小麦秸秆还田和施钾对棉花产量与养分吸收的效应

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张凡, 睢宁, 余超然, 刘瑞显, 杨长琴, 宋光雷, 孟亚利, 周治国. 小麦秸秆还田和施钾对棉花产量与养分吸收的效应. 作物学报, 40(12): 2169-2175
ZHANG Fan, SUI Ning, YU Chao-Ran, LIU Rui-Xian, YANG Chang-Qin, SONG Guang-Lei, MENG Ya-Li, ZHOU Zhi-Guo. Effects of Wheat Straw Returning and Potassium Fertilizer Application on Yield and Nutrients Uptake of Cotton. Acta Agronomica Sinica, 40(12): 2169-2175 复制到剪切板

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作物学报编辑部

小麦秸秆还田和施钾对棉花产量与养分吸收的效应

张凡¹, 睢宁¹, 余超然¹, 刘瑞显², 杨长琴², 宋光雷¹, 孟亚利^1,^*, 周治国¹

¹南京农业大学农学院 / 农业部南方作物生理生态重点开放实验室, 江苏南京 210095

²江苏省农业科学院经济作物研究所, 江苏南京 210014

^*通讯作者(Corresponding author): 孟亚利, E-mail:mengyl@njau.edu.cn, Tel: 025-84396813

收稿日期:2014-09-16

基金:本研究由国家自然科学基金项目(31371583)和江苏省农业科技自主创新资金项目(CX(12)3034)资助;

摘要

在长江流域麦棉两熟制条件下, 以Bt转基因抗虫棉为材料, 设置不同秸秆还田量(4500 kg hm^-2和9000 kg hm^-2, 即半量还田和全量还田)与施钾量(K₂O, 150 kg hm^-2和300 kg hm^-2)田间定位试验, 研究小麦秸秆还田对棉花产量和主要养分吸收累积的影响及其与化肥钾的差异。结果表明, 在施用氮磷肥的基础上, 与对照相比, 秸秆全量还田处理显著提高了铃数、铃重和皮棉产量, 还田第2年和第3年产量增长率分别达143.5%和93.7%; 显著提高了各生育时期尤其是吐絮期生物量和氮磷钾养分吸收量, 延缓了棉花衰老。秸秆还田对钾吸收的促进效应大于氮磷, 还田第3年棉株钾累积总量较对照增加335.1%, 每生产100 kg皮棉钾吸收比例增大112.1%。秸秆全量还田处理(K₂O, 约折合150 kg hm^-2)促进养分吸收、防止早衰及增产效应均显著大于秸秆半量还田处理, 但显著低于施钾量(K₂O) 300 kg hm^-2处理, 与施钾量(K₂O) 150 kg hm^-2处理的增产效果相当, 但养分吸收量较150 kg K₂O hm^-2处理下降。

关键词: 秸秆还田; 化学钾; 棉花; 养分吸收; 产量

Effects of Wheat Straw Returning and Potassium Fertilizer Application on Yield and Nutrients Uptake of Cotton

ZHANG Fan¹, SUI Ning¹, YU Chao-Ran¹, LIU Rui-Xian², YANG Chang-Qin², SONG Guang-Lei¹, MENG Ya-Li^1,^*, ZHOU Zhi-Guo¹

¹Nanjing Agricultural University / Key Laboratory of Crop Physiology #cod#x00026; Ecology in Southern China, Ministry of Agriculture, Nanjing 210095, China

²Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China

Abstract

A three-year stationary experiment with treatments of wheat straw (4500 kg ha^-1 and 9000 kg ha^-1) mulching and K fertilizer (150 kg K₂O ha^-1 and 300 kg K₂O ha^-1) application was conducted using insect-resistant cotton under wheat-cotton double cropping system in the Lower Reaches of Yangtze River (Nanjing). The results showed that compared with control (without K fertilizer and wheat straw returning), total wheat straw returning significantly increased boll number, boll weight and lint yield of cotton with lint yield increasing rate of 143.5% and 93.7% in the second and third years after straw returning, respectively. Biomass and nutrients absorption at different growth stages were significantly improved by total wheat straw returning, especially in the boll opening stage, and the senescence of vegetative organs was delayed. Wheat straw returning promoted K absorption much greater than N and P absorption. Compared with control, total K uptake by cotton plant and K uptake per 100 kg lint increased by 335.1% and 112.1% respectively in the third year after straw returning. The treatment of total wheat straw returning much promoted nutrients uptake, yield, and delaying premature senescence than the treatment of half wheat straw returning, while significantly less than the treatment of 300 kg K₂O ha^-1. The yield-increasing effect was equal but the nutrients uptake per 100 kg lint was less in the treatment of total wheat straw returning than in the treatment of 150 kg K₂O ha^-1.

Keyword: Wheat straw returning; K fertilizer; Cotton; Nutrients absorption; Yield

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近年来, 转基因抗虫棉在我国种植面积迅速扩大, 其源小库大的特点造成了源库之间的不平衡, 加之后期根系衰老快, 与常规棉相比, 土壤钾素不足时更易出现缺钾性早衰, 导致棉花产量和品质下降^{[ 1]}。我国钾矿资源缺乏, 进口依赖度高, 然而作物秸秆资源丰富, 含钾量高, 且还田后释放速度快, 但目前我国棉田的秸秆还田率较低, 如果秸秆还田率能提高10个百分点, 就相当于180万吨钾肥补充到农田中^{[ 2]}, 一定程度上可以弥补我国钾资源不足, 缓解土壤钾素亏缺状况。

国内外大量研究已表明秸秆还田具有普遍的增产效应^{[ 3, 4]}, 但在不同作物和不同种植制度中表现不同^{[ 5, 6]}。刘冬青等^{[ 7]}认为小麦秸秆覆盖可以提高棉花叶面积指数, 延长叶片功能期, 提高棉株的光合能力从而防止棉花早衰, 增加铃重, 提高棉花产量。Gwathmey等^{[ 8]}研究指出, 小麦秸秆还田6年后棉花皮棉产量提高11%。Rafique等^{[ 9]}在巴基斯坦麦棉轮作系统研究中指出, 平衡施肥条件下, 麦秸秆覆盖还田提高了棉株氮浓度和产量, 且随试验年份延长提高愈显著。总的来说, 国内关于秸秆还田影响棉花生长的研究较为缺乏, 尚未明确长江流域麦棉两熟种植制度下秸秆还田对棉花产量与养分吸收的影响。本文拟通过设置不同的小麦秸秆还田量和施钾量, 研究小麦秸秆还田量对棉花生物量、养分累积分配及与产量形成的影响, 及其与化学钾肥的比较, 为提高秸秆资源利用率, 缓解土壤钾素亏缺状况提供理论支撑。

