• Journal of The Korean Society of Grassland and Forage Science
• /
• v.7 no.1
• /
• pp.25-30
• /
• 1987

There are differences in opinion as to whether nitrogen fertilizer should be used when establishing alfalfa (Medicago sativa L.). Various reports show that under a hot environment, rhizobia (Rhizobium meliloti) are not as effective in fixing atmospheric nitrogen as they are under moderate temperatures. It is also believed that the addition of nitrogen fertilizer inhibits nodulation of alfalfa seedlings. A replicated experiment was conducted under controlled environmental conditions at the University of Nevada-Reno, Reno, Nevada, USA, to determine the effects of nitrogen application on seedling growth and nodulation of alfalfa grown in a hot environment. Sterile sand was used as the growing media to which a complete nutrient solution minus nitrogen was applied volumetrically to each pot daily. In addition, half of the pots received NH4-$NO_3$, at the rate of 11.2 kg per ha at seeding and at two and four weeks after planting giving a total nitrogen application rate of 33.6 kg per ha during the seven-week experimental period. Rhizobia inoculant (R-12) consisted of a mixture of strains 171-15a, 1682c and 80 PI 265 of (Rhizobium meliloti). Inoculant was applied to the seeds prior to planting and to the sand media at two and four weeks after seeding. Twenty seeds were planted in pots 14.0 cm in diameter and 11.5 cm deep. Plants were thinned to ten plants per pot after emergence and were grown in a controlled environment chamber with a 16-hour light period. Soil temperature at 6 cm depth ranged from 17.4^{\circ}C.$ to 31.1^{\circ}C.$ and had a daily mean of 26.5^{\circ}C.$. Plants were harvested at weekly intervals for seven weeks. Root, shoot and total length, dry weight, volume and number of nodules per plant were determined. Root, shoot, and total length were greater in seedlings grown in soil where nigrogen was applied than that grown in soil to which no nitrogen was applied. The average size of the seedlings as determined by volume and weight was more than two times greater where plants were fertilized with nitrogen. Nodule number per seedling was also greater when nitrogen was applied compared to those which received no nitrogen. The differences were greater as the plants became older. The rhizobia did not fix enough nitrogen for adequate growth of seedlings. This is probably due to high temperature growing conditions that caused the rhizobia to become relatively ineffective as compared to cooler growing conditions. Data suggests it would be desirable to apply nitrogen at seeding when alfalfa is established under hot conditions that occur in mid- or late summer.

• Korean Journal of Agricultural Science
• /
• v.6 no.2
• /
• pp.105-111
• /
• 1979

This experiment was carried out to define the affinity of alfalfa varieties to nodule bacteria and the effects of nodule bacteria on the growth of alfalfa varieties. The results obtained are summarized as follows; 1. The ability of nodule formation on the roots of alfalfa was significantly different among the strains of nodule bacteria, Rhizobium meliloti SU 47 formed nodules on the roots of two alfalfa varieties, Luna and Von arnims altd bost. Nodules were not formed at the roots of all varieties by inoculation of Rhizobium meliloti M1 but a lot of nodules were formed at the roots of all varieties by inoculation of Rhizobium meliloti M14. 2. When the Rhizobium meliloti M14 was inoculated in the media, the largest numbers of nodules were formed on the roots of alfalfa cultivar Franks hangmeiler and the least numbers of nodules were formed on the roots of cultivar Elga. 3. The plant height and the dry matter weight of all alfalfa cultivars were significantly increased by inoculation of Rhizobium meliloti M14, and also those were increased by applying nitrogen, but when the alfalfa cultivars were grown on the media inoculated Rhizobium M1, the plant height and the dry matter weight of alfalfas were not increased and they were same as those grown on check media. 4. The significant correlation were not detected between the number of nodules formed on the, roots of alfalfa cultivars and the plant height or the dry matter weight of alfalfa cultivars.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.2
• /
• pp.84-89
• /
• 1991

This experiment was carried out to determine the effects of oversowing and other seeding methods (oversowing+ raking, oversowing+ raking+compaction, tillage+ broadcasting+ compaction and tillage + drilling+ compaction) on growth, dry matter and crude protein yield of alfalfa (Medicago satiua L.). The results obtained are summarized as follows:1. Soil pH and soil properties were improved by tillage.2. Establishment of alfalfa was increased with raking and compaction, and more by tillage than by oversowing(P

• Journal of Animal Science and Technology
• /
• v.65 no.5
• /
• pp.939-950
• /
• 2023

