关键词: 常绿阔叶林, 常绿阔叶林, 海拔梯度, 土壤动物群落, 地表凋落物, 哀牢山

Abstract: The paper aims to study the effects of N fertilizer on the yield, quality and Se absorption of naked oat, and provide theoretical guidance for naked oat (Avena nuda) cultivation technology leading to high yield, high quality and Se-rich in Bashang area of north Hebei Province. Naked oat variety‘Bayou No.1’was used as the material. 6 levels of urea were applied in three-leaf stage and jointing stage, respectively, and all treatments were applied with two kinds of Se foliar fertilizer in three-leaf stage, jointing stage and heading stage and 10 days before maturity. Samples were taken from experimental plots at mature stage, and the indoor measurement of the economic characters, yield components, seed yield and biomass of naked oat were carried out. Semi-Micro Kjeldahl Method was used to determine the crude protein of the grain, Soxhlet extraction method was used to determine the crude fat content of the grain, acid-hydrolysis method was used to determine the crude starch content of the grain, and atomic fluorescence photometer method was used to determine the Secontent of the grain. The results showed that with the increasing urea application amount, the growth periods also increased. And the spikelets per spike, grain weight per spike, number of spike, grains per spike, grain yield, biomass and crude protein content of naked oat increased first and then decreased. N fertilizer increased the absorption of Se fertilizer, and the highest Se contents appeared under treatment N4 (applying 210 kg/hm2 urea in three-leaf stage and 240 kg/hm2 urea in jointing stage) in both of the two years. Spike length, crude fat and starch content were not affected significantly (P＞0.05). The plant height and 1000-grain weight had different results between 2013 and 2014, the plant height and 1000- grain weight were not affected significantly (P＞0.05) by applying urea in 2013, but increased in 2014.