• Journal of Animal Environmental Science
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• v.7 no.2
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• pp.127-136
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• 2001

This experiment was carried out to investigate the effect of supplementing phosphorus to Korean cow manure on the growth and cast production of earthworm(Eisenia Foetida), and to estimate the optimal phosphorus level for the growth and cast production of earthworm and ratios of available phosphorus and calcium content of cast in optimal phosphorus levels. Phosphorus supplementing ratios to Korean native cow were 0, 1%, 2%, 4% and 8A%, respectively. The volume of raising box was 3375cm$^3$(15$\times$15$\times$15cm), and 500g of cow manure filled up to 10cm layer. Raising density was 90㎤ per worm during the experimental period(60 days). The maximum fresh weight and cast production of earthworm were obtained at 2~4% and 1% levels of phosphorus supplementation to Korea native cow manure. The total phosphorus and available phosphorus contents of earthworm tissues were not significant among in all treatments. There was a positive significantly differences between total phosphorus and available phosphorus of cast and residual matters. Available phosphorus content of cast were ranged from 9.3mg/g to 17.3mg/g at 1~4% levels of phosphorus supplementation. Ratios of available phosphorus and calcium contents of cast were 1.94~3.15:1 and 0.87~1.33:1 at 2~4% and 0~1% levels of phosphorus supplementation.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.1
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• pp.21-29
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• 1988

A laboratory experiment was conducted to evaluate the phosphorus status and define the relationship between composition of phosphorus forms and available phosphorus with 149 phosphorus accumulated soil samples. Distribution percentage of inorganic, organic and available phosphorous to total phosphorus were 68.9 (Saloid-p 2.7, Al-p 26.4, Fe-p 27.6, Ca-p 12.2%), 6.7 and 26.0%, respectively. In the relationship between available phosphorus and inorganic phosphorus in soil, Al-p, Saloid-P, and Ca-P showed significant correlation with available phosphorus which did not showed significant one with Fe-p. Multiple liner regression equation between available and inoganic phosphorus abtained as follow, $Av.P=81.694+0.858Sa-p^{***}+0.648Al-p^{***}+0.091Ca-p^{**}(R=0.826^{***})$ and contribution rates of Saloid-p, Al-p, and Ca-p to available phosphorus were 26.1, 65.2, and 8.7%, respectively. Relationship between available and water soluble phosphorus, water soluble phosphorus and $0.01M-CaCl_2-p$ were highly significant, respectively, and soil solution P extracted with $0.01M-CaCl_2$ for 30 minutes was selected as one of usable diagnostic techniques for soil P status.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.3
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• pp.195-202
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• 2017

The volcanic ash soils from the Jeju province have low available phosphate because of the high phosphate fixing power of the soils. Phosphorus fertilizerwas dressed after cultivating green manure crops and before cultivating potatoes in order to investigate potato yields, the available phosphate contents, and phosphorus balance in the soils. Green manure crops cultivated in this study were hairy vetch alone and hairy vetch and rye. During potato cultivation, four treatments were conducted in the experiments; NF (non fertilizer), P fertilizer ($N-P-K=0-25-0kg\;10a^{-1}$), NK fertilizer ($N-P-K=18-0-19kg\;10a^{-1}$), and NPK fertilizer ($N-P-K=18-25-19kg\;10a^{-1}$). There were no differences in the yields of potato stem and tuber from the cultivation plots of different green manure crops. However, in the plots with single-sown hairy vetch and mixed-sown hairy vetch and rye, the yields of potato stem and tuber were higher in the P fertilizer plot than in NF plot. The yield of tuber among the treatments with mixed-sown hairy vetch and rye was the highest in the NPK fertilizer plot. The available phosphate content in soils initially increased with time in all plots, but began to decrease gradually after Oct. 18. The available phosphate contents were high in the plots for phosphate fertilization, and the difference in available phosphate content between non-phosphorus fertilizer plots and phosphorus fertilizer plots increased with time. In the single-sown hairy vetch and mixed-sown hairy vetch and rye plot, the phosphorus balances in NF plot and NK fertilizer plot were very low, while those in the P fertilizer plot and NPK fertilizer plot were high. In conclusion, available phosphate contents in soil and the potato yields were increased by phosphorus fertilization when potatoes planted after cultivating hairy vetch and rye together, compared to hairy vetch alone.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.3
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• pp.93-97
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• 1981

Laboratory experiment was carried out to investigate the changes in the amount of inorganic phosphorus fractions of native and applied phosphorus and to compare the some analytical methods of soil phosphorus in volcanic ash. The rates of inorganic phosphorus to total-pP were varied with the kinds of soil in the ranges of 6.9 to 28.8% for Al-P, 24.1 to 26.9% for Fe-P, 7.4 to 11.9% for Ca-P and 0.7 to 8.0% for available phosphorus. The composition of inorganic phosphorus after incubation for 60 days was in the order of Al-P>Fe-P>Ca-P in Black soil, Fe-P>Al-P>Ca-P in Very dark brown soil, Fe-P>Ca-P>Al-P in Dark brown soil and Fe-P Al-P>Ca-P on Red yellow soil. The amounts of phosphorus extracted from soil varied with the methods for available phosphorus estimation. The magnitute of available P measured by Bray No. 2 method was the greatest. In relationship between inorganic phosphorus forms and available phophorus, Bray No. 2 method was closely related to Ca-P only and Olsen method correlated to Al-P, Fe-P, Ca-P and Total-P.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.50-54
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• 2008

