• Korean Journal of Medicinal Crop Science
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• v.7 no.4
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• pp.282-287
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• 1999

This study was conducted to investigate the effects of different soil texture in agronomic characteristics, root yield and quality of baloon flower (Platycodon grandiflorum A. DC.). Three kinds of soil texture, sandy loam, silt loam and clay loam, were tested for two years. Baloon flowers were seeded with 20cm row space and cultivated in the one square meter pot with 0. 6m depth. Fifty plants per pot were remained. In growth characteristics of one-year-old plants, shooting date was not significantly different according to the changes of soil texture. The ratio of stem growth was highest between July and August. In two-years-old plants, it was showed between May and June. Plants grown on clay loam showed the highest growing characteristics than those of other soil textures. Dry root weight cultivated on clay loam was 274kg/10a in one-year-old and 934kg/10a in two-years-old plants. The content of ethanol extracts from root was highest at those of sandy loam as 47.1 % in one-year-old root. The crude saponin content was not different significantly among the three kinds of soil texture.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.29-34
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• 1987

This experiment was designed to find out the effects of soil conditioner, Polyacrylamide (PAM) and Bitumen, on the changes of soil aggregate properties and crop yields. The soil conditioners were treated at the rates of 0.5% and 1% to sandy loam and silty clay loam soils. The aggregate stability, wetting angle, mean weight diameter and air permeability were analyzed. Pot experiments were carried out to investigate the soybean growths and soil property changes after the soil conditioners were sprayed to surface soils. Soil aggregate stability was increased remarkably by the soil conditioner, PAM and Bitumen, treatments. PAM was more effective in sandy loam than silty clay loam, but Bitumen was better in silty clay loam. Wetting angle of the soil was changed slightly by PAM treatment, but it was greatly changed to hydrophobic by Bitumen treatment. Air permeability, water infiltration rate and moisture retention of the soils were increased by surface application of soil conditioners, PAM and Bitumen. The growths of soybean in conditioner applicated pots were better than those of untreated pots from early stage, and the yields were increased 6-13%.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.340-349
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• 1995

Effects of the zeolite particle size on the soil chemical properties and on rice growth was investigated on the pot with the loamy sand (Sadu series) and silty clay loam(Paju series) soils. All the zeolite treatments brought the increase of unhulled grain yield on the both loamy sand and silty clay loam soils. Unhulled grain yield increased with increasing the amount of zeolite applied and with decreasing the amount of particle size of zeolite applied on both soils. Unhulled grain yield increased significantly by 11.1% (22.79g/head) with 2ton/10a of smaller than $106{\mu}m$ size zeolite on the loamy sand soil and on the silty clay loam soil, yield increased by 9.3% (24.98g/head) with 1.5ton/10a of smaller than $106{\mu}m$ size zeolite. CEC, pH and contents of exchangeable cations of the soil after experiment were raised by increasing the amount of zeolite and also by decreasing the particle size of zeolite at both soil. At the heading stage, the zeolite treatments improved the growth of rice plant compared to control. The nutrient contents(T-N, Ca, Mg, K, Na), except phosphorus, in the rice plant grown on the zeolite treated soils were higher than control plot.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.249-255
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• 1995

This study was conducted to investigate the effects of some soil conditioners, such as polyacrylamide(PAM), polyvinylalcohol(PVA) and Bitumen emulsion, on aggregate formation and stability, wetting angle, sorptivity and penetrability of the soil with different textures : sand, sandy loam, loam and clay loam. A pot experiment was carried out to find out the effect of treatment on the germination and growth of lettuce with three textures : sand, sandy loam and silt loam. Soil aggregates larger than 2mm in untreated soils at dry condition were naught in sand, 45% in sandy loam, 80% in loam and 90% in clay loam. Treatments of soil conditioners tended to increase the occurrence of soil aggregate larger than 2mm, which were 20~25% in sand, 55~75% sandy loam, but not affected greatly aggragate occurence in loam and clay loam. The aggregate instability was decreased by the soil conditioner treatment. The wetting angles of the soils were greatly changed by hydrophobic of Bitumen, but those were changed slightly by PVA and PAM application. The sorptivity and penetrability data indicated that the effects of different materials on these parameters differed depending upon soil texture. Application of PVA and PAM were no effect exceptive in sand. Application of Bitumen revealed that water movement was not showed in all soils. The germination rate, root weight and top plant weight of lettuce were increased in all soils by PAM treatment as compared to untreated soils. Particularly the greater effect was occurred in sand soil than in sandy loam and silt loam. PAM increased greatly the moisture content and air phase of soils.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.35-44
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• 1987

