PHOSPHORUS AND POTASSIUM SUPPLY FOR ALFALFA IN SOILS SAMPLED AT DIFFERENT DEPTHS

1957 ◽  
Vol 37 (1) ◽  
pp. 63-72 ◽  
Author(s):  
R. L. Halstead ◽  
K. F. Nielsen ◽  
A. J. MacLean

Results of a greenhouse experiment, comprising soil samples taken at three depths from each of six locations in eastern Ontario, indicated that the phosphorus-supplying power of the surface was considerably greater than that of the corresponding subsurface samples of four of the soils. The relative amounts of total phosphorus in surface and subsurface samples varied with the soils, the most pronounced variation being an increase in a sandy soil with depth. The proportion of the total phosphorus found in organic form varied from 18 to 56 per cent in the surface and from 5 to 33 per cent in the subsurface samples. The amounts of acid-soluble phosphorus extracted from five of the soils increased with depth. The amounts of NaHCO3-soluble phosphorus were higher in the surface than in the subsurface samples of five of the soils. The values for acid-soluble phosphorus in five of the soils and for NaHC03-soluble phosphorus in three of the soils were not in agreement with greenhouse results.The data from the greenhouse experiment did not indicate a pronounced difference between the potassium-supplying powers of corresponding surface and subsurface samples. Exchangeable potassium did not vary appreciably between surface and subsurface samples of four of the soils but decreased in two of the soils with depth. Water-soluble potassium decreased with depth in most instances.

2013 ◽  
Vol 726-731 ◽  
pp. 3799-3802
Author(s):  
Bin Wu ◽  
Zhen Yao Xia ◽  
Lin Lin Zhang ◽  
Shi Feng Guan ◽  
Ming Yi Li ◽  
...  

This paper selected various types of slope soil under different restoration modes of Xiangjiaba hydropower construction to study the fractionation of inorganic phosphorus. The results showed that the content of inorganic phosphorus was lower.In seven different types of slop soil,the content of total inorganic phosphorus was between 254.43 mg·kg-1 and 992.98 mg·kg-1,and accounted for between 22.60% and 47.12%.The content of soil total inorganic phosphorus and the raito of Water-soluble phosphorus,Al-P to total phosphorus increased as the content of soil total P increase,but the ratio of soil O-P,Ca-P to total phosphorus decreased.The Water-soluble phosphorus and Al-P in Vegetation-growing concrete gunning were the highest,the O-P in Natural secondary forests were the highest and Ca-P in External-soil spray seeding were the highest among all the types of slope soil.


1964 ◽  
Vol 44 (1) ◽  
pp. 66-75 ◽  
Author(s):  
A. J. MacLean ◽  
R. L. Halstead ◽  
A. R. Mack ◽  
J. J. Jasmin

Determination of the cation-exchange capacity of 17 organic soils by the ammonium acetate method or by measurement of H replaced from HCl-treated samples by neutral 1 N NH4OAc, 1 N and 0.5 N Ba(OAc)2, and 0.5 N KOAc gave results which were closely related. The magnitude of the values varied with procedure, however, and 1 N Ba(OAc)2 gave the highest results.In a greenhouse experiment, the average uptake of potassium and of phosphorus by plants was higher at a soil temperature of 75° F than at 57° F. Percentage uptake of potassium by the plants was significantly correlated with the following criteria of potassium supply in the soils: exchangeable K, water-soluble K, [Formula: see text] and per cent K saturation. The corresponding percentage uptake of phosphorus was significantly correlated with the amounts of phosphorus extracted from the soils with 0.03 N NH4F + 0.1 N HCl, 0.5 N HOAc, water, and 0.5 M NaHCO3. The results indicated that water might serve as a suitable extractant of both potassium and phosphorus.


