• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.172-178
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• 2009

Relation between spatial variation of soil salinity and emergence of five upland crops such as sudan grass, sesbania, barnyard grass, corn and soybean was studied in the three reclaimed lands of Korea during two years from 2007 to 2008. Although soil salinity is vary high at seeding season, desalting treatment by three days-flooding before seeding, reach at favorable level lower than $6dS\;m^{-1}$ of soil salinity for emergence of soiling and forage crops and then plant number emerged(No. $m^{-2}$) was 55~149 for sudan grass, 118~266 for barnyard grass, 46~115 for sesbania, 3~11 for corn and 6~19 for soybean in 2007. However plant number emerged under no desalting treatment varies place by place because of soil salinity difference in 2008. Plant number emerged after seeding according to soil salinity was well expressed as logarithmic function, and sharply decrease with increase of soil salinity. It is accordingly concluded that desalting treatment of flooding before seeding of upland crops is essential for good emergence in the newly reclaimed land from tidal flat.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.179-186
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• 2009

Relation between soil salinity and forage yield of five upland crops such as sudan grass, sesbania, barnyard grass, corn and soybean was studied in the three reclaimed lands of Korea during two years from 2007 to 2008. Although plant number emerged was obtained satisfactory by desalting treatment, further growth of crops was sharply affected by re-salting process according to soil drying. Soil salinity varied place by place and changed constantly, crop growth was differently responded to soil salinity according to the specific conditions of the reclaimed lands. In the Iweon reclaimed land with higher soil water conductivity and sandy soil texture, crop growth and yield sharply decrease with increase of soil salinity. Relation between soil salinity and crop growth and yield was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the tallest height of crops was $5dS\;m^{-1}$ for soybean, $6dS\;m^{-1}$ for corn and $7dS\;m^{-1}$ for sudan grass, sesbania, and barnyard grass by logarithmic function. In the Hwaong and Yeongsangang reclaimed lands with low soil conductivity and finer soil texture, plant growth response to salt stress was statistically vague by mixing of harmful influence from flooding and wet injury. However, it is observed that crop growth and yield on the place of lower salinity was better than crop growth on the place of higher salinity. It is accordingly concluded that flooding control during summer rainy season is vary important as well as desalting process for good growth of soiling and forage crops in the newly reclaimed land from tidal flat.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.4
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• pp.283-295
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• 1979

A new Farmland Expansion and Development Promotion Law was enacted in 1975. This law authorizes the Government to undertake development within a declared "reclamation area", wherever the land owners are unable to do so. In order to give additional impetus to conversion of waste hilly land into productive farmland, these hilly land development projects were conducted as large scale scheme which include soil fertility improvements such as the application of lime and phosphate. Farmland Expansion and Development Promotion Corps has attempted to undertake annual farm surveys in order to obtain some information about hilly land agriculture and farming operations within the reclamation project areas since 1976. As survey data accumulates, more and more clear picture of hilly land farming come to appear and enable us to conduct in-depth study. Effects of such upland reclamation include converting of previously unproductive slopeland into cultivable farmland for lucrative and commercial farming or food production. Furthermore, idle or marginal resources such as farm labor, equipment and compost would be fully employed. Socio-economic effects would include increases in land value and attitude change of farmers. On the other hand the preservation of natural environments might be damaged to the some extend by the projects. As shown in Table 7, the average farm size increased from 3,156 pyeong($3.3m^2$) to 5,562 pyeong, a 76.2% increase. The proportion of small farms with less than I ha dropped from 59.8% to 34.4%, but that of the large farms over 2 ha rose from 13.1% to 32.0% (See Table 8). The survey results indicate that as the farming on reclaimed uplands become time-honored, the acreage devoted for food crop production decreases against the economic crop growing acreage (see Table 6). For example, in the case of uplands reclaimed in 1972, the ratio of food crop acreages decreased from 99.7% in 1972 to 62.5% in 1977, whereas that of economic crop acreages increased from 0.3% in 1972 to 37.5% in 1977. The government used to actively encourage the farmers to carry out food crop production in the reclaimed upland targting toward the realization of self-sufficiency in food grains. It is, however, apparent that the farmers did hardly take the government advises as far as their economic interest were concerned. Yield per 10a. of various crops from the reclaimed uplands by year were surveyed as seen in Table 12. On the average, barley production in the reclaimed areas achieved 83.3% of the average unit yield from the existing upland in its 5 th year. Soybean yields showed a modest increase from 64% in the first year to 95%, in the 5 th year. In contrast, economic crops such as red pepper, totacco and radish achieved their maximum target yields in 3 years from starting to cultivate on the reclaimed farms. In order to test the post economic viability, an economic analysis was performed for each of selected subprojects on the basis of the data obtained through survey. The average actual internal economic rate of return on upland reclamation investments was found to be 20.3% which exceeded other types of projects of land and water development such as tidal land reclamation, irrigation or paddy rearrangement. The actual IRRs of subcategories of upland reclamation projects varied from 17.9% to 21.4% depending upon the kinds of cropping system adopted in each reclaimed areas such as food, economic, fruit or forage crops.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.669-685
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• 2012