Differing in water conditions, the dry matter weight per plant was highest at 0 cm flooding depth, and was decreased at above 2 cm flooding depths. The shoot and spikes per pot developed best at flooding depths of 0 and 2 cm, but worst at -5cm or above 4cm flooding depths. The dry matter weight of shoots was linearly increased, but the weight of roots was sharply decreased according to high temperature after flower initation. The shoots and spikes per pot developed more effectively at 25$^{\circ}C$ than at 35 or 15$^{\circ}C$. The number of shoot and spike per pot were decreased according to higher shading. The effects of shading of 25-45% were not significantly small. The natural white and yellow spectra were the most effective to increase dry matter weight, shoots and spikes per pot. The dry matter weights of shoot and root per plant were not significantly different among at: 50 and 75% clay. The number of shoots were best and continuously increased at 75% clay, and the increments at 0 and 100% clays showed the lag period at early stage. The pattern of spikes was similar to shoots with less difference in various clay composition. The dry matter weight per plant in paddy field and upland field was basically similar. The numbers of shoot and spike were increased in response to increased fertilizer levels up to 20Kg per 10a of each component.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.96-106
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• 1998

Rice plants were grown for 42 days in the specially made micro-ecosystem(pot) containing two different soils treated with fresh and 60-day-aged residues of [$^{14}C$]quinclorac, respectively, to elucidate the behaviour of the herbicide quinclorac residues in the soils. Amounts of $^{14}CO_{2}$ evolved from two soils treated with different residues with and without vegetation were all less than 2.2% of the total $^{14}C$, indicating that there was little microbial degradation of quinclorac in soil. $^{14}C$-Radioactivity absorbed and translocated into rice plants from soil A and B containing fresh quinclorac residues was 8.4 and 24.2%, respectively, of the originally applied $^{14}C$, while 5.5 and 17.7%, in aged residue soils. These results indicate that larger amounts of $^{14}C$ were absorbed by rice plants from soil B with less organic matter and clay than soil A, and the uptake of [$^{14}C$]quinclorac and its degradation products decreased with aging in soil. After 42 days of rice growing, 84.5 and 61.8% of the $^{14}C$ applied freshly to soil A and B, respectively, remained in soil, whereas, in the case of aged soils, 86.3 and 67.7% of the $^{14}C$ applied did. Meanwhile, without vegetation, more than 98.3% of the $^{14}C$ applied, in both fresh and aged residues, remained in soil, suggesting that quinclorac was relatively persistent chemically and microbiologically. Most of the non-extractable soil-bound residues of [$^{14}C$]quinclorac were incorporated into the organic matter and largely distributed in the fulvic acid portion.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.129-134
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• 1997

Effect of soil moisture level on the growth of ginger plant was investigated through a pot experiment. The soil used for this study was collected from a newly reclaimed hillside land. The soil was a silty clay loam(19% sand, 57% of silt and 24% of clay), acidic in soil rection(pH 4.7, in $H_2O$) and low in organic matter content(1.2%). Soil moisture levels selected for the experiment were 10, 15, 20, 25, and 30% on weight basis. Under the soil moisture of 20-25%, the emergence ratio was 80-100%, 25 days alter planting. The performance of above ground parts was best under 20-25% of soil moisture. When the soil moisture content was far from 25%, high or low, the die out of above ground parts of ginger tended to increase. Under 20-25% of soil moisture the growth of roots was best and the occurrence of root rot was minimal.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.1
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• pp.72-86
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• 1990

