%0 Journal Article %T 配施有机肥减少太湖地区稻田土壤硝态氮淋失的机理研究 %T Study on Mechanism of Reducing Nitrate Leaching with Organic Addition from Paddy Field in Taihu Lake Region %A 张 敏,姚元林,曾 科,李冰洋,田玉华,尹 斌 %A ZHANG,Min %A YAO,Yuanlin %A ZENG,Ke %A LI,Bingyang %A TIAN,Yuhua %A YIN,Bin %J 土壤 %J Soils %@ 0253-9829 %V 52 %N 4 %D 2020 %P 766-772 %K 水稻;有机肥;淋溶;机制;太湖地区 %K Rice; Organic fertilizer; N leaching; Mechanism; Taihu Lake region %X 采用田间小区试验,设计两种无机氮肥梯度,研究配施有机肥对太湖地区水稻季土壤氮素淋失的影响,并从水/土NO3--N迁移研究其对土壤NO3--N淋失的影响机制。设置的处理有:对照(CK)、常规施氮(CT)、减氮施肥(RT)、常规施氮下配施有机肥(CT+M)、减氮施肥下配施有机肥(RT+M)。结果发现:①除去2015年的CT处理,两年里30 cm处配施有机肥和单施无机肥处理之间的土壤NO3--N淋失均没有显著差异;80 cm处,CT+M处理的NO3--N淋失较CT处理减少41%,RT+M处理较RT处理减少12%。②无机肥处理的田面水NO3-- N和土壤淋溶水NO3-- N之间存在极显著线性相关,但是有机肥的参与会削弱二者之间的相关性。③配施有机肥有利于土壤有机质含量的提高,CT+M处理的有机质含量较CT处理提高6.7%。0 ~ 20 cm土层,配施有机肥处理土壤NO3--N含量明显高于无机肥处理;而20 ~ 40 cm土层,二者之间的土壤NO3--N含量差异很小。这表明配施有机肥是通过提高土壤有机质含量,增强土壤表层对NO3--N的吸附固持,从而抑制土壤NO3--N的向下迁移,而不是通过减少田面水NO3--N浓度来实现的。此外,配施有机肥还可以提高土壤质量和水稻产量,促进作物对土壤氮素的吸收,这也是稻田土壤NO3--N淋失减少的一个原因。研究结果为减少农田土壤NO– 3-N淋失提供了科学依据。 %X Field plot experiment with two nitrogen (N) applying rates was conducted to study the effect of organic addition on N leaching in rice season of Taihu Lake Region, and the mechanism was also studied through nitrate (NO3- -N) migration of water and soil. The designed treatments included no nitrogen (CK), conventional chemical N fertilizer (CT, N 300 kg/hm2), reducing N (RT, N 225 kg/hm2), CT+ rapeseed cake fertilizer (CT+M, M 2 250 kg/hm2), RT+rapeseed cake fertilizer (RT+M). The results showed that: 1) There was no significant difference in soil NO3- -N leaching between organic addition and inorganic fertilizer treatments at 30 cm depth during the two rice seasons of 2014 and 2015 except CT treatment in 2015. NO3- -N leaching at 80 cm depth in CT+M was 41% lower than that in CT, and RT+M produced 12% lower NO3- -N leaching loss compared to RT. 2) Floodwater NO3- -N under chemical N treatments was significant correlated with soil NO3- -N leaching, but the involvement of organic fertilizer weakened the correlation. 3) Organic addition increased soil organic matter content (SOM), and CT+M achieved 6.7% higher than CT. Organic N treatments showed higher soil NO3- -N content at 0–20 cm layer compared to chemical N treatments. And soil NO3- -N content at 20–40 cm layer differed little between organic N and chemical N treatments. These indicated that organic addition enhanced the absorption and fixation of NO3- -N by soil through the improved SOM and thus inhibited the migration of NO3- -N to deep soil. The reduced NO3- -N leaching under organic addition was not achieved by reducing floodwater NO3- -N concentration. Additionally, organic addition improved soil quality and rice yield, promoted crop N uptake, and thus could also explain the reduced NO3- -N leaching loss. The results provide scientific basis for decreasing NO3- -N leaching in farmland. %R 10.13758/j.cnki.tr.2020.04.016 %U http://soils.issas.ac.cn/tr/home %1 JIS Version 3.0.0