This study was conducted to assess the impact of growing condition variables on alfalfa (Medicago sativa L.) productivity. A total of 197 alfalfa yield results were acquired from the alfalfa field trials conducted by the South Korean National Agricultural Cooperative Federation or Rural Development Administration between 1983 and 2008. The corresponding climate and soil data were collected from the database of the Korean Meteorological Administration. Twenty-three growing condition variables were developed as explaining variables for alfalfa forage biomass production. Among them, twelve variables were chosen based on the significance of the partial-correlation coefficients or potential agricultural values. The selected partial correlation coefficients between the variables and alfalfa forage biomass ranged from -0.021 to 0.696. The influence of the selected twelve variables on yearly alfalfa production was summarized into three dominant factors through factor analysis. Along with the accumulated temperature variables, the loading scores of the daily mean temperature higher than 25℃ were over 0.88 in factor 1. The sunshine duration at temperature between 0℃-25℃ was 0.939 in factor 2. Precipitation days were 0.82, which was the greatest in factor 3. Stepwise regression applied with the three dominant factors resulted in the coefficients of factors 1, 2, and 3 for 0.633, 0.485, and 0.115, respectively, and the R-square of the model was 0.602. The environmental conditions limiting alfalfa growth, such as daily temperature higher than 25℃ or daily mean temperature affected annual alfalfa production most substantially among the growing condition variables. Therefore, future cultivar selection should consider the capability of alfalfa to be tolerant to extreme summer weather along with biomass production potential.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.20 no.1
• /
• pp.67-76
• /
• 2000

An experiment was conducted to evaluate the effects of lime, zeolite, and rock phosphate as coating materials and coated seed size on germination, establishment, and early growth of pasture species at the experimental livestock farm, Yonam College of Agriculture in 1997. Germinating energy and germination of coated tall fescue and orchardgrass seeds were lower than those of non-coated seeds. Coated seed of tall fescue with 70% lime and 15% rock phosphate was the best in germination. The germination of small size seed (< ${\varnothing}2$ mm) was better than those of medium (> ${\varnothing}2$ mm and < ${\varnothing}2$ mm) and large size seeds (> ${\varnothing}2$ mm). Germination of coated orchardgrass seed with 55% lime and 30% rock phosphate treatment was higher than that of other coated seeds, and germination of small size seed was higher than those of medium and large size seeds (p<0.05). Germination energy and germination of coated alfalfa and birdsfoot trefoil seeds were lower than those of non-coated seeds. Germination of coated alfalfa seed with 70% lime and 15% rock phosphate, and 45% lime and 55% rock phosphate was higher compared with other coated seeds. Germination of medium size seed was higher than those of small and large size seeds (p<0.05). Among coated birdsfoot trefoil seed, 45% lime and 40% rock phosphate treatment resulted in higher germinating energy and germination than other treatments. There was no significant difference in establishment and early growth of coated tall fescue and orchardgrass seeds. However, tall fescue and orchardgrass coated with 45 % lime and 40% phosphate rock showed higher establishment and early growth. There was also no significant difference in establishment and early growth of coated alfalfa among the treatments. Among coated treatments, establishment and early growth of alfalfa coated with 75% lime and 10% rock phosphate were the highest and showed 46.4% and $72.6\;g/\textrm{m}^2$, respectively. Establishment and early growth of coated birdsfoot trefoil with 55% lime and 30% rock phosphate were the highest among coated birdsfoot trefoil seed (p<0.05) and recorded 46.4% and $44.6\;g/\textrm{m}^2$, respectively. Results of this study indicate that the germination of coated grass and legume seed may be improved by increasing the percentage of rock phosphate and decreasing that of lime. With regard to seed size, the germination of pasture species with small seed size (< ${\varnothing}2$ mm) may be better than medium and large size seeds except alfalfa. Establishment and early growth of grasses can be also improved by increasing the percentage of rock phosphate and decreasing that of lime.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.2
• /
• pp.228-235
• /
• 1997

This experiments were conducted to determine the effect of allelopathy and autotoxicity in alfalfa. Among several alfalfa cultivars, the substances exudated from seven cultivars including Medicago sativa, c.v. Luna, Sparta, Magnum, Husky, Milkmaker, Challenger and Anchor inhibited the germination and seedling growth of radish, ranging from 60 to 80％. When allelopathic substances were exudated from the soil of the alfalfa-cultivated field, the increased levels of substance retarded the germination rate and seedling growth of radish and alfalfa. The inhibition rate was about 80％, compared with that of control. Thus, this study indicates that the allelopathy and autotoxicity substances of alfalfa influenced the germination and seedling growth in alfalfa itself and radish. When allelopathic substances were analysed by using gas chromatograph, several kinds of phenol compounds were detected as follows; Salicylic acid, hydroxybenzoic acid, vanillic acid, syringic acid, coumaric acid, and ferulic acid.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.3
• /
• pp.145-152
• /
• 1991

