灌溉对沙拐枣幼苗根区土壤氮素营养特征的影响  

Effects of Irrigation on Nitrogen Nutrition Characteristics in the Rootzone Soil of Calligonum caput-medusae Schrenk Seedlings

作　　者：黄彩变[1,2] 曾凡江[1,2] 雷加强[1,2] 徐立帅[1,2] 高欢欢[1,2] 

机构地区：[1]中国科学院新疆生态与地理研究所,乌鲁木齐830011 [2]新疆策勒荒漠草地生态系统国家野外科学观测研究站,新疆策勒848300

出　　处：《水土保持学报》2013年第6期152-157,共6页Journal of Soil and Water Conservation

基　　金：中国科学院西部博士项目(XBBS201002);国家科技支撑计划项目(2009BAC54B01);国家自然科学基金(31200352);国家博士后面上基金(20100471680)

摘　　要：采用盆栽试验，研究不同灌溉梯度下（4．6，6．1，7．7，9．2，13．0kg／株·次）沙拐枣幼苗根区氮素营养变化特征及植物吸氮能力差异。结果表明，自然土壤种植沙拐枣后，不同季节幼苗根区硝态氮和铵态氮含量均成降低趋势，季末分别降低70．9％～92．4％和20．3％～51．6％，且灌溉量越高降低越明显；根区全氮和有机质含量则成增加趋势，随灌溉量增加全氮含量变化较小，但有机质含量有降低的趋势。与4．6kg／（株·次）处理相比，季末整株吸氮量分别增加10．8％，79．8％，85．4％和290．2％，干物质累积量相应增加13．2％，97．8％，197．6％和394．6％，但在最高灌溉量下植物出现严重病害。这表明灌溉后根区矿化氮亏缺主要与植物大量吸收和消耗有关。由此可见，灌溉量过低和过高均不利于沙拐枣幼苗生长，结合根区氮素供应变化，中等灌溉量7．7～9．2kg／（株·次）更为适宜。The pot experiment was carried out to study the nitrogen （N） characteristics in the rootzone soil, as well as N uptake capacity of Calligonum caput-medusae Schrenk seedlings under different irrigation treat- ments （4.6, 6.1, 7.7, 9.2, 13.0 kg/plant each time）. The results showed that both nitrate-N and ammoni- um-N contents in the rootzone soil decreased significantly with irrigation amount. The mean values of nitrate- N and ammonium-N contents in the rootzone soil of C. caput-medusae Schrenk were 70.9 % ~ 92.4 %fro and 20.3%~51.6% lower than these in the desert soil at the end of plant growth stage respectively. However, total N and organic matter contents in the rootzone soil were higher than these in natural soil. This suggested that C. caput-medusae Schrenk seedlings had relatively stable soil N pool at early growth stage. Total N content was not affected by the increasing irrigation amount, but soil organic matter content decreased, espe- cially under the highest irrigation amount. The N uptake of whole plant under different irrigation treatments declined by 10.8%, 79.8%, 85.4%, and 290.2% respectively compared to that under the treatment of 4.6 kg/plant each time. Corresponding values for dry matter accumulation of whole plant increased by 13.2%, 97.8%, 197.6%, and 394.6% respectively, but the serious powdery mildew of seedlings occurred at high ir- rigation level （13.0 kg/plant each time）. This indicated that the deficiency of nitrate-N and ammonium-N in the rootzone soil was mainly due to plant absorption and consumption. Considering plant growth and soil N application, medium irrigation level （7.7~9.2 kg/plant each time） was the recommended for C. caput-me- dusae Schrenk seedlings at early growth stage.

关 键 词：沙拐枣幼苗 灌溉 硝态氮 铵态氮 全氮 有机质 

分 类 号：S158.3[农业科学—土壤学] S275.3[农业科学—农业基础科学]