半湿润地区农田夏玉米氮肥利用率及土壤硝态氮动态变化  

Utilization rate of fertilizer N and dynamic changes of soil NO_3^--N in summer maize field in semi-humid area of Northwest China.

作　　者：范亚宁[1] 李世清[1] 李生秀[2] 

机构地区：[1]西北农林科技大学/中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《应用生态学报》2008年第4期799-806,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金资助项目(930571116,30670326)

摘　　要：以土垫旱耕人为土为供试土壤,通过田间试验,研究了不同施氮量下(0、45、90、135和180 kg.hm-2)夏玉米生育期土壤剖面NO3--N的变化特征、氮素利用率及施氮量与土壤NO3--N残留的关系.结果表明:在整个生育期内,土壤NO3--N含量均以0~20 cm土层最高,且施氮量越高,NO3--N含量也越高;0~60 cm土层NO3--N含量变化显著,60~100 cm土层NO3--N含量变化不大.夏玉米整个生育期,受玉米对氮素的需求和降雨的影响,0~100cm土层NO3--N累积量呈波动式降低趋势;当施氮量小于135 kg.hm-2时,作物氮肥利用率随施氮量的增加而显著提高,但当施氮量超过135 kg.hm-2时呈下降趋势.氮肥农学利用率随施氮量的增加而减小,氮肥生理利用率随施氮量的增加而递增.土壤中残留NO3--N与施氮量呈极显著正线性相关关系(R2=0.957**,n=5);施氮处理籽粒产量显著高于不施氮处理(P<0.05);施氮量与籽粒产量呈极显著正线性相关关系(R2=0.934**,n=5).在本试验条件下,夏玉米生长季适宜施氮量为135 kg.hm-2.该施氮水平可保证效益和环境的双赢.A field experiment on manual loessial soil was conducted to study the dynamic changes of NO3^--N in soil profile, utilization rate of fertilizer N, and relationships between N application rate and soil residual N accumulation during the growth period of summer maize under different N application rates （0, 45, 90, 135, and 180 kg·hm^-2）. The results showed that in the whole growth period of summer maize, the NO3^- -N concentration in the soil profile was the highest in 0-20 cm layer, and increased with increasing N application rate. The NO3^--N concentration in 0-60 cm soil layer changed significantly, but no significant change was observed in 60-100 cm soil layer. In the growth season of summer maize, soil NO3^- -N accumulation presented a fluctuated decreasing trend due to the N uptake by crop and the precipitation. The N utilization rate （NUR） increased with increasing N application rate when the application rate was less than 135 kg·hm^-2, but tended to decrease when the application rate exceeded 135 kg·hm^-2. With the increase of N application rate, the N agronomy efficiency （NAE） decreased but the N physiology efficiency （NPE） increased. There was a significant positive correlation between soil residual N accumulation and N application rate （R^2 =0. 957 ^＊ ＊ , n = 5 ）. The grain yield under N application was significantly higher than that without N application （P 〈 0.05 ）, and there existed a significant positive correlation between grain yield and N application rate （R^2 = 0. 934^＊ ＊ , n = 5 ）. In our experiment, the optimal application rate of fertilizer N was 135 kg·hm^-2, which could harmonize the relationship between economic benefits and environment.

关 键 词：施氮 夏玉米 氮肥利用率 硝态氮 

分 类 号：S513[农业科学—作物学]