (P) availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR) and Mixed Resin (MR), to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2) + 3] x 4 factorial design, with four replications, testing the response of three soils with different texture: a very clayey Red Latosol (LV), a sandy clay loam Red Yellow Latosol (LVA), and a sandy loam Yellow Latosol (LA), to three sources (triple superphosphate, reactive phosphate rock from Gafsa-Tunisia; and natural phosphate from Araxá-Minas Gerais) at two P rates (75 and 150 mg dm-3), plus three control treatments (each soil without P application) after four contact periods (15, 30, 60, and 120 days) of the P sources with soil. The soil acidity of LV and LVA was adjusted by raising base saturation to 60 % with the application of CaCO3 and MgCO3 at a 4:1 molar ratio (LA required no correction). These samples were maintained at field moisture capacity for 30 days. After the contact periods, the samples were collected to quantify the available P concentrations by the three extractants. In general, all three indicated that the available P-content in soils was reduced after longer contact periods with the P sources. Of the three sources, this reduction was most pronounced for triple superphosphate, intermediate for reactive phosphate, while Araxá phosphate was least sensitive to the effect of time. It was observed that AR extracted lower P levels from all three soils when the sources were phosphate rocks, while MR extracted values close to Mehlich-1 in LV (clay) and LVA (medium texture) for reactive phosphate. For Araxá phosphate, much higher P values were determined by Mehlich-1 than by the resins, because of the acidity of the extractor. For triple superphosphate, both resins extracted higher P levels than Mehlich-1, due to the consumption of this extractor, particularly when used for LV and LVA.

scholarly journals Phosphorus dynamics during early soil development in extreme environment

2021 ◽  
Author(s):  
Zuzana Frkova ◽  
Chiara Pistocchi ◽  
Yuliya Vystavna ◽  
Katerina Capkova ◽  
Jiri Dolezal ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Soil Development ◽  
Parent Material ◽  
Available P ◽  
Extreme Condition ◽  
Organic P ◽  
Soil P ◽  
Early Stages ◽  
P Pools ◽  
Microbial P

Abstract. At the early stages of pedogenesis, the dynamics of phosphorus (P) in soils are controlled by microbial communities, the physicochemical properties of the soil and the environmental conditions. While various microorganisms involved in carrying out biogeochemical processes have been identified, little is known about the actual contribution of microbial processes, such as organic P hydrolysis and microbial P turnover, to P cycling. We thus focused on processes driven by microbes and how they affect the size and cycling of organic and inorganic soil P pools along a soil chronosequence in the Chamser Kangri glacier forefield (Western Himalayas). The rapid retreat of the glacier allowed us to study the early stages of soil formation under cold arid climate. Biological P transformations were studied with the help of the isotopic composition of oxygen (O) in phosphate (δ18OP) coupled to sequential P fractionation performed on soil samples from four sites of different age spanning 0 to 100–150 years. The mineral P, i.e. 1M HCl-extractable P, represented still 95 % of the total P stock after approximately 100 years of soil development. Its isotopic composition was similar to the parent material also at the most developed site. Primary phosphate minerals, therefore, mostly composed this pool. The δ18OP of the available P and the P bound to Fe and Al oxides instead differed from that of the parent material, suggesting that these pools underwent biological turnover. The isotopic composition of O in of the available P was mostly controlled by the microbial P, suggesting fast exchanges occurred between these two pools possibly fostered by repeated freezing-thawing and drying-rewetting cycles. The release of P from organic P become increasingly important with soil age, constituting one third of the P flux to available P at the oldest site. Accordingly, the lighter isotopic composition of the P bound to Fe and Al oxides at the oldest site indicated that this pool contained phosphate released by organic P mineralization. Compared to previous studies on early pedogenesis under alpine or cold climate, our findings suggest a much slower decrease of the P-bearing primary minerals during the first 100 years of soil development under extreme condition. However, they provide evidence that, by driving short-term P dynamics, microbes play an important role in controlling the redistribution of primary P into inorganic and organic soil P pools.

