The nature of available phosphorus in some acid pasture soils and a comparison of estimating procedures

1965 ◽  
Vol 5 (17) ◽  
pp. 125 ◽  
Author(s):  
KD McLachlan
Keyword(s):  
Soil Phosphorus ◽  
Physical Nature ◽  
Fertilizer Application ◽  
The Other ◽  
Available Phosphorus ◽  
Aluminium Phosphate ◽  
Phosphorus Status ◽  
The Common ◽  
Pasture Plants ◽  
Made In

Several methods of evaluating the phosphorus status of soils for the growth of pasture plants were compared. NaHCO3 and NH4F in HCl were the most suitable extractants used. On these soils, differing widely in origin and fertilizer history, phosphorus values of 30 p.p.m, as determined by three of the methods distinguished responsive from unresponsive soils. For the other, the bicarbonate method of Olsen et al. (1954), the corresponding value was 15 p.p.m. The evidence suggests that in the soils examined, all inorganic forms of soil phosphorus, as determined by the method of Chang and Jackson (1957), contributed in some degree to the pasture plants needs. The principal source of available phosphorus, however, was the aluminium phosphates. On the other hand, the evidence suggests that the principal loss in the availability of residual phosphorus to the plant may be through its conversion to organic forms. Iron phosphates appeared to be the least available of the inorganic forms. The common ability of the four successful methods to efficiently extract phosphorus from the aluminium source appears to be the prime reason for their measuring the soil phosphorus status for plants equally well. The physical nature of aluminium phosphate, however, has a marked effect on its ability to supply the plant's phosphorus needs. A crystalline form was less available than an amorphous one. The greater availability of the amorphous forms, of both iron and aluminium phosphates, appeared to depend more upon their solubility than on their positional availability due to the greater specific surface presented. Fertilizer application enriches the aluminium phosphate content of the soils, but, in these experiments, the quantities found were related significantly to the total applications made in the previous three years only.

XXIII. On the water-barometer erected in the hall of the Royal Society

1832 ◽  
Vol 122 ◽  
pp. 539-574 ◽  
Keyword(s):  
Royal Society ◽  
Physical Science ◽  
The Other ◽  
Metallic Tube ◽  
French Academy ◽  
History Of ◽  
The Subject ◽  
The Common ◽  
Academy Of Sciences ◽  
Made In

I have for some time entertained an opinion, in common with some others who have turned their attention tot he subject, that a good series of observations with a Water-Barometer, accurately constructed, might throw some light upon several important points of physical science: amongst others, upon the tides of the atmosphere; the horary oscillations of the counterpoising column; the ascending and descending rate of its greater oscillations; and the tension of vapour at different atmospheric temperatures. I have sought in vain in various scientific works, and in the Transactions of Philosophical Societies, for the record of any such observations, or for a description of an instrument calculated to afford the required information with anything approaching to precision. In the first volume of the History of the French Academy of Sciences, a cursory reference is made, in the following words, to some experiments of M. Mariotte upon the subject, of which no particulars appear to have been preserved. “Le même M. Mariotte fit aussi à l’observatoire des experiences sur le baromètre ordinaire à mercure comparé au baromètre à eau. Dans l’un le mercure s’eléva à 28 polices, et dans Fautre l’eau fut a 31 pieds Cequi donne le rapport du mercure à l’eau de 13½ à 1.” Histoire de I'Acadérmie, tom. i. p. 234. It also appears that Otto Guricke constructed a philosophical toy for the amusement of himself and friends, upon the principle of the water-barometer; but the column of water probably in this, as in all the other instances which I have met with, was raised by the imperfect rarefaction of the air in the tube above it, or by filling with water a metallic tube, of sufficient length, cemented to a glass one at its upper extremity, and fitted with a stop-cock at each end; so that when full the upper one might be closed and the lower opened, when the water would fall till it afforded an equipoise to the pressure of the atmo­sphere. The imperfections of such an instrument, it is quite clear, would render it totally unfit for the delicate investigations required in the present state of science; as, to render the observations of any value, it is absolutely necessary that the water should be thoroughly purged of air, by boiling, and its insinuation or reabsorption effectually guarded against. I was convinced that the only chance of securing these two necessary ends, was to form the whole length of tube of one piece of glass, and to boil the water in it, as is done with mercury in the common barometer. The practical difficulties which opposed themselves to such a construction long appeared to me insurmount­able; but I at length contrived a plan for the purpose, which, having been honoured with the approval of the late Meteorological Committee of this Society, was ordered to be carried into execution by the President and Council.

