Effect Of Irrigation And Fertilization Proportion On Yield,Quality And Water-Fertilizer Use Efficiency Of Welsh Onion

In order to optimize water and fertilizer management technology and achieve the objective of water-saving and fertilizer-reducing,Using the split plot design,welsh onion cultivars‘Yuanzang'was used as the tested crops to investigated the effect of three irrigation methods drip irrigation?Di?,sprinkler irrigation?Si?,furrow irrigation?Fi?and eight fertilization ratios?N₀P₀K₀?N?P?K?PK?NK?NP?NPK?on the yield,N,P₂O₅,K₂O accumulation and the efficiency of water and fertilizer productivity.The main results are as follow:1.The dry matter accumulation of roots,cauloid and leaves of welsh onion was higher by drip irrigation,followed by sprinkler irrigation and lower furrow irrigation.The dry weight of leaves increased by 7.76%and 4.02%.The yield of welsh onion under drip irrigation and sprinkler irrigation reached 80.83 t/hm² and 78.50 t/hm²,which was 8.00%and 4.90%higher than that of furrow irrigation,but there was no significant difference between drip irrigation and sprinkler irrigation.The yield of welsh onion treated with NPK was higher,reaching117.55 t/hm².Other processing is NPK>NK>NP>PK>N>P>K>N₀P₀K₀.When a single fertilization is applied,the yield of N-treated is higher,P-treated is the second and K-treated is the lowest.When two fertilizers combined,the effect of N deficiency on the yield is large.2.The contents of nitrogen and potassium in the organs of welsh onion were higher by drip irrigation.The phosphorus content in the roots was higher by sprinkler irrigation in seeding oversummer stage.During cauloid expanding stage,the accumulation of nitrogen in roots,cauloid and leaves of drip irrigation and sprinkler irrigation increased by 19.79%,20.22%,20.30%,19.44%,13.79%and 11.05%.The absorption and accumulation of N,P and K in the harvest stage were higher with drip irrigation,followed by sprinkler irrigation,lower furrow irrigation,and nitrogen accumulation were 69.64,61.55,58.24 g/plant;phosphorus accumulation was 49.99,41.08,40.09 g/plant;potassium accumulation was 79.49,67.93,55.04 g/plant.The absorption and accumulation of N,P and K in different fertilization treatments were higher with NPK total fertilization,and N₀P₀K₀ was lower.The contents of N,P and K in single fertilization treatments were higher by the application of the fertilizer.When combined,the N,P,K content and accumulation were lower in the absence of the fertilizer,fertilization can significantly increase the absorption and accumulation of the N,P,K on welsh onions.3.Fertilizer use efficiency,fertilizer agronomic efficiency,fertilizer partial productivity,irrigation water use efficiency and water production efficiency of different irrigation methods are higher with drip irrigation,lower furrow irrigation and sprinkler irrigation.The nitrogen use efficiency of drip irrigation and sprinkler irrigation increased by 65.36%and 31.77%,Phosphorus use efficiency increased by 63.43%and 57.02%;potassium use efficiency increased by 27.64%and 11.64%;The agronomic efficiency of fertilizer increased by 34.84%and 28.76%,respectively.The irrigation water use efficiency increased by 64.02%and34.38%,the water saving rate reached 34.19%and 21.99%.The NPK utilization rate of different fertilization ratio treatments was higher by NPK treatment,the single fertilization treatment was lower and the two treatments were in the middle.The agronomic efficiency of single fertilization fertilizer is N>P>K;The agronomic efficiency of the two combined fertilizers is NK>NP>NP.There is a significant difference in irrigation water use efficiency and water production efficiency.The treatment with NPK is higher,reaching 45.59/kg·m³ and18.06 kg/m³,N₀P₀K₀ is lower,only 22.56 kg/m³ and 8.97 kg/m³,indicating that rational fertilization will also improve water use efficiency.4.The soil water and nutrient distribution under drip irrigation is closer to the root area of the scallions than the furrow irrigation,which is beneficial to the absorption and utilization of welsh onions.Before the soil was cultivated,the furrow irrigation water was mainly distributed in the 40-60 cm soil layer,causing a large amount of irrigation water infiltrate into the deep layer.After the soil was cultivated,due to the change of irrigation ditch,the relative water content of the soil at 30 cm from the onion was too high,which intensified the infiltration of furrow irrigation to the deep soil,while the high ridge where the onion plant was located had lower water content.5.Drip irrigation and sprinkler irrigation significantly increased the content of chlorophyll and carotene in leaves of weish onion and increased their net photosynthetic rate,stomatal conductance and instantaneous water use efficiency.The photosynthetic parameters of Vigorous growth stage were more obvious than the Seeding oversummer stage.On vigorous growth stage,The Pn of drip irrigation,sprinkler irrigation and furrow irrigation were 26.05,25.3 and 23.35?mol·m^-2·s^-1.Drip irrigation and sprinkler irrigation increased by11.56%and 8.35%.