• 한국토양비료학회지
• /
• 제50권3호
• /
• pp.195-202
• /
• 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.

• 한국초지조사료학회지
• /
• 제21권4호
• /
• pp.181-190
• /
• 2001

This study was conducted to investigate the effect of swine liquid manure(SLM) and phosphorus fertilizer from September, 1998 to July, 1999 on the soil fertility on Italian ryegrass field, Cheju volcanic ash soil. pH(lst investigated), Mg (2nd investigated) and Cu content (2nd investigated) on soil grown by Italian ryegrass were significantly increased by an increase of fertilizer P(P

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.279-281
• /
• 2003

This study is intended to give information on agricultural nonpoint source pollution and transport related to fertilizer application and irrigation practice. Field-simulated soil columns were set up and leaching studies on fertilizer components such as nitrogen and phosphorus were performed. Nitrogen and phosphorus in the leachate showed different trends in each column and nonpoint source pollution in agricultural areas may be expected to depend on planted crops, soil conditions, and climate as well as irrigation and fertilizing management.

• 한국연초학회지
• /
• 제8권2호
• /
• pp.43-49
• /
• 1986

Field experiment was conducted to investigate the effect of vinyl mulch on phosphate availability of soil and fertilizer in 1982. Growth of tobacco was more vigorous at each level of phosphate treatment in vinyl mulched than in bare soil. There was significant culture x Phosphorus treatment interaction for the yields of cured tobacco leaves. These results indicated that vinyl mulch was effective to improve phosphate availability of soil and fertilizer. Increase in soil temperature and maintenance of bulk density suitable for Phosphorus diffusion by vinyl mulch were likely to Play major roles on Phosphate availability, but other unknown factors appeared to be involved.

• 한국환경농학회지
• /
• 제36권3호
• /
• pp.141-146
• /
• 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.

• 한국토양비료학회지
• /
• 제49권6호
• /
• pp.789-794
• /
• 2016

Continuous excessive application of phosphorus (P) fertilizer and manure in plastic film house soils can lead to an accumulation of P in soils. The understanding of P sorption by soils is important for fertilizer management. In this study, 9 samples were collected for acidic and calcareous soils as non-cultivated soil and plastic film house soils as cultivated soil Phosphorus sorption data of acidic soils fit the Langmuir equations, Freundlich equations in calcareous and plastic film house soils. In calcareous and plastic film house soils, the slope of isotherm adsorption changed abruptly, which could be caused P precipitation with $CaCO_3$. The calculated Langmuir adsorption maximum ($S_{max}$) varied from 217 to 1,250, 139 to 1,429, and $714mg\;kg^{-1}$ for acidic soils, calcareous soils, and plastic film house soils with low available phosphate concentration, respectively. From this result, maximum P adsorption by the Langmuir equation could be regarded as threshold of P concentration to induce the phosphate precipitation in soil. Phosphate-sorption values estimated from one-point isotherm for acidic and calcareous soils as non-cultivated soils were comparable with the $S_{max}$ values calculated from the Langmuir isotherm.

• Asian-Australasian Journal of Animal Sciences
• /
• 제10권2호
• /
• pp.196-200
• /
• 1997

Glasshouse investigations were carried out to investigate the development and yield of Atylosia scarabeoides on soils of the northern guinea savanah zone of Nigeria. Seeds were sown at four rates 50, 75, 100 and 125 kg/ha. Single superphosphate (SSP) fertilizer was applied at sowing at four rates 0, 60, 90 and 120 kg/ha. Seeding (plant) population at one month and at harvest was significantly (p < 0.01) influenced by seeding rate but not fertilizer level. Fresh herbage yield was strongly (p < 0.01) dependent on fertilizer level, with the highest (not significant) dry matter yield at 90 kg SSP/ha. Seeding rate had no significant effects on herbage yield. The crude protein content of herbage rose with increase in fertilizer level although there were no significant differences between the various seeding and phosphorus rates. No significant interactions were observed between seeding rate and phosphorus lever. The yields were generally high, indicating good prospects for pasture development with A. scarabeoides in the zone, although field trials would be of benefit.