1 材料与方法

1.1 试验设计

于2011—2013年在江苏省农业科学院试验站(32°02' N,118°50' E)进行田间定位试验。供试土壤为黏土, pH 5.7, 含有机质12.9 g kg^-1、全氮0.90 g kg^-1、速效氮6.5 mg kg^-1、速效磷12.1 mg kg^-1、全钾9.1 g kg^-1、速效钾154.6 mg kg^-1; 次年棉花移栽前土壤速效钾各小区平均为128.4 mg kg^-1, 较上一年明显下降, 而其他土壤养分含量基本未变。试验田种植模式为小麦棉花一年两熟。

根据小麦籽粒产量6000 kg hm^-2可生产小麦秸秆量9000 kg hm^-2 (约折合150 kg K₂O hm^-2), 试验设4500 kg hm^-2(半量还田, W4500)和9000 kg hm^-2(全量还田, W9000) 2个秸秆还田量处理, 150 kg K₂O hm^-2(K150)和300 kg K₂O hm^-2 (K300) 2个施钾量处理, 以不施钾肥和无秸秆处理为对照(CK), 共5个处理。完全随机区组设计, 3次重复, 小区面积55 m²。小麦满幅种植(11月5日至10日播种), 品种为宁麦13, 氮肥240 kg N hm^-2, 按基肥50%、拔节肥30%~35%、孕穗肥15%~20%施用; 磷肥基施120 kg P₂O₅ hm^-2, 不施钾肥和秸秆。每年小麦收获时, 将秸秆粉碎后覆盖还田, 待棉花盛花期结合中耕培垄翻入约10 cm深耕层。供试棉花品种为转基因抗虫棉泗杂3号, 营养钵育苗移栽, 4月25日育苗, 6月5日左右移栽, 行株距为1.0 m×0.3 m。各处理氮磷肥正常施用, 氮肥240 kg N hm^-2, 按基肥40%、花铃肥60%施用; 磷肥225 kg P₂O₅ hm^-2, 于棉花移栽时一次施入。田间管理按高产栽培要求进行。

1.2 测定指标及方法

2012年和2013年均从7月15日起每15 d取样一次, 每小区随机取2株(7月15日取4株), 分器官放入105℃烘箱杀青30 min, 再以80℃烘干至恒重后称干重。粉碎后以H₂SO₄-H₂O₂消解定容后用连续流动分析仪测定植株全氮含量, 用钼锑抗吸光光度法测定植株全磷含量, 用火焰光度计测定植株全钾含量。吐絮期取上、中、下各20个棉铃测定单铃重和衣分, 取平均值, 计算产量。氮(磷、钾)养分利用效率=皮棉产量/植株氮(磷、钾)吸收量^{[ 10]}; 100 kg皮棉养分吸收量=植株养分吸收量/皮棉产量×100^{[ 10]}。

1.3 气象资料和数据统计分析

采用Microsoft Excel数据处理软件分析数据和制作表格, 用SPSS 17.0 统计软件进行方差分析, 用LSD法检验处理间平均值差异显著性。气象数据来自中国气象网。

表1 棉花不同生育时期的气象条件 Table 1 Weather factors at different growth stages of cotton

2 结果与分析

2.1 产量与产量构成

与对照相比, 连续麦秸秆还田和施钾处理均显著提高棉花铃数和铃重, 进而提高皮棉产量, 对衣分影响不显著( 表2)。不同秸秆还田量处理间比较, 随秸秆还田量的增加, 皮棉产量、铃数和铃重2年均呈升高趋势, 2012年差异较小, 未达到显著水平, 2013年差异达显著水平。不同施钾量处理间比较, 2年皮棉产量及其构成因子差异均不显著。秸秆还田与施钾处理间比较, 2012年差异不显著, 但秸秆还田处理较CK平均增产137.8%, 高于施钾量处理111.3%的增产幅度; 2013年秸秆还田处理较CK平均增产69.0%, 远低于施钾量处理133.0%的增产幅度, 其中W9000处理皮棉产量及铃数显著低于K300, 与K150差异不显著。年际间比较发现, 2013年除W4500处理外, 其余处理皮棉产量均呈升高趋势。

表2 产量及其构成因子比较 Table 2 Comparison of yields and yield components

2.2 生物量累积动态

2012年秸秆还田和施钾处理均较CK显著提高了棉株生物量, 但不同秸秆还田量处理和施钾量处理之间差异均不显著(图略); 而在2013年, 不仅秸秆还田和施钾处理较CK显著提高了棉株生物量, 而且不同秸秆还田量处理和施钾量处理之间差异也逐渐达到显著( 图1)。由图1可以看出, 各处理生物量之间的差异随移栽天数增加逐步增大, 至盛絮期(移栽后100 d) K300处理的棉株总生物量、营养器官和生殖器官生物量均显著高于其他处理, W9000和K150处理间生物量差异较小, 但均明显高于处理W4500。值得注意的是, 不施秸秆和钾肥的CK处理, 吐絮期营养器官生物量过早降低, 表现明显早衰现象。

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	图1 棉株生物量(A)、营养器官生物量(B)和生殖器官生物量(C)累积动态(2013)缩写同表2。Abbreviations are the same as those given in Table 2.Fig. 1 Dynamics of biomass accumulation in cotton plant (A), vegetative organs (B), and reproductive organs (C) in 2013

2.3 氮、磷、钾累积与分配动态

2.3.1 氮累积与分配 2013年各生育时期秸秆还田和施钾处理均较对照显著提高了植株氮累积量, 处理间差异随生育进程逐渐增大( 图2-A), 在移栽70 d后呈现不同模式, CK棉株氮累积量快速下降, K300继续快速增长, 其他3个处理平缓增长或降低。盛絮期(移栽后100 d)时K300、K150、W9000、W4500植株氮累积总量较CK分别增加219.4%、137.6%、102.0%、92.2%, 差异显著。说明秸秆还田和施钾均有利于棉花对氮素养分的吸收, 有效延迟了生育后期早衰, 秸秆还田效果小于施钾。各处理生殖器官氮累积趋势与植株基本相同, 但CK生殖器官降低时期发生晚( 图2-B)。不同秸秆还田量和施钾量处理植株氮向生殖器官分配的经济系数随移栽天数的增加趋势基本相同( 图2-C), 秸秆还田处理在前期向生殖器官分配比例高于施钾处理, 各时期秸秆还田和施钾处理的氮经济系数均显著高于CK, 说明秸秆还田和施钾均提高了氮向生殖器官的分配比例。

