两种灌溉系统对宁夏葡萄园土壤氧化亚氮排放的影响

Influences of two irrigation systems on soil N20 emissions from vineyards in Ningxia, China

在宁夏回族自治区的葡萄种植园中,现多采用沟灌结合冲施肥的灌溉方法,部分种植园已施行滴灌结合随水施肥的灌溉方法.为探讨沟灌-冲施肥系统和滴灌-随水施肥系统对宁夏葡萄园土壤氧化亚氮（N2O）排放的影响,应用静态箱-气象色谱技术对该问题展开研究.结果表明：在2012年和2013年葡萄生长季中,较之于沟灌系统,滴灌系统可分别减少N2O年均排放量（18.24±2.79）kg/（hm^-2·a^-1）和（3.37±0.37）kg/（hm^-2·a^-1）,约占沟灌系统排放量的61.1%和78.9%.在此基础之上计算排放系数,可估算出应用滴灌系统替换宁夏现有葡萄园中全部沟灌系统后,N2O减排总量分别约为2012年的704 264-770 756 kg和2013年的215 550-223 920 kg.可见,滴灌系统可以有效减少土壤N2O的排放损失,是一种更具N2O减排潜力的灌溉方式.

The system of furrow irrigation which can dissolve solid fertilisers in irrigation water（ FIS） is widely applied in vineyards in Ningxia Hui autonomous region. Meanwhile the system of drip irrigation and fertigation（ DIS） has also been employed in some areas. These irrigation systems may affect nitrous oxide（ N2O） emissions from the soil. Therefore,it is important to study the differences in N2 O emissions and identify farmland management methods that limit N2 O emissions. During the July-August 2012 and JulySeptember 2013 growing seasons,this study was conducted by using the static chamber-gas chromatograph technique to observe the soil N2 O emissions from vineyards in Ningxia. The results showed that： the annual N2 O emission reductions reached（ 18. 24 ± 2. 79） kg /（ hm^-2·a^-1）（ 61. 1%） in 2012 and（ 3. 37 ± 0. 37）kg /（ hm^-2·a^-1）（ 78. 9%） in 2013 by changing FIS for DIS. The annual reduction amounts of N2 O emissions,estimated by using emission factor, were approximately 704 264-770 756 kg and 215 550-223 920 kg in 2012 and 2013,respectively,after changing FIS for DIS in the vineyards in Ningxia. In conclusion,DIS has greater reduction potential for N2 O emissions in Ningxia vineyards.