青贮玉米氮投入对坡耕地土壤侵蚀及水稳性团聚体的影响  

Impact of Nitrogen Input of Silage Maize on Soil Erosion and Water-stable Aggregates in Sloping Farmland

作　　者：赵桂茹[1] 安曈昕[1] 欧阳铖人[1] 邓宗澳 吕凯 杨友琼[1] 周锋[1] 吴伯志[1] ZHAO Guiru;AN Tongxin;OUYANG Chengren;DENG Zongao;Lü Kai;YANG Youqiong;ZHOU Feng;WU Bozhi(Key Laboratory for Crop Production and Smart Agriculture of Yunnan Province,aculty of Agronomy and Biotechnology,Yunnan Agricultural University,Kunming 650201)

机构地区：[1]云南农业大学农学与生物技术学院云南省作物生产与智慧农业重点实验室,昆明650201

出　　处：《水土保持学报》2021年第5期72-79,共8页Journal of Soil and Water Conservation

基　　金：云南省重点研发计划项目(2018BB015);云南省重大科技专项-绿色食品国际合作研究中心项目(2019ZG00902)。

摘　　要：为探讨不同氮投入对红壤坡耕地水土流失及土壤水稳性团聚体的影响,在种植青贮玉米的坡耕地上设置4个不同氮投入处理(N1:300.00 kg/hm^(2);N2:225.00 kg/hm^(2);N3:150.00 kg/hm^(2)和N4:75.00 kg/hm^(2)),用湿筛法获得>2,1~2,0.5~1,0.25~0.5,<0.25 mm粒径的团聚体组分并计算出水稳性团聚体含量(WSA_(>0.25))、平均重量直径(MWD)、几何平均直径(GMD)和分形维数(PD)的含量。结果表明:(1)不同氮投入处理的坡面产流产沙特征与降雨强度关系密切,在低强度、中强度和高强度降雨条件下,N1和N2处理的径流量和产沙量均显著小于N3和N4处理(P<0.05),N2与N1处理径流量及产沙量差异均未达到显著水平(P>0.05),但在极高强度降雨下,各处理径流量和产沙量的差异均不显著(P>0.05)。(2)N2处理的WSA_(>0.25)、MWD和GMD比其他3个处理大,而PD却比较小,此外,WSA_(>0.25)、MWD和GMD三者之间相互存在极显著正相关性(P<0.01),而与PD、径流量和产沙量均呈现出极显著负相关关系(P<0.01)。(3)N1和N2处理土壤容重显著低于N3和N4处理的容重(P<0.05),但其孔隙度和田间持水量显著高于N3和N4处理(P<0.05)。因此,在当地常规施肥水平上减少25%氮投入量不会加剧土壤侵蚀,还可通过改善土壤物理性质以维持红壤坡耕地的生产能力。In order to explore the effects of different nitrogen inputs on soil erosion and soil water-stable aggregates in red soil slope farmland,four nitrogen treatments including N1(300.00 kg/hm^(2)),N_(2)(225.00 kg/hm^(2)),N3(150.00 kg/hm^(2))and N4(75.00 kg/hm 2)were designed,and the runoff and sediment yield were measured during the whole growth period of silage maize.Meanwhile,the aggregate components with particle size>2,1~2,0.5~1,0.25~0.5 and<0.25 mm were obtained by wet screening method,and the content of water-stable aggregates(WSA>0.25),mean weight diameter(MWD),geometric mean diameter(GMD)and parting dimension(PD)were calculated.The results showed that:(1)The characteristics of runoff and sediment yield of different nitrogen inputs were closely related to rainfall intensity.The runoff and sediment yields of N1 and N2 treatments were significantly lower than those of N3 and N4 treatments under the condition of low,medium and high intensity rainfall(P<0.01),and there was no significant difference in runoff and sediment yield between N1 and N2 treatment(P>0.05).Whereas,the differences in runoff and sediment yield were not significant among different treatments under extremely high intensity rainfall(P>0.05).(2)WSA>0.25,GMD and MWD of N2 treatment were higher than those of the other three treatments,but the PD was relatively low.Additionally,there was a very significant positive correlation among WSA>0.25,MWD and GMD,but an extremely significant negative correlation with PD,runoff and sediment yield.(3)The soil bulk densities of N1 and N2 treatments were significantly lower than those of N3 and N4 treatments(P<0.01),but the porosity and soil water holding capacity of N1 and N2 treatments were significantly higher than those of N3 and N4 treatments(P<0.05).Therefore,reducing 25%of nitrogen input at the local fertilization level will not aggravate soil erosion,and improve the soil physical properties to maintain the productivity of red soil sloping farmland.

关 键 词：青贮玉米 氮投入 土壤侵蚀 土壤团聚体 稳定性 

分 类 号：S157.4[农业科学—土壤学]