田间土壤氨挥发的原位测定——风洞法

详细介绍了农田土壤氨挥发风洞法测定系统的原理、构造和特点,并通过回收率试验和田间试验进行了验证。所选用的德国风洞主要包括采样箱、采样系统和控制系统3部分,系统内部的气压、温度、湿度、风速等微气象条件接近自然环境条件,测量结果有较好的代表性。回收实验结果表明,回收率为90%,说明风洞的密闭性和浓度分布的均匀程度较好,适合于土壤氨挥发的多处理、多重复的田间原位测定,尤其适用于多因子对比实验。风洞法测定不受天气的影响,对实验区面积要求不高,重复性及可靠性较好,不仅可以测定农田土壤的氨挥发,还可以测定有机肥贮存和施用以及各种肥料形态的氨挥发状况。

German Wind-Tunnel System for Measuring Ammonia Volatilization from Agricultural Soil

Principle, structure and characteristic of German wind-tunnel system consisting of measurement chambers, sampling unit and control unit to measure ammonia volatilization from agricultural soil were introduced in detail in this paper, and a recycling experiment was also conducted to validate it. Result showed that air pressure, temperature, humidity, wind speed inside chambers were similar to outside environment, and average ammonia recovery was over 90%, which suggested it had a qualified hermitic and homogeneous concentration-distribution environment and suitable for measuring ammonia volatilization measurements under conditions of multitreatments and repetitions in original fields, particularly for multi-factors comparison experiments. With no or less influence from weather condition, low requirement to experimental plot area, good repetition and high reliability, German wind-tunnel system can measure ammonia volatilization not only from agricultural soils, but also from storage and application of organic fertilizers as well as from various fertilizer forms.