• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.2
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• pp.75-80
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• 2019

Oilseed rape is known to crop having low nitrogen use efficiency (NUE) but requires high levels of N fertilizer. NUE is associated with N remobilization from source to sink organ, consequently affects seed yield. Remobilization of leaf N is also related to transport of C/N metabolites in phloem. However, interaction between seed yield and phloem transport was not fully documented. In response to seed yield, N and C metabolites and their transport into seed from bolting to pod filling stage investigated in two contrasting genotypes (Capitol and Pollen) cultivated under ample (HN) or limiting nitrate (LN) supply. Seed yield was significantly reduced in N limitation and its reduction rate was much lower in Capitol than in Pollen compared to HN treated plants. Amino acid and protein content was higher in Capitol than in Pollen at bolting stage. They gradually decreased during plant development but not significant between two cultivars and/or two treatments. Glucose, fructose and sucrose content were 1.8-,1.6- or 1.25-fold higher in LN condition than in HN condition, respectively. Amino acid and sucrose content in phloem were largely higher in Capitol than in Pollen under LN condition. These results indicate that the higher seed yield might be related to greater transport ability of amino acid and sucrose in phloem under LN condition.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.195-200
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• 2022

Sulfur is an essential element in plants, including amino acids, vitamin synthesis, and acting as an antioxidant. However, the interaction between endogenous sulfur and proline synthesis has not been yet fully documented. White clover (Trifolium repens L.) is known as a species highly sensitive to sulfate supply. Therefore, this study aimed to elucidate the role of sulfur in regulating proline metabolism in relation to ammonia detoxification and hydrogen peroxide (H₂O₂) accumulation in white clover. The detached leaves of white clover were immersed in solution containing different concentration of sulfate (0, 10, 100, and 1000 mM MgSO₄). As MgSO₄ concentrations were increased, the concentration of H₂O₂ increased up to 2.5-fold compared to control, accompanied with H₂O₂ detection in leaves. Amino acid concentrations significantly increased only at higher levels (100 and 1000 mM MgSO₄). No significant difference was observed in protein concentration. Proline and ∆^1-pyrroline-5-carboxylate (P5C) concentrations slightly decreased at 10 and 100 mM MgSO₄ treatments, whereas it rapidly increased over 1.9-fold at 1000 mM MgSO₄ treatment. Ammonia concentrations gradually increased up to 8.6-fold. These results indicate that exogenous sulfur levels are closely related to H₂O₂ and ammonia synthesis but affect proline biosynthesis only at a higher level.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.1
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• pp.56-61
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• 2023

The germination process is critical for plant growth and development and it is largely affected by environmental stress, especially salinity. Recently, hydrogen sulfide (H₂S) is well known to act as a signaling molecule in a defense mechanism against stress conditions but poorly understood regulating seed germination. In this study, the effects of NaHS (the H₂S donor) pretreatment on various biochemical (hydrogen peroxide (H₂O₂) content and amylase and protease activity) and physiological properties (germination rate) during seed germination of oilseed rape (Brassica napus L. cv. Mosa) were examined under salt stress. The seed germination and seedling growth of oilseed rape were inhibited by NaCl treatment but it was alleviated by NaHS pretreatment. The NaCl treatment increased H₂O₂ content leading to oxidative stress, but NaHS pre-treatments maintained much lower levels of H₂O₂ in germinating seeds under salt stress. Amylase activity, a starch degradation enzyme, significantly increased over 2-fold in control, NaHS pretreatment, and NaHS pretreatment under NaCl during seed germination compared to NaCl treatment. Protease activity was highly induced in NaHS-pretreated seeds compared to NaCl treatment, accompanied by a decrease in protein content. These results indicate that NaHS pretreatment could improve seed germination under salt stress conditions by decreasing H₂O₂ accumulation and activating the degradation of protein and starch to support seedling growth.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.2
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• pp.133-139
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• 2024

