To investigate the effects of potassium() fertilization levels on the dry matter(DM) yield, nutrition yield, and efficiency of forages in mixed sward of alfalfa-grasses, a field experiment arranged by randomized complete block design with five treatments
Background : Ginseng (Panax ginseng C. A. Meyer) is a perennial crop grown for more than 4 years in the same place. Therefore, it is highly affected by soil environment, especially nutrients on soil. This study was carried out to investigate the effects of application levels of nitrogen, phosphate, potassium on growth and soil chemical properties of ginseng. Methods and Results : 0, 1, 4, 8, 16, 32 ㎏/10 a of Urea, fused superphosphate, potassium chloride were each treated at 3.3 ㎡ of the field and ginseng cultivar 'Geumpoong' was transplanted. Growth characteristics were investigated by growth period and soil chemical properties were investigated every 3 months. As the levels of treated nitrogen increased, root weight increased from 0 ㎏/10 a to 4 ㎏/10 a and then decreased. Electrical conductivity (EC) and the NO3 content tended to increase as time goes by. As the levels of treated phosphate increased, the SPAD content increased. Soil analysis of October showed that the NO3 content of phosphate 32 ㎏/10 a treatment increased to 80.25 ㎎/㎏. In the case of potassium 32 ㎏/10 a treatment, the emergence rate was 74% and root weight was 2.06 g, which were the worst in all treatments. When the levels of treated potassium increased, the EC tended to increase gradually and the pH was decreased. Conclusion : These results indicate that the application levels of Nitrogen, phosphate, potassium influence growth of ginseng and soil chemical properties. Further research will be needed to establish appropriate standards of soil chemical properties for ginseng cultivation.
This study was to verity that the uptake inhibition and accumulation of nitrogen in different potassium levels. Lettuce was used as model plant in this study and grown in pot of 10cm's in diameter and depth with mixture media of vermiculite and perlite under supply of different culture solution for three weeks. Nitrogen absorption at root was inhibited by increased potassium concentration in nutrient solution, and nitrate accumulation of plant was depended on absorption of nitrogen because nitrate content of 0 K level was 4-5 times higher than that of 2 K level, Concentration of ascorbic acid was decreased by increasing the nitrogen absorption, since ascorbic acid (AsA) content of 2K level was higher than those of OK level in both of old leaf and flesh leaf
Field experiment was conducted during 1993-94 season to determine the pattern of nutrient uptake and productivity of maize/sweet potato intercropping system. Four levels of nitrogen (0, 50, 100 and 150kg N ha-1 ) and four levels of potassium (0, 40, 80 and 120kg K2 O ha-1 ) formed treatment variables. Plants were sampled periodically to determine dry matter and tissue concentrations of N and K in the individual plant components of intercropped maize and sweet potato. Nitrogen and potassium fertilizer did not interact significantly to nutrient uptake by any plant parts of intercropped maize and sweet potato. But application of N fertilizer independently enhanced N uptake in all the plant parts of maize and sweet potato. The uptake of N in leaf, leaf sheath, stem, husk, and cob of maize increased upto 90 days after planting (DAP) but grain continued to accumulate N till its maturity. Sweet potato exhibited a wide variation in N uptake pattern. Sweet potato leaf shared the maximum uptake of N at 50 DAP which rapidly increased at 70 DAP and then declined. Declination of N uptake by petiole and stem were observed after 120 DAP whereas N uptake by tuber increased slowly upto 90 DAP and then rapidly till harvest. Rate of applied K had very little effect on the uptake patterns in different components of intercropped maize. Pattern of K uptake by leaf, petiole and stem of sweet potato showed almost similar trend to N uptake. But uptake of K by tuber increased almost linearly with the K application. Pattern of N and K uptake by grain and tuber paralleled the grain yield of maize and sweet potato respectively. Intercropped productivity of maize and sweet potato found to be better by the application of 100kg N and 120 kg K2 O ha-1