密度、氮肥互作对旱砂田西瓜产量、品质及氮肥利用率的影响

为了探明旱砂田西瓜产量、品质及氮肥利用率同步提高的最佳施氮量和种植密度,制定合理的栽培措施,本试验以中晚熟品种陇抗九号为试材,在砂田条件下设置了3个种植密度(9525、12120、16680株/hm2)和4个施氮水平(0、100、200、300 kg/hm2),研究了氮密互作对西瓜产量、品质和氮素利用率的影响.结果表明,种植密度和施氮量均显著影响西瓜产量及品质,但两者互作效应不显著,两因素中密度是导致产量变化的主导因素,西瓜产量为高密度＞中密度＞低密度,高密度处理的平均西瓜产量较中、低密度分别显著提高了23.46％和45.58％；而施氮量对西瓜品质的调控具有显著作用,施氮量在0～200 kg/hm2范围内,西瓜产量及品质随施氮量的增加而提高,之后有下降趋势,N200处理的西瓜含糖量较N0和N300分别显著提高了1.43％和1.92％,Vc含量分别提高了13.09％和8.42％.西瓜产量提高引起氮肥偏生产力和氮肥吸收利用率的协同提高.综合考虑产量、品质和氮素利用率等因素,在本试验条件下,砂田全膜覆盖栽培西瓜的适宜种植密度为16680株/hm2、适宜的施氮量为200kg/hm2,其西瓜产量、含糖量及氮肥吸收利用率分别为61754 kg/hm2、10.59％和22.29％.

Effects of interaction between density and nitrogen on the yield,quality and nitrogen use efficiency of watermelon in gravel-mulched field

In order to verify the optimum nitrogen application rate and planting density for higher yield、quality and nitrogen use efficiency of watermelon in gravel mulched field, and to provide basis for the development of rational cultivation measures, Longkang 9 representing late variety was used in this study. Under field condition, three planting densities (9525, 12120, 16680 plant/ha) and four nitrogen rates (0, 100, 200, 300 kg/ha) were applied to study the interaction between nitrogen and density on yield、quality and nitrogen use efficiency of watermelon in Gravel mulched field. The results show that planting density and nitrogen rate have significant effects on yield and quality of watermelon, but the interactive effect between them was not significant. Compared with the nitrogen rates planting density is a key factor for increasing the yield, with increased planting density, the yield of watermelon has improved, the yield of high density increased by 23.46% and 45.58% respectively compared to middle density and low  density. The nitrogen rate have significant regulating effect for quality of watermelon, when nitrogen application rate increased from 0 up to 200 kg/ha, the yield and quality were also increased with nitrogen application rate, and lowered while continue to increase amount of nitrogen fertilizer, the N200 treatment increased sugar content of watermelon by 1.43% and 1.92%, and of the Vc content by 13.09% and 8.42% compared to N0 and N300.The partial factor productivity and recovery efficiency of applied N were improved for increasing yield of watermelon. In this study, taking yield、quality and nitrogen use efficiency into consideration, the appropriate plant density and nitrogen rate of watermelon in sandy field are 16680 plant/ha and N 200 kg/ha respectively, the yield、sugar content and nitrogen recovery efficiency of which were 61754 kg/ha, 10.59% and 22.29%.