夏秋反季节无公害胡萝卜氮肥适宜用量研究

Quantity of N applied for off-season production of no-polluted carrot

田间试验研究表明:氮肥(尿素)采用分两次对水浇施,用量为150～250mg/hm2,可获得较高的产量(≥38 98t/hm2)和较高的产投比(≥3 64)。硝酸盐含量及亚硝酸盐含量低于国标(GB/1846 1-2001)规定的根茎菜类硝酸盐及亚硝酸含量的限量标准,这为无公害胡萝卜的生产提供了氮肥适宜用量的参考依据。

Experiment showed that dissolving 150-250 kg/ hm^2 N(Carbamide) into water for adding carrot twice, high yield (about 38.98 t/ hm^2) and high proportion (about 3.64) of outcome to investment could be obtained.The content of nitrate and nitrite in root was lower than national standard (GB/ 1846.1-2001) content.