Efects of N，P，K combinations on nitrate accumulation and nutrient quuality of foliage vegetables grown in soil-less culture

The effects of N，P，K combinationsN：P₂0₅：K₂o=1：1：1(B_NPK)，3：1：2(H_NK)，2：1：3(H_KN)，2：3：1(H_PN)and 3：2：1(H_NP<)，respectivelyon nitrate accumulation and nutrient quality of foliage vegetables grovcn in soil-less culture were studied．The results show that the growth，yield，the contents of VC，soluble sugar(except H_PN treatment)and amino acid(except H_PN and H_NP treatments)are reduced in all treatm ents，but there is no different effect on the nitrate accumulation in celery．The yields(except H_NP treatment)and the contents of VC(except H_PN treatment)，soluble sugar (except H_KN and H_NK treatments)and amino acid(except H_NP treatment)in romaine lettuce are increased，but the nitrate contents of romaine lettuce are decreased by 4．5％-41．8％ (except H_NK treatment)．