Effect of different N application rates on yield, qualities and N uptake of ginger

Field experiments were conducted to study the effects of different nitrogen (N) application rates on yield and qualities in ginger (Zingiber officinale) rhizome and absorption of nutrient. The results showed that there were obvious effects of different N application rates on ginger rhizome yield and qualities, a rational N application could remarkably increase rhizome yield and improve nutrition and security quality. At two different basal fertility soils, ginger rhizome yield all increased first and dropped later along the increase of N application rates with a parabola relationship between yield and applying N rates, and the highest rhizome yield was obtained by the treatment of N450.The results of quality analyses indicated that a suitable N application rate could improve the content of protein, vitamin C, sugar and essential oil in ginger rhizome remarkably and control the concentration of nitrate and nitrite efficiently. The content of vitamin C reached the highest value respectively for the treatment of N225 and N450 at higher and lower basal soil fertility. The highest and lowest value of rough protein was obtained by the treatment N225 and N450 respectively at higher basal soil fertility, but it might rise when increased N application rate, and the highest was obtained by the treatment N600 at lower soil fertility. The concentration of essential oil and soluble sugar all reached the highest by the treatment N600 and N450 at two different soil fertilities respectively. The content of nitrate and nitrite in ginger rhizome all increased along with the increases of N application rates with very significant positive relationship. The N concentration in ginger shoot and rhizome rose significantly, and the uptake of N in ginger shoot and rhizome increased outstandingly compared the treatment applied N with the control.