This study aimed to evaluate the efficiency of combining acidification with adsorbents (zeolite and biochar) to mitigate the environmental impacts of pig slurry, focusing on ammonia (NH₃) emission and nitrate (NO₃^-) leaching. The four treatments were applied: 1) pig slurry (PS) alone as a control, 2) acidified PS (AP), 3) acidified pig slurry with zeolite (APZ), and 4) acidified pig slurry with biochar (APB). The AP mitigates NH₃ emission and NO₃^- leaching compared to PS alone. Acidification reduced the cumulative NH₃ emission and its emission factor by 35.9% and 12.5%, respectively. The APZ and APB increased NH₄⁺-N concentration, with the highest level in APB, compared to AP. The NH₄⁺ adsorption capacity of APB (0.90 mg g^-1) was higher than that of APZ (0.63 mg g^-1). The APB and APZ treatments induced less NH₃ emission compared to AP. The cumulative NH₃ emission was reduced by 12.2% and 27.6% in APZ and APB, respectively, compared to AP treatment. NO₃^- leaching began to appear on days 12 and 13, and its peak reached on days 16 and 17, which were later than AP. The cumulative NO₃^- leaching decreased by 17.7% and 25.0% in APZ and APB, respectively, compared to AP treatment. These results suggest that combining biochar or zeolite with acidified pig slurry is an effective method to mitigate NH₃ emission and NO₃^- leaching, with biochar being particularly effective.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.3
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• pp.204-209
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• 2024

Drought is one of the environmental factors inhibiting plant productivity and growth, leading to oxidative damage. This study aims to identify the role of sodium hydrosulfide (NaHS) as a hydrogen sulfide (H₂S) donor in drought stress tolerance in Brassica napus. Drought-induced stress symptoms appeared eight days after treatment, showing wilted leaves and a significant reduction of leaf water potential. Drought-induced increase of lipid peroxidation was significantly reduced by NaHS application. NaHS-treated plants mitigated stress symptoms under drought conditions by reducing hydrogen peroxide (H₂O₂) content, confirmed with H₂O₂ localization in situ. Furthermore, NaHS promotes photosynthetic activity by maintaining chlorophyll and carotenoid content, thereby supporting plant growth under drought conditions. Pyrroline-5-carboxylate and proline contents were significantly increased by drought but further enhanced by NaHS treatment, indicating the important roles of proline accumulation in drought stress tolerance. In conclusion, this study provides valuable insight into the roles of NaHS in alleviating drought stress by reducing oxidative stress and promoting proline accumulation. Therefore, NaHS may serve as an effective strategy to enhance crop production under drought-stress conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.2
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• pp.97-104
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• 2005

This experiment was conducted to introduce strip croppings fur decreasing the damage of the continuous com cultivation at the experimental field of Grassland and Forage Crops division, National Livestock Research Institute from 1999 to 2000. Introduced mps for strip cropping to the continuously com cultivated field were red clover (RC), alfalfa(AL), and mixture of grass md legume. Fall panicum(FP), which is one of warm season's weeds was focused on its emerged quantity in com field changed by the level of soil water content and degree of the continuous corn cultivation. The ranges of yearly gained forage fresh yields including weeds like mainly FP were 119.4 ${\~}$ 169.6 in the continuous cultivation with com and rye and 64.9 ${\~}$ 83.3 ton / ha in the corn mono-cropping. Meanwhile, the percentages of pure com in continuous com cultivation plot were only $31-38\%$. This was for the mainly emergence of FP in the continuously com cultivated field. The ranges of average fresh yield of emerging FP were 45.6${\~}$63.4 ton/ ha in the continuously com cultivated field which were over the ranges of yields of rye, 28.2 ${\~}$ 41.6 ton/ ha. The dry matter yields of red clover, alfalfa and mixture with grass and legume introduced for strip cropping were 10.2, 10.6 and 10.6 ton / ha, respectively and these were about the 1/4 average fresh com yield. After strip cropping of red clover, alfalfa and mixture with grass and legume, the yields of corn increased to 56, 82, 88 and 79 ton / ha, respectively and com yield was much better in the alfalfa strip cropping.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.271-279
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• 2016

