摘要
Abstract
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.关键词
氮/控释肥/水稻/15N示踪/氮肥利用率Key words
nitrogen/controlled fertilizer/rice/N fertilizer recovery分类
农业科技