This experiment was carried out to investigate the effects of liming, manure application, and inoculation with Rhizobium on the early growth, nodulation, seedling establishment, winter survival, and forage yield and quality of alfalfa(Medicago sativa L.) at the Experimental Livestock Farm, College of Agriculture, Seoul National University, Suweon in 1985 and 1986. The results obtained are as follows: 1. Seedling vigor and nodule formation of alfalfa at early stage were the best in the treatments of liminginoculation( L1) and liming-manure-inoculation(LM1). 2. Seedling establishment was not significantly affected by the treatments of liming, manure application, nodulation and the combination of these. 3. The LI and LMI treatments showed the highest winter survival of 94.3 and 83.5%, respectively, but the lowest winter su.rvival of 55.9 and 58.5% was found in no treatment(None) and inoculation( I ), respectively. 4. No differences in crude protein(CP1, acid detergent fiber(ADF) and neutral detergent fiber(NDF) contents were found among the treatments. 5. There were significant differences in the total dry matter yield of alfalfa among the treatments. The total dry matter yields of 10,618, 11,830, 11,855 and 13,456 kg/ha from the treatments of L, LM, LI and LMI, respectively, were significantly higher than those of None, M and I treatments. 6. Based on the results of the experiment, it appears that the dry matter yield of alfalfa could be enhanced by the treatments of liming with Rhizobium inoculation and also liming, manure application and Rhizobium inoculation as a practical method.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.41 no.3
• /
• pp.210-216
• /
• 2021

Pollution of agricultural soil by alkaline salts, such as Na₂CO₃, is a critical and long-lasting problem in cultivable land. The aim of the study was to examine the putative role of citric acid (CA) in alleviating Na₂CO₃-stress in alfalfa. In this study, Na₂CO₃ significantly induced leaf chlorosis, inhibited plant growth and photosynthesis related parameters, increased hydrogen peroxide (H₂O₂) and reduced major antioxidant enzymes (SOD, CAD, APX) in alfalfa. However, the presence of CA these negative effects of Na₂CO₃-stress largely recovered. Interestingly, expression of antioxidant and ion transporter genes (Fe-SOD, CAT, APX, DHAR and NHX1) involved in Reactive oxygen species (ROS) homeostasis and oxidative stress tolerance in alfalfa. These findings suggest that CA-mediated Na₂CO₃ stress alleviation is an ecofriendly approach that would be useful to local farmer for alfalfa and other forage crop cultivation in alkaline soils.

• Plant Resources
• /
• v.7 no.1
• /
• pp.69-76
• /
• 2004

Lettuce (Lactuca sativa L.) is known to contain water-soluble substances that are biologically active. Aqueous or methanol extracts and residues from leaves of lettuce plants were assayed to determine their allelopathic effects, and the causative allelochemicals from fractions were quantified by means of HPLC analysis and bioassayed. Extracts from oven-dried leaf samples were more phytotoxic than those from freeze-dried samples. Leaf extracts of 40 g L$^{-1}$ were completely inhibitory on root growth of alfalfa (Medicago sativa L.), while root growths of barley (Hordeum vulgare L.) and soybean (Glycine max L.) were less sensitive. Early seedling growth of both alfalfa and barnyard grass (Echinochloa crus-galli) was significantly reduced by methanol leaf extracts. The major allelopathic substances analyzed by HPLC were coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid and chlorogenic acid. Of them p-coumaric acid was found as the greatest amount (8.9 mg 100 g$^{-1}$ ) in the EtOAc fraction; only coumarin was found in all the fractions. Hexane and EtOAc fractions of L. sativa reduced alfalfa root growth more than did BuOH and water fractions. These results suggest that lettuce had potent herbicidal activity, and that its activity differed depending on type and amount of causative compounds by fraction.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.4
• /
• pp.303-307
• /
• 2003

Some Compositae plants are known to contain biologically active substances that are allelopathic to weeds species as well as antioxidant to foods. Aqueous extracts from leaves of 3 plant species, Cirsium japonica, Kalimeris yomena, and Lactuca saliva, were bioassayed against alfalfa (Medicago saliva) to determine their allelopathic effects. The extracts applied on filter paper in bioassay significantly inhibited root growth of alfalfa. Extracts of 20 g dry tissue $\textrm{L}^{-1}$ from Lactuca sativa showed the most inhibitory effect on alfalfa seedling growth and followed by Cirsium japonica and Kalimeris yomena. Oxidative stability by Rancimat method and antioxidant activity by TBA method for the ground samples were the greatest in Lactuca sativa although were less than that of a commonly used antioxidant, 1% ascorbic acid. Antioxidant activity of methanol extracts on storing meat was stably kept for 28days and was excellent compared to control. These results suggest that three Compositae plants have potent allelopathic and antioxidant effects, and that their activities differ, depending on plant species.