摘要
连续两年施用不同氮肥和用量,考察了夏玉米(郑单958)根系在不同土层的分布与含氮量,分析其与产量、地上部氮素累积量的相关性。结果表明:1)施氮抑制夏玉米生育前期根系生长与下扎,抑制作用表现为复合肥>包膜尿素>尿素;施氮使吐丝期0—25与50—80 cm土层根量增大,25—50 cm土层根量减少;总根量表现出尿素>复合肥>包膜尿素,且差异显著。2)施氮显著提高夏玉米9叶展开期0—25 cm土层与吐丝期25—80 cm土层根系含氮量;氮肥类型影响根系含氮量,且差异显著。3)吐丝期25—80 cm土层根系含氮量与产量呈显著正相关(P<0.05),与地上部氮素累积量呈极显著正相关(P<0.01);在25—50 cm,根系鲜重密度、体积密度和干重密度与产量及氮素累积量表现为负相关,在其他土层表现为正相关。其中,0—80 cm土层根系干重密度与产量呈显著正相关(P<0.05),0—25 cm土层根系鲜重密度与产量,0—80 cm土层根系鲜重密度与氮素累积量呈明显正相关(P<0.1)。可见,玉米根系分布与含氮量明显受到氮肥类型与施氮量的影响,施氮主要通过提高表土层根系鲜重、根系总鲜重与总干重及中下层根系含氮量实现夏玉米增产增效目的。
A fertilization experiment on different types and rates of N fertilizers was conducted in successive two years, the distribution of roots and N content of summer maize （ Zea mays L. , eultivar： Zhengdan958） were investigated and their correlations to yield and shoot N accumulation were analyzed. The main results show that： 1 ）growth and downward extending of roots before the 9-leaf stage of summer maize are restrained by N application, and the restraining effect indicates a trend of compound fertilizer 〉 coated urea 〉 urea. Amounts of roots are increased in 0-25 cm and 50-80 cm soil layers, while decreased in 25-50 cm soil layer by N application at the silking stage. Total amount of roots indicates a trend of urea 〉 compound fertilizer 〉 coated urea, and significant differences among three types of N fertilizers are ob- served. 2） N contents in roots are improved significantly by N fertilization in 0-25 cm soil layer at the 9-leaf stage and 25 -80 em soil layer at silking stage. N content of roots is affected by type of N fertilizer, and significant differences among N fertilizers are observed. 3）Positive correlation at 0.05 and 0.01 probability level exist between yield, N accumulation amount of shoot and N content of roots in 25-80 cm soil layer at the silking stage, respectively. Correlations of roots density of fresh weight, volume and dry weight to yield and N accumulation amount of shoot are negative in 25-50 cm soil layer respectively, while they are positive in other soil layers, there into positive correlation at 0.05 probability level between yield and roots density of dry weight in 0-80 cm soil layer, and positive correlation at 0.10 probability level between yield and roots density of fresh weigh in 0-25 cm soil layer, and between N accumulation amount of shoot and roots density of fresh weigh in 0-80 cm soil layer are observed. These results show that root distribution and N content of summer maize are obviously affected by types and rates of N fertilization. The effects of N application on increasing of yield and N efficiency of summer maize are achieved mainly by improving fresh weight of roots in topsoil, total fresh weight and dry weight of roots and N content of roots in middle and lower soil layers.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2009年第1期91-98,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(30471015
30571089)
国家科技支撑计划项目(2006BAD17B05
2006BAD02A13-2)资助。
关键词
玉米
根系分布
根系含氮量
氮肥类型
施氮量
maize
distribution of roots
N content of roots
type of N fertilizer
N application amount
作者简介
易镇邪（1975-），男，湖南冷水江市人，副教授，博士，主要从事作物高产与资源高效利用研究。E-mail：yizhenxie@sina．com
通讯作者Tel：010—62733611，E-mail：wangpu@eau．edu．cn