2.3.2 磷累积与分配与植株氮累积相比, 各处理植株磷累积呈现前期慢后期快、处理差异前期小、CK降低时期出现晚的特点( 图3-A)。与CK相比, 秸秆还田和施钾处理植株磷累积量增加, 且随移栽天数推进增加幅度加大, 至盛絮期K300、K150、W9000和W4500处理植株磷累积量显著高于CK, 分别增加318.1%、212.8%、146.8%和113.8%。生殖器官磷累积趋势及处理间差异趋势与植株磷累积相似( 图3-B), 不同的是移栽85 d后各处理生殖器官磷累积均已基本稳定, 而此期植株磷累积仍有较高的增加, 这说明增加的主要是营养器官磷累积。秸秆还

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	图2 棉株氮累积(A)、生殖器官氮累积(B)动态和经济系数(C)变化(2013)Fig. 2 Dynamics of N accumulation in cotton plant (A), and reproductive organs (B), and economic coefficient of N (C) in 2013 缩写同表2。Abbreviations are the same as those given in Table 2.

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	图3 棉株磷累积(A)、生殖器官磷累积(B)动态和经济系数(C)变化(2013)Fig. 3 Dynamics of P accumulation in cotton plant (A), reproductive organs (B), and economic coefficient of P (C) in 2013 缩写同表2。Abbreviations are the same as those given in Table 2.

田和施钾处理均提高了植株磷向生殖器官的分配比例, 前期秸秆还田处理分配比例更高, 但在盛絮期均显著减少( 图3-C)。

2.3.3 钾累积与分配不同于氮和磷的累积情况, 秸秆还田处理与施钾处理植株钾累积模式和累积量差异较大( 图4-A)。2个施钾量处理整个生育期始终保持较高的累积速率, 而2个秸秆还田量处理与施钾处理相比, 移栽55 d后累积速率即开始明显下降, 其后一直以较低的速率累积, W4500处理近似于CK累积动态, 后期累积量显著下降, 至盛絮期K300、K150、W9000和W4500植株钾累积总量较CK提高幅度依次为753.1%、653.7%、334.3%和136.6%。由此可见, 秸秆还田和施钾对棉花钾素吸收的促进作用大于氮磷, 并随秸秆还田量和施钾量的增加而增大, 但秸秆还田促进钾素吸收的效应小于施钾处理。

生殖器官钾累积趋势与植株钾累积基本相同( 图4-B), 在移栽后85 d处理间差异达显著水平, 秸秆还田处理显著低于施钾处理。相比氮磷累积经济系数的变化趋势, 秸秆还田与施钾处理钾经济系数较CK提高( 图4-C), 但在后期则明显低于CK, 尤其是移栽后85 d。

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	图4 棉株钾累积(A)、生殖器官钾累积(B)动态和经济系数(C)变化(2013)Fig. 4 Dynamics of K accumulation in cotton plant (A), and reproductive organs (B), and economic coefficient of K (C) in 2013 缩写同表2。Abbreviations are the same as those given in Table 2.

2.4 养分利用效率

每生产100 kg皮棉氮磷吸收量在处理间差异不显著, 钾吸收量处理间差异较大( 表3)。K300、K150和W9000处理每生产100 kg皮棉钾吸收量显著高于CK, 分别增加248.4%、252.6%、124.4%, K300和K150显著高于W9000, W9000显著高于W4500, W4500与CK差异不显著。说明秸秆还田和施钾处理显著增大了单位皮棉生产对钾素的吸收量, 改变了养分吸收比例, 其中秸秆还田处理的影响小于施钾处理。养分利用效率则与每生产100 kg皮棉养分吸收量呈相反趋势, 秸秆还田和施钾处理较对照明显降低了棉株钾素利用效率。由变异系数也可以看出, 与氮磷相比, 钾吸收量及利用效率对试验处理反应更敏感。

表3 棉株氮、磷、钾吸收比例与养分利用效率(2013) Table 3 Uptake percent and utilization efficiency of N, P, and K in cotton plants in 2013

3 讨论

国内外众多研究表明, 合理施用秸秆可以提高作物产量^{[ 11, 12]}。本研究在麦棉两熟制条件下进一步证实了前人的结论, 小麦秸秆覆盖还田显著增加了棉花皮棉产量, 且随秸秆还田量增加效果愈显著。但关于秸秆还田作物产量提高幅度的研究结果差异较大^{[ 11]}。本研究2012年和2013年不同秸秆还田量处理较不施秸秆和钾肥的对照平均增产分别为137.8%和69.0%, 明显高于刘冬青等^{[ 7]}在山东棉区的20.9%增产幅度和Jalota等^{[ 13]}、Reiter等^{[ 11]}在印度、巴基斯坦等地区对棉花的研究结果。究其原因主要是本研究对照的棉花产量是在麦棉两季连续不施钾不施秸秆的第4季和第6季产生的, 土壤钾素消耗较多, 棉花又是一个对缺钾敏感的作物, 转基因棉花品种较常规品种对钾亏缺更敏感^{[ 14]}。而前面提到的有关研究结果都是在氮磷钾肥正常施用情况下得出的, 且其他研究的地域、种植制度、秸秆还田方式和品种等差别也较大。

秸秆含有大量的碳、氮、磷、钾等营养元素, 是土壤养分的补给源。关于作物秸秆与化学钾肥的增产与培肥效果, 王志勇等^{[ 5]}、孙丽敏等^{[ 15]}、谭德水等^{[ 16]}在不同条件下的长期定位试验研究中均得出较一致的结论, 在氮、磷肥充足的情况下, 钾肥的增产效应大于秸秆还田, 效果最佳的则是秸秆与钾肥配施。本研究结果显示, 2013年除W4500处理外, 其余处理皮棉产量明显高于2012年; K150处理与含钾量相当的麦秸秆全量还田处理相比, 2年均差异不显著, 但年际间增产幅度差异较大, 2012年秸秆全量还田处理和K150处理与对照相比的增产幅度分别为143.5%和120.4%, 而2013年秸秆全量还田增产幅度(93.7%)则低于K150 (121.8%)。2013年较2012年皮棉产量增加是因为7月至10月日均温较高, 8月更是高出2.7℃, 而这一时期是蕾铃数形成的关键时期, 温度越高越有利于铃数的增加^{[ 17]}, 2013年铃数平均较2012年高14.7万个 hm^-2, 促进了皮棉产量的增加; 秸秆还田增产效果降低的原因, 与小麦秸秆K含量降低, 使实际K投入量减少有关(2012年W9000处理小麦秸秆K含量为17.0 g kg^-1, 2013年则降为14.7 g kg^-1, 相应地K投入量由153 kg降为132 kg); 另外也可能与2013年6月秸秆还田初期降雨量过多(较2012年多142 mm), 致使秸秆覆盖降低了土壤通气性和温度, 不利于棉花根系生长, 也不利于秸秆快速腐解等有一定关系。Wu等^{[ 6]}研究指出小麦秸秆养分释放主要集中在前30 d, 且土壤水分含量较多不利于土壤微生物和酶活性提高, 降低秸秆腐解率。可见, 秸秆还田对作物生长的影响不同于矿物钾肥, 涉及多方面影响因素, 区域间和年际间稳定性较低。

