直播旱作水稻的吸氮特征与土壤氮素表观盈亏  

Absorption and apparent budget of nitrogen by direct-seeding rice cultivated in aerobic soil with or without mulching

作　　者：殷晓燕[1] 徐阳春[1] 沈其荣[1] 周春霖[2] Klaus Dittert 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095 [2]江苏沿海地区农业科学研究所,盐城224002 [3]德国基尔大学

出　　处：《生态学报》2004年第8期1575-1581,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 ( 3 0 0 70 44 6)~~

摘　　要：水稻旱作是水稻节水栽培中最有效的方式。通过田间试验研究旱作直播条件下水稻对氮素的吸收利用特征以及土壤矿质氮的动态变化 ,并对土壤氮素的表观盈亏量进行了估算。结果表明 ,直播旱作水稻较水作水稻更注重中后期对氮素养分的吸收 ,尤其是对土壤氮素的吸收 ;幼穗分化后水稻的土壤吸氮量占阶段吸氮总量的 6 9.5 % ,比水作水稻多 17.8%。对 0～ 4 0 cm土层土壤矿质氮含量时空变化的研究表明 ,直播旱作水稻生育前期土壤表层矿质态氮大量累积 ,在灌水和降雨的影响下 ,向下层的迁移增加 ,基肥施用后裸地处理 2 0～ 4 0 cm土层的矿质氮高达 10 4 kg N/hm2 。对水稻各生育期土壤氮素盈亏的计算结果表明 ,自分蘖盛期后旱作各处理都表现出土壤氮素不同程度上的表观亏缺 ,然而就全生育期土壤氮素盈余量而言 ,旱作处理平均高达 12 7kg N/hm2 ,生育前期氮肥的大量投入是氮素盈余的主要原因。本试验结果表明 ,直播旱作水稻生育前期对施用的肥料氮吸收很少 。Rice production in aerobic soil with mulching is one of the most important cropping systems for water-saving agriculture. In this system, the rice plant (not upland variety but traditional paddy rice variety with high yield potential) is grown during whole growth stage in soil with water content being 70%~90% of water holding capacity (WHC). The total shift of the growth environment from traditional waterlogged to aerobic conditions greatly changes rice growth, i.e. the characteristics of rice growth and development, the yield formation and the nitrogen forms that the rice takes up. The objective of the present study is to determine the effects of direct-seeding rice cultivated in aerobic soil with mulching on characteristics of nitrogen uptake and apparent budget to provide the basis for nitrogen management practices for rice cultivation in aerobic soil condition. A field experiment was carried out in sandy loam soil in Yancheng, Jiangsu province (33°27′N, 120°11′E) in 2001. There were three treatments in rice cultivation in aerobic soil, including the soil being covered with plastic film (PF), with rice straw (RS) and the soil without any mulching (B). The control for the experiment was the rice grown in waterlogged soil (W). The main field experiment, which was subdivided into one waterlogged area and one large aerobic area, was constructed in a one-factorial block design with three replications each treatment. The experimental block of waterlogged rice production was separated from the aerobic block by a strong plastic foil vertically inserted into depth of 60 cm for hydrological isolation. After sowing, plastic film was used to cover all surface of aerobic treatments to ensure seedling emergence. At the 3-leaf stage, the plastic film was removed in RS and B treatments. The soil surface in RS treatment was then covered with semi-decomposed rice straw (about 6000 kg dry straw/hm^2). Two water tensionmeters with tips at 18 cm depth were installed in each plot to indicate that soil water content was mainta

关 键 词：旱作水稻 吸氮量 土壤矿质氮 土壤氮素表观盈亏 

分 类 号：S511.06[农业科学—作物学]