| 摘要: |
| 利用砂培试验,研究了铵态氮和硝态氮,以及不同铁供应水平对旱稻和水稻生长与铁营养状况的影响。结果表明:供铁显著促进了水稻和旱稻的生长,提高了铁吸收量;与铵态氮相比,不供铁时硝态氮加重了缺铁旱稻和水稻的铁缺乏状况。就氮素形态的影响而言,铵态氮明显促进了旱稻和水稻的生长,表现在株高、地上部干重的显著增加,植株铁营养状况的显著改善,叶片SPAD值和植株铁含量、铁吸收量的显著增加,尤其是不供铁条件下,这种促进作用更加明显。同时,铵态氮还促进了植物体内铁的转移。硝态氮的作用则与此相反,特别是在铁供应不足的情况下,硝态氮的供应降低了叶片SPAD值和植株铁含量,加重了铁缺乏症状。以上结果表明,铵态氮有利于旱稻摄取更多的铁营养,并改善生长状况;土壤中氮素以硝态氮为主可能是水作转为旱作后旱稻缺铁黄化的主要原因之一。 |
| 关键词: 氮素形态 旱稻 水稻 生长 铁营养 |
| DOI：10.11841/j.issn.1007-4333.2007.04.082 |
| 修订日期：2007-03-21 |
| 基金项目:国家自然科学基金;引进国际先进农业科技计划(948计划) |
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| Effect of ammonium and nitrate nitrogen on the growth and iron nutrition of up- and lowland rice |
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| Abstract: |
| The change in rice production system is becoming essential due to water constraints.The traditional flooded cultivation has shifted to upland cultivation.Up to now,the area of cultivation of upland rice is only 2% of total rice cultivation area.However,iron deficiency in upland rice production is widespread,which limits improvement of the yield and quality of upland rice.The reasons leading to the Fe deficiency in upland rice remain unclear.One hypothesis is that the shift from ammonium to nitrate nitrogen(N) in soil induces Fe deficiency.The aim of this study was to elucidate the effect of ammonium and nitrate supply on rice growth and Fe nutrition and to make some comparisons on response to nitrogen form between upland and lowland rice.The results showed that Fe application enhanced the growth and Fe uptake of both rice types.Compared with ammonium N,nitrate N caused Fe chlorosis plants under Fe deficiency.Ammonium N better improved plant height and shoot dry weight and Fe uptake than nitrate N.The leaf SPAD reading,Fe concentration in shoots and roots and uptake were significantly higher in rice treated with ammonium N,especially when Fe was not supplied.The translocation of Fe was different between two nitrogen forms,especially for lowland rice.Ammonium N application induced more Fe translocation to shoots of lowland rice.Nitrate N accelerated Fe deficiency in plants,including decreasing leaf SPAD reading and Fe concentration when Fe was not supplied.All these results indicated that ammonium N was a better N source for the growth and Fe nutrition of upland and lowland rice.The dominance of nitrate N in upland soils was one of the reasons for Fe deficiency in rice production. |
| Key words: nitrogen form,upland rice,lowland rice,growth,iron nutrition |
