供钾水平对宁南山区花椰菜产量及钾素平衡的影响

Effect of potassium supply level on yield of cauliflower and potassium balance in soil

【目的】为宁夏冷凉花椰菜生产中钾肥合理施用提供科学依据。【方法】以宁夏冷凉主导花椰菜为试验材料,设置0(K_(0))、10(K_(10))、20(K_(20))、30(K_(30))、40 kg/667m^(2)(K_(40))5个施钾水平,通过田间试验,研究供钾对露地花椰菜产量、钾素吸收分配利用及土壤根层钾素质量与平衡的影响。【结果】供钾显著增加花椰菜产量,增产率在5.32%~16.24%,供钾水平与花球产量呈极显著的二次抛物曲线关系,最高产量为3 529.43 kg/667 m^(2),最佳供钾水平为24.28 kg/667 m^(2)。在苗期和莲座期茎叶是花椰菜钾元素的累积中心,不同处理茎叶分配比例在49.67%~90.49%,进入成熟期花球是花椰菜钾元素的累积中心,不同处理花球累积分配比例在42.25%~53.73%,整株花椰菜钾素累积量苗期以K_(30)处理最高,莲座期和成熟期均以K_(20)处理最高,较对照分别显著提高69.40%、79.38%。钾肥利用效率为21.77%~40.31%,以K20处理的钾肥利用率、贡献率及农学效率均最高,分别为45.28%,21.31%、38.670 kg/kg。供钾水平低于20 kg/667 m^(2)时,土壤钾素平衡表现为亏缺,供钾水平超过30 kg/667 m^(2)钾素盈余由负转正,再继续投入钾肥,钾素盈余。【结论】综合考虑花椰菜钾素吸收利用分配与产量和土壤钾素有效性与菜田钾素收支平衡等因素,建议宁夏南部山区花椰菜适宜的供钾水平为21.82~29.24 kg/667 m^(2)。

【Objective】 This study aimed to provide a scientific basis for the rational application of potassium fertilizer in cold cauliflower production of Ningxia.【Method】 Field experiments were conducted with Ningxia Lengliang dominant cauliflower as the experimental material.Five treatments were established:0(K_0),10(K_(10)),20(K_(2)0),30(K_(30)),and 40(K_(40)) kg/667m^(2).The effects of potassium supply on yield,potassium absorption,allocation and utilization in open field cauliflower,as well as potassium quality and balance in the soil root layer,were investigated.【Result】 The results demonstrated that potassium supply significantly increased cauliflower yield,with an increase rate ranging from 5.32% to 16.24%.The relationship between potassium supply level and flower bulb yield followed a significant quadratic parabolic curve,with the highest yield observed at 3 529.43 kg/667 m^(2) and the optimal potassium supply level at 24.28 kg/667m^(2).During the seedling and rosette stages,stems and leaves were the main accumulation centers of potassium in cauliflower,with distribution ratios ranging from 49.67% to 90.49% under different treatments.As the cauliflower entered the mature stage,the flower bulb became the main accumulation center of potassium,accounting for 42.25% to 53.73% under different treatments.The highest potassium accumulation in the whole plant occurred under the K30 treatment during the seedling stage.During the rosette and mature stages,the K20 treatment exhibited the highest accumulation,with a significant increase of 69.40% and 79.38% compared to the control,respectively.The utilization efficiency of potash fertilizer ranged from 21.77% to 40.31%,and the K20 treatment showed the highest utilization rate,contribution rate,and agronomic efficiency,which were 45.28%,21.31%,and 38.670 kg/kg,respectively.When the potassium supply level was below 20 kg/667m^(2),the soil K balance indicated a deficit.When the potassium supply level exceeded 30 kg/667m^(2),the K surplus changed from negative to positive,suggesting the need for continued potassium fertilizer application to achieve a surplus.【Conclusion】 Considering factors such as potassium absorption,utilization,distribution,and cauliflower yield,as well as the potassium availability and budget balance in vegetable fields,it is recommended that the appropriate potassium supply level for cauliflower in the southern mountainous area of Ningxia is 21.82~29.24 kg/667m^(2).