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应用~(15)N示踪技术研究了塑膜覆盖生态系统中肥料氮的循环。结果表明,在覆盖及玉米秸秆还田条件下氮的18.56％被第一季玉米所吸收,59.09％残留在土壤中。第二季小麦和第三季夏谷又分别回收秸秆氮4.0％和2.9％。玉米对硫酸铵氮的利用率为38.4％,其中15.8％分布在茎叶和根茬中,参与养分再循环,但氮素损失大,接近施肥量的50％。残留在土壤中的秸秆氨3.4％存在于未分解的秸秆中,3.5％移动到土壤下层(30～50cm),45.8％与土壤矿物结合。化肥氮残留很少,大部分进入土壤有机无机复合体中,而部分土壤氮被活化。
The ~ (15) N tracer technique was used to study the circulation of fertilizer nitrogen in the plastic film mulching ecosystem. The results showed that 18.56% of nitrogen was covered by corn in the first season and 59.09% remained in the soil under the condition of covering and returning corn stalks. The second quarter of wheat and the third season summer valley were recovered 4.0% of straw nitrogen and 2.9%. The utilization rate of ammonium nitrogen to maize was 38.4%. Among them, 15.8% was distributed in stem and leaf and root stubble, and was involved in nutrient recycling. However, the nitrogen loss was large, close to 50% of the amount applied. 3.4% of the straw residue remaining in the soil was present in the undecomposed straw, 3.5% moved to the lower part of the soil (30-50 cm) and 45.8% bound to soil minerals. Fertilizer nitrogen remains very little, most of them enter the soil organic-inorganic complex, while part of the soil nitrogen is activated.