不同氮、钾用量对嫁接苦瓜养分吸收、分配及产量的影响

为解决目前冬季北运苦瓜生产上肥料过量施用问题,探讨氮、钾不同施用量对嫁接苦瓜养分吸收分配及产量的影响,以苦瓜嫁接苗为试材,以6个不同的N、K施肥量为处理,对嫁接苦瓜产量和各生育期不同器官干物质累积量及氮、磷、钾养分累积吸收量进行测定。结果表明：不同处理嫁接苦瓜各器官干物质积累量均随生育期的延伸有不同程度增加,在幼苗期和初瓜期同等施钾条件下,茎、叶、果干物质积累量与供氮水平呈显著正相关;在盛果期,在同等施氮条件下,茎、叶、果干物质积累量随供钾水平提高而显著增加;其中T₂处理在不同生育期各器官的干物质积累量均显著高于其他处理,且在盛果期干物质积累总量和果实干物质分配率均达到最大,分别为590.76 g/株、43%。不同处理嫁接苦瓜各器官氮、磷、钾养分累积量变化随生育期的延伸呈上升趋势,嫁接苦瓜对钾需求量较高,其次是氮,磷最少;T₂处理在各生育期氮、磷、钾累积量持续呈较高水平,成熟期累积量达到最高分别为每株20.9、3.5、27.3 g,较其他处理分别平均增加52.7%、43.2%、38.5%;与其他处理相比,T₂处理明显增强叶片（源）向 果实（库）的养分供应能力,氮、磷、钾果实干物质分配率在成熟期分别为59%、48%、48%,显著高于其他处理。不同处理对嫁接苦瓜产量均有差异,同等施钾条件嫁接苦瓜产量与供氮水平呈显著正相关,其中T₂处理嫁接苦瓜单瓜重、产量均显著较其他处理分别平均增加37.1%、46.4%。综合研究嫁接苦瓜生长量及氮、磷、钾养分的有效利用性,T₂处理（N 260 kg/hm²、K₂O 430 kg/hm²）对嫁接苦瓜增产的促进作用最显著,可根据具体情况在生产上推广应用,实现农业绿色“加减法”。

Effects of Different Amounts of Nitrogen and Potassium on Nutrient Absorption,Distribution and Yield of Grafted Bitter Gourd

The influence of different application rates of nitrogen and potassium on nutrient absorption and distribution and yield of grafted bitter gourd was discussed to solve the problem of over-application of fertilizers in the production of bitter gourd in winter. The bitter gourd grafted seedlings were treated with a control (T₁), N 260 kg/hm², K₂O 430 kg/hm² (T₂), N 416 kg/hm², K₂O 768 kg/hm² (T₃), N 416 kg/hm², K₂O 192 kg/hm² (T₄), N 104 kg/hm², K₂O 768 kg/hm² (T₅), N 104 kg/hm², K₂O 192 kg/hm²(T₆). The dry matter accumulation of different organs and the accumulation of nitrogen, phosphorus and potassium nutrients were determined in each growth period. The dry matter accumulation of various organs of grafted bitter gourd in different treatment increased with the extension of the growth period. Under the same condition of potassium application in the seedling and initial stages, the dry matter accumulation of stems, leaves and fruits was positively related with the nitrogen supply level. In the fruit-bearing period, under the same nitrogen application conditions, the dry matter accumulation of stems, leaves, and fruits increased significantly with the increase of potassium supply. Among them, the dry matter accumulation of all organs in different growth periods was equal to T₂ treatment, significantly higher than that of other treatments. The total dry matter accumulation and fruit dry matter distribution rate reached the maximum in the full fruit stage, which was 590.76 g/plant and 43% respectively. The accumulation of nitrogen, phosphorus, and potassium in various organs of grafted bitter gourd with different treatment showed an upward trend with the extension of growth period. Grafted bitter gourd had a higher demand for potassium, followed by nitrogen and phosphorus. The accumulation of potassium continued to be at a high level, and the accumulation reached the highest level of 20.9, 3.5, 27.3 g per plant in the mature stage, respectively, an average increase of 52.7%, 43.2%, and 38.5% compared with the other treatments. Compared with the other treatments, T₂ treatment significantly enhanced the nutrient supply capacity of the leaves (source) to the fruit (sink), and the dry matter distribution rate of nitrogen, phosphorus, and potassium in the fruit was 59%, 48%, and 48% at the mature stage, which was significantly higher than that of other treatments. Different treatment had differences in the yield of grafted bitter gourd. The yield of grafted bitter gourd under the same potassium application was significantly positively correlated with the nitrogen supply. The weight and yield of grafted bitter gourd in T₂ treatment increased significantly by 37.1% and 46.4% respectively compared with the other treatments. Comprehensive research on the growth of grafted balsam pear and the effective utilization of nitrogen, phosphorus and potassium nutrients, T₂ treatment (N 260 kg/hm², K₂O 430 kg/hm²) had the most significant effect on increasing the yield of grafted balsam pear. Promote the application and realize the “addition and subtraction” of green agriculture.