氮肥施用量对火龙果枝条生长及养分积累的影响

Effects of Nitrogen Application Rate on the Growth and Nutrient Accumulation of Pitaya Shoots

以1年生火龙果苗为材料,研究不同氮肥施用量(0,130,185,245,345 kg·hm-2)对火龙果幼苗生长发育的影响。结果表明:氮肥能促进火龙果枝条的生长。5种施肥处理火龙果植株地上部氮元素(N)质量含量范围为17. 49～18. 59 g·kg^(-1),磷素(P)质量含量范围为4. 86～6. 18 g·kg^(-1),钾素(K)质量含量范围为57. 01～61. 28 g·kg^(-1)。不同元素在相同部位的分布存在差异,同一元素在不同部位的分布及累积量也存在差异。各处理单株氮、磷、钾累积量以及总累积量分别占其总干质量的1. 70%,0. 45%,5. 75%和8%以上;施氮肥会导致火龙果幼苗根冠比降低。火龙果植株地上部中各矿质元素含量均为K﹥N﹥P,K含量是N含量的3倍多,是P含量的12倍多,在火龙果的生产实践中,建议施用高钾型肥料。

One-year-old plants of pitaya(Hylocereus undulatus)were treated with nitrogen fertilizer at the rate of 0(T0),130(T1),185(T2),245(T3)or 345 kg·hm^-2(T4)to study the effects of different application rates of nitrogen fertilizer on the root system and growth of young pitaya plants.The results showed that nitrogen fertilizer promoted the growth of pitaya lateral shoots.The content of nitrogen in the shoots of pitaya plants under 5 treatments ranged from 17.49 g·kg^-1 to 18.59 g·kg^-1,the phosphorus content from 4.86 g·kg^-1 to 6.18 g·kg^-1,and the potassium content from 57.01 g·kg^-1 to 61.28 g·kg^-1.The distribution of different nutrient elements in the same position of pitaya plants was different,and the distribution or accumulation of the same nutrient element in different parts of the pitaya plants was also different.The cumulative content and total cumulative content of nitrogen,phosphorus and potassium of each pitaya plant in each treatment accounted for 1.70%,0.45%,5.75%and more than 8%of the total dry weight,respectively.The application of nitrogen fertilizer resulted in a lower root/shoot ratio of the young pitaya plants.The contents of mineral elements in the aboveground parts of the pitaya plants were all in the order of K>N>P.K content was 3 times higher than N content,or 12 times higher than P content.In pitaya production fertilizer with high potassium is recommended.