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Effects of Side Deep Fertilization on Yield Formation and Nitrogen Utilization of Mechanized Transplanting Rice
ZHU CongHua1,2, ZHANG YuPing1, XIANG Jing1, ZHANG YiKai1, WU Hui1, WANG YaLiang1, ZHU DeFeng1, CHEN HuiZhe![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/REemail.gif)
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责任编辑: 杨鑫浩
收稿日期:2019-04-3接受日期:2019-06-3网络出版日期:2019-12-01
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Received:2019-04-3Accepted:2019-06-3Online:2019-12-01
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朱从桦,Tel:0571-63136702;E-mail:zchsicau@163.com
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朱从桦, 张玉屏, 向镜, 张义凯, 武辉, 王亚梁, 朱德峰, 陈惠哲. 侧深施氮对机插水稻产量形成及氮素利用的影响[J]. 中国农业科学, 2019, 52(23): 4228-4239 doi:10.3864/j.issn.0578-1752.2019.23.004
ZHU CongHua, ZHANG YuPing, XIANG Jing, ZHANG YiKai, WU Hui, WANG YaLiang, ZHU DeFeng, CHEN HuiZhe.
0 引言
【研究意义】当前我国水稻生产中普遍存在施肥均匀性差、施肥机械缺乏、施氮偏多、产量较低、氮肥利用效率低、生产效益较低等问题,其主要原因有:(1)随着水稻规模化生产蓬勃发展,新型经营主体为降低用工成本,水稻生产季仅施肥1—2次,忽视追肥和穗肥[1,2,3];(2)水稻生产中氮肥以尿素、碳铵等速效肥为主,增加氮素通过径流、挥发、渗透等途径的损失量[1, 4];(3)施肥主要依靠人力或简易机械进行表面撒施[1, 4-5],增加施肥劳作强度,施肥深度和单位面积施肥量很难精确控制,降低种植作业效率。为解决上述问题,研究机械侧深施氮[6],对提升水稻机械化精确定量施肥水平,提高水稻氮肥利用效率和产量,实现水稻节本增效目标具有重要意义。【前人研究进展】围绕提高水稻氮肥利用率和产量,国内外主要从施氮量[7]、氮肥深施[8,9,10]、氮肥运筹策略[11]、平衡施肥[12]、水氮管理、抑制剂研发[13]、肥料类型[14,15]、实时实地氮肥管理[16]等方面开展研究,其中施用控释尿素、侧深施肥是实现肥料利用率和稻谷产量协同提高的有效途径。尿素和控释尿素是两类重要的氮肥,在影响水稻生长和产量形成方面存在较大差异,其中尿素养分释放快,有利于水稻早生快发;控释尿素养分释放缓慢,释放周期长,能够减少土壤氨挥发损失量,在整个生长期都能持续为水稻提供养分,保证水稻稳产,提高氮肥利用效率[7, 17-18]。控释尿素一次性撒施能够满足水稻整个生育期对氮素的需求,提高土壤碱解氮和植株体内氮含量,增强光合生产能力[19];施用控释尿素能够改善水稻根系生长,延长氮素释放供应期,促进稻株积累氮素,提高氮肥利用率[14,15];但是,控释尿素作底肥一次撒施或者单独施用的效果因作物类型、土壤环境和养分释放特性不同而存在较大差异。氮肥表面撒施是一种粗放的施肥手段,氮肥损失量较大[9, 17],而浅层施肥可以促进表层根系生长,有利于秧苗生长[20,21],深施肥进一步将养分精确送达根区,减少氮素等养分损失,提高氮肥利用率和稻谷产量[8-10, 22-23]。尿素深施可以减少稻田N2O和NO释放量[24],减少氮素通过径流损失[25],增加养分在土壤中的贮存时间,提高氮肥利用率和稻谷产量[9, 26-27]。目前,为实现水稻节肥增效目标,水稻机插同步侧深施肥技术已经大面积运用,能够显著提高种稻效率,提高稻谷产量和经济效益[6, 10, 28-29]。【本研究切入点】在耙地、镇压、磨平基础上,侧深施肥插秧机将秧苗栽插和侧深施肥同步完成,降低水稻种植施肥劳作强度和用工成本,精确控制施肥量和施肥深度。然而,不同类型氮肥机械侧深施用对水稻产量形成及氮素利用的影响鲜见报道,此外难以准确评估控释氮肥机械侧深施用的增产效应,限制了控释氮肥机械侧深施用配套技术的推广。【拟解决的关键问题】本研究以尿素和控释尿素为氮源,在水稻季节开展机械侧深施氮试验,明确不同氮肥类型机械侧深施用对水稻氮素利用和水稻产量形成的影响,为水稻机械侧深施肥配套种植技术提供理论支持。1 材料与方法
