江淮丘陵区不同氮肥管理模式下稻田氨挥发损失特征研究

为了探索减少江淮丘陵区稻田氨挥发损失和提高其氮肥利用率的途径,采用密闭室连续抽取法,研究了不同氮肥管理模式对稻田氨挥发损失特征和氮肥利用率的影响。结果表明,整个稻季,氨挥发损失率以分蘖肥期最高,基肥期次之,穗肥期最低。较常规施肥(CN),缓释尿素与普通尿素配施(CRU)处理稻季氨挥发损失总量和损失率分别降低了26.23%和4.52%,氮肥利用率提高了6.07%;各施肥处理的氨挥发量与同期田面水中的铵态氮浓度呈线性正相关。综合分析,缓释尿素与普通尿素配施既能减少氨挥发损失,又能获得较高的经济效益,在江淮丘陵区具有推广应用价值。

Study on the Ammonia Volatilization Under Different Nitrogen Schemes from Paddy Field in Jianghuai Hilly Region

Ammonia volatilization was a major path of nitrogen losses in Paddy field.In order to evaluate the effects of different nitrogen schemes on ammonia volatilization and nitrogen use efficiency from paddy field in Jianghuai hilly region,a field experiment by the closed airflow chamber method was conducted.The results showed that the ammonia volatilization loss ratio was the highest at tillering stage,followed by basal stage,finally heading stage.Compared with the conventional fertilization,the ammonia volatilization loss amount and ratio under the application of slow release urea combined with common urea were decreased by 26.23％ and 4.52％,respectively,while the nitrogen use efficiency increased by 6.07％.Ammonia volatilization loss was positive correlated with ammonium nitrogen concentration on the surface water.Therefore,the application of slow-release urea combined with common urea can not only reduce ammonia volatilization loss,but also obtain higher economic benefit,which is suitable to be recommended in Jianghuai hilly region.