Richard William Southern 1912–2001

2003 ◽  
Author(s):  
Alexander Murray
Keyword(s):  
The Other ◽  
Practical Action ◽  
Contemporary World ◽  
The World ◽  
History Of ◽  
The Common ◽  
Deep Thought ◽  
Life Work ◽  
Made In ◽  
Do So

People with a logical turn of mind say that the history of the world can be summarised in a sentence. A précis of mediaval historian Richard William Southern's work made in that spirit would identify two characteristics, one housed inside the other, and both quite apart from the question of its quality as a work of art. The first is his sympathy for a particular kind of medieval churchman, a kind who combined deep thought about faith with practical action. This characteristic fits inside another, touching Southern's historical vision as a whole. Its genesis is traceable to those few seconds in his teens when he ‘quarrelled’ with his father about the Renaissance. The intuition that moved him to do so became a historical fides quaerens intellectum. Reflection on Southern's life work leaves us with an example of the service an historian can perform for his contemporary world, as a truer self-perception seeps into the common consciousness by way of a lifetime of teaching and writing, spreading out through the world (all Southern's books were translated into one or more foreign language).

The Letter of Recommendation as Strange Work

PMLA ◽  
2012 ◽  
Vol 127 (4) ◽  
pp. 954-962
Author(s):  
Margaret Ferguson
Keyword(s):  
The Other ◽  
Free Lunch ◽  
Other Hand ◽  
The Gift ◽  
English Major ◽  
The Common ◽  
The One ◽  
Gift Certificate ◽  
Time And Energy ◽  
Made In

On the one hand, the gift presents itself as a radical Other of the commodity—and therefore also of work, insofar as the latter is understood as an investment of time and energy made in the expectation of wages or profit. On the other hand, the idea of the gift seems constantly to be drawn back under the horizon of rational exchange, and to be thus endlessly re-revealed as a secret ally of both work and the Work.—Scott Cutler Shershow, The Work and the GiftI have put together all these details to convince you that this recommendation of mine is something out of the common.Quae ego omnia collegi, ut intellegeres non vulgarem esse commendationem hanc meam.—Cicero, Epistulae ad familiares, book 13LAST FALL I FOUND IN MY OFFICE MAILBOX AN ENVELOPE FROM A SOPHOMORE ENGLISH MAJOR WHO HAD ASKED ME DURING THE SUMMER for a last-minute letter of recommendation for a scholarship competition. The envelope contained a handwritten thank-you note—and a gift certificate for a local restaurant. I e-mailed the student to thank her and to tell her that I couldn't accept the gift certificate since the letter I had written for her was part of my job as a teacher. She insisted; I insisted. She said that several teachers had turned her down before I agreed (from a hotel in Germany) to write for her. I felt rueful, as well as grateful to her for the token of gratitude that I couldn't accept. Eventually she won the debate: I accepted the printed piece of paper and took my daughters out to a free lunch.

Effects of Long-Term Compost and Fertilizer Application on Soil Phosphorus Status Under Paddy Cropping System

2004 ◽  
Vol 35 (11-12) ◽  
pp. 1635-1644 ◽  
Author(s):  
Myungsu Park ◽  
Olayvanh Singvilay ◽  
Wansik Shin ◽  
Eunhee Kim ◽  
Jongbae Chung ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Cropping System ◽  
Fertilizer Application ◽  
Phosphorus Status

Impact of Fertilization and Soil Phosphorus Status on Phosphorus Leaching from Soil in Vegetable Greenhouse

2012 ◽  
Vol 610-613 ◽  
pp. 2968-2973 ◽  
Author(s):  
Ya Jie Zhao ◽  
Xin Chen ◽  
Yi Shi ◽  
Cai Yan Lu ◽  
Bin Huang ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Fertilizer Application ◽  
Organic Manure ◽  
Chemical Fertilizer ◽  
Phosphorus Leaching ◽  
Greenhouse Condition ◽  
Greenhouse Soil ◽  
Leaching Loss ◽  
Phosphorus Status ◽  
The Impact

