基于枣粮间作复合生态系统内部异质性,通过在系统内不同位置采样,分析了枣粮间作系统内土壤氮素水平分布特性.结果表明:①枣粮间作生态系统中,在小麦收获期和玉米收获期两个时期,土壤全氮和硝态氮含量均存在明显的水平变异性.土壤全氮含量在距枣行1~6. m范围内,随着与枣行距离的缩短,呈先增加后降低的变化趋势,最高值出现在距枣行3 m处.土壤硝态氮含量随着与枣行距离的缩短而迅速增加.而土壤铵态氮含量极低且没有明显的水平变异;②氮素施用量对土壤全氮和硝态氮空间变异有正向作用,而植株对氮的吸收利用可以降低土壤氮素分布空间差异程度.各因子对土壤全氮空间变异影响强弱顺序为氮吸收量>氮素施用量>土壤含水量;对土壤硝态氮空间变异影响强弱顺序为氮素施用量>土壤全氮含量>氮素吸收量>土壤含水量.
关键词:
枣粮间作; 土壤; 全氮; 硝态氮; 分布
In order to understand the horizontal heterogeneity of soil nitrogen in the jujube2crop intercropping ecosys2 tem(J IE),the experiment was carried out at village Dashujin,Nanpi County,Hebei Province during 2005 - 2006. The soil samples were collected from different site in J IE,i1e10125,2,3,415 and 615 m away from the jujube row to determine the horizontal distribution characteristics of soil total nitrogen (TN),nitrate nitrogen (NO3 - 2N) and ammonium nitrogen (NH4 +2N). The results showed that the horizontal variances of soil TN and NO3 - 2N distribution were obvious at harvest stages of wheat and maize in J IE,but the distribution of soil NH4 +2N had no obvious horizontal variance.When the dis2 tance to the jujube tree row(JTR) decreased from 6. 5 m to 1 m,the soil TN concentration increased first and then de2 creased,and the highest soil TN concentration came from the 3 m sampling site. However,the NO3 - 2N concentration in2 creased rapidly along with the shortened distance to JTR. The results also showed that fertilizer application rate had a great positive effect on the horizontal variances of soil TN and NO3 - 2N,whereas N uptake had a negative effect on them. The main factor affecting the spatial variance of soil TN was N uptake,followed by N application rate and soil water content, while the order of affecting the spatial variance of soil NO3 - 2N was N application rate > soil TN concentration > N uptake > soil water content.
[1] 李文华,赖世登.中国农林复合经营[M].北京:科学出版社994:157-166.
[2] 同金霞,李新岗,窦春蕊,等.枣粮间作的生态影响及效益分析[J].西北林学院学报,20038(1):89-91.
[3] Dalal R C,Strong W M,Cooper J E,et al.Prediction of grain protein in wheat and barley in subtropical environment from available water and nitrogen in Vertisols at sowing[J].Australian Journal of Experimental Agriculture997,37:351-357.
[4] Henning H J,Bea N,Stig M T.Productivity and quality,competition and facilitation of chicory in ryegrass/legume-based pastures under various nitrogen supply levels[J].European Journal of Agronomy,2006,24(3):247-256.
[5] Read J J,Reddy K R,Jenkins J N.Yield and fiber quality of Upland cotton as influenced by nitrogen and potassium nutrition[J].European Journal of Agronomy,2006,24(3):282-290.
[6] Zhu J G,Liu G,Han Y,et al.Nitrate distribution and denitrification in the saturated zone of paddy field under rice/wheat rotation[J].Chemosphere,2003,50:725-732.
[7] S nchez-Pérez J M,Antiguedad I,Arrate I,et al.The influence of nitrate leaching through unsaturated soil on groundwater pollution in an agricultural area of the Basque country:a case study[J].The Science of the Total Environment,2003,317:173-187.
[8] Basso B,Ritchie J T.Impact of compost,manure and inorganic fertilizer on nitrate leaching and yield for a 6-year maize-alfalfa rotation in Michigan[J].Agriculture Ecosystems and Environment,200508:329-341.
[9] 鲍士旦.土壤农化分析[M].3版.北京:中国农业出版社,2000.
[10] Dilly O,Blume H P,Sehy U,et al.Variation of stabilized,microbial and biologically active carbon and nitrogen in soil under contrasting land use and agricultural management practices[J].Chemosphere,2003,52:557-569.
[11] 尹飞,熊瑛,李友军,等.农林复合生态系统土壤特征研究进展[J].河南农业科学,2009(2):16-20.
[12] 刘荣,朱清科.黄土残塬沟壑区混农林系统土壤养分研究初报[J].西北林学院学报993,8(2):46-51.
[13] 尹飞,毛任钊,傅伯杰,等.枣粮间作养分利用与表观损失空间差异性研究[J].生态学报,2008,28(6):2715-2721.