秸秆还田与施钾对生物量与养分吸收累积的促进作用是作物增产的重要原因。贾仁清等^{[ 18]}、王娇等^{[ 19]}认为, 随施钾量增加磷的吸收量增加幅度较小, 钾素增加最多。王志勇等^{[ 5]}研究表明施钾肥和秸秆还田均能促进作物对钾素养分的吸收, 增加作物的吸钾总量。本研究也得到类似结果, 麦秸秆还田与施钾均显著促进了棉花植株对氮磷钾养分的吸收与累积, 特别是钾素养分的吸收, 维持生育后期营养器官较高的生物量, 有效防止棉花早衰。刘冬青等^{[ 7]}通过对土壤养分和叶面积指数的研究指出, 秸秆覆盖还田在棉花生长后期, 可以提高叶面积指数, 延长叶片功能期, 提高棉株的光合能力从而防止棉花早衰。本研究还进一步表明, 秸秆还田和施钾有利于提高植株氮磷钾养分向棉铃的分配, 但吐絮盛期有所减少, 而向根茎叶分配增多, 尤其是钾素, 这与Mullins等^{[ 20]}的研究结果较一致。这是否与延缓早衰有关, 还需要通过进一步的试验研究来解释。

4 结论

在长江流域麦棉两熟制条件下, 小麦秸秆还田显著提高了棉花铃数、铃重和皮棉产量, 2012年和2013年全量秸秆还田处理较不施秸秆和钾肥的对照分别增产143.5%和93.7%。秸秆还田显著提高了各生育时期棉花生物量和氮磷钾养分吸收量, 增大了每生产100 kg皮棉植株的钾素吸收比例, 缓解了转基因抗虫棉生长发育后期对钾的需求从而有效防止了棉花早衰。秸秆全量还田效果优于半量还田, 施钾量300 kg K₂O hm^-2优于150 kg K₂O hm^-2。秸秆全量还田处理虽与施钾量150 kg K₂O hm^-2两年皮棉产量差异不显著, 但稳定性低于后者。

The authors have declared that no competing interests exist.

