The Effect of Excessive Application of K2O during Root Production on Plant Growth, Mineral Concentration and Yield of Edible Part in Witloof Chicory (Cichorium intybus L.)

Abstract

level of ruminants with considerable probability. There is a possibility to use forage chicory as the material for removing the extra K in the soil, not for the feed crops. However, reports on the potassium uptake capacity of witloof chicory is limited and detailed information is necessary for using witloof chicory as a K-scavenger. The present study describes the efforts to examine the plant growth and K absorption capacity of witloof chicory and the change of soil chemical profiles during growing pe-riods. The witloof type chicory was considered, comparing to forage type chicory, under K 2 O rich conditions, growing with a modelled K 2 O accumulated soils that were made by excessive application of chemical fertilizers. Experimental forcing cultures were also conducted in order to verify the influence of stress caused by K 2 O rich conditions on the yield and quality of the edible part of witloof chicory. Under a high-K stressful condition in a greenhouse pot cultivation, the biomass production and the K absorption capacity of witloof chicory ( Cichorium intybus L.) were compared with forage chicory. The root biomass of witloof chicory was greater than that of forage chicory among all treatments, indicating that witloof chicory has a certain level of tolerance against high K stressful conditions. As K 2 O application increased, the biomass, in top and root, tended to decrease in both types, however, there was not a significant negative impact on the yield or quality of the obtained roots in witloof type at the treatments under 2,000 kg ha (cid:4) 1 level. The K-uptake amount per plant of witloof chicory was 40% to 58% greater comparing forage chicory, at the K 2 O treatments from 1,000 to 2,000 kg ha (cid:4) 1 . The quality of the etiolated heads, obtained after the forcing culture, could be kept at the same level of the commercially available fresh products when the K 2 O application was lower than 2,000 kg ha (cid:4) 1 . Through this experiment, witloof chicory showed its potential to be utilized as a remedy for K accumulated soils, concurrently, obtaining an agricultural income from the forcing culture by using roots which absorbed K from soils.