• Korean Journal of Soil Science and Fertilizer
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• v.11 no.1
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• pp.43-50
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• 1978

In order to compare the effectiveness of different phosphorus forms (pulverized as regranulized) and formulars (compound fertilizers) of fused phosphate and to compare the effectiveness of boron from different forms (straight borax, granulized with fused phosphate and included in compound fertilizer), a field experiment was conducted on a relatively fertile upland soil using soybean as a test crop. Results are summarized as following. 1. Yield of soybean was significantly higher in the plots fertilized with P when compared to check plot (no p). However, no significant differences were observed among the different forms or formulars of fused phosphate, indicating that the regranulization or formulation of compound fertilizer did not influence the effectiveness of phosphorus. 2. The application of boron, regardless of its formular, brought about higher B content in plant tissue and higher grain yield. There was a tendency that boron contained in ragranulized fused phosphate was more effective than straight borax. The results also indicated that when boron is to be included in NPK compound fertilizer, its content should be at the least 1.5% as $B_2O_3$. 3. The effectiveness of boron appeared as increased number of pod, higher B, and Ca contents in plant and the amounts of uptake of these elements by soybean. 4. The analysis of soil after the experiment indicated that different forms or formulars of fused phosphate were similarly effective in increasing the available P, Ca, and Mg contents in the soil. 5. Slight increase in available B contents in the experimental plot soils applied with boron fertilizer was observed after the trial.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.25-32
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• 1972

The effects of limestone and wollastonite on an acid sulfate soil were studied. In addition, the effect of wollastonite was analyzed in terms of those due to calcium and to silica in the paddy field and in the laboratory with equivalent amounts of lime and wollastonite on a calcium basis. 1. Lime and wollastonite as liming materials were equally effective in neutralizing the soil acidity. 2. Lime, however was more reactive, raising the pH up to neutralization point in three days under waterlogged conditions at $25^{\circ}C$, in the lab study, and introduced alkali damage to transplanted rice seedlings showing marked restrictions of tillering in the field even though lime was applied two weeks before transplanting. On the other hand, wollastonite reacted very slowly, taking one week to two weeks to reach neutralization even when thoroughly mixed, and did not restrict the tillering. 3. Both lime and wollastonite effectively reduced the toxic aluminium in soil as well as in the soil solution but not always in the case of ferrous iron. However the reduction effect of the toxic substances in the experimental field was not so great as expected, because typical toxic symptoms were mild only. 4. Lime considerably increased the availability of silica in soil resulting in an increase of silica content in straw. Wollastonite released extra available silica itself resulting in a greater uptake of silica. 5. Increase of silica uptake by these materials was effective in reducing rate of infection of neck blast and resulted in higher rate of ripening, and in turn increased the paddy yield. 6. Application of either one significantly diminished the effect of the other. 7. Wollastonite markedly increased tillering in the early growing stage, but decreased the rate of effective tillers finally, resulting in about the same number of ears per hill at harvesting. 8. These liming materials appear to increase the number of grains per panicle slightly.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.4
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• pp.265-272
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• 2001

A manure compost has been identified as an alternative to fertilizer to increase soil fertility and crop production in farming fields. The aim of the present study was to evaluate the effects of pig manure compost on soil properties and rice productivity as well as to determine the optimum application rate. In 1997, a field experiment was carried out to evaluate the growth of rice on sandy loam, loam, and clay loam soils amended with 0, 5, 10, and $20Mg\;ha^{-1}$ of pig manure compost plus NPK, which decided by soil testing. Rice yields were higher in soils receiving manure compost amendment. The maxim um yields were evaluated with $7,520kg\;ha^{-1}$ in the levels of $4.2Mg\;ha^{-1}$ of pig manure compost application plus NPK in sandy loam, $7,320kg\;ha^{-1}$ in the levels of $10.7Mg\;ha^{-1}$ in loam, and $6,320kg\;ha^{-1}$ in $17.2Mg\;ha^{-1}$ in clay loam soil. The optimum application rate of pig manure compost, which decided for 95% of maximum yields, was $4.0Mg\;ha^{-1}$ in sandy loam and $7.0Mg\;ha^{-1}$ in loam and clay loam soils under the condition of chemical fertilization by soil diagnosis. An increase in rice yield indicated a better nutrient status in compost-amended soil which was supported by the higher nutrient contents of N, P and K in shoot of plants grown in soil with manure compost amendment. Addition of manure compost increased available phosphate, silicate and exchangeable K in the amended soils according to the rate of compost application rate. It can be concluded that the manure compost could be a suitable organic fertilizer for improving rice productivity and soil fertility, and an application rate of $4.0Mg\;ha^{-1}$ in sandy loam and $7.0Mg\;ha^{-1}$ in loam and clay loam soils would give the optimum rice yields in the standard fertilization by chemical fertilization.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.4
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• pp.292-301
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• 2001

