[Appropriate soil nitrate N content for a winter wheat/summer maize rotation system in North China Plain].
A field experiment with 12-level N fertilization in winter wheat growth season and zero-N in summer maize growth season was conducted to study the appropriate soil nitrate N content for a winter wheat/summer maize rotation system in North China Plain. The results showed that when the soil mineral N content before sowing was higher, a split application of 150 kg N x hm(-2) in winter wheat growth season could meet the N demand of both winter wheat and summer maize in the rotation system. The N use efficiency of winter wheat in different N treatments was only from 11% to 23%, while the residual N use efficiency of summer maize ranged from 30% to 52%. When the nitrate N content in top 90 cm soil layer before maize sowing was up to 82 and 151 kg x hm(-2), respectively, the N demand of summer maize at its ten-leaf stage and in its whole growth season could be met with no N application. However, when the nitrate N content in top 90 cm soil layer was less than 46 and 65 kg x hm(-2) at maize ten-leaf stage and after harvest, respectively, no N application could impact maize growth, and decrease its grain yield. With the maize yield and environmental protection considered comprehensively, the nitrate N content in top 90 cm soil layer should be maintained at an appropriate level from 65 to 151 kg x hm(-2) during maize growth season.
Cui
Zhen-Ling
ZL
College Resource and Environmental Sciences, China Agricultural University, Beijing 100094, China. cuizl@cau.edu.cn
Chen
Xin-Ping
XP
Zhang
Fu-Suo
FS
Xu
Jiu-Fei
JF
Shi
Li-Wei
LW
Li
Jun-Liang
JL
D000383:Agriculture / Q000379:methods; D002681:China; D005308:Fertilizers; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D012621:Seasons; D012987:Soil / Q000032:analysis*; D014908:Triticum / Q000254:growth & development*; D003313:Zea mays / Q000254:growth & development*
D005308:Fertilizers; D009566:Nitrates; D012987:Soil; D009584:Nitrogen