EFFICIENCY OF PHOSPHATIC FERTILIZERS OF VARYING WATER-SOLUBILITY

1961 ◽  
Vol 41 (1) ◽  
pp. 68-80 ◽  
Author(s):  
J. Hagin ◽  
J. Berkovits

Three fertilizers containing various amounts of citrate- and water-soluble phosphates were compared with superphosphate and rock phosphate in field and greenhouse experiments.Yield curves and equations were calculated and drawn and, from these, availability coefficients were calculated.The phosphate availability of the fertilizers was reduced as the relative amount of water-soluble phosphate they contained was reduced. However, in fertilizers that contained a relatively large amount of water-soluble phosphorus, the citrate-soluble fraction was partly available.

1981 ◽  
Vol 97 (1) ◽  
pp. 197-203 ◽  
Author(s):  
H. S. Hundal ◽  
B. R. Arora ◽  
G. S. Sekhon

SUMMARYNitric phosphates containing 80, 50 and 30% water-soluble phosphorus, and Mussoorie rock phosphate, alone or with Amjhore pyrites, farmyard manure or straw, were compared relative to concentrated superphosphate for each of three cycles of a clusterbean–wheat and a groundnut–wheat rotation. Both the field experiments were made on alkaline P-deficient Samana sands. All phosphatic fertilizers were applied to each crop at the rate of 10, 20 and 30 kg P/ha. Dry forage of clusterbean, groundnut pods and grain yield of wheat were measured. The model of concurrent straight line response was employed to calculate availability coefficient ratios which express the relative effectiveness of the different phosphatic fertilizers.Nitric phosphate containing 80 % water-soluble phosphorus and concentrated superphosphate were almost equal in their effectiveness in both 3-year rotational studies of clusterbean–wheat and groundnut–wheat. The relative efficiency of the nitric phosphates increased with the amount of water-soluble phosphorus they contained. Mussoorie rock phosphate was the least effective source of fertilizer phosphorus, although its efficiency is considerably higher for the legume clusterbean and for groundnut than for the cereal wheat. The efficiency of Mussoorie rock phosphate increased when it was mixed with the soil together with Amjhore pyrites, farmyard manure and straw respectively. These materials were more effective for clusterbean and groundnut than for wheat.


1972 ◽  
Vol 79 (3) ◽  
pp. 485-492 ◽  
Author(s):  
B. P. Govil ◽  
Rajendra Prasad

SUMMARYA field experiment was made during the rainy seasons of 1968 and 1969 on a sandy loam soil to study the response of Sorghum hybrid CSH–1 to phosphorus in relation to content of water-soluble phosphate in fertilizers. Triple superphosphate, dicalcium phosphate, rock phosphate (200-mesh), nitrophosphate and mixtures of triple superphosphate with dicalcium phosphate and rock phosphate in 3:1, 2:2 and 1:3 ratios were studied. The amounts of phosphorus applied were 30 and 60 kg P2O5/ha. Phosphorus application significantly affected dry matterproduced, plant height, days to 50% bloom, number of grains per ear, thousand-grain weight, stover and grain yield. Triple superphosphate and 3:1 triple superphosphate/dicalcium phosphate mixture were the most effective while rock phosphate and 1:3 triple superphosphate/rock phosphate mixture the least. Differences among sources were more marked in 1968 and at the higher amount i.e. 60 kg P2O5/ha. The response of sorghum to phosphorus was considerably lowered when the water solubility waa below 50% in triple superphosphate/dicalcium phosphate mixtures and below 75% in triple superphosphate/rock phosphate mixtures. Relative effectiveness was assessed by calculating ‘superphosphate equivalents’ and ‘multiple regressions’. Using superphosphate equivalents dicalcium phosphate, nitrophosphate and rock phosphates were 47–53%, 35–56% and 3–25%, respectively, as effective as triple superphosphate.


2010 ◽  
Vol 101 (2) ◽  
pp. 551-554 ◽  
Author(s):  
Marzieh Mohammady Aria ◽  
Amir Lakzian ◽  
Gholam Hosain Haghnia ◽  
Ali Reza Berenji ◽  
Hosein Besharati ◽  
...  