The vegetable utilization rate of phosphorus fertilizer in greenhouse condition was low in the season of fertilizer application, resulting in phosphorus accumulation in the top soil year after year. The risk of phosphorus loss through leaching increased under the circumstance of inappropriate watering management and fertilization. In this study, leaching experiments using columns packed with a greenhouse soil with different soil phosphorus status (low, medium and high levels) were carried out under greenhouse condition to investigate the impact of fertilizer application on phosphorus leaching from greenhouse soil. The fertilization treatments included no fertilizer [CK], organic manure and chemical fertilizer [M+NPK], organic manure [M], chemical fertilizer [NPK]. The vertical migration and leaching loss of soil phosphorus were measured. Results were as follows: (1) total phosphorus (TP) content increased with the extension of leaching time. In the low-level- and medium-level-phosphorus greenhouse soils, TP concentration in the effluent increased with the application of manure; (2) In the high-level-phosphorus greenhouse soil, phosphorus in the effluent from the treatment with the use of fertilizer was the highest TP, with accumulative leaching amount of 2.85 mg in 51 days. The leaching of phosphorus became small after 36 days of leaching experiment. Our study showed that application of manure and chemical fertilizer at proper rates according to soil phosphorus status is beneficial to reduce the leaching loss of phosphorus to the environment.

The response of pastures in Northern Ireland to N, P and K fertilizers and to animal slurries: III. Effects in experiments continued for either two or three years

1974 ◽  
Vol 82 (1) ◽  
pp. 129-137 ◽  
Author(s):  
S. N. Adams
Keyword(s):  
Northern Ireland ◽  
Mineral Content ◽  
Soil Phosphorus ◽  
Potassium Content ◽  
Mineral Fertilizers ◽  
Factorial Experiments ◽  
Phosphorus Status ◽  
Made In

SUMMARYThree factorial experiments made in 1969 on Northern Ireland pastures to measure effects upon yield and mineral content of 0, 180 and 360 kg N, 0, 30 or 60 kg P and 0, 150 or 300 kg K/ha/year, both with and without 1380001 slurry/ha, were continued on the same sites with the same treatments in 1970 and two of them were continued again in 1971.Responses to nitrogen in the second and third seasons were similar to those of the first season. There was no evidence that large nitrogen dressings plus slurry were causing nitrogen to accumulate in the soil.Repeated cutting of herbage given neither fertilizer potassium nor slurry was beginning to reduce both yield and the potassium content of the herbage in the second and third years. Giving fertilizer potassium prevented these losses, but the potassium in the slurries was less effective because it did not maintain the potassium content of the herbage. Reasons for, and implications of this effect are discussed.There was no evidence that soil phosphorus reserves were becoming depleted, when judged by the % P in herbage receiving neither fertilizer nor slurry even after the herbage had been cut and removed for two or three years. As there was no immediate need for fertilizer phosphorus, the P in the slurries, even though slower acting than that in mineral fertilizers, seemed suitable for maintaining the phosphorus status of these pasture soils.

Starch equivalents, ration standards and milk production

1956 ◽  
Vol 1956 ◽  
pp. 3-31 ◽  
Author(s):  
K. L. Blaxter
Keyword(s):  
Milk Production ◽  
The Other ◽  
Basic Information ◽  
Energy Value ◽  
The Common ◽  
Made In

The methods which we use in this country to calculate the rations for our livestock are based on studies made in Germany during the period 1890-1909, and in America at about the same time. These methods have been amended from time to time as the results of other studies have accrued, but, in the main, their basis lies in a few dozen experiments made by Kellner and Kuhn at Leipzig with steers and a very much smaller number made with milking cows. This basic information, expanded in many respects and certainly extrapolated well beyond its admittedly limited experimental foundation, is collected in two sets of tables in the books dealing with the feeding of livestock. One gives the requirements of different classes of stock in terms of energy values and the other gives the energy value of the common feeding stuffs.

scholarly journals Estimating Soil Available Phosphorus Content through Coupled Wavelet–Data-Driven Models