NIR spectroscopy is newly developed tools determining the soil properties. Phosphorus in soil is one of the most difficult and time consuming elements to assess for plant needs. The calibration coefficient(R) of NIR method for total phosphorus by $HClO_4$ and $Na_2CO_3$ P was 0.91 and 0.88, and available phosphorus by Lancaster and Bray 1. extractant was 0.88 and 0.82. According to Williams guidelines for the calibration coefficient, NIR method could also be used for estimating total and available phosphorus if one performed optimal calibration for predicting soil properties. Applicability of NIR spectra, if improved accuracy, may allow the use of soil testing.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.141-146
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• 2017

BACKGROUND: Phosphorus(P) is a vital factor for rice but excess input of phosphorus fertilizer can cause environmental risk and waste of fertilizer resources. We studied to assess the change of available phosphate, P balance, critical concentration of available phosphate under a rice single system. METHODS AND RESULTS: The changes of available phosphate of paddy soil were examined from long-term fertilization experiment which was started in 1954 at the National Academy of Agricultural Science. The treatments were no phosphate fertilization(No fert., and N), phosphate fertilization(NPK, NPKC, and NPKCLS). The available phosphorus concentrations in treatments without phosphate fertilizer (No fert. and N) were decreased continuously. But, after 47 years, available phosphate content in phosphate fertilizer treatment (NPK, NPKC, and NPKCLS) reached at the highest ($245{\sim}331mg\;kg^{-1}$), showing a tendency to decrease afterward. The mean annual P field balance in these treatments (NPK, NPKC, and NPKCLS) had positive values that varied from 16.6 to $17.5kg\;ha^{-1}year^{-1}$, and ratio of residual P were increased. These showed that phosphate fertilizer in soil were converted into the form of residual phosphorus which was not easily extracted by available phosphate extractant. Also, It was estimated that the critical value of available phosphate for rice cultivation was $120mg\;kg^{-1}$ using Cate-Nelson equation. CONCLUSION: We concluded that no more phosphate fertilizer should be applied in rice single system if soil available phosphate is higher than the critical P value.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.272-279
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• 1988

A pot experiment was conducted to define the effect of various soil phosphorus fractions for soybean yield and the relations of between various soil phosphorus fraction and each other in 11 upland soils with different capacities of phosphorus fixation and physico-chemical properties of soils. The effect of phosphorus fertilization was high in soils with high capacities of phosphorus fixation and low available phosphorus, and soybean yield was showed significant relationship with available phosphorus and inorganic soil phosphorus fractions. Fractional recovery of added phosphorus in soils were showed various range of 2.5-91.7%, and mean value of soils was 48.5%. In the relationships among the soybean yield, plant phosphorus content, phosphorus uptake and available phosphorus, inoganic phosphorus at flowering stage, soybean yield were showed significant relationship with available phosphorus content, phosphorus uptake were all showed significant correlation without Fe-P, but Fe-P was showed except Jeju soil. Al-P/Fe-P ratio was increased by phosphorus fertilization in soils at flowering stage, and in the relationships between Al-P/Fe-P ratio and soybean yield, phosphorus uptake, soil and plant phosphorus were showed high significant correlation, but Fe-P was not showed at flowering stage. P sorbed by soils from P 20ppm solution was decreased by phosphorus fertilization, and then decreasing rate was higher in soils with low capacity of phosphorus fixation then high phosphorus fixing soils. Also P sorbed was showed negatively high significant correlation with available phosphorus, plant phosphorus, phosphorus uptake and soil inorganic phosphours except Fe-P, and soybean yield was not showed.

• Journal of Plant Biology
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• v.11 no.3
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• pp.18-22
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• 1968

Determination of the pH value and analyses of the available phosphorus of some soils under the forest and grassland Kwang-nung have been examined to study the relationship between the soil pH and available phophorus. The results might be summarized as follows: 1) The available phosphorus decrease steadily as the pH goes up to 5.2. However, at the pH 5.2∼6.3, it shows an increase and decreases again as the rise above pH 6.3. 2) There is a significant difference in the amounts of the soil phosphate among the areas sampled. 3) The statistical analysis of the data obtained shows that soil phosphate is limiting factor governing the distribution of natural vegetal pattern.

• Journal of Environmental Science International
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• v.21 no.5
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• pp.641-646
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• 2012

Available phosphorus($P_2O_5$) in conventionally cultivated soil was more abundant in two fold than that of organically cultivated soil. Relative density of Arbuscular Mycorrhizal Fungi (AMF) was higher in organically cultivated soil, That of welsh onion cultivated soil was the highest, that of strawberry was followed and then that of pepper, respectively. Relative density of AMF was inversely proportioned to available soil phosphorus. Phosphorus content of crop and relative density of AMF were more abundant in organically cultivated crop or soil. However available soil phosphorus content was much in conventionally cultivated soil. The phosphorus contents between soil and crop were negatively correlated. The phosphorus content of crop was increased as the relative density of AMF increased. Relative density of AMF in the organically cultivated soil and phosphorus content of the crop with organic cultivation were higher than those of conventionally cultivated.

• Korean Journal of Microbiology
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• v.5 no.1
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• pp.34-38
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• 1967

Theoretical analysis reported in this paper is on the varities of the growth rate of Chlorella ellipsoidea due to the amount of available phosphorus for the purpose of the continual mass culture. Available phosphorus in the culture media of the Chlorella was also estimated at a limiting factor as this experiment. The equation between the concentration of Chlorella n and growth period t is $\frac{dn}{dt}=Kn$, and the functional relation between the Specific growth rate K and steady state period T is the following: $K=\frac{2.303}{T}$log\frac{n}{no}$ ($n_o$=initial concentration).