The objective of this study was to determine the effect of the moisture content and pellet mill type on the physical and chemical characteristics of Italian ryegrass (IRG) pellet. Moisture content of raw material significantly (p<0.05) affected IRG pellet formation. Moisture content at 25% was the best condition for IRG pellet formation in terms of shape, power load and temperature changes. The hardness of pellet was decreased when moisture content was increase. However, the hardness of pellet was not affected by pellet mill type. Moisture content at 30% dramatically (p<0.05) decreased the durability compared to moisture content at 25%. Dry matter content of IRG pellet was increased (p<0.05) after pelleting. Total count of microorganism was decreased in pellet due to pressure heat and moisture losses during the pelleting process. These results indicated that the proper moisture content of Italian ryegrass pelleting would be at 25%. In addition, Roll & flat die type would be more suitable than Ring die and Die & flat die type in IRG pelleting. Pelleting works would be beneficial for improving forage quality and long storage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.269-274
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• 2007

This experiment was conducted to determine the effect of seeding method on winter survival and dry matter yield of Italian ryegrass(Lolium multiflorum Lam. "Kospeed") in paddy field for two years. The experiment was arranged in randomized complete block design with three replications. The treatment consisted of four different seeding methods, R-LS-P(rotary-line sowing-packing), R-BS-P(rotary-broadcast seeding-packing), R-BS(rotary-broadcast seeding), R-BS-TR(rotary-broadcast seeding-trifling rotary), BS-TR(broadcast seeding-trifling rotary). The emergence ratio of broadcast was decreased by 12% and winter survival was decreased by 17% compared with line sowing. The R-BS-TR treatment which was practical seeding method of rye was decreased seeding stand ratio by 65.2% and winter survival by 6.7% compared with others seeding methods. Dry matter yield of line sowing(8,151 kg/ha) was higher than that of broadcast(6,281 kg/ha) and R-BS-P treatment was the highest DM yield as 7,166 kg/ha. There was not found significant difference among seeding method in forage quality. The results of this experiment indicated that R-BS-P(rotary-broadcast seeding-packing) was recommendable the best seeding method after harvested whole crop rice in paddy field.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.103-110
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• 2009

Rape plants, especially forage type, are known as one of high S-demanding plants. Their productivity and quality have often limited under S-deficient condition. To investigate the effect of S-deficiency on N uptake and its assimilation, $NO_3^-$ absorption, nitrate reducatse (NR) and glutamine synthetase (GS) activity in leaf and root tissues as affected by different S-supplied level was determined. $NO_3^-$ uptake was not significant between control and S-deficient treated plants, while significantly depressed in S-deprived plants for the early 8 h. NR activity decreased as S-availability decreased, especially in young and middle leaves, representing more than 35% of decrease in S-deficient and 70% in S-deprived plants when compared with control. In roots, a significant decrease (-29%) in NR was observed only in S-deprived plants. Relatively higher GS activity was found in young leaves for three all treatments. As a whole leaf tissue, S-limited conditions resulted in a reduction of GS activity. In root which showed the lowest activity, a significant decrease (-30%) was observed only in S-deprived plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.95-102
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• 2009

To determine $SO_4^{2-}$ uptake and its assimilation in response to the exogenous $SO_4^{2-}$supply level in forage rape (Brassica napus L.), the concentration of this element in plant tissues and the activity of ATP sulfurylasc and APS reductase was measured after 25 hours of treatment (1.0 mM $SO_4^{2-}$, control; 0.1 mM $SO_4^{2-}$, S deficiency; 0 mM $SO_4^{2-}$, S deprivation). $SO_4^{2-}$ uptake and the concentration in the plant tissues significantly decreased in S-deficient and S-deprived condition, while it maintained at nearly same level in the control. The activity of ATP sulfurylase tended to increase with decreasing the exogenous $SO_4^{2-}$ supply, while that of APS reductase to decrease. A significant change in both enzymes responding to S-deprivation treatment was observed only young and middle leaves. The results indicated that $SO_4^{2-}$ assimilation in young leaf tissues would be much more sensitively responded to S-limited nutrition.