2020 ◽  
Vol 12 (5) ◽  
pp. 2150 ◽  
Author(s):  
Jalal Shiri ◽  
Ali Keshavarzi ◽  
Ozgur Kisi ◽  
Sahar Mohsenzadeh Karimi ◽  
Sepideh Karimi ◽  
...  
Keyword(s):  
Gene Expression Programming ◽  
Soil Phosphorus ◽  
Clay Content ◽  
The Other ◽  
Data Driven ◽  
Support Vector ◽  
Available Phosphorus ◽  
Discrete Wavelet ◽  
Soil P ◽  
Soil Available Phosphorus

Soil phosphorus (P) is a vital but limited element which is usually leached from the soil via the drainage process. Soil phosphorus as a soluble substance can be delivered through agricultural fields by runoff or soil loss. It is one of the most essential nutrients that affect the sustainability of crops as well as the energy transfer for living organisms. Therefore, an accurate simulation of soil phosphorus, which is considered as a point source pollutant in elevated contents, must be performed. Considering a crucial issue for a sustainable soil and water management, an effective soil phosphorus assessment in the current research was conducted with the aim of examining the capability of five different wavelet-based data-driven models: gene expression programming (GEP), neural networks (NN), random forest (RF), multivariate adaptive regression spline (MARS), and support vector machine (SVM) in modeling soil phosphorus (P). In order to achieve this goal, several parameters, including soil pH, organic carbon (OC), clay content, and soil P data, were collected from different regions of the Neyshabur plain, Khorasan-e-Razavi Province (Northeast Iran). First, a discrete wavelet transform (DWT) was applied to the pH, OC, and clay as the inputs and their subcomponents were utilized in the applied data-driven techniques. Statistical Gamma test was also used for identifying which effective soil parameter is able to influence soil P. The applied methods were assessed through 10-fold cross-validation scenarios. Our results demonstrated that the wavelet–GEP (WGEP) model outperformed the other models with respect to various validations, such as correlation coefficient (R), scatter index (SI), and Nash–Sutcliffe coefficient (NS) criteria. The GEP model improved the accuracy of the MARS, RF, SVM, and NN models with respect to SI-NS (By comparing the SI values of the GEP model with other models namely MARS, RF, SVM, and NN, the outputs of GEP showed more accuracy by 35%, 30%, 40%, 50%, respectively. Similarly, the results of the GEP outperformed the other models by 3.1%, 2.3%, 4.3%, and 7.6%, comparing their NS values.) by 35%-3.1%, 30%-2.3%, 40%-4.3%, and 50%-7.6%, respectively.

Phosphorus fixation studies with tomatoes on a krasnozem soil

1966 ◽  
Vol 6 (20) ◽  
pp. 31 ◽  
Author(s):  
JD Hughes ◽  
RC Merary
Keyword(s):  
Soil Samples ◽  
The Other ◽  
Available Phosphorus ◽  
Virgin Soil ◽  
Plant Weight ◽  
Phosphorus Accumulation ◽  
Phosphorus Fixation ◽  
Plant Data ◽  
Phosphorus Status ◽  
Lower Plant

A series of glasshouse experiments was conducted with a krasnozem soil to determine the effect of previous applications of superphosphate on the rate at which the soil was able to fix further additions of phosphorus. Two soil samples were investigated, one a virgin soil, and the other a cultivated soil which had been fertilized with superphosphate. Fixation of currently applied phosphorus was measured by comparing plant data from treatments in which time of contact between soil and applied phosphorus varied from 0 to 16 weeks. Sixteen weeks contact between soil and fertilizer phosphorus prior to planting resulted in lower plant weight and less uptake of phosphorus on both soils but the effect was greater on the virgin soil. This showed that the rate of fixation was reduced by the phosphorus accumulation. The quantity of phosphorus extracted by 0.01 N sulphuric acid may be useful in detecting changes in phosphorus status, but is unreliable for assessing available phosphorus on this soil.

A method for observing the eclipses of the moon, free from the common inconveniencies, as it was left by the learned Mr. Rook, late Gresham-Professor of Geometry

1665 ◽  
Vol 1 (22) ◽  
pp. 388-390
Keyword(s):  
The Other ◽  
The Moon ◽  
The Common ◽  
The Difference ◽  
Made In

Eclipses of the moon are observed for two principal ends; one astronomical, that by comparing observations with calculations, the Theory of the moons motion may be perfected, and the tables thereof reformed: the other, geographical, that by comparing among themselves the observations of the same ecliptick phases, made in divers places, the difference of meridians or longitudes of those places may be discerned.

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