• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.1
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• pp.53-65
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• 2001

To estimate agricultural water demand, many factors such as weather, crops, soil, cultivation method, crop coefficient and cultivation area, etc. must be considered. But it is not easy to estimate water demand in consideration of these factors, which are variable according to growth stage and regional environment. This study provides estimation system for agricultural water demand(ESAD) in order to estimate water demand easily and accurately, and arranges all factors needed for water demand estimation. This study identifies the application of estimation system for agricultural water demand with the data observed in the other studies, and analyzes nationwide agricultural water demand. The results are as follows. 1) The practice of different rice cultivation in the paddy field resulted in different water demands. Water depth and infiltration ratio in paddy are the most important factors to estimate water demand. The water depths in paddy simulated by ESAD is very similar to the observed ones. 2) Water demand of upland crops varies with the crops, soil, etc.. Effective rainfall estimated by daily routing of soil moisture varies according to the crops, soil, and effective soil zone(root depth). As crop root become grown, effective rainfall and an amount of irrigation water has been increased. 3) The current unit water demand of upland crops applied as 500mm or 550mm to estimate water demand does not reflect the differences caused by the crops, regional surrounding, weather condition, etc. Results from ESAD for the estimation of water demand of upland crops show that ESAD can simulate the actual field conditions reasonably because it simulates the actual irrigation practices with the daily routing of soil moisture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.577-584
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• 1994

A field trial was carried out to select suitable crops for diverted upland from paddy field and to investigate response of several forage crops to soil properties and ground water levels of the diverted upland at Suwon area of Korea in 1992 and 1993. Experiments were conducted in sandy loam plot and comparatively clay loam plot having higher ground water level. Rye (Paldang), triticale (Shinki), italian ryegrass (Tetraflorum) were used as wintering forage crops and maize(Suwon 19), sorghum-sudangrass hybrid(Pioneer855F), pearl millet(Suwon 6), japanese millet (King) were used as summer forage crops. Growth and yield of forage crops were better and higher in sandy loam soil having low ground water level. Among wintering forage crops, triticale recorded the highest forage yield. Rye showed high forage yield in sandy loam soil and italian ryegrass hardly survived in diverted upland of Suwon area during winter. Among summer forage crops, forage yield of sorghum-sudangrass hybrid was highest. Yield of japanese millet was not affected by soil conditions in both plots. Yields of pearl millet and maize remained relatively low in both plots.

• Korean Journal of Organic Agriculture
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• v.21 no.2
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• pp.247-263
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• 2013

This study was conducted to investigate the effect of cattle manure application on productivity, feed value, and stock carrying capacity of forage crops in upland and paddy fields at Gang-Wondo area. In the result, dry matter yield of sorghum ${\times}$ sudangrass hybrids obtained was 15.12 ton/ha at the level of 150kg N/ha of composted cattle manure. Significantly highest values of crude protein and total digestible nutrients (TDN) yields obtained were 0.59 and 5.35 ton/ha at the level of 150kg N/ha of composted cattle manure in the first cutting, and 0.44 and 3.70 ton/ha at the level of 150kg N/ha of organic raw cattle manure in the second cutting, respectively. The values of $K_{CP}+K_{TDN}/2$ and $K_{ME}$ of sorghum ${\times}$ sudangrass hybrids obtained was 7.76 and 4.46 head/ha at the level of 150kg N/ha of composted cattle manure. The dry matter yield, crude protein and TDN yields of rice straw were 4.95, 0.16 and 2.75 ton/ha at the level of 100kg N/ha of organic raw cattle manure, and the values of $K_{CP}+K_{TDN}/2$ and $K_{ME}$ of rice straw were 1.89 and 3.43 head/ha. The dry matter yield of winter crops, rye+red clover was 4.36 ton/ha in upland field, and rye+hairy vetch was 4.19 ton/ha in paddy field at the level of 100kg N/ha of composted cattle manure. Crude protein and TDN yields of rye+red clover was 0.29 and 2.38 ton/ha at the level of 100kg N/ha of composted cattle manure in upland field, and rye+hairy vetch was 0.30 and 2.48 ton/ha at the level of 80kg N/ha of composted cattle manure in paddy field. The values of $K_{CP}+K_{TDN}/2$ and $K_{ME}$ of rye+red clover was 2.34 and 2.15 head/ha in upland field, and rye+hairy vetch were 2.27 and 2.11 head/ha in paddy field, respectively. As the result, the productivity, feed value, and stock carrying capacity of sorghum ${\times}$ sudangrass hybrids showed higher values with composted cattle manure than organic raw cattle manure. rye+red clover in upland field and rye+hairy vetch in paddy field were most adaptable mixed combinations for roughage production at Gang-wondo area, it may due to their highly productivity, feed value, and stock carrying capacity.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.687-706
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• 2018

