5种茄果类蔬菜氮素经济效益最佳施用量研究

Optimum Nitrogen Rates for Best Economic Benefits in Five Vegetable Crops

在甘肃张掖市连续种植6~11年的日光温室内,采用田间小区试验方法,研究了5种茄果类蔬菜氮素经济效益最佳施用量。结果表明:氮素施用量与西葫芦、黄瓜、茄子、辣椒和番茄产量呈显著的正相关关系,相关系数分别为0.8388、0.8812、0.8044、0.8418和0.9058;随着氮素施用量梯度的增加,茄果类蔬菜产量在增加,但边际利润和单位氮素增产量则随氮素施用量梯度的增加而递减,出现了报酬递减律。经回归统计分析,西葫芦、黄瓜、茄子、辣椒和番茄氮素经济效益最佳施用量分别为450 kg·hm^(-2)、360 kg·hm^(-2)、240 kg·hm^(-2)、420 kg·hm^(-2)和480 kg·hm^(-2)时,理论产量分别为129.7 t·hm^(-2)、96.2 t·hm^(-2)、82.5 t·hm^(-2)、69.3 t·hm^(-2)、105.7 t·hm^(-2),统计分析结果与田间试验结果基本吻合。

The optimum nitrogen application rates for best economic benefits in five vegetablecrops were investigated under greenhouses which have been cultivated for six to ten years in Zhangye. The results showed that the nitrogen application rates were positively correla- ted to the yields of zucchini, cucumber, eggplant, pepper and tomato, and the correlation coefficient were 0. 8388, 0. 8812, 0. 8044, 0. 8418 and 0. 9058, respectively. Though the yields were increased with the increase of nitorgen application rates, the profit margins and yield increase by unit nitrogen applied decreased, i. e. showing the diminishing return. The regression analysis indicated that the op- timum nitorgen rates for best economic benefits in zucchini, cucumber, eggplant, pepper and tomato were 450 kg·hm^-2, 360 kg·hm^-2, 240 kg·hm^-2, 420 kg·hm^-2, 480 kg·hm^-2 respectively; and the theoretical yield was 129. 7 t·hm^-2, 96. 2 t·hm^-2, 82. 5 t·hm^-2, 69. 3 t·hm^-2 and 105.7 t·hm^-2 ; respectively; which was consistent with the results of field experiments.