1977 ◽  
Vol 88 (3) ◽  
pp. 625-630 ◽  
Author(s):  
H. S. Hundal ◽  
P. S. Deol ◽  
G. S. Sekhon

SUMMARYA field experiment was made on Gurdaspur clay loam to assess the relative efficiency of various sources of fertilizer phosphorus for a paddy-wheat cropping sequence. Urea ammonium phosphate, superphosphate, a nitrophosphate fertilizer containing 30% water-soluble P and fertilizers containing 50 and 70% water-soluble P prepared from the nitrophosphate and superphosphate, dicalcium phosphate and rock phosphate were applied to the paddy crop at the rate of 0, 15, 30, 45 and 60 kg p2O6/ha and to wheat at double these rates.The cumulative yield data for paddy and wheat show a slight reduction in efficiency of phosphatio fertilizers, with the exception of dicalcium phosphate, as their watersoluble content decreased below 70%. In general, the relative efficiency of the less water-soluble sources and of rock phosphate was considerably higher for paddy than for wheat.The results show that the relative efficiency of low water-soluble phosphate fertilizers increased with time. The efficiency of phosphorus fertilizers declined with the rate of their application, more so in the case of higher water-soluble materials.


1968 ◽  
Vol 70 (2) ◽  
pp. 131-138 ◽  
Author(s):  
G. E. G. Mattingly ◽  
A. Penny

SUMMARYThree granular nitrophosphates containing 5, 26 and 50 % of their total phosphorus in a water-soluble form, granular potassium metaphosphate, Gafsa rock phosphate and basic slag (both as powders) were compared with granular superphosphate and powdered dicalcium phosphate as standards in two annual experiments with ryegrass and in three experiments with barley.In 1960 total yields of ryegrass during a whole season were similar with all fertilizers. Nitrophosphate-5, Gafsa rock phosphate and basic slag acted more slowly than granular superphosphate and grass grew less well and took up less phosphorus during the first 12 weeks. Over the whole growing season more phosphorus was taken up by grass from powdered dicalcium phosphate and from granular potassium metaphosphate (0.5–2.0 mm) than from granular superphosphate (1.0–4.0 mm).Powdered dicalcium phosphate was equivalent to about 60% as much phosphorus applied as superphosphate to barley. Rock phosphate was almost inert and percentage granular superphosphate equivalents of basic slag and potassium metaphosphate were 22 and 23% respectively. Percentage superphosphate equivalents of the granular nitrophosphates were 1, 25 and 53% and almost equal to the water-soluble phosphate they contained.


1964 ◽  
Vol 36 (1) ◽  
pp. 65-76
Author(s):  
Armi Kaila

The distribution of soluble phosphate in various fractions of soil phosphorus was studied by treating 1 g-samples of 180 mineral soils with 50 ml of a KH2PO4- solution containing P 5 mg/l for 24 hours, and carrying out the fractionation by the method of CHANG and JACKSON after the solution was removed and the moist samples had stood for 3 days at room temperature. The amount of retained phosphorus in the different fractions was computed by taking the difference between the treated and check samples. In the 70 samples of clay soils, the mean proportion of the retained phosphorus was 57 per cent of the 250 mg/kg applied, in the 62 samples of the sand and fine sand soils the corresponding part was 45 per cent, and in the 48 samples of loam and silt soils it was 44 per cent. The higher retention in the clay soils was mainly due to a higher retention in the alkali-soluble fraction. The net increase in the fluoride-soluble forms was of the same order in these three soil groups. On the average, more than 95 per cent of the sorbed phosphorus was found in the fluoride-soluble and alkali-soluble fractions. In one third of the samples a low net increase in the acid soluble fraction was detected, but this may be partly due to changes in the solubility of the native phosphorus in the treated samples. Owing to the fairly large variation, the tendency to somewhat higher mean values for the sorption in the subsoils compared with those of the topsoils was not statistically significant. The ratio between the sorbed amounts of fluoride-soluble and alkali soluble forms was higher in the sand and fine sand soils than in the clay soils. Only in 15 samples, most of them Litorina-soils, the net increase in the alkali-soluble forms was higher than in the fluoride-soluble fraction. Probably, because an equilibrium in the phosphorus conditions was not yet reached at the end of the treatment, the attempt failed to find any clear connection between the distribution of the sorbed phosphorus and such soil properties as pH, the contents of acid oxalate soluble aluminium and iron, organic carbon, the phosphate sorption capacity and the degree of phosphate saturation. Only in the subsoil samples, 76 per cent of the variation in the net increase in the fluoride-soluble fraction could be explained by the variation on the content of oxalate-soluble aluminium, and in the topsoil samples the oxalate-soluble iron and pH determined 61 per cent of the variation in the net increase in the alkali-soluble phosphorus. The ratio of oxalate-soluble aluminium to iron was more closely correlated with the ratio between the total amounts of fluoride-soluble and alkali-soluble phosphorus than with the ratio between the corresponding sorbed amounts. In the topsoils, it explained 70 per cent of the variation in the former. The distribution of the retained phosphorus did not depend on the soil pH, its content of organic carbon, or its degree of phosphate saturation but there was some tendency to a higher accumulation of alkali-soluble phosphorus compared with the fluoride-soluble forms with an increase in the phosphate sorption capacity of the soil.