The objectives of this study were to measure the changes in soil moisture regimes and the distribution patterns of inorganic N derived from the fertigated $^{15}N$-labeled urea, and compare them with the results obtained from broadcast-applied soil under the same drip irrigation domain. In fertigated soil, a $^{15}N$-labeled urea solution of $117mg\;N\;L^{-1}$ was applied by surface drip irrigation for 4 weeks. In broadcast-applied soil, no the other hand, 4 g of $^{15}N$-labeled urea(1.87 g N) mixed thoroughly with 5 kg of soil was placed on the surface of packed soil. Soil water status was controlled by drip irrigation scheduled at soil matric potential of -50 kPa. A calibrated time-domain reflectometry probe was installed in the soil vertically 15 cm apart from a drip emitter to control drip irrigation. About 60% of urea-derived inorganic nitrogen was remained in the top zone between 0 and 10 cm depth of fertigated soil, while, most of the inorganic nitrogen (91%) was accumulated in the top zone of broadcast-applied soil. Of inorganic nitrogen derived from urea, the percentage of $NO_3{^-}$ was much higher for fertigation (99%) than for surface application (62%). The relatively lower recovery of urea-derived inorganic nitrogen of broadcast-applied urea-N (51%) than that of fertigated urea-N (89%) was attributable to enhanced $NH_3$ volatilization.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.694-699
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• 2012

To examine the EC model in a culture medium, basic culture medium of Rush (2005) and EC model of Robinson and Strokes (1959) were applied analyzing the equivalence ion total amount, the EC variable of cation and anion. Following the experiential translation by Steiner (1980), 130 optimized domestic and foreign culture media for crop growth were utilized, and estimated EC model was also demonstrated. Results from basic culture medium of Rush (2005) suggests an estimated EC by equivalence ion total amount and high reliable regressive model with 0.96 y = 1.33x - 0.23 of 0.96 as value $R^2$. It was found out that the change in concentration of positive ion and anion did not differ significantly with the increase and decrease of EC, however, there occurred a slight variable range. The change brings about a bigger anion influence than the previously reported positive ion, seemingly like those based on nitride ion and sulfur ion. The above EC estimated models confirmed that with optimized 130 domestic and foreign culture media for crop growth, the value derived will be as follows: $R^2$ = 0.98 with y = 1.23x - 0.02. In addition, the contour analysis of positive ion and anion for EC, with popularly known concentration range of EC $1.5-2.5dS{\cdot}m^{-1}$ reveals an equivalent of more than $11meq{\cdot}L^{-1}$ for positive ion and $15meq{\cdot}L^{-1}$ for anion. On the other hand, the left bottom, low concentration $1.5dS{\cdot}m^{-1}$ and the right above, high concentration $2.5dS{\cdot}m^{-1}$, for both positive ion and anion existed differently in a proper culture medium concentration. This study adapted variables of both positive ion and anion of EC simultaneously, unlike in the previous culture medium by ion ratio in mutual ratio of Steiner (1980), and offers an EC model that can estimate levels or positive ion and anion in proper concentration, EC $1.5-2.5dS{\cdot}m^{-1}$, with distributed features of ions.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.231-238
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• 2006

