水溶肥追肥量与追肥频次对叶用甘薯品质及产量的影响OA

[Objective]This study aimed to systematically analyze multiple quality indicators of leaf sweet po-tato stem tips by setting different topdressing amounts and frequencies of water-soluble fertilizers,explore an opti-mized fertilization plan,to improve their nutritional quality and provide a theoretical basis for efficient cultivation.[Method]Taking'Tainong 71'leafy sweet potato as the test material,this experiment set topdressing amounts of four water-soluble fertilizers(S1:0 kg·hm-2)S2:120 kg·hm-2 S3:180 kg·hm-2 S4:240 kg·hm-2),three topdressing frequen-cies(D1:once;D2:2 times;D3:3 times(12 treatments in total),to explore the effects of different topdressing treat-ments on the stem tip quality and yield of leafy sweet potatoes.[Result]The yield of leaf sweet potato stem tips was significantly increased after the application of water-soluble fertilizer,and it showed an upward trend with the in-crease of concentration and the frequency of top dressing.The contents of protein and starch reached the maximum values of 29.37 and 68.85 mg·g-1,respectively,under the treatment of S3D2.The soluble sugar content in the stem tips of leafy sweet potatoes reached the maximum value of 2.98 mmol·L-1 under the S4D2 treatment,and the calci-um content reached the maximum value of 0.02 mmol·g-1(prot)under the S3D1 treatment.The optimal treatments of chlorophyll a,b and a+b contents were S4D3(3.84 mg·L-1),S3D3(0.89 mg·L-1)and S4D3(4.69 mg·L-1),corre-spondingly.The total carotene content reached the maximum value of 1.39 mg·L-1 under the S2D2 treatment.[Conclusion]The comprehensive evaluation and analysis of each index through the membership function method indicated that the S3D2 treatment(with a water-soluble fertilizer top-dressing amount of 180 kg·hm-2 and two top-dressings during the growth period)had the best overall performance,which provides a theoretical basis for im-proving the comprehensive quality of leafy sweet potatoes and the rational application of water-soluble fertilizers.