作者已声明无竞争性利益关系。

参考文献

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[1]	范希峰, 王汉霞, 田晓莉, 段留生, 王保民, 何钟佩, 李召虎. 钾肥对棉花产量的影响及最佳施用量研究. 棉花学报, 2006, 18: 175-179 Fan X F, Wang H X, Tian X L, Duan L S, Wang B M, He Z P, Li Z H. Effect of potassium on yield of cotton (Gossypium hirsutum L. ) and optimal quantity of potassium in Huanghuaihai Plain, China. Cotton Sci, 2006, 18: 175-179 (in Chinese with English abstract) [本文引用:1] [CJCR: 1.462]
[2]	白由路. 高价格下我国钾肥的应变策略. 中国土壤与肥料, 2009, 221(3): 1-4 Bai Y L. Response strategy of potassium fertilizer under high price in China. Soil Fert Sci China, 2009, 221(3): 1-4 (in Chinese with English abstract) [本文引用:1] [CJCR: 0.8]
[3]	Wang X B, Wu H J, Dai K. Tillage and crop residue effects on rainfed wheat and maize production in northern China. Field Crops Res, 2011, 1: 106-116 [本文引用:1] [JCR: 2.474]
[4]	刘义国, 刘永红, 刘洪军, 商健, 于淙超, 林琪. 秸秆还田量对土壤理化性状及小麦产量的影响. 中国农学通报, 2013, 29: 131-135 Liu Y G, Liu Y H, Liu H J, Shang J, Yu Z C, Lin Q. Effects of straw returning amount on soil physical and chemical properties and yield of wheat. Chin Agric Sci Bull, 2013, 29: 131-135 (in Chinese with English abstract) [本文引用:1]
[5]	王志勇, 白由路, 杨俐苹, 卢艳丽, 王磊, 王贺. 低土壤肥力下施钾和秸秆还田对作物产量及土壤钾素平衡的影响. 植物营养与肥料学报, 2012, 18: 900-906 Wang Z Y, Bai Y L, Yang L P, Lu Y L, Wang L, Wang H. Effects of application of potassium fertilizer and straw returning on crop yields and soil potassium balance in low-yielding fields. Plant Nutr Fert Sci, 2012, 18: 900-906 (in Chinese with English abstract) [本文引用:2] [CJCR: 1.883]
[6]	Wu J, Guo X S, Wang Y Q, Xu Z Y, Zhang X L, Lu J W. Decomposition characteristics of rapeseed and wheat straw under different water regimes and straw incorporating models. J Food Agric Environ, 2011, 9: 572-577 [本文引用:1] [JCR: 0.435]
[7]	刘冬青, 辛淑荣, 张世贵. 不同覆盖方式对旱地棉田土壤环境及棉花产量的影响. 干旱地区农业研究, 2003, 21(2): 18-21 Liu D Q, Xin S R, Zhang S G. Effects of difference mulching on the soil environment and cotton yield of cotton in dry land field. Agric Res Arid Areas, 2003, 21(2): 18-21 (in Chinese with English abstract) [本文引用:3]
[8]	Gwathmey C O, Bradley J F, Chambers A Y, Howard D D, Tyler D D. Physiological responses to tillage systems, cover crops, and residue management. In: James M S, Derrick O, James J H, Jack M. Physiology of Cotton. New York: Springer, 2010. pp246-254 [本文引用:1]
[9]	Rafique E, Mahmood-Ul-Hassan M, Rashid A, Chaudhary M F. Nutrient balances as affected by integrated nutrient and crop residue management in cotton-wheat system in Aridisols. I. Nitrogen. J Plant Nutr, 2012, 35: 591-616 [本文引用:1] [JCR: 0.526]
[10]	王克如, 李少昆, 曹连莆, 宋光杰, 陈刚, 曹栓柱. 新疆高产棉田氮, 磷, 钾吸收动态及模式初步研究. 中国农业科学, 2003, 36: 775-780 Wang K R, Li S K, Cao L P, Song G J, Chen G. Cao S Z. A preliminary study on dynamics and models of N, P, K absorption in high yield cotton in Xinjiang. Sci Agric Sin, 2003, 36: 775-780 (in Chinese with English abstract) [本文引用:2] [CJCR: 1.889]
[11]	Reiter M S, Reeves D W, Burmester C H, Torbert H A. Cotton nitrogen management in a high-residue conservation system: cover crop fertilization. Soil Sci Soc Am J, 2008, 72: 1321-1329 [本文引用:2] [JCR: 1.821]
[12]	杨帆, 董燕, 徐明岗, 包耀贤. 南方地区秸秆还田对土壤综合肥力和作物产量的影响. 应用生态学报, 2012, 23: 3040-3044 Yang F, Dong Y, Xu M G, Bao Y X. Effects of straw returning on the integrated soil fertility and crop yield in southern China. Chin J Appl Ecol, 2012, 23: 3040-3044 (in Chinese with English abstract) [本文引用:1] [CJCR: 1.742]
[13]	Jalota S K, Buttar G S, Sood A, Chahal G B S, Ray S S, Panigrahy S. Effects of sowing date, tillage and residue management on productivity of cotton (Gossypium hirsutum L. )-wheat (Triticum aestivum L. ) system in northwest India. Soil Till Res, 2008, 99: 76-83 [本文引用:1] [JCR: 2.367]
[14]	Zhang Z Y, Tian X L, Duan L S, Wang B M, He Z P, Li Z H. Differential responses of conventional and Bt-transgenic cotton to potassium deficiency. J Plant Nutr, 2007, 30: 659-670 [本文引用:1] [JCR: 0.526]
[15]	孙丽敏, 李春杰, 何萍, 刘孟朝, 胡景辉. 长期施钾和秸秆还田对河北潮土区作物产量和土壤钾素状况的影响. 植物营养与肥料学报, 2012, 18: 1099-1106 Sun L M, Li C J, He P, Liu M C, Hu J H. Effects of long-term K application and straw returning on crop yield and soil K status in fluvo-aquic soil of Hebei Province. Plant Nutr Fert Sci, 2012, 18: 1099-1106 (in Chinese with English abstract) [本文引用:1] [CJCR: 1.883]
[16]	谭德水, 金继运, 黄绍文. 长期施钾与秸秆还田对西北地区不同种植制度下作物产量及土壤钾素的影响. 植物营养与肥料学报, 2008, 14: 886-893 Tan D S, Jin J Y, Huang S W. Effect of long-term K fertilizer application and returning wheat straw to soil on crop yield and soil K under different planting systems in northwestern China. Plant Nutr Fert Sci, 2008, 14: 886-893 (in Chinese with English abstract) [本文引用:1] [CJCR: 1.883]
[17]	Wells R, Stewart A M. Morphological alterations in response to management and environment. In: James M S, Derrick O, James J H, Jack M. Physiology of Cotton. New York: Springer, 2010. pp24-32 [本文引用:1]
[18]	贾仁清, 叶德柱, 石吟梅. 高产棉花的干物质积累和氮磷钾养分的吸收分配规律探讨. 中国棉花, 1981, 8(5): 27-30 Jia R Q, Ye D Z, Shi Y M. Discussion on accumulation and distribution of dry matter and nutrients of high yield cotton. China Cotton, 1981, 8(5): 27-30 [本文引用:1] [CJCR: 0.3221]
[19]	王娇, 佀传亚, 张成, 殷志峰, 徐文修, 马晓勇. 不同施钾量对陆地棉干物质积累, 养分吸收和产量的影响. 新疆农业科学, 2012, 49: 2163-2169 Wang J, Si C Y, Zhang C, Yin Z F, Xu W X, Ma X Y. Effect of different amounts of potassium on dry matter accumulation, nutrient absorption and yield of land cotton. Xinjiang Agric Sci, 2012, 49: 2163-2169 (in Chinese with English abstract) [本文引用:1] [CJCR: 0.778]
[20]	Mullins G L, Burmester C H. Relation of growth and development to mineral nutrition. In: James M S, Derrick O, James J H, Jack M. Physiology of Cotton. New York: Springer, 2010. pp97-105 [本文引用:1]

2006

0.0

1.462

... 近年来, 转基因抗虫棉在我国种植面积迅速扩大, 其源小库大的特点造成了源库之间的不平衡, 加之后期根系衰老快, 与常规棉相比, 土壤钾素不足时更易出现缺钾性早衰, 导致棉花产量和品质下降^[1] ...

2009

0.0

0.8

白由路. 高价格下我国钾肥的应变策略. 中国土壤与肥料, 2009, 221(3): 1-4

Bai

Y L.

Response strategy of potassium fertilizer under high price in China. Soil Fert Sci China, 2009, 221(3): 1-4 (in Chinese with English abstract)

在国际市场钾肥价格居高不下的情况下,从我国钾肥的供需形势、钾肥需求的弹性分析人手,阐述了我国近期钾肥的应变措施为合理养分比例、加强秸秆资源利用和短期内减少钾肥的施用等.从中长期角度,我国钾肥的战略应是加强资源勘查,积极扩大国内钾盐供应,建立国家钾肥战略贮备制度,调节钾肥市场,加强钾肥循环利用并加强技术支撑研究,提高我国钾肥生产的可持续发展能力.

... 我国钾矿资源缺乏, 进口依赖度高, 然而作物秸秆资源丰富, 含钾量高, 且还田后释放速度快, 但目前我国棉田的秸秆还田率较低, 如果秸秆还田率能提高10个百分点, 就相当于180万吨钾肥补充到农田中^[2], 一定程度上可以弥补我国钾资源不足, 缓解土壤钾素亏缺状况 ...