The physical properties of seven perlites different in particle size distribution were investigated to develop perlite bag culture in Korea. Particle sizes of 1.0-2.8mm and larger than 2.8 mm were rather evenly distributed in S-1 (1.2-5 mm), S-2 (0.15-5 mm) and S-5 (parat No.1). Larger particles were less in S-3 (1-3 mm), S-4 (Parat No.2), S-6 (OTAVI) and S-7 (Agroperl B-3). S-4, S-6 and S-7 contained lots of particles less than 1 mm in size. Total porosity was similar among substrates with the value of $59{\sim}62%$. Container capacity was between 35-40% regardless of substrates except in S-2 with 27.7%. Water content, which was about 60% at 0 kPa, was decreased sharply at 4.90 kPa regardless of substrates, which meant the easily available water was plenty in any kind of perlite tested. Substrates, S-1, S-2 and S-3 with different particle size distribution, were investigated to evaluate for perlite bag culture. Six tomatoes (Licopersicon esculentum Mill. cv. Rokkusanmaru) were planted in a perlite bag of 40 liters with the dimension of 120cm in length and 34cm in width. The amount of nutrient solution supplied and its drainage dependent on daily integrated radiation didn't show any regular trend during the growth. Roots in the bag were distributed evenly in S-1 and S-2 than in S-3. Plant grown in S-1 showed the highest total and marketable yield of 8,628 and 7,759 kg/10a, respectively. The number of small size fruits and malformed fruits were more in S-3. Consequently, S-1 with the particle size distribution of 1.2-5 mm is suggested as desirable substrate for perlite bag culture.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.151-156
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• 2006

This study was conducted to investigate effects of granular silicate fertilizer(GSF) on growth, nutrient uptake and quality rice during cultivation. Then the chemical properties of paddy soil used for the cultivation test were pH 5.9, O.M. $13.7g\;kg^{-1}$, avail. $P_2O_5$ $48.9mg\;kg^{-1}$, and avail. $SiO_2$ $79.8mg\;kg^{-1}$. The amounts of GSF treated in the paddy soil were 0, 76, 185, 229, 413 and $489kg\;10a^{-1}$ for control, S-100(control amounts of soil available $SiO_2$), S-130, S-160, S-190 and for S-210 treatments, respectively. At results of rice growth leaf length and tiller number were more remarkable results at treatments of GSF than control. The leaf length of rice at S-100 treatment was the highest as 99.4 cm and the tiller number was the highest as 18.9 ear number at S-130 treatment. At the results of rice yield parameters, the grain and straw yield of rice were showed that all of the GSF applicated treatments were more predominant level than at the control, especially their levels were the highest values as 841.5 and $815.2kg\;10a^{-1}$ at the S-160 treatment, respectively. Also at the results of quality parameters on rice grain, a perfect kernel in the GSF applicated treatments was more increased than at control, but a broken kernel rate was inversely decreased. In results of these aspects, the chemical properties of white rice and the taste of rice by the Toyo MA-90A(Toyo rice quality taster) instrument, amylose content was the lowest value as 18.7%(generally about 20%) at S-160 treatment. Also, Mg/K ratio and rice taste value were the highest level as 0.58 and 69.1 at the S-190 and S-160 treatments respectively. The harvest yields of rice at S-160 and S-190 treatments from these growth factors were more produced about 8-13% than control. Therefore, the GSF application for rice cultivation from these results should be expected to obtain the positive effects as enhancement of rice harvest yield and improvement of quality on the cooked rice taste. Amount of GSF application could be recommended as around $200mg\;kg^{-1}$ for optimal and economical rice cultivation.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.298-304
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• 2010