P Solubility of Inorganic and Organic P Sources

2016 ◽  
pp. 127-154 ◽  
Author(s):  
Sylvia Kratz ◽  
Judith Schick ◽  
Anne Falk Øgaard
Keyword(s):  
Organic P ◽  
P Sources ◽  
Inorganic And Organic

Do methanotrophs drive phosphorus mineralization in soil ecosystem?

2020 ◽  
Author(s):  
Santosh Ranjan Mohanty ◽  
Adarsh Kumar ◽  
Rakesh Parmar ◽  
Garima Dubey ◽  
Ashok Kumar Patra ◽  
...  
Keyword(s):  
Consumption Rate ◽  
Organic P ◽  
Soil Ecosystem ◽  
Inorganic P ◽  
Sodium Phytate ◽  
Feeding Cycle ◽  
Consumption Rates ◽  
Phosphorus Mineralization ◽  
Absolute Control ◽  
P Sources

Experiments were carried out to elucidate linkage between methane consumption and mineralization of P from different phosphorous sources. The treatments were no CH4 no P amendment absolute control, with CH4 no P amendment control, with CH4 + inorganic P as Ca3(PO4)2 and with CH4 + organic P (sodium phytate). P sources were added at 25 µg P g-1 soil. Soils were incubated to undergo three repeated CH4 feeding cycle referred as feeding cycle I, feeding cycle II, and feeding cycle III. CH4 consumption rate k (µg CH4 consumed g-1 soil d-1) was 0.297 ± 0.028 in no P amendment control, 0.457±0.016 in Ca3(PO4)2, and 0.627 ± 0.013 in sodium phytate. Rate k was stimulated by 2 to 6 times over CH4 feeding cycles and followed the trend of sodium phytate > Ca3(PO4)2 > no P amendment control. CH4 consumption stimulated P solubilization from Ca3(PO4)2 by a factor of 2.86. Acid phosphatase (µg paranitrophenol released g-1 soil h-1) was higher in sodium phytate than no P amendment control. Abundance of 16S rRNA and pmoA genes increased with CH4 consumption rates. The study suggested that CH4 consumption drive mineralization of unavailable inorganic and organic P sources in the soil ecosystem.

scholarly journals Effects of air-drying and freezing on phosphorus fractions in soils with different organic matter contents

2011 ◽  
Vol 57 (No. 5) ◽  
pp. 228-234 ◽  
Author(s):  
G. Xu ◽  
J.N. Sun ◽  
R.F. Xu ◽  
Y.C. Lv ◽  
H.B. Shao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Waters ◽  
Organic Matter Content ◽  
Phosphorus Fractions ◽  
Climate Change Scenarios ◽  
P Availability ◽  
Organic P ◽  
Air Drying ◽  
Soil P ◽  
Labile P

Little is known about the effects of air-drying and freezing on the transformation of phosphorus (P) fractions in soils. It is important that the way in which soils respond to such perturbations is better understood as there are implications for both P availability and loss to surface waters from soils. In this study, the effects of air-drying and freezing were investigated using two soils, one being a forest soil (FS) high in organic matter and the other being a sterile soil (SS) low in organic matter. Soil P was fractionated using a modified Hedley fractionation method to examine the changes of phosphorus fractions induced by air-drying and freezing. Generally, there were no significant differences of total phosphorus among the three treatments (CV% &lt; 10%). Compared with field moist soils, freezing the soil evoked few changes on phosphorus fractions except that the resin-P increased in FS soil. On the contrary, air-drying significantly changed the distribution of phosphors fractions for both soils: increased the labile-P (especially resin-P) and organic-P (NaHCO<sub>3</sub>-Po, NaOH-Po and Con.HCl-Po) at the expense of NaOH-Pi and occlude-P (Dil.HCl-P and Con.HCl-Pi). Resin-P significantly increased by 31% for SS soil and by 121% for FS soil upon air-drying. The effect of air-drying seemed to be more pronounced in the FS soil with high organic matter content. These results indicated that drying seem to drive the P transformation form occlude-P to labile-P and organic-P and accelerated the weathering of stable P pool. This potentially could be significant for soil P supply to plants and P losses from soils to surface waters under changing patterns of rainfall and temperature as predicted by some climate change scenarios. &nbsp;

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