2011

2.474

0.0

2013

0.0

刘义国, 刘永红, 刘洪军, 商健, 于淙超, 林琪. 秸秆还田量对土壤理化性状及小麦产量的影响. 中国农学通报, 2013, 29: 131-135

Liu

Y G

, Liu

Y H

, Liu

H J

, Shang

, Yu

Z C

, Lin

Effects of straw returning amount on soil physical and chemical properties and yield of wheat. Chin Agric Sci Bull, 2013, 29: 131-135 (in Chinese with English abstract)

In order to determine the appropriate amount of wheat straw returning, a field experiment was conducted to study different amount of straw returning treatment influence on soil physical and chemical properties and yield in the following season wheat fields. The results indicated that, straws increased soil moisture, the impact of humidity above the surface layer (60 cm) was the biggest. Meanwhile, straw mulch increased the soil organic matter, total nitrogen, available nitrogen, available phosphorus content .With the amount of coverage increasing the magnitude increased, straw mulch decreased the soil bulk density, increased the porosity, and better protect the soil physical structure. There was no significant difference among the treatments straw amount of 7500 kg/hm2 and 6000 kg/hm2 synergistic effect on soil. Straw mulch treatment increased wheat yield and factors of yield components, yield increased with straw amount increasing in different magnitude, the highest yield was 6000 kg/hm2 treatment. Based on the results in this experimental condition, 6000 kg/hm2 was the appropriate amount of wheat straw cover.

为了确定适宜的小麦秸秆还田量，通过设置不同的秸秆还田量处理，研究其对后茬麦田的土壤理化性状及产量的影响。结果表明，秸秆还田能增加土壤湿度，对表层(60 cm)以上湿度的影响最大。同时秸秆覆盖能使土壤有机质、全氮、碱解氮、速效磷含量增加，随覆盖量的增加其增加幅度加大，秸秆覆盖使土壤容重降低，孔隙度加大，更好地保护了土壤的物理结构。秸秆还田量7500 kg/hm2处理与秸秆（麦秸）还田量6000 kg/hm2的处理对土壤的增效作用差别不大。秸秆覆盖处理提高了小麦产量及产量构成因素，随秸秆还田用量增加产量有不同幅度的增加，以6000 kg/hm2处理产量最高。综合研究结果在本试验条件下，以小麦秸秆覆盖6000 kg/hm2为比较适宜的秸秆覆盖还田量。

2012

0.0

1.883

王志勇, 白由路, 杨俐苹, 卢艳丽, 王磊, 王贺. 低土壤肥力下施钾和秸秆还田对作物产量及土壤钾素平衡的影响. 植物营养与肥料学报, 2012, 18: 900-906

Wang

Z Y

, Bai

Y L

, Yang

L P

, Lu

Y L

, Wang

Effects of application of potassium fertilizer and straw returning on crop yields and soil potassium balance in low-yielding fields. Plant Nutr Fert Sci, 2012, 18: 900-906 (in Chinese with English abstract)

Microcosm experiments were conducted to study the effects of fulvic acid (FA) and organic manure (OM) on soil phosphorus availability and acidic phosphatase activity in black soil at 10℃. The results showed that both FA and OM could enhance the availability of the soil P. Compared with the control, addition of FA and OM increased Olsen-P content by 54.5% and 111.5%, respectively. The phosphorus activation coefficients of FA and OM were 40.6% and 70.9%, respectively. During the period of incubation, soil organic phosphorus content reduced progressively in both FA and OM treatments. However, compared with the control (CK), soil organic phosphorus content in FA and OM treatments was increased by 20.8% and 42.3%, respectively. Moreover, treatment with both FA and OF was found to enhance acidic phosphatase activity, and soil organic carbon and dissolved organic carbon contents. Compared with CK, acidic phosphatase activity in FA and OM treatments was increased by 35.8%, 50.9%, and soil organic carbon content was increased by 42% and 35%, and dissolved organic carbon by 70.2% and 63.7%, respectively. The positive correlation was found either between acidic phosphatase activity and soil available phosphorus (r=0.925, p <0.01) or between DOC and soil available phosphorus (r=0.765, p <0.01) Fulvic acid- and organic manure-mediated phosphorus mobilization in the black soil tested may be attributed mainly to the enhancement of DOC content and acidic phosphatase activity caused by FA and OM.

1 College of Resources and Environment, Nanjing Agricultural University, Nanjing 210095, China;2 Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture, Beijing 100081, China

采用恒温控湿培养法，研究了低温（培养温度10℃）条件下，黄腐酸（FA）和有机肥（OM）对黑土磷素有效性、酸性磷酸酶活性等的影响。结果表明，黄腐酸（FA）和有机肥（OM）均能提高土壤磷素的有效性，与对照相比，土壤有效磷（Olsen-P）分别提高54.5%和111.5%， FA和OM对黑土磷素活化系数分别为40.6%和70.9%。在整个培养过程中，FA和OM处理土壤有机磷含量均随培养时间逐渐降低。但是，与对照相比，FA和OM处理的有机磷含量分别增加了20.8%和42.3%。FA和OM能够提高土壤酸性磷酸酶活性，增加土壤有机质和溶解性有机碳的含量。与对照相比，FA和OM处理土壤酸性磷酸酶活性增加35.8%和50.9%，有机碳（SOC）增加42.0%和35.0%，溶解性有机碳（DOC）增加70.2% 和63.7%。相关性分析表明，土壤有效磷与酸性磷酸酶、DOC呈极显著的正相关，相关系数分别为0.925和0.765（p<0.01）。黄腐酸和有机肥对黑土磷素的活化机制可能是由于黄腐酸和有机肥处理增加了黑土DOC含量，提高了土壤酸性磷酸酶的活性，促进了黑土磷素的转化，进而增加了黑土磷素的有效性。

... 关于作物秸秆与化学钾肥的增产与培肥效果, 王志勇等^[5]、孙丽敏等^[15]、谭德水等^[16]在不同条件下的长期定位试验研究中均得出较一致的结论, 在氮、磷肥充足的情况下, 钾肥的增产效应大于秸秆还田, 效果最佳的则是秸秆与钾肥配施 ...

... 王志勇等^[5]研究表明施钾肥和秸秆还田均能促进作物对钾素养分的吸收, 增加作物的吸钾总量 ...

2011

0.435

0.0

... Wu等^[6]研究指出小麦秸秆养分释放主要集中在前30 d, 且土壤水分含量较多不利于土壤微生物和酶活性提高, 降低秸秆腐解率 ...

2003

0.0

... 刘冬青等^[7]认为小麦秸秆覆盖可以提高棉花叶面积指数, 延长叶片功能期, 提高棉株的光合能力从而防止棉花早衰, 增加铃重, 提高棉花产量 ...

... 0%, 明显高于刘冬青等^[7]在山东棉区的20 ...

... 刘冬青等^[7]通过对土壤养分和叶面积指数的研究指出, 秸秆覆盖还田在棉花生长后期, 可以提高叶面积指数, 延长叶片功能期, 提高棉株的光合能力从而防止棉花早衰 ...