• 한국토양비료학회지
• /
• 제50권4호
• /
• pp.203-214
• /
• 2017

Environmental toxicity due to cadmium (Cd) pollution in croplands causes critical problems worldwide. Rice (Oryza sativa L.) is an important crop in Asia, including South Korea, and numerous studies have evaluated the relationship between Cd and antioxidants to alleviate Cd uptake from the soil into plants. However, information about the relationship between phosphorus (P) and antioxidants in rice seedlings is still limited with regard to Cd phytotoxicity. We therefore investigated the physiological responses of rice (Oryza sativa L. cv 'Dongjin') seedlings to Cd toxicity and the effect of P application on reactive oxygen species (ROS) and antioxidant changes. The exposure of rice seedlings to $30{\mu}M$ Cd inhibited plant growth; increased the contents of superoxide, hydrogen peroxide, and malondialdehyde; and induced Cd uptake by the roots and leaves. Application of P to Cd-exposed seedlings decreased Cd-induced oxidative stress by enhancing the capacity of ascorbate (AsA) production and ROS-scavenging, and decreased Cd transfer from the roots to the leaves. These results suggest that P application alleviated Cd-induced growth inhibition and oxidative damage by restricting Cd translocation from the roots to the leaves and maintaining sufficient levels of AsA.

• 한국잠사곤충학회지
• /
• 제35권1호
• /
• pp.11-16
• /
• 1993

인산이 축적된 뽕밭에서 인산 시비량을 조절하기 위하여, 유효인산 300ppm 정도 포장 2개소, 450 ppm정도 포장 1개소에서 인산 표준시비량구(13kg/10a), 반량구, 무인산구, 무시비구 등을 설정하여 4년동안의 포장시험과 엽질검정을 위한 누에 사육시험을 3년동안 수행한 결과 다음과 같았다. 1. 토양유효인산 함량이 450ppm포장에서는 4년간 계속된 인산 무시비구에서도 뽕잎 수량감소가 없었으나, 300ppm포장에서의 무인산구에서는 3년차 봄부터, 인산 반량구에서는 4년차 가을부터 감수가 시작되었다. 2. 연차별로 토양 인산의 감소에 따른 수량감소와의 관계에 의하여 인산시비 개시 시기를 조사한 결과, 토심 10~20cm 부위에서 유효인산의 함량이 150ppm 이하로 떨어졌을 때 인산시비를 개시하는 것이 적당한 것으로 나타났다. 3. 인산 감량시비에 따른 뽕잎 중의 인산함량은 표준량 시비구 대비 0.18%까지 감소하였다. 4. 인산의 감량시비가 뽕잎의 질에 미치는 영향을 알기 위하여 3년간 토양인산 300ppm 포장의 뽕잎으로 누에를 사육하여 검정한 결과, 인산 무시비에 의해 수량이 감소하고, 엽중의 인산 함량이 최저 1.13%까지 감소하였어도, 수견량 및 견질에는 영향을 주지 않았다.

• 한국토양비료학회지
• /
• 제49권3호
• /
• pp.265-270
• /
• 2016

Accumulated Phosphate can be released by ligand exchange reaction of organic acids. The objective of this study was to evaluate effects of the organic acids on the availability of phosphate and the growth of crop in phosphate and salts accumulated soil. Soil samples were collected from farmer's plastic film house. Available phosphate and electrical conductivity of soil were $3,005mg\;kg^{-1}$ and $16.63mg\;kg^{-1}$ which were 6 and 8 times higher than the optimum range of soil for crop growth, respectively. Corns were cultivated in pots for 2 months. Treatments were no treatment (control), phosphate fertilizer (P), citric acid (CA) 1, 5, 10 mM, and oxalic acid (OA) 1, 5, 10 mM. Water soluble phosphorus, available phosphate, corn growth and uptake were determined after cultivation. Results showed that organic acids increased water soluble phosphorus and available phosphate. For the level of 10 mM, the order of effectiveness of organic acids for water soluble P was citric acid (44%) > oxalic acid (32%). Height and dry weight of corns were increased significantly by the treatment of citric acid 1 and 5 mM. Also, corn absorbed more phosphorus, nitrogen, potassium, calcium and magnesium in the treatment of citric acid 1 mM than these of other treatments. Even though phosphate availability of soil was enhanced by addition of citric acid 10 mM, the growth of corns decreased because high concentration of citric acid caused salt damage by increasement of electrical conductivity. Thus, the citric acid of 1 mM has the potential to improve the availability of phosphate and the healthy growth of corns.