This study was carried out to get the basic information of irrigation plans for upland crops such as the optimum irrigation level and the project water requirement. Red peppers and cucumbers were cultivated in PVC pot lysimeters filled with 60cm deep clay loam soil. Four tensiometers were installed in each pot to measure the soil water pressure head. Six levels of irrigation were used. The results obtained from this study are summarized as follows: 1.The optimum irrigation level. The irrigation level of FC-PF2.7 was found to be the optimum level for both red pepper and cucumber with respect to the yield and the weight per fruit. In case of FC-PF2.7, total ET during the irrigation period were 1005.2mm for red pepper, and 429.6mm for cucumber, respectively. 2.soil moisture extraction patterns. Average soil moisture extraction patterns (SMEP)during the irrigation period were from 1st soil layer 43% : 32% : 16% : 9% for red pepper and 39% : 34% : 15% : 12% for cucumber, respectively. The extraction ratio of the upper soils showed very large values during the early stage of growth and decreased largely during the middle stage, and became larger in the last stage. 3.The project water requirement. Among the reference crop evapotranspiration(ETo) computation methods presented by FAO, the Penman method was found to be the best. The effective rainfall was computed by a modified USDA-SCS curve number equation. Availability ratios of the total rainfall during irrigation season were 59.2% for red pepper and 48.9% for cucumber, respectively. Net project water requirement of design year are 837.3mm for red pepper. and 502.Smm for cucumber, respectively.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.479-492
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• 2003

Wheat, barley, rye, and maize were grown in field and pot experiments at various non-contaminated soils in order to establish uptake rates for added selenate, and to find baseline concentrations for various soil types. Edible parts (grains) and stalks of the crops were analyzed separately for Se, as well as for Ca, Cu, Fe, Mn, P, S, and Zn. The addition of Na-selenate in admixture with the NPK 20:8:8 fertilizer had no influence on the composition of the other elements investigated. The proportions of added nitrate: selenate, and sulfate:selenate were kept constant. The Se- uptake rate differed among the cereals tested, it was highest for winter wheat. Utilization of added Se in the field ranged from $0,4-4,7\%$, and and in the pots from $3,3-5,4\%$, it was markedly lower in clay soil. Whereas P and Zn were preferably found in the grains, Ca-Fe-Mn-S got enriched in the stalks. For the fields, the location had some influence upon Fe, Mn, and Zn, whereas it was not important for P, S, Cu, and strikingly, Ca. Pot and field experiments on similar soils led to different results, except for P and S. Maize (whole grains) was significantly lower in Ca, Cu, and Mn, and might even cause trace element deficiencies, if exclusively fed. Few correlations between the trace elements investigated led to the conclusion that most element contents were governed by plant metabolism. Variations of mobile Fe in the soils were balanced by uptake into the stalks. The data are compared with data from other presumably non-contaminated sites.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.97-103
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• 2016

BACKGROUND: Clay mineral is well known to improve physico-chemical of soil. The objective of this study was to investigate the growth characteristics and inorganic nutrient contents of crops with application levels of phyllite.METHODS AND RESULTS: Both young radish and lettuce were selected as target crops for this study. The experiment was conducted in a wagner pot(1/5000a) in glass house at Sunchon National University. Treatment conditions were divided P0NPK(No phyllite + NPK), P5NPK(phyllite 5 Mg/ha + NPK), P10NPK(phyllite 10 Mg/ha + NPK) and P15NPK(phyllite 15 Mg/ha + NPK) by crops, respectively. Bulk density and porosity of soil in control without treatment conditions were ranged from 1.02 ∼1.04 g/cm³ and 56.5∼57.0%, respectively, and those for treatments with phyllite were in the ranged from 0.94∼1.00 g/cm³ and 58.4∼63.5%, respectively. Dry weights of young radish and lettuce were higher in P15NPK treatment than those in other treatments. The amounts of T-N, T-P and K uptake in young radish with phyllite application treatments were increased 36∼115, 18∼67 and 20∼76% than without phyllite application treatment, respectively. In lettuce treatments, amounts of T-N, T-P and K uptake were intended to all tested treatments similar with result of young radish treatment.CONCLUSION: Therefore, these results confirm that phyllite application to the soil improves physico-chemical of soil in addition to improving growth of young radish and lettuce.