2010

0.0

... Gwathmey等^[8]研究指出, 小麦秸秆还田6年后棉花皮棉产量提高11% ...

2012

0.526

0.0

... Rafique等^[9]在巴基斯坦麦棉轮作系统研究中指出, 平衡施肥条件下, 麦秸秆覆盖还田提高了棉株氮浓度和产量, 且随试验年份延长提高愈显著 ...

2003

0.0

1.889

王克如, 李少昆, 曹连莆, 宋光杰, 陈刚, 曹栓柱. 新疆高产棉田氮, 磷, 钾吸收动态及模式初步研究. 中国农业科学, 2003, 36: 775-780

Wang

K R

, Li

S K

, Cao

L P

, Song

G J

, Chen

Cao

S Z.

A preliminary study on dynamics and models of N, P, K absorption in high yield cotton in Xinjiang. Sci Agric Sin, 2003, 36: 775-780 (in Chinese with English abstract)

兵团绿洲生态农业重点实验室/石河子大学新疆作物高产研究中心

对 30 0 0kg·ha-1皮棉高产测定的结果表明 ,棉花叶片、茎枝、蕾铃中的氮、磷、钾含量随生育进程呈明显下降趋势 ,且下降幅度大于 2 0 0 0kg·ha-1对照产量棉田。整个生长期 ,叶片、蕾铃中氮的百分含量明显高于对照产量棉田 ,尤以果枝叶最明显 ;蕾铃中的磷和茎枝的钾百分含量高于对照棉田 ;棉株群体中氮、磷、钾的积累可用Lo gistic曲线方程表达 ,拟合良好。养分吸收最快的时间 :氮约在出苗后 90d ,磷在 92d ,钾则偏早 ,约在出苗后 85d。在 30 0 0kg·ha-1皮棉高产条件下 ,棉株从土壤中吸收的氮、磷、钾分别为 385 .8、2 44 .7和 34 0 .3kg。每生产 10 0kg皮棉和相应的茎叶需吸收氮 12 .5kg、磷 8.0kg和钾 11.1kg。

... 氮(磷、钾)养分利用效率=皮棉产量/植株氮(磷、钾)吸收量^[10] ...

... 100^[10] ...

2008

1.821

0.0

... 但关于秸秆还田作物产量提高幅度的研究结果差异较大^[11] ...

... 9%增产幅度和Jalota等^[13]、Reiter等^[11]在印度、巴基斯坦等地区对棉花的研究结果 ...

2012

0.0

1.742

2008

2.367

0.0

Jalota

S K

, Buttar

G S

, Sood

, Chahal

G B S

, Ray

S S

, Panigrahy

. Effects of sowing date, tillage and residue management on productivity of cotton (Gossypium hirsutum L. )-wheat (Triticum aestivum L. ) system in northwest India. Soil Till Res, 2008, 99: 76-83

Abstract

In southwestern region of Punjab in north India, sowing dates of cotton crop in cotton (Gossypium hirsutum L.)–wheat (Triticum aestivum L.) system are staggered from last week of April to mid of May depending upon the surface water supply from canal as ground water is not fit for irrigation. Further, farmers practice intensive cultivation for seedbed preparation and burning of wheat straw before sowing of cotton crop. With the present farmers’ practices, yields have become static and system has become non-profitable. Field experiments were conducted on Entisols for two rotations of cotton–wheat system during the years of 2004–2005 and 2005–2006 in split plot design to study the direct and interactive effects of date of sowing and tillage-plus-wheat residue management practices on growth and yield of cotton and wheat and to increase the profitability by reducing the tillage operations, which costs about 50% of the sowing cost. The pooled analysis showed that in cotton crop, there was a significant interaction between year × dates of sowing. Among different tillage-plus-wheat residue management practices yields were 23–39% higher in tillage treatments than minimum-tillage. In wheat, grain yield in tillage treatments were at par. Water productivity amongst the tillage treatments in cotton was 19–27% less in minimum tillage than others tillage treatments. Similar trend was found in wheat crop. Remunerability of the cotton–wheat system was more with a combination of reduced tillage in cotton and minimum tillage in wheat than conventional tillage.

... 9%增产幅度和Jalota等^[13]、Reiter等^[11]在印度、巴基斯坦等地区对棉花的研究结果 ...

2007

0.526

0.0

... 究其原因主要是本研究对照的棉花产量是在麦棉两季连续不施钾不施秸秆的第4季和第6季产生的, 土壤钾素消耗较多, 棉花又是一个对缺钾敏感的作物, 转基因棉花品种较常规品种对钾亏缺更敏感^[14] ...

2012

0.0

1.883

孙丽敏, 李春杰, 何萍, 刘孟朝, 胡景辉. 长期施钾和秸秆还田对河北潮土区作物产量和土壤钾素状况的影响. 植物营养与肥料学报, 2012, 18: 1099-1106

Sun

L M

, Li

C J

, He

, Liu

M C

, Hu

J H.

Effects of long-term K application and straw returning on crop yield and soil K status in fluvo-aquic soil of Hebei Province. Plant Nutr Fert Sci, 2012, 18: 1099-1106 (in Chinese with English abstract)

With the aim to provide the theoretical basis for sustainably increasing crop yield, productivity, and nutrient management in fluvoaquic soil of Hebei Province, the effects of the longterm application of K fertilizers and straw returning on crop yield, soil K content and potassium balance were analyzed using the data obtained from the longterm K localization experiment (1992-2009) under wheatmaize rotation system. The results reveal that the 17-year average yields of wheat and maize are in an order as NPKSt > NPK > NPSt > NP, which is similar to the effects of the K fertilizer application. Compared to the NP mode, the yields of wheat and maize under the NPKSt mode are increased by 9.37% and 19.23% respectively, the yields of wheat and maize under the NPK mode are increased by 6.32% and 18.25% respectively, and the yields of wheat and maize under the NPSt mode are increased by 2.76% and 9.60% respectively. The nutrient analysis indicates that the contents of available potassium and slowly releasing potassium in the 0-20 cm soil layers under the modes of NPKSt, NPK and NPSt are significantly different from those under the NP mode, showing an order as NPKSt > NPK > NPSt > NP, while no significant differences in the contents of available potassium and slowly releasing potassium in 20 to 40 cm soil layers are found between the four fertilizing modes. The nutrient balance analysis discloses that the profit and loss annually of K under the NP mode is -170.0 kg/ha, indicating that potassium is seriously deficiency in soil, the real surplus and deficit rate under the NPSt mode is -584% and the annual profit and loss of K is -150.6 kg/ha, the profit and annual loss of K and the real surplus and deficit rate under the NPK mode are nearly in balance and they are -3.1 kg/ha and -1.0% respectively, while under the NPKSt mode, the balance index of K is 1.37, the real surplus and deficit rate is 36.8% and the profit and loss annually of K is 111.4 kg/ha. These results demonstrate that the longterm application of K fertilizers and straw returning in fluvo-aquic soils of wheatmaize rotation fields have significant effects on yield increase and soil potassium balance.

