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首页> 外文学位 >A STUDY OF NITROGEN IN SOIL-PLANT SYSTEM IN RELATION TO GROWTH AND YIELD OF WETLAND RICE AS INFLUENCED BY NITROGEN SUPPLY AND CROP MANAGEMENT.
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A STUDY OF NITROGEN IN SOIL-PLANT SYSTEM IN RELATION TO GROWTH AND YIELD OF WETLAND RICE AS INFLUENCED BY NITROGEN SUPPLY AND CROP MANAGEMENT.

机译：氮素供应和作物管理对湿地水稻生长发育与产量关系的土壤植物系统氮素影响研究。

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摘要

Two greenhouse and one field experiments were conducted during December 1978 and January 1980 at the International Rice Research Institute to study the behavior of nitrogen in soil-plant system and thus to explore some possible means to improve N-fertilizer use efficiency in wetland rice culture.; Current research has demonstrated that placement of ammonium sources of nitrogen several cm below the soil surface at planting is usually a very effective way to fertilize flooded rice, at least under conditions of continuous flooding where seepage losses are not excessive. However, there are social, economic, and agronomic situations where such placements are not practical. The objective of this thesis was to examine some alternatives to deep placement at planting.; In the first greenhouse experiment, 5 rice soils varying in physico-chemical properties were air-dried, crushed and passed through a 5 mm sieve. A 10 kg sample of air-dry soil per pot was thoroughly mixed with 4 levels of N (0, 40, 80 and 120 ppm) using (NH(,4))(,2)SO(,4). Variety IR36 was grown until maximum tillering stage (45 DAT). In the second greenhouse experiment, wet soil collected directly from a fallow rice field was partly treated with ammonium nitrogen to create low ((TURN) 40 ppm) and high ((TURN) 140 ppm) inorganic nitrogen soil. A 9.0 kg sample of wet soil containing 145% moisture was used per tray. A single rate of N (60 kg/ha) from (NH(,4))(,2)SO(,4) was applied by best split (N(,B)) and modified split (N(,M)) method. An untreated control (N(,O)) treatment was also included. Variety IR36 was grown at 2 plant densities (2 hills and 4 hills/tray) until maturity. In the field experiment, graded amount of basal N (0, 20, 40 and 60 kg/ha) from (NH(,4))(,2)SO(,4) was applied and thoroughly incorporated in addition to one untreated control-N(,O(C)) treatment. Except N(,O(C)), all other treatments received 30 kg N/ha in two splits after maximum tillering stage. Two varieties (IR36-high tillering, Kaohsiung-low tillering) were grown at 3 plant densities (20 x 20; 20 x 15 and 20 x 10 cm spacing).; Inorganic nitrogen-N(,1) (2NKCl extractable NH(,4)('+)-N) in wet soil, total N in plant tops, tillering pattern and dry matter production were measured periodically. Leaf area index (LAI) at flowering, yield components and grain yield at maturity were also measured.; Increase in tiller number and dry matter production at maximum tillering stage (45 DAT) was associated with an increase in inorganic N at O DAT in some soils only. Addition of nitrogen did not benefit the plant at the early stage of growth (0-30 DAT) if the soil contained about 50-60 ppm N(,1) during that period. Nitrogen content (%) in plant tops at early growth stage (0-15 DAT) was not a useful tool in predicting tiller number at maximum tillering stage (45 DAT) and N-fertility of the soil. Nitrogen loss and N-supplying capacities varied considerably among soils.
机译：1978年12月至1980年1月，国际水稻研究所进行了两个温室和一个田间试验，研究了氮在土壤-植物系统中的行为，从而探索了提高湿地水稻栽培中氮肥利用率的一些可能方法。 ;当前的研究表明，种植时在土壤表层以下几厘米处放置铵态氮源通常是施肥淹稻的一种非常有效的方法，至少在连续淹没且渗流损失不过度的条件下。但是，在一些社会，经济和农艺环境下，此类安置不切实际。本文的目的是研究种植时深层种植的一些替代方法。在第一个温室试验中，将5种物理化学性质不同的水稻土壤风干，压碎并通过5毫米筛。使用（NH（，4））（，2）SO（，4）将每锅10公斤的风干土壤样品与4种水平的N（0、40、80和120 ppm）充分混合。品种IR36一直生长到最大分er期（45 DAT）。在第二个温室实验中，直接从休耕稻田中收集的湿土壤用铵氮进行了部分处理，从而形成了低（TURN）40 ppm和高（TURN）140 ppm的无机氮土壤。每个托盘使用9.0 kg含145％水分的湿土样品。通过最佳分割（N（，B））和修改后的分割（N（，M））应用来自（NH（，4））（，2）SO（，4）的单个N（60 kg / ha）方法。还包括未处理的对照（N（，O））处理。 IR36品种以2种植物密度（2个小丘和4个小丘/托盘）生长直至成熟。在野外实验中，除一种未经处理的对照品外，还施用了来自（NH（，4））（，2）SO（，4）的基础N的分级量（0、20、40和60 kg / ha），并充分掺入-N（，O（C））处理。在最大分N期后，除N（，O（C））外，所有其他处理均分两批接受30 kg N / ha。以两个植物密度（20 x 20； 20 x 15和20 x 10 cm的间距）种植了两个品种（IR36高分ing，高雄低分er）。定期测量湿土壤中的无机氮-N（，1）（2NKCl可萃取的NH（，4）（'+）-N），植株顶部的总氮，分till模式和干物质产生。还测量了开花时的叶面积指数（LAI），成熟时的产量成分和籽粒产量。仅在某些土壤中，最大分ing期（45 DAT）分till数的增加和干物质生产的增加与O DAT处无机氮的增加有关。如果在生长的早期阶段（0-30 DAT）添加氮对植物无益，但在此期间土壤中的N（，1）含量约为50-60 ppm。生长初期（0-15 DAT）植物顶部的氮含量（％）不能用于预测最大分till期（45 DAT）的分number数和土壤的N肥力。氮素流失和氮素供应能力在土壤之间差异很大。

著录项

  • 作者

    BHUIYAN, NURUL ISLAM.;

  • 作者单位

    Cornell University.;

  • 授予单位 Cornell University.;
  • 学科 Agriculture Agronomy.
  • 学位 Ph.D.
  • 年度 1980
  • 页码 153 p.
  • 总页数 153
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 农学（农艺学）;
  • 关键词

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