• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.1
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• pp.63-69
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• 1987

This field experiment was undertaken to assess the effectiveness of magnesium- and boronenriched complex fertilizer ($N-P_2O_5-K_2O-MgO-B_2O_3$ : 8-25-7-3-0.2) compared with some straight fertilizers on the hilly pasture establishment. This second part was concerned with the changes in the forage yields, yield components, botanical and chemical compositions in a mixed grassclover sward (orchardgrass, tall fescue, Kentucky bluegrass, and ladino clover). The results from a two-year experiment are summarized as follows: 1. Dry matter yields of whole mixed forages were significantly reduced in control by 54.5% and the NK-plot ($P_o$ by 35.0%, compared with the normal NPK-plots. 2. The yields of oversown grasses were significantly reduced in control by 79.7% and the NKplot ($P_o$) by 52.196, compared with the normal NPK applications. At the normal NPK applications, the oversown grasses were lowest in the yields when provided with double superphosphate with no significant differences. The yields of weeds were not significantly influenced by the treatments. 3. The significant differences in the legume yields (relative yield, %) were laid in the follow. ing increasing order; complex fertilizer (178.5%) > NPK-fused superphosphate (139.5%) > NPK-double superphosphate (100.0%) = control > NK (51.1%). The legume yield was much more depressed in the NK-plot ($P_o$) than in control ($N_oP_oK_o$). 4. The rate of oversown grasses and whole forages were increased by the normal NPK applications, showing little difference among the kinds of fertilizers. It was recognized that the application of complex fertilizer contributed to the increasing of legume rate in the mixed sward. This contribution turned out to be due to the rather enhanced performance and yield-increase of legume, compared with the straight fertilizers. 5. With the NK-treatment ($P_o$) the P concentration in mixed forages dropped below the critical level (0.2%). The Mg concentrations in mixed forages were lower in all the plots than the critical level (0.2%). Therefore, a sufficient amount of Mg was desirably to be applied It is recommended that, in relation to its effectiveness and simplification of fertilizer application, the application of this complex fertilizer for pasture establishment be carried out. The change of the constituent ratio of complex fertilizer to the standard of "8 - 15-20 - 7 - 5-10 - 0.2" considering the need of sufficient Mg supply and the continuous accumulation of P in the top-surface soil is possibly recommended.commended.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.477-483
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• 2012

This study was carried out to investigate the influence of copper concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. The characterization of toxicity symptoms as well as tissue analyses based on dry weight of above ground tissue were also conducted to determine the threshold levels in plants when toxicity developed in copper. The dry weights of the above ground tissue were not significantly different among the treatments of 0.25 mM to 1.0 mM in 'Keumhyang' and 'Maehyang' strawberries and that of 0.25 mM to 3.0 mM in 'Seolhyang' strawberry. This indicates that the 'Seolhyang' strawberry is more tolerant to copper toxicity than 'Keumhyang' or 'Maehyang' strawberries. Application of copper at high concentrations resulted in severe toxicity such as death of extensive areas of leaves. The lower leaves became yellow and die rapidly as the symptoms spread up the plants. The leaf blades and petioles died back to the crown and hang on by mechanical attachment. Symptoms of copper toxicity in lower leaves developed as browning on leaf margins and in patches between leaf veins that became necrotic. The elevation of copper concentrations in fertilizer solution did not influence the tissue phosphorus, potassium, calcium, and magnesium contents based on the dry weight of the above ground tissue. The tissue copper contents increased lineally as the copper concentrations in fertilizer solution were elevated. But the tissue iron, manganese and boron contents were not influenced by the concentrations. When the concentration of copper at which growth of a plant is retarded by 10% is regarded as threshold level, the copper contents based on dry weight of above ground plant tissue should be lower than 71.4, 57.9 and 74.8 $mg{\cdot}kg^{-1}$ in 'Keumhyang', 'Maehyang' and 'Seolhyang' strawberries, respectively. The symptom characterization and established threshold level in copper toxicity would help growers to prevent the reduction of crop growth and yield in 'Seolhyang' strawberry cultivation.