1 College of Resource and Environmental Sciences, Hebei Agricultural University, Baoding 071001, China; 2 Institute of Agroresources and Environment, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang050051,China; 3 Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081,China; 4 Agricultural Information and Economic Research Institute, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, China

以河北冲积平原典型潮土区小麦-玉米轮作长期定位试验（19922009年）为基础，分析了长期施用钾肥和秸秆还田对作物产量、土壤钾含量及钾素平衡的影响。研究结果表明，不同处理下小麦、玉米17年平均产量均表现为NPKSt>NPK>NPSt>NP，其中，小麦、玉米NPKSt处理比NP处理分别增产9.37%和19.23%，NPK处理比NP处理分别增产6.32%和18.25%; NPSt处理比NP处理分别增产2.76%和9.60%; 长期定位施肥下，各处理耕层土壤（0—20 cm）各施钾肥的处理其速效钾、缓效钾含量均与NP处理差异极显著，且表现为NPKSt>NPK>NPSt>NP; 各处理下层土壤（20—40 cm）的速效钾、缓效钾含量差异均不显著，从钾素平衡看，NP处理钾素表观年盈亏量为-170.0 kg/hm²，土壤钾严重亏缺; NPSt处理实际平衡盈亏率-58.4%，表观年盈亏量为-150.6 kg/hm²; NPK处理钾素表观年盈亏量-3.1 kg/hm²，盈亏率-1.0%，基本接近平衡; NPKSt处理实际平衡盈亏率36.8%，表观年盈亏量为111.4 kg/hm²。试验结果说明，在潮土区，在施氮、磷肥的基础上，配施钾肥或秸秆还田不仅能持续提高小麦、玉米的高产、稳产生产能力，而且对保持农田土壤钾素平衡、有效改善耕层土壤钾素状况、提高土壤肥力有重要的作用。

2008

0.0

1.883

谭德水, 金继运, 黄绍文. 长期施钾与秸秆还田对西北地区不同种植制度下作物产量及土壤钾素的影响. 植物营养与肥料学报, 2008, 14: 886-893

Tan

D S

, Jin

J Y

, Huang

S W.

Effect of long-term K fertilizer application and returning wheat straw to soil on crop yield and soil K under different planting systems in northwestern China. Plant Nutr Fert Sci, 2008, 14: 886-893 (in Chinese with English abstract)

Experiments of long-term K fertilizer application and returning wheat straw to soil in Ningxia irrigation silting soils and Qinghai castanozems in northwestern China were started in 1992. Effect of K fertilizer application and returning wheat straw to soil on crop yield and soil K status in the plough layer under different planting systems was studied. The results showed that K fertilizer and wheat straw could improve crop yield significantly in Ningxia site, with the treatments being in the following order: NPK+Straw>NPK>NP+Straw>NP. The time when the positive effect of K application on yield became significant in Ningxia differed with varieties, however, K application or returning wheat straw to soil did not have any significant effect on wheat yield in Qinghai. Coefficient of variance of wheat yield in each treatment of Ningxia was lower than in Qinghai and was higher than maize, but yield efficiency of K fertilizer application was on the contrary. Except for treatment NPK+Straw, soil K was deficient in each treatment of the two fixed sites, and the consumption of soil K was more serious in the rotation system of Ningxia than in wheat monoculture of Qinghai. K fertilizer and straw could improve content of water-soluble K, non-specifically adsorbed K, non-exchangeable K and total K in contrast to NP, however reduce proportion of mineral K and improve those of

others in the two fixed sites, and content and proportion of specifically adsorbed K had no relations with K fertilizer and straw. Compared with the beginning of the experiment, temporal variability characteristics of content and

proportion of different forms of K differed between two soil types, which were closely related to K status of original soil and planting system.

1 Institute of soil and fertilizer, Shandong Academy of Agricultural Sciences, Jinan 250100,China; <BR>2 Institute of Agricultural Resources and Regional Planning, CAAS, Beijing 100081,China <BR>

研究了在西北地区代表性的灌淤土、栗钙土上连续13年施用钾肥和小麦秸秆还田对作物产量和耕层土壤钾素的影响。结果表明，施用化学钾肥和小麦秸秆还田能显著增加宁夏轮作种植制度下作物产量，表现为：氮磷钾肥配合秸秆还田>只施用氮磷钾肥>氮磷肥配合秸秆还田>只施用氮磷肥；且作物种类对施钾措施的显效时间上有差异，而钾素投入对青海点小麦产量无显著作用。宁夏点作物年际间产量变异系数低于青海点，小麦的产量变异系数大于玉米但钾肥产量效应却低于玉米。两定位点除氮磷钾+秸秆还田外，其余处理土壤钾素均表现亏缺，轮作制度下土壤钾素亏缺量较小麦单作制大。两定位点施钾或秸秆还田处理的水溶性钾、非特殊吸附钾、非交换性钾和全钾含量均不同程度高于只施氮磷处理；除矿物钾外，其余几种形态钾比例均高于氮磷处理，特殊吸附钾不受施钾措施的影响。与定位开始相比，两种类型土壤各形态钾含量和比例随时间变异特点不同，与原始土壤钾素状况及种植制度密切相关。

2010

0.0

... 7℃, 而这一时期是蕾铃数形成的关键时期, 温度越高越有利于铃数的增加^[17], 2013年铃数平均较2012年高14 ...

1981

0.0

0.3221

... 贾仁清等^[18]、王娇等^[19]认为, 随施钾量增加磷的吸收量增加幅度较小, 钾素增加最多 ...

2012

0.0

0.778

... 贾仁清等^[18]、王娇等^[19]认为, 随施钾量增加磷的吸收量增加幅度较小, 钾素增加最多 ...

2010

0.0

... 本研究还进一步表明, 秸秆还田和施钾有利于提高植株氮磷钾养分向棉铃的分配, 但吐絮盛期有所减少, 而向根茎叶分配增多, 尤其是钾素, 这与Mullins等^[20]的研究结果较一致 ...