氮肥施用对岩溶区石灰土种植火龙果品质的影响

Effects of nitrogen fertilizer application on the quality of pitaya planted in calcareous soil in karst area

关键词:  氮肥, 岩溶石灰土, 火龙果, 果实品质, 矿质营养

Key words:  nitrogen fertilizer, karst calcareous soil, pitaya, fruit quality, mineral nutrition

摘要:

为探究岩溶区石灰土条件下火龙果的氮肥施用水平对其果实品质的影响,该文模拟岩溶区石灰土土壤环境开展盆栽试验,以“台湾大红”火龙果为材料,在磷(P)、钾(K)分别为0.216、0.324 kg的基础上,设置4种施氮(N)水平(CK、T1、T2、T3),测定21个果实品质指标,比较不同施氮水平的火龙果品质差异,同时利用主成分分析法对11个外观品质指标进行了综合分析。结果表明:(1)施氮可提高果实可溶性糖含量及可溶性固形物含量,降低蛋白质含量及膳食纤维含量,高N处理(T3)与其他处理差异显著; 随施N量增加,果实可滴定酸含量、维生素C含量呈先升后降的趋势,而固酸比随施N量呈先降后升的趋势; 高N处理明显提高了果实的纵径、横径、果形指数及单果重。(2)施N处理降低了火龙果果实N含量,提高了P含量,各处理间的N、P含量差异显著; 果实K含量随着施N量的增加而提高; 施N增加了果实硼(B)含量,降低了果实铜(Cu)含量; 不同处理果实锰(Mn)、铁(Fe)、钙(Ca)、镁(Mg)含量高低排序为T3>T1>CK>T2; 锌(Zn)含量随施N量呈先降低后增加的趋势。(3)高N处理的主成分综合评价得分最高,说明选择桂林岩溶区棕色石灰土种植火龙果时辅以一定量的P肥、K肥,高N处理更有利于提高火龙果品质。因此,在实际生产中需根据种植园的土壤肥力状况进行适当调整。

Abstract:

Effects of different nitrogen fertilizer application rates on fruit quality of pitaya under the condition of calcareous soil in karst area were discussed in order to investigate the effects of nitrogen fertilizer application level on fruit quality of pitaya under calcareous soil condition in karst area. The ‘Taiwan Dahong' pitaya were used as the experiment material. Based on 0.216 kg of phosphorus(P)and 0.324 kg of potassium(K), four nitrogen(N)application levels(CK, T1, T2, T3)were setted. Twenty-one fruit quality indexes were determined, and the quality differences of pitaya with different N application levels(CK, T1, T2, T3)were compared. At the same time, eleven appearance quality indexes were comprehensively analyzed by principal component analysis. The results were as follows:(1)Compared with the control, N application could increase the contents of soluble sugar and soluble solids of fruit, reduce the contents of protein and dietary fiber, and the high nitrogen treatment(T3)was significantly different from other treatments. With the increase of N application, the contents of titratable acid and vitamin C of fruit increased firstly and then decreased, while the solid-acid ratio decreased firstly and then increased. T3 significantly increased the fruit vertical and horizontal diameters, fruit shape index and single fruit weight.(2)Compared with the control, N application treatment reduced the N content of pitaya fruit and increased the P content, and the N and P contents of each treatment were significantly different. The K content of fruit increased with the increase of N application. N application increased fruit boron(B)content and decreased fruit cuprum(Cu)content. The contents of manganese(Mn), ferrum(Fe), calcium(Ca)and magnesium(Mg)in different treatments were ranked as T3 > T1 > CK > T2. The content of zinc(Zn)decreased firstly and then increased with the increase of N application.(3)The principal component comprehensive evaluation score of the high N treatment was the highest, indicating that when selecting brown calcareous soil in Guilin karst area to grow pitaya, supplemented by a certain amount of P and K fertilizers, high N treatment was more conducive to improving the quality of pitaya. Therefore, in actual production, it is necessary to make appropriate adjustments according to the soil fertility status of the plantation.