Organic agriculture is well known to be not only affecting the physical and chemical status of the soil but also closely connected to the biodiversity through complex community structure and ecological interactions. Current study monitored and analyzed the invertebrate biodiversity of organic and conventional paddy fields and upland fields from April, 2017 to August, 2017. Total of 680 species (with 14,371 individuals) were confirmed - more number of species were identified at the organic agriculture practicing fields. According to the various indices analysis, organic paddy field showed about 40% higher diversity index, while organic upland field showed about 10% higher diversity index. Richness index at organic paddy field was 60% higher compared to conventional paddy field, while organic upland field showed 40% higher value. Dominance and evenness index at conventional agriculture practicing fields were low, which possibly indicate at least partial dominance phenomenon. Hemipteran, dipteran and aranean species showed highest diversity in all fields, while dipteran, hemipteran, aranean and coleopteran species had highest diversity in conventional agriculture practicing fields.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.296-302
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• 1994

To alter the paddy field to upland, mole drainages were constructed under 30cm of the surface of(Jeon buk silt loam) which is not appropriate for cultivation of upland crops. Intervals of the moles were 50cm, 100cm and 150cm and diverted to upland for soybean cultivation. By construction of the mole drainage, about 75% to 45% of the rainfall was drained and the ground water level was maintained below 40cm. After a year of drainage, the blocky surface was changed to granular or nutty structure which is common in upland fields. Oxidation was progressed to the deep layer because of soil dryness. Soybean yield were increased by 11% to 22% in the mole drained plots, but wet injury was occurred in the nontreated check plot with relatively poor growth status.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.202-202
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• 2022

Recently days, soybean production in paddy field is increasing, from 4,422 ha in 2016 to 10,658 ha in 2021 in Korea. It is easy for Phytophthora stem and root rot (PSR) occurring in paddy field condition, when it is poorly drained soils with a high clay content, and temporary flooding and ponding. Therefore PSR resistant soybean cultivar is required. The objective of this study is to identify QTL region and candidate genes relating to PSR resistance of the race in main soybean cultivation area in Korea. 210 soybean materials including cultivars and germplasm were used for inoculation and genome-wide association study (GWAS). Inoculation was conducted using stem-scar method with 2 replications in 2-year for the race 3053 from Kimje and 3617 from Andong. 210 materials were genotyped with Soya SNP 180K chip, and structure analysis and association mapping were conducted with QTLMAX V2. The results of inoculation showed that survival ratio ranged from 0% to 96.7% and mean 9.7% for 3053 and ranged from 0% to 100% and mean 7.6% for 3617. Structure analysis showed linkage disequillibrium (LD) was decayed below r²=0.5 at 335kb of SNP distance. Significant SNPs (LOD>7.0) were identified in Chr 1, 2, 3, 4, 5, 11, 14, 15 for 3053 and Chr 1, 2, 3, 7, 10, 14 for 3617. Especially, LD blocks (AX-90455181;15,056,628bp~AX-90475572;15,298,872bp) in Chr 2 for 3053 and 3067 were duplicated. 29 genes were identified on these genetic regions including Glyma.02gl47000 relating to ribosome recycling factor and defense response to fungus in Soybase.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.7-16
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• 1997