2021 ◽  
Author(s):  
Gerhard Soja ◽  
Dominik Tauber ◽  
Jan Höllrigl ◽  
Andrea Mayer ◽  
Christoph Pfeifer

<p>Food processing creates many by-products, and not all of them are used efficiently. Especially animal-based side products are frequently considered as waste with costly disposal requirements. For recycling of the nutrients contained in these residues, also under consideration of the hygienic specifications, pyrolysis can be used to create animal bone-based biochars. A lab-scale pyrolysis reactor (Pyreka 3.0) was used to produce biochars from different bone fractions of cattle and pigs after these bones had originated as waste from abbatoir operations. This study had the objective to investigate the potential of the bone chars to serve as a phosphorus (P) supply for agricultural purposes and to study the ammonium sorption potential of these chars.</p><p>The total phosphorus content of bones reached up to 140 mg/g. The water-soluble phosphorus content was in the range of 0.16 – 0.93 mg/g, an increase in pyrolysis temperature from 350 °C to 500 °C or 650 °C increased the water-soluble content by 13.3 or 12.2 % respectively. The citric acid soluble phosphorus content was between 1.75 – 2.19 mg/g. After pyrolysis temperatures of 350 °C, slightly more phosphorus dissolved in the coal products than at 500 °C (+2.7 %) and at 650 °C (+5.5 %).</p><p>The ammonium sorption capacity of biochars produced by varying pyrolytic processes was investigated by a series of sorption experiments. The removal of ammonium by the biochars from an aqueous ammonium solution was measured by using colorimetric determination of the ammonium content. The maximum ammonium sorption results were achieved by biochars produced from bovine heads and feet respectively at a temperature of 900°C and activated with H<sub>2</sub>O.</p><p>When exposed to a solution containing 50 mg/L of ammonium, these biochars adsorbed 1.23 and 1.14 mg ammonium/g biochar, respectively. The possibility to enrich abattoir waste biochars, which are depleted in nitrogen because of the pyrolysis process, with ammonium gained from a nitrogen-enriched biogas slurry produced from animal residues of the meat production process was tested using a substitute slurry made with ammonium sulfate. The highest absorbance rate using the substitute slurry containing 10 g/L ammonium was achieved by biochar made from bovine heads and resulted in 43.1 mg ammonium/g biochar.</p><p>This study shows that bone-based biochars enriched with nitrogen from e.g. biogas digestates have significant potential as an NP-fertilizer that supports the strategies of circular economy.</p>


2020 ◽  
Vol 175 ◽  
pp. 12022
Author(s):  
Guriyat Podvolotskaya ◽  
Sergey Belopukhov ◽  
Vitaly Savich ◽  
Andrey Sorokin ◽  
Nikolay Tyutrin

Soil solutions and the surface waters are characterized by properties, processes and regimes. Soil solutions of different soils and their surface water have different biological activity and change the activity of dissolved stimulants and inhibitors. The object of the study are soil solutions of the main types of soils obtained in the model experiments with the ratio of soils: water equal to 1:1 and 1: 2, soil solutions and surface water in the flooding of soils with water for 1 week – 3 months. The research method consisted in the assessment of pH, Eh, activity of K, NO3, NH4, Ca, Mg by conventional methods, assessment of concentrations of water-soluble compounds extracted from soils by ionite membranes, in the assessment of biological activity of solutions using biotests. The following is suggested for additional evaluation: the using of cation and anion membranes, determination of interrelation between the properties of waters, equation of pair correlation and multiply regression. The informative value of the gradient of surface water concentrations at different distances from the floor of the reservoir, at different depths of the overwatered soils is shown. The mobility of Ca, Mg, Fe, Mn in soils and the content of their water-soluble forms depends on both pH and Eh, whose influence on the content of water-soluble forms of the considered cations shows the effects of synergy and antagonism. The rate of change in the composition of soil solutions during soil flooding depends on a combination of soil properties, temperature, and duration of flooding. Soil solutions of different soils and their surface waters have differentrates.


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