Effect Of Combined Application Of Nitrogen, Phosphorus And Potassium On The Physiological Characteristics Of Formation For Yield And Quality Of Chinese Spring Onion

Chinese spring onion occupies an important place in the vegetable production in our country. The cultivation management is very extensive because of its strong adaptability. The production of Chinese spring onion according to traditional experience for a long time, and the phenomena of blind fertilizing is very prominent on the production.This will not only increase the cost of production and pollute the environment, but also affect the yield and quality of green Chinese onion. In order to confirm the response characteristics of Chinese spring onion to rhizosphere fertilizer and provide theoretical basis for the Chinese spring onion efficient fertilization, the variety of "Tianguang" was taken as material to study the optimization of NPK fertilization scheme on chinese spring onion, discuss fertilization and green Chinese onion nutrient uptake characteristics, analyze the influence of different NPK scheme on the growth and development of Chinese spring onion, production quality and some physiological characteristics by "3414" test design scheme. The main results were as follows:1. Chinese spring onion grow slowly in seedling stage, lthough the. duration accounted for31.82%of the whole growth period, but accumulation of dry matter is less,the absorption rate of nitrogen, phosphorus and potassium is low, uptake accounted for only about5%of the whole growth period; N, P, K uptake accounted for the whole growth period is about6%in seeding oversummer stage; the plant grow fast in vigorous growth stage N, P2O5, K2O respective absorption rate were6.80,3.80and6.41mg/(plant-d), uptake accounted for about80%of the whole growth period; the absorption rate is low in cauloid expanding stage, the N and P2O5uptake accounted for about6%of the whole growth period, but K2O uptake accounted for more than10%of the whole growth period. The proportion of Chinese spring onion absorption to N, P2O5, K2O in whole growth period was1:0.56:0.97, along with the growth of phosphorus ratio gradually reduce, potassium absorption rate increased, the ratio was1:0.49:1.59in cauloid expanding stage. Chinese spring onion in prophase NPK mainly distribution on the blade, at later growth stage is mainly distribution in cauloid. Every1000kg cauloid product,the demands for N, P2O5, K2O were about4.27,2.40,4.17kg.2. Deficiency fertilization significantly reduced the missing elements in the Chinese spring onion content in different organs, reduce the uptake of N, P2O5, K2O and significant impact on absorption ratio. The N, P2O5, K2O uptake of nutrient deficiency treatment accounts for48.4%～86.9%of balanced fertilization treatment, the N-deficiency treatment (N0P2K2) N, P2O5, K2O absorption ratio of whole growth period was1:0.73:1.12, the P-deficiency treatment (N2P0K2) N, P2O5, K2O absorption ratio of whole growth period was1:0.45:0.87, the K-deficiency treatment (N2P2K0) N, P2O5, K2O absorption ratio of whole growth period was1:0.58:0.58. The nutrient deficiency treatments also affected allocation proportion in different organs in the harvest stage, compared with N2P2K2, N0P2K2can reduced the distribution rate of N, P2O5, K2O in leaf,N2P2Ko reduced the distribution rate of N, P2O5, K2O in cauloid; N2P0K2effect on distribution rate of N, P2O5, K2O is not serious.3. N, P and K significantly influenced yield and quality of Chinese spring onion, with N having the biggest effect followed by K and P. The interaction of N, K for ginger yield and quality were significant, with the biggest interaction area being N at315-675kg/hm2and K2O at337.5-900kg/hm2. In this experiment, when the fertilizer rates were N at422.1-639.3kg·hm-2, P2O5at329.4～486.2kg/hm2and K2O at499.1～810.4kg/hm2, yield reached75t/hm2and quality grade passed85. The most suitable ratio of N:P2Os:K2O was1:0.77:1.25.The potassium fertilizer utilization rate of N, P2O5, K2O in N2P2K2treatment respectively was22.96%,16.13%,20.11%, all was significantly higher than nutrient deficiency treatment.4. N, P and K has significantly influenced growth of green Chinese spring onion, but their influence degree is different. N main influenced Chinese spring onion plant height, leaf number and dry matter weight, in1st October, N0P2K2plant height, leaf number and whole plant dry matter weight only84.36%,79.47%and53.74%of N2P2K2; P main influenced Chinese spring onion root, N2P0K2root dry matter weight only86.78%of N2P2K2in1st October; K main influenced Chinese spring onion cauloid, N2P2K0cauloid length and roughness only87.28%and80.69%in1st October.5. N, P and K has significantly influenced physiological characters of green Chinese spring onion, but their influence degree is different. N main influenced NR, GS, Pn, Tr, chlorophyll content, chlorophyll fluorescence parameters. In vigorous growth stage, the N0P2K2activity of NR, GS were only57.40%,63.40%of N2P2K2; the chlorophyll content, Pn, Tr were only74.93%,71.96%,77.46%of N2P2K2; the Fv/Fm, ΦPS Ⅱ, qP were significantly lower than N2P2K2. P main affect the root activity. In vigorous growth stage, the N2P0K2root activity was only70.91%of N2P2K2.