Potential of Controlled Irrigation and Drainage for Reducing Nitrogen Emission from Rice Paddies in Southern China

Guang-Cheng Shao,Min Yuan,Shuang-En Yu,Ming-Hui Wang,Na Liu,Meng-Hua Xiao

doi:10.1155/2015/913470

Abstract

The effect of controlled irrigation and drainage (CID) at different growth stages of rice on nitrogen (N) from rice paddy was studied. Submergence at different stages was imposed in specially designed experimental tanks in 2009 and 2010 based on alternate wetting and drying technology (AWD, the control, CK). Treatments include CID treatment at tiller stage (T1), jointing-booting stage (T2), panicle initiation stage (T3), and milky stage (T4). Results showed that fertilization could significantly increase the concentration ofNH4+-N and TN in surface water but had a little influence onNO3--N. The concentrations ofNH4+-N andNO3--N in surface water increased at first and then decreased after fertilization, while the concentrations ofNH4+-N and TN in groundwater kept on being relatively stable. Compared to CK, CID significantly increased the concentration ofNH4+-N in surface water at four stages. However, it reduced the concentration ofNO3--N. Consistent with the reduction of drainage, CID at four stages could significantly decrease the amount ofNH4+-N andNO3--N losses by runoff in relation to CK.

Highlights

License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
The rice season in Southern China coincides with the summer wet season and the annual average precipitation is more than 1000 mm
NO3 − -N and TN in surface water and groundwater were measured after fertilization application from tillering to jointingbooting stage in 2009 and 2010 (Figure 2 and Table 2)

Summary

Introduction

License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Results showed that fertilization could significantly increase the concentration of NH4 + -N and TN in surface water but had a little influence on NO3 − -N. Compared to CK, CID significantly increased the concentration of NH4 + -N in surface water at four stages. It reduced the concentration of NO3 − -N. Irrational drainage shortens the residence time of water in the biologically active unsaturated zone and substantially alters the water regime. This results in an increase in nitrate losses from the agricultural fields to surface recipients [1, 2]. The quantity and quality of drainage water are primarily controlled by irrigation and fertilization activities, and transport of non-point-source pollution is largely dependent on the drainage process [4]

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Results

Discussion

Conclusion