Nutrient uptake by plants and drainage ratio in culture beds can affect ion balance and concentrations of nutrient solutions in electrical conductivity (EC)-based closed-loop soilless culture. This study was conducted to analyze ion concentration changes with time and drainage ratio under EC-based nutrient control in closed-loop soilless culture for sweet pepper plants (Capsicum annum L. 'Boogie'). At first experiment, ion concentrations of the nutrient solution were periodically analysed while collected drainage was being reused by mixing with fresh nutrient solution at a dilution rate of EC $2.2\;dSm^{-1}$. Changes in ion concentrations of $K^+$, $Ca^{2+}$, $Mg^{2+}$, $NO_3^-$, $SO_4^{2-}$, and $PO_4^{3-}$ were 1.13, 5.35, 0.92, 0.9, 1.10, $0.19\;meq{\cdot}L^{-1}$, respectively. Ion balance such as $K^+$ : $Ca^{2+}$ and $SO_4^{2-}$ : $NO_3^-$ were mainly affected during the recirculation of nutrient solution. At second experiment, ion concentrations and EC of drainage were compared before and after replenishment under different four drainage ratios of 7%, 16%, 39%, and 51%. Ion ratios of the recirculated nutrient solutions such as $K^+$ : $Ca^{2+}$ for cation and $SO_4^{2-}$ : $NO_3^-$ for anion were investigated. ECs of drainage decreased with increase of drainage ratio and each ion concentration showed the same trends as EC did. Ion balances in drainage with drainage ratio were a little different from each other, but each ratio could be corrected by replenishment process. The ion balance at 7% drainage ratio was closest to initial ratio and followed by 16%, 51%, and 39% in the order. Ion balance such as $K^+$ : $Ca^{2+}$ and $NO_3^-$ : $PO_4^{3-}$ were mainly affected the correction process.

• Journal of Plant Biology
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• v.12 no.3
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• pp.26-34
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• 1969

Through immersing barley seeds (variety; Suwon No. 6) into different dilution of carrier-free P-32 original solution (Total activity; 90mc, To; 3/21) for 24 hours at room temperature, four groups of seeds (each group consists of 200 seeds) having activity levels of 1.6$\times$10-3$\mu$c 32P/grain, 2.3$\times$10-1$\mu$c 32P/grain 6.9$\times$100$\mu$c 32P/grain and 2.5$\times$101$\mu$c 32P/grain respectively, were obtained. To investigate the effects of various activity levels of P-32 absorbed upon the test plants, the seeds were germinated, transplant into the pots, and the growth was observed for three months after germination. After harvest, the inorganic contents in the leaves and the stems were also analyzed. The results: 1) Until four days after the beginning of germination, the rate of germination was found the lowest at the strongest activity level of 2.5$\times$101$\mu$c/grain. At the other P-32 levels treated, it showed generally higher than the control. 2) Before transplanting the seedlings of both 1.6$\times$103$\mu$c/grain and 2.3$\times$10-1uc/grain levels showed more vigorous growth than the control, whereas at the 6.9$\times$100 uc/grain level a retarded growth was conspicuous and all of plants belonging to the highest activity level of 2.5$\times$101$\mu$c/grain were withered owing apparently to the radiation damage. 3) This trend of growth promotion was continnually observed at the low activity levels even after transplanting the seeldings to the pots. As for the plants belonging to 6.9$\times$100$\mu$c/grain level, a clear sign of gradual recovery from the damage afflicted at the earlier stage was observable, and as a result the plants showed more growth than those of control two months after transplanting. 4) The number of stems diverged was found somewhat small in the blocks treated with P-32, compared with that of control until two months after germination. At the later stage of growth there seemed no significant difference among the themselves. 5) The dry weight of leaves and stems was proved that the lower the activity, the mroe it was produced. The relative increase of dry matter in each treatment compared with the control was 2% at 6.9$\times$105$\mu$c/grain level, 9% at 2.3$\times$10-1$\mu$c/grain and 35% at 1.6$\times$10-3$\mu$c/grain respectively. 6) The inorganic contents of the leaves and stems harvested were proved that: (1) Nitrogen was highest at the lowest activity level of 2.3$\times$10-1$\mu$c/grian. (2) Phosphorus showed generally higher contents in the treated blocks than in control, with the peak being at 2.3$\times$10-1$\mu$c/grain. (2) Phosphorus showed generally higher contents in the treated blocks than in contro, with the peak being at 2.3$\times$10-1$\mu$c/grain level in the leaves and at 6.9$\times$100$\mu$c/grain in the stems. (3) These was no significant difference in potassium contents in the leaves between treatment and control, whereas in the stem the treated blocks were higher than control roughly in propotion to the activity level. (4) Calcium in the lesves was richer in treated blocks than control while in the stem no difference was seen. (5) Magnesium contents both in leaves and in stems there was no difference among treatments.