冬小麦等4种作物对铵、硝态氮的吸收能力

Uptake capacity of ammonium and nitrate to several crops

采用水培试验探讨了冬小麦、大豆、油菜和莴笋４ 种作物对硝、铵态氮的相对吸收能力以及这两种氮源对它们生长发育的影响。试验表明：（１）不同氮源对供试作物的生长发育影响极大。供给硝态氮，这些作物生长发育良好；供给等量的ＮＯ－３ 和ＮＨ＋４ （１∶１）时，蔬菜作物莴笋生长量下降幅度最大；供给铵态氨，莴笋和大豆极为敏感，在生长后期发生萎蔫。（２）供试作物在水培期间的总吸氮量与供给的氮源关系密切。供给ＮＯ－３ 时莴笋吸氮量显著高于供给等氮量ＮＯ－３ 和ＮＨ＋４ ，莴笋、小麦供给等量ＮＯ－３ ＋ ＮＨ＋４ 与单独供给ＮＯ－３ 时吸氮量大体相当；油菜、大豆供应等量ＮＯ－３ 和ＮＨ＋４ 时吸氮量最大，供给ＮＯ－３ 时显著下降。除油菜外，其余３ 种作物供给ＮＨ＋４ 时吸氮量均比其它氮源显著降低。（３）多数供试作物对ＮＯ－３ 和ＮＨ＋４ 的吸收具有明显的偏向性。供给等量ＮＯ－３ ＋ ＮＨ＋４ 时，油菜与冬小麦吸收的ＮＯ－３ 显著多于ＮＨ＋４ ，表现出喜硝性，莴笋与此相反，表现出喜铵性，而大豆对两种形态氮素的吸收量相差不多，表现出兼性吸收的特点。但上述偏向性具有阶段特点，即喜硝的作物可能在某一阶段表现出喜铵性状。

The solution culture experiment was conducted in order to investigate the relatively uptake capacity of lettuce,rape,soybean and wheat to nitrate and ammonium,as well as the influence of 3 different nitrogen sources on growth and development of these four crops.The obtained results showed that:(1) When the distilled water was supplied as the growth medium in the nutrient solution,different nitrogen sources greatly affected on the growth and development of lettuce,rape,soybean and wheat.When nitrate was solely supplied,all of these crops growed very well;when the same amount of nitrate and ammonium was supplied as nitrogen source,to some extent the growth amount of lettuce decreased;While ammonium was solely supplied,the growth amounts of these crops decreased greatly except rape,lettuce and soybean were very sensitive to NH + 4-N,and withering took place at late growing stage.(2) During the water culture,the total nitrogen uptake amount of the tested crops had close relation to the nitrogen source.To lettuce,the nitrogen uptake amount as nitrate supplied was significantly higher than that when the same amount of nitrate and ammonium was supplied,if comparing the same amount of NO - 3+NH + 4 treatment with solely supplying nitrate nitrogen treatment,and the nitrogen uptake amounts of lettuce and wheat were almost same;While supplying the same amount of NO - 3+NH + 4,the nitrogen uptake amount of soybean and rape was the largest,when solely supplying nitrate it greatly decreased.When ammounium was supplied,except rape the nitrogen uptake amount of other crops was the lowerest.(3) The tested crops had apparent preference on the uptake of nitrate and ammonium.When the same amount of ammonium and nitrate was supplied,the uptaked nitrate by rape and wheat was larger than ammonium,but the lettuce was vice verse,and the absorped nitroten of two forms by soybean were almost the same.The preference had characteristics of stage,generally speaking,the crop which prefer to nitrate maybe show property of favours ammonium.