This study was carried out to investigate the nutrient value and yield response of corn, barley, and sudangrass by the application of anaerobic liquid fertilizer in two tidal land soil in order to design the resource recycling agricultural system between livestock and forage crop cultivation in a environment friendly agricultural region. Forage crop yields at reclaimed tidal soil during were at the level of 64~76% comparing with forage crop yields at upland soil in the cropping system of corn, barley, and sudangrass. And yields of forage crops were in the order of barley > corn > sudangrass in the cultivated cropping system for 2 year. Relative feed values (RFVs) of forage crops were 88%~106% for corn, 90%~111% for barley, and 91%~113% for sudangrass, and the carrying capacity of beef cattle (Hanwoo) was 5.8~8.6 head/year/ha for the corn-barley cropping system of one year, and 4.8~6.7 head/year/ha for the barley-sudangrass cropping system of one year. Also, carrying capacity of beef cattle (Hanwoo) was highest in the application level of anaerobic liquid fertilizer 200%.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.586-593
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• 2014

Newly reclaimed tidal land is known to be in low status of soil fertility. The incorporation of crop residue is an effective method to improve soil properties and fertility in reclaimed saline soils. The objective of this study was to evaluate the efficiency of rice straw (RS) application to improve physico-chemical properties of saline-sodic soil and its contribution to productivity of whole crop barley. Increasing rate of rice straw improved growth parameter related to yield of whole crop barley, which increased tiller number significantly (p<0.05).The yield increased by 15% (F.W) and 9% (D.W) in rice straw-amended plots. The content of soil organic matter (SOM) in the surface soil (0-20cm) with rice straw incorporation increased by 5~9% (RS 2.5~RS 7.5) compared to RS 0, in which the content of SOM decreased after two consecutive cultivations. Rice straw incorporation promoted soil physico-chemical properties and nutrient-availability of the test crop, as indicated in change in soil bulk density, porosity and increased nutrient uptake of plant. Especially, the P content and uptake of whole crop barley increased with increasing the rate of rice straw application. In conclusion, the rice straw application at rates of $5.0-7.5ton{\cdot}ha^{-1}$ in reclaimed saline soils effectively improved soil properties and crop productivity, which has potentials to reduce the loss of chemical fertilizers and facilitate the favorable condition for crop growth under adverse soil condition.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.135-142
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• 2012

Exchangeable cations are often overestimated especially in salt-affected soils due to the presence of high levels of soluble ions in soil solution. Thus, quantitative analysis of the soil exchangeable cation based on ammonium acetate extraction method {(Exch. Cation)$_{total}$} requires additional process to remove the free ions (pre-washing) in soil with distilled water or alcohol {(Exch. Cation)$_{pw}$} or subtraction of the soluble ion contents from the total exchangeable cations {(Exch. Cation)$_{ref}$}. In this research, we compared the three different methods for the determination of exchangeable cations in soils affected by different types of salt accumulation such as the soils from upland, plastic film house, and reclaimed tidal land. In upland soils, non-saline and non-sodic soils, the regular ammonium acetate extraction method did not have any problem to determine the content of exchangeable cations without any additional process such as the pre-washing method or the subtraction method. However, the contents of exchangeable cations in the salt-affected soils might be determined better with the pre-washing method for the plastic film house soils and with the subtraction method for the reclaimed tidal land soils containing high Na.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.2
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• pp.66-71
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• 2003

This study was carried out to obtain basic data for selecting the applicable crops in reclaimed land and to provide guidelines for the rotation between paddy and upland cropping. Field experiment was conducted with six summer crops(garland chrysanthemum, young radish, small radish, kale, lettuce, red lettuce) at Dae-Ho reclaimed experiment plots in Dangjin province. Dry weights and plant heights of harvested crops were measured and soil chemical properties were analyzed. Plant height and dry weight decreased significantly with increasing soil saturation paste extract electrical conductivity(ECe) and sodium adsorption ratio(SAR). The threshold ECe of salt inhibition for six crops was less than $1dS\;m^{-1}$ for young radish and kale, greater than $4dS\;m^{-1}$ for garland chrysanthemum, and greater than $6dS\;m^{-1}$ for small radish, lettuce, and red lettuce. At higher ECe that inhibits crop growth, with every increase in $1dS\;m^{-1}$, dry weight index decreased by 3.35 for kale, 3.92 for small radish, 3.98 for young radish, 4.66 for lettuce, 7.57 for garland chrysanthemum, and 8.45% for red lettuce, respectively. The ECe causing 50% reduction of dry weight index was $18.9dS\;m^{-1}$ for small radish, $17.3dS\;m^{-1}$ for lettuce, $15.4dS\;m^{-1}$ for kale, $12.0dS\;m^{-1}$ for red lettuce, $11.3dS\;m^{-1}$ for young radish, and $11.0dS\;m^{-1}$ for garland chrysanthemum. Among the tested 6 summer crops through field experiment and in-situ survey, kale was proved to be a favorable vegetable crop at reclaimed tidal land.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.464-464
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• 2011