1974 ◽  
Vol 83 (1) ◽  
pp. 177-179 ◽  
Author(s):  
B. P. Govil ◽  
R. Prasad

SUMMARYA field experiment was made with sorghum hybrid CSH-1 during the rainy seasons of 1968 and 1969 on a sandy loam soil to study the influence of amounts and sources of phosphate fertilizer on phosphorus nutrition. Concentration of P in the crop and uptake increased with increasing amounts of phosphate and with increasing proportions of water-soluble P in triple superphosphate-dicalcium phosphate and triple superphosphate-rock phosphate mixtures. Relative effectiveness values were calculated from P uptake at harvest by a multiple regression method. For triple superphosphate, nitrophosphate (30% water soluble P), dicalcium phosphate and rock phosphate (from Jordan) the values were respectively, 100, 74, 61 and 22.


2005 ◽  
Vol 7 (2) ◽  
pp. 77-80
Author(s):  
Yudi Sastro ◽  
Donny Widianto ◽  
Irfan D Prijambada

The study is intended to examine the survival of Aspergillus niger and its phosphate solubilizing ability when pelletedwith rock phosphate. An A. niger YD 17 obtainedfrom the Laboratory of Microbiology. Faculty of Agriculture, Gadjah MadaUniversity was used. The pellet was made by mixing rock phosphate (80%) with organic matter (J 3. 9% waste of tapioca. 6% rice bran, and 1% starch) and spore of A. niger. The experimental design was the Complete Randomized Design 5x4 with 3 replicatiOns. The first factor was sources of rock phosphate (Christmas Island. Jordan, China, Ciamis, and Madura). The secondfactor was the number ofinoculums i.e. control without inoculums, 107 • J(t and J(t cfu.g·'. The colony of A. niger that formed at medium of potatoes dextrose agar (PDA) and the amount of soluble phosphorus in the Pikovskaya liquid medium were parameters. Experimental results indicated that sources of rock phosphate and the number of inoculums itif1uence the A. niger survivability and its phosphorus solubilizing ability. Rock phosphate from Ciamis gave the best support for fungus survival and rock phosphate from Christmas Island was the best substrate for phosphate solubilization. The highest soluble phosphate was achieved by ul inoculums.


1960 ◽  
Vol 11 (6) ◽  
pp. 926 ◽  
Author(s):  
JS Russell

The fate of phosphorus applied as superphosphate and rock phosphate to grassland plots at Kybybolite established in 1919 on solonetzic soils has been studied by soil analytical techniques. The additional effect of the amendments lime and gypsum has also been examined. From past records of phosphorus added as fertilizer, the probable amounts of phosphorus removed in animal products, and present phosphorus levels of the surface 8 in. of soil, it has been possible to draw up a balance sheet of gains and losses. The results show that considerable penetration of phosphorus applied in the water-soluble form has occurred. Less than half the phosphorus applied as superphosphate can be accounted for in the surface 8 in. The remainder is presumed to have been leached to lower soil horizons. In contrasting these results with those of other areas of similar rainfall where little movement of applied water-soluble phosphate has occurred, it is believed that the greater penetration at Kybybolite can be explained on the basis of the coarse texture and the low fixing capacity of the surface soil. Where acid-soluble phosphate has been applied, less movement through the soil is apparent, and 75–89 per cent. of the residual phosphorus applied as rock phosphate can be accounted for in the surface soil, mostly in the top 2 in. Lime has resulted in an increased retention of phosphorus in the surface soil. Gypsum, on the other hand, has not resulted in increased retention. The need for a reappraisal of the present widespread practice of continuous mono-application of superphosphate to pastures after residual levels in the soil have been raised is discussed. In particular, the possible role of acid-soluble phosphate is examined.


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