The effects of liming and inoculation of nodule bacteria on the growth and yield of soybeans in the 1st and 3rd year paddy-upland rotated paddy fields was investigated. Compared with the 1st rotated field, the degree of nodulation was much higher in the 3rd rotated one with greater difference at flowering stage than at the early stage of soybean growth. At the same time, greater difference in the degree of nodulation was also recognized between soybean varieties. In the 3rd year rotated field, a great deal of nodulation effect was recognized in the no-limed field but not in the limed one. The growth of soybean was not much affected by liming and nodulation at early stage but it was much increased by liming at flowering stage, especially in Williams 79, indeterminate type variety. Most of yield components and yield of soybean at maturity was much increased by liming with greater in Williams 79 than in Namhaekong. Nodulation effect on the yield components and yield was great in the no-limed filed but not in the limed one for both varieties. The yield and yield components of soybean, without no relation with liming and nodulation, was much great in the 3rd year rotated paddy fields than in the 1st year one, which was inferred that the more rotated fields the more yield and better growth of soybeans could be possible in the paddy-upland rotatonal soybean croppings.

• Korean Journal of Organic Agriculture
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• v.6 no.2
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• pp.127-140
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• 1998

Organic farming excludes any use of the herbicide. The present paper reviews what can be done for effective weed control with existing weed control technology by farmers crop-ping paddy rice, field crops, vegetables, and fruit trees. If condition of the crop-land-al-lows diversified rotational use of the paddy land as paddy and upland field would minimize weed problem. Practising this is limited in acreage due to extremely limited governmental investment to the land for the purpose. Secondly, rotation of crops in the upland field breaking life cycles of various weeds adapted to each crop should reduce the weed problem. This is also limited as only a few crops are making the farmer profitable. In addition climate and tolerance of crops to high and low temperature. Monsoon rains and poor drainage restrict the freedom of choice. For any crop land year-round multiple cropping in denser planting shall lessen the weed problem, this multiple cropping practiced by 1960s has been abandoned due to laborshortage and increased production cost. Deep flooding the rice is impractical at present in Korean. Mulching crop with transparent, black , or combinated polyethylene sheet, hs been in-creasingly used. Progresses in development and use of mulch with allelopathic crop residues. inexpensive paper mulch, allelopathic crop residues, inexpensive paper mulch, allelopathic crop cultivar development, recently developed ex-perimental weeding machinaries, flamers, microbial herbicides, biological control organisms, soil sterilization techniques have been critically reviewed for their adoption into existing in-tegrated weeding system. Unfortunately, information on cost-benifit, and labor-benefit, for the various methods above mentioned are lacking. Urgent need for the research on rational weeding in organic farming, and herbicide low-input farming is emphasized.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.6
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• pp.133-144
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• 2018

To suggest the field maintenance plan considering the geographical characteristics of the region, we selected representative regions(plain regione and mountain region) and compared spatial distribution of cultivated land in Muan-gun and Hwasun-gun. Firstly, we examined the distribution characteristics of cultivated land according to the scope of the maintenance object with Fragstats. As a result of that, it was found that the cultivated area except rice paddy had the highest aggregation effect. And then, we developed type classification of maintenance considering geographic characteristics and cultivated crops information. As a result of classification, plain land type Muan region was mostly cultivated land suitable for integrated maintenance. On the other hand, Hwasun, a mountainous terrain, needs small-scale maintenance and road maintenance. Based on these results, it was found that more detailed planning is needed for the upland field infrastructure improvement considering the topographic characteristics.

• Proceedings of the Korean Society of Crop Science Conference
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• 1995.05a
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• pp.84-85
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• 1995