새만금지구 간척사업은 지난 1990년대 초반 이래로 국책사업으로 수행되어 왔다. 그러나, 하류에 조성될 새만금호의 수질에 대한 일반의 우려가 높아 배수갑문을 개방하여 해수 유통을 허용하고 있고, 원래 목적인 담수호 조성이 지체되고 있다. 농업비점오염부하가 담수호의 주요 오염원의 하나로 인식되고 있고, 담수호 수질 개선을 위해서는 농업비점 저감대책이 강구되어야 한다. 본 연구의 목적은 저염도 새만금 간척지 밭을 대상으로 비종에 따른 비점오염 배출부하량을 모니터링하고 이를 정량적 평가를 하는 데 있다. 계화방조제 전면의 간석지에 간척농지 시험포장을 조성하였다. 비종으로 축분퇴비와 화학비료를 적용하고, 무시비 대조구와 비교하여 동계 청보리, 하계에 콩과 수수 작물 재배 시험을 수행하였다. 시험포장의 수문, 수질, 토양, 지하수 모니터링을 통하여 간척지 밭으로부터 오염물질 배출기작을 규명하고 비점부하를 정량적으로 산정하였다. 본 연구 결과는 염도가 높은 간척농지에서 밭작물 재배에 따른 비점부하 배출기작에 대한 이해를 증진하고, 나아가 농업비점오염 저감을 위한 영농개선 기법 개발에 중요한 기초자료를 제공할 것으로 판단된다.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.16-24
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• 2010

Effect of flooding on the desalting efficiency and the growth of sudan grass, barnyard grass, sesbania and corn was studied in a sandy soil of the Iweon reclaimed tidal land. Flooding plots were treated by 400 (one time flooding), 800 (two times flooding), and 1,200 mm(three times flooding) of water, respectively, and then soil salinities of the treated plots were compared with salinity of the control plot (not flooded) for estimation of desalting effect. Desalting ratio of 1,200 mm treatment was 78.3% for depth 0-20 cm, 70.5% for depth 20-40 cm and 60.8% for depth 40-60 cm, and then the soil salinity reached at 3~6 dS $m^{-1}$. Consequently, it was considered that sandy saline soil was satisfactorily desalted for upland crops to be cultivated by 1,200 mm flooding, but insufficiently desalted by 400 mm and 800 mm flooding because of high salinity ranged 5~14 dS $m^{-1}$ even after flooding treatment. In addition, it was estimated that soil salinity should be controled lower than 7.7 dS $m^{-1}$ in order to obtain more than 80%of crop emergence when four crops are simultaneously cultivated by inter- or mixed cropping in a field. Dry matter yields (kg $10a^{-1}$) was 1,068 for sudan grass, 696for barnyard grass, 1,426 for sesbania, and 1,164 for corn by 1,200 mm flooding treatment, but only 46.8~74.3% by 800 mm flooding treatment and 2.9~25.5% by 400 mm flooding treatment. Therefore, it is concluded that the flooding treatment more than 1,200 mm is necessary for satisfactory desalinization in order for the low salt tolerance crops to be cultivated in the sandy reclaimed tidal land.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.347-354
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• 2016

This study was conducted to investigate the physical and chemical properties of soils in Saemangeum reclaimed lands. The investigated areas were total 5,020 ha which included 220 ha for Agricultural Life site, 2,450 ha for Tourism & Leisure site, 1,130 ha for Industrial & Research site, 820 ha for Bioenergy crop production site, and 400 ha for Rural City site. Soil samples consisting of the upper 20 cm from the surface were collected in every $200m{\times}500m$ of the each site in March and September, 2015. Particle size distribution of soils in the reclaimed land was 83.2% sand, 8.6% silt and 8.2% clay in average. Soil texture was distributed as 40.8% sandy soil, 35.5% loamy sand, and 19.7% sandy loam. Based on the investigation of soil chemical properties conducted in March, 2015, soil pH, electrical conductivity of a saturated soil paste extract (ECe), and exchangeable (Exch.) $K^+$ and $Mg^{2+}$ concentrations were higher than those of the optimum levels for upland soil, whereas soil organic matter content, available (Avail.) phosphate concentration, and Exch. $Ca^{2+}$ concentration were lower than those of the optimum ranges. Depending on the results of the soil chemical properties measured in September, 2015, soil pH, ECe, and Exch. $K^+$ concentration were higher than those of the optimum levels, but soil organic matter, Avail. phosphate, and Exch. $Ca^{2+}$ concentration were lower than the optimum ranges. In addition, distribution of sodic soil ranged between 41.4% and 50.0%, and saline soils were from 16.4 to 31.8%. Soils with pH values above 7.0 increased from 15.3% in March to 35.2% in September. Soils with ECe values over $4.8dS\;m^{-1}$ increased from 45.6% to 50.7%, whereas soils with the values below $2.0dS\;m^{-1}$ decreased from 42.8% to 36.9%.