Zhang Hao, Zeng Fuping, Zou Zhigang, Zhang Zhenqian, Li Youzhi
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Guangxi University Nanning China.
Key Laboratory of Agro-Ecological Processes in Subtropical Region Institute of Subtropical Agriculture Chinese Academy of Sciences Changsha China.
Ecol Evol. 2017 Sep 10;7(20):8419-8426. doi: 10.1002/ece3.3295. eCollection 2017 Oct.
Nitrogen (N) deficiency occurs in over 80% of karst soil of southwest China, which restricts regional agricultural production. To test whether N fixed by legumes becomes available to nonfixing companion species, N fluxes between soybean and maize under no, partial, and total restriction of root contact were measured on a karst site in southwest China. N content and its transfer between soybean and maize intercrops were explored in a 2-year plot experiment, with N movement between crops monitored using N isotopes. Mesh barrier (30 μm) and no restrictions barrier root separation increased N uptake of maize by 1.28%-3.45% and 3.2%-3.45%, respectively. N uptake by soybean with no restrictions root separation was 1.23 and 1.56 times higher than that by mesh and solid barriers, respectively. In the unrestricted root condition, N transfer from soybean to maize in no restrictions barrier was 2.34-3.02 mg higher than that of mesh barrier. Therefore, it was implied that soybean/maize intercropping could improve N uptake and transfer efficiently in the karst region of southwest China.
中国西南地区80%以上的喀斯特土壤存在氮素缺乏问题，这限制了该地区的农业生产。为了测试豆科植物固定的氮是否能被非固氮伴生植物利用，在中国西南地区的一个喀斯特地点，测量了大豆和玉米在根系接触无限制、部分限制和完全限制条件下的氮通量。通过为期两年的小区试验，探究了大豆和玉米间作体系中的氮含量及其在两者间的转移情况，并利用氮同位素监测了作物间的氮素移动。网室隔离（30μm）和不隔离根系分别使玉米的氮吸收量增加了1.28%-3.45%和3.2%-3.45%。根系不隔离时大豆的氮吸收量分别比网室隔离和实体隔离高出1.23倍和1.56倍。在根系无限制条件下，不隔离根系时大豆向玉米的氮转移量比网室隔离高出2.34-3.02mg。因此，这表明大豆/玉米间作能够有效提高中国西南喀斯特地区的氮吸收和转移效率。
