控释氮肥对水稻的增产效应及提高肥料利用率的研究

田间试验在日本山形县鹤冈市进行 ,探讨了树脂包膜类控释氮肥基施与尿素、硫铵分次施肥对单季稻的增产效应 ;应用15N示踪法研究了不同施肥处理水稻的吸氮模式及肥料利用率。结果表明 ,移栽稻以尿素与控释氮肥 (LPS-100)按 1∶1混合基施产量最高 ,分别比尿素和硫铵分次施肥增产23.6%和9.2% ;直播稻以LP-100基施产量最高 ,分别增产 9.2%和4.0% ;控释肥基施 ,水稻自移栽 (或直播 )至幼穗分化期吸氮量明显高于尿素或硫铵分次施肥。15N示踪研究表明 ,最高分蘖前水稻从尿素和硫铵基肥中吸收的氮素只占基肥氮总吸收量的 33%～ 45% ,水稻从基肥中吸收氮素可延续至抽穗期 ,而从LP-100中吸氮可持续至收获期。15N示踪法测得的氮素总回收率 ,以尿素处理最高 ,硫铵和LP-100接近 ;差减法测得的氮素总回收率以LP-100为最高 ,尿素 /LPS-100、尿素、硫铵三者接近 ;基肥的氮素回收率以LP-100硫铵 尿素。尿素 /LPS-100和LP-100一次基施 ,氮素生理效率和农学效率明显高于尿素和硫铵 ,是高产的主要原因

Effects of controlled release fertilizer on rice yield an d N recovery

Field experiment was conducted at Tsuruoka City, Yamagat aPrefecture, Japan in 1998. 15N trace method was used to test the ef f ects of polyolefin coated urea (controlled release fertilizer) as basal on rice yield, the pattern of N absorption and N recovery rate compared with urea and am monium sulfate with split application. Results indicated that: 1) For transplan t ing rice, the highest yield was obtained by the blend of urea and LPS-100 in th e ratio of 1:1 as basal, and increased by 23.6% and 9.2% compared with urea an d ammonium sulfate, respectively. For the direct seeding rice the highest yield w a s obtained by LP-100 as basal, and increased by 9.2% and 4.0% compared with u re a and ammonium sulfate, respectively. Controlled release fertilizer treatments c ould give more effective panicles and filled grains of rice than urea and ammoni um sulfate treatments. 2) No significant difference was observed in total N upt a ke among fertilizer treatments. But the N accumulation from transplanting (or s e eding) to panicle initiation in plants treated with controlled fertilizer were m uch more than conventional fertilization, resulting in the greater number of pan icles per unit area and filled grains per panicle. 3) 15N labeled exp e riment indicated that up to maximum tiller stage N absorption of rice from basal fertilizer of urea and ammonium sulfate accounted for 33%～45% of total N absor ption from basal fertilizer only. N uptake from basal fertilizer lasted to head i ng stage in urea or ammonium sulfate plots and to harvesting stage in LP-100 pl ot. While N uptake from topdressing applied at panicle initiation stage complet ed on 45 days after application.4) The total N recovery rate tested using 15N method was higher in urea plot than ammonium sulfate and LP-100, while that tested using difference method was higher in the LP-100 than other treatme nts. The N recovery rate of basal fertilizer was in the order of LP-100＞ammon i um sulfate＞ urea . Basal application of urea/LPS-100 blend and LP-100 had hi g her physiological and agronomic efficiency of N than urea and ammonium sulfate, that may be the main reason for getting high yield by controlled fertilizer in t he trail.