摘要
在江汉平原典型农业区选定不同水稻种植年限(2、18、>100a)的稻田,采用野外调查与室内分析相结合的方法,量化不同稻田土壤剖面基本性质和水–氮分布特征,以揭示内在原因,探讨适宜不同水稻种植年限稻田的水–氮管理方式,为提高稻田水–氮利用率和减少稻田面源污染提供科学依据。结果表明:对于不同水稻种植年限农田,土壤剖面基本性质差异明显。耕作层和犁底层厚度随水稻种植年限的延长而增加;土壤有机质在耕作层富集,且随水稻种植年限的延长含量增加;耕作层土壤容重随水稻种植年限的延长而减小,犁底层土壤容重则增大;受耕作和淋溶条件的影响,犁底层和心土层的黏粒含量随水稻种植年限的延长而增加;饱和导水率(Ks)随水稻种植年限的延长而降低,犁底层Ks差异较大,2、18、>100a稻田犁底层Ks分别为37.02、8.45、3.11cm/d。土壤剖面基本性质的差异影响水–氮的剖面分布特征。土壤水分和硝态氮含量随水稻种植年限的延长而增加,2、18、>100 a稻田土壤剖面(0~100 cm)平均含水量分别为0.39、0.46、0.54cm3/cm3,硝态氮含量分别为3.75、6.27、9.85mg/kg。铵态氮储量远低于硝态氮储量,且受水稻种植年限影响较小;2、18、>100 a稻田土壤剖面铵态氮与硝态氮储量比值分别为0.61、0.39和0.30。在灌溉和施肥方式上,水稻种植年限短的稻田适合少量多次的管理方式以减少渗漏损失;而年限长的稻田可适当提高单次灌溉量以减少灌溉次数,进而减少劳力消耗。
In order to improve the water/nitrogen utilization efficiency and reduce the agricultural non-point source pollution, field investigation and lab analysis have been conducted to quantify the characteristics of water/nitrogen distribution and to explore the optimal irrigation and fertilizer schedules in paddy fields with different cultivation years(2 a, 18 a and >100 a) in the Jianghan Plain. The results showed that significant differences in soil properties were observed among the paddy fields. With the increase of paddy cultivation year, the thickness of plough layer and plow pan, bulk density of plow pan, and clay content of subsoil layer and plow pan were all increased, whereas bulk density of the plough layer was decreased. Significant differences in saturated hydraulic conductivity(Ks) were observed in soil profiles between the paddy fields, especially for the plow pan. The highest average Ks of the plow pan was observed in the 2 a field(37.02 cm/d), followed by the 18 a field(8.45 cm/d) and the >100 a field(3.11 cm/d). The profile distribution of water/nitrogen were affected by soil properties significantly. With the increase of paddy cultivation year, water/nitrate nitrogen(NO–3-N) content increased gradually, the average soil water content was 0.39, 0.46 and 0.54 cm3/cm3, while the average soil NO–3-N content was 3.75, 6.27 and 9.85 mg/kg for the 2 a, 18 a and >100 a paddy fields, respectively. However, little difference was observed in ammonium nitrogen(NH4+-N) in the paddy fields. The ratios of NO–3-N and NH4+-N in 2 a, 18 a and >100 a fields were 0.61, 0.39 and 0.30, respectively. In order to reduce water/nitrogen percolation for the short-year paddy field, the strategies of more times but less amount in irrigation and fertilization could be applied, but for the longer-year paddy field, fewer times but high amount in irrigation and fertilization could be applied to cut the labor costs.
作者
张君
刘目兴
易军
张海林
李胜龙
段赫
杨倩
ZHANG Jun;LIU Muxing;YI Jun;ZHANG Hailin;LI Shenglong;DUAN He;YANG Qian(Key Laboratory for Geographical Process Analysis&Simulation,Wuhan 430079,China;College of Urban and Environmental Sciences,Central China Normal University,Wuhan 430079,China)
出处
《土壤》
CAS
CSCD
北大核心
2019年第6期1188-1195,共8页
Soils
基金
国家自然科学基金项目(41601215,41771261)
湖北省自然科学基金创新群体项目(2016CFA027)
华中师范大学中央高校基本科研业务费项目(CCNU16A05015,CCNU17TS0001)资助
关键词
水稻种植年限
土壤基本性质
饱和导水率
水–氮分布
江汉平原
Paddy cultivation year
Soil basic property
Saturated hydraulic conductivity
Water and nitrogen distribution
Jianghan Plain
