scholarly journals Impact of Plant Invasion and Increasing Floods on Total Soil Phosphorus and its Fractions in the Minjiang River Estuarine Wetlands, China

Wetlands ◽  
2015 ◽  
Vol 36 (1) ◽  
pp. 21-36 ◽  
Author(s):  
Wei-Qi Wang ◽  
Jordi Sardans ◽  
Cong-Sheng Zeng ◽  
Chuan Tong ◽  
Chun Wang ◽  
...  
Keyword(s):  
Plant Invasion ◽  
Soil Phosphorus ◽  
Estuarine Wetlands ◽  
Minjiang River ◽  
Total Soil ◽  
Total Soil Phosphorus ◽  
River Estuarine

Prediction of yield responses to phosphorus by established Greenleaf desmodium/grass pastures in south-east Queensland using chemical tests

1980 ◽  
Vol 20 (105) ◽  
pp. 477
Author(s):  
GE Rayment ◽  
RC Bruce ◽  
BG Cook
Keyword(s):  
Soil Phosphorus ◽  
Residual Variance ◽  
Total Soil ◽  
Plant Chemical ◽  
Diagnostic Samples ◽  
Total Soil Phosphorus ◽  
Independent Variable ◽  
Phosphorus Status ◽  
Yield Responses ◽  
Phosphorus Levels

Phosphorus topdressing experiments (rates to 60 kg P ha-1) on 18 commercial Desmodium intortum cv. Greenleaf/grass pastures were conducted over a 4-year period in south-east Queensland. The aim was to determine whether yield responses, which occurred only in the Greenleaf component at six sites, could be predicted using soil or plant chemical tests. Acid-(0.005 M H2SO4) and bicarbonate-(0.5 M NaHCO3) extractable tests of phosphorus status in 0-10 cm soil samples each explained about 60% of the variance in Greenleaf relative yields. The residual variance was not significantly reduced by the inclusion of terms for total soil nitrogen, total soil phosphorus, exchangeable calcium and pH into the independent variable. These empirical soil phosphorus tests had higher predictive value than plant tests based on phosphorus concentrations in tops and diagnostic samples of Greenleaf. With both acid- and bicarbonate-extractable phosphorus, yield responses are likely in the Greenleaf component when phosphorus levels in most soils are below 22 ppm. Above 29 ppm, no response would be expected

An attempted fractionation of the soil phosphorus

1938 ◽  
Vol 28 (2) ◽  
pp. 234-246 ◽  
Author(s):  
L. A. Dean
Keyword(s):  
Sodium Hydroxide ◽  
Organic Phosphorus ◽  
Soil Phosphorus ◽  
Inorganic Phosphorus ◽  
Soil Extracts ◽  
Soil Calcium ◽  
Soluble Phosphorus ◽  
Total Soil Phosphorus ◽  
Continued Use ◽  
Phosphatic Fertilizers

1. Extractions of soils with sodium hydroxide, followed by an acid, have been used in an attempt to fractionate the soil phosphorus.2. Colorimetric methods for the estimation of the organic and inorganic phosphorus in alkali soil extracts have been suggested.3. The amount of soil phosphorus soluble in sodium hydroxide is affected by the active soil calcium. It is suggested that sodium-saturated soils be used when studying the alkali-soluble phosphorus.4. The acid-soluble phosphorus remaining in soil after extraction with sodium hydroxide was determined. This fraction appears by analogy to be similar to the apatites.5. The largest fraction of the total soil phosphorus was not dissolved by the sodium hydroxide and acid extractions. This fraction was not increased by the long-continued use of phosphatic fertilizers at Rothamsted and Woburn.6. Relatively large amounts of organic phosphorus were found in soils and the amounts were closely related to the carbon contents.

The impact of runoff flux and reclamation on the spatiotemporal evolution of the Yellow River estuarine wetlands

2021 ◽  
Vol 212 ◽  
pp. 105804
Author(s):  
Dongxue Yu ◽  
Guangxuan Han ◽  
Xiaojie Wang ◽  
Baohua Zhang ◽  
Franziska Eller ◽  
...  
Keyword(s):  
Yellow River ◽  
The Yellow River ◽  
Spatiotemporal Evolution ◽  
Estuarine Wetlands ◽  
River Estuarine ◽  
The Impact

PHOSPHORUS FRACTIONS IN A SOIL SAMPLED AT DIFFERENT DEPTHS AND THE EFFECT OF LIME AND FERTILIZER ON OATS AND CLOVER IN A GREENHOUSE TEST

1960 ◽  
Vol 40 (1) ◽  
pp. 71-79
Author(s):  
H. A. Hamilton ◽  
J. R. Lessard
Keyword(s):  
Surface Soil ◽  
Crop Yields ◽  
Organic Phosphorus ◽  
Soil Phosphorus ◽  
Phosphate Fertilizer ◽  
Iron Phosphate ◽  
Soil Layers ◽  
Surface Samples ◽  
Different Depths ◽  
Total Soil Phosphorus

Soil samples were collected at four different depths from a virgin soil, and in a region where deep ploughing has been a common practice. Chemical analyses revealed that the sub-surface samples were more highly saturated with bases than were the surface samples. In the 0–6 inch layer the percentage contribution of calcium, aluminium and iron phosphate to total soil phosphorus was 41.1, 10.4 and 2.8 respectively; while, in the 18–24 inch layer the percentages were 88.4, 2.8 and 0.5 respectively. Organic phosphorus decreased with depth.In the greenhouse there were highly significant differences between oat yields on the various layers, the surface soil giving the highest yields. Clover crop yields tended to be better as depth of profile increased. Phosphorus increased oat yields and clover yields on all soil layers. As a result of over-liming in certain instances clover yields were depressed in the absence of applied phosphate fertilizer, whereas oat yields were unaffected.

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