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通过盆栽试验和田间N~(15)同位素试验,研究了碳铵粒肥在水田深施的氮素供应状况。结果表明,在碳铵粒肥深施情况下,土壤氮素总供应量在整个水稻生长期中,土壤NH_4-N量和速效氮量在施肥后持续30天的时间内,均显著高于粉肥表施和粉肥混施。粒肥深施对水稻的供氮特点是缓、稳、长,这反映在不同时间水稻的氮素积累量、干物质积累量和长势的变化上。粒肥深施明显地增进了水稻对肥料氮素的吸收。通过N~(15)的田间示踪试验表明,即使在重肥条件下,水稻对深施碳铵粒肥的氮素利用率也高达75.5±1.8%,水稻总积累氮量中有54.6±3.4%是来自于深施碳铵粒肥的。深施碳铵粒肥在田间的有效供肥范围为施肥点四周的第一圈稻株,约占碳铵总供肥量的90%以上,而第三圈已完全无效。
The pot experiment and field N ~ (15) isotope experiment were carried out to study the nitrogen supply status of ammonium bicarbonate fertilizer deeply in paddy field. The results showed that under the condition of deep application of ammonium carbonate fertilizer, the total nitrogen supply of soil was significantly higher than that of the fertilizer application during the rice growth period, while the amount of NH_4-N and available nitrogen in the soil after 30 days post-fertilization Table Shi and fertilizer mixed. The characteristics of nitrogen supply to rice by deep applying fertilizer are slow, steady and long, which is reflected in the changes of nitrogen accumulation, dry matter accumulation and growth of rice at different time. The deep application of granule fertilizer obviously enhanced the nitrogen absorption of fertilizer to rice. The results of field tracing experiments with N ~ (15) showed that even in the condition of heavy fertilizer, the nitrogen utilization efficiency of rice with deep fertilization was 75.5 ± 1.8% and that of rice with total accumulation of nitrogen was 54.6 ± 3.4% Is from the deep carbon ammonium fertilizer. The depth of application of ammonium fertilizer in the field of available fertilizer for the first round of fertilization points around the rice plants, accounting for more than 90% of the total supply of ammonium bicarbonate, and the third lap has been completely null and void.