1.1 试验点概况
试验于2017年7—11月在浙江省金华市婺城区琅琊镇琅新粮食合作社农场(119°28′ E,29°01′ N)、2018年5—10月在浙江省杭州市富阳区中国水稻研究所试验农场(119°55′ E,30°04′ N)实施,两地均属于亚热带季风气候,水稻季月平均气温、最高温度、最低温度、蒸发量、降水量、相对湿度和日照时数详见表1。2017年试验地土壤为黄泥田水稻土,试验前0—25 cm耕层土壤pH 5.38、有机质30.16 g·kg-1、全氮1.69 g·kg-1、速效氮86.80 mg·kg-1、有效磷9.08 mg·kg-1、速效钾70.00 mg·kg-1;2018年试验地土壤为黏性水稻土,试验前0—25 cm耕层土壤pH 5.63、有机质35.89 g·kg-1、全氮1.76 g·kg-1、速效氮79.58 mg·kg-1、有效磷8.11 mg·kg-1、速效钾82.00 mg·kg-1。Table 1
表1
表1水稻生长季平均气温、最高温度、最低温度、蒸发量、降水量、相对湿度和日照时数
Table 1
年份 Year | 月份 Month | 平均气温 Average air temperature (℃) | 最高温度 Maximum temperature (℃) | 最低温度 Minimum temperature (℃) | 蒸发量 Vaporization (mm) | 降水量 Precipitation (mm) | 相对湿度 Relative humidity (%) | 日照时数 Sunshine hours (h) |
---|---|---|---|---|---|---|---|---|
2017 | 7月 July | 31.65 | 41.10 | 23.80 | 162.10 | 41.32 | 64.94 | 273.00 |
8月 August | 30.95 | 39.10 | 24.10 | 163.40 | 48.02 | 69.26 | 250.10 | |
9月 September | 27.03 | 38.20 | 18.20 | 121.20 | 66.61 | 73.17 | 157.70 | |
10月 October | 20.51 | 36.60 | 8.30 | 102.60 | 37.62 | 73.10 | 146.30 | |
11月 November | 14.21 | 26.10 | 6.10 | 60.30 | 138.61 | 78.87 | 95.80 | |
2018 | 5月 May | 23.74 | 37.40 | 12.80 | 148.20 | 233.40 | 80.39 | 141.60 |
6月 June | 25.45 | 36.30 | 17.20 | 166.90 | 228.50 | 82.07 | 187.20 | |
7月 July | 29.74 | 38.70 | 24.10 | 250.90 | 272.10 | 78.35 | 250.90 | |
8月 August | 29.38 | 37.30 | 22.30 | 256.20 | 232.20 | 78.06 | 225.10 | |
9月 September | 25.30 | 35.60 | 16.90 | 162.80 | 133.20 | 81.73 | 154.00 | |
10月 October | 18.14 | 27.80 | 8.60 | 118.00 | 21.00 | 72.65 | 180.10 |
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1.2 供试材料
水稻品种为天优华占,籼型三系杂交水稻,2017年作为晚稻平均生育期119.5 d,2018年作为中稻平均生育期142.2 d。氮肥类型为尿素(N含量≥46.7%,中化化肥控股有限公司生产)和控释尿素(N含量≥41.6%,金正大生态工程集团股份有限公司生产,25℃释放期为60 d)。1.3 试验设计
试验采用随机区组设计,设置5种施氮方式,即N0:不施用氮肥;CUB:氮肥类型为尿素,按基肥﹕分蘖肥﹕穗肥=5﹕3﹕2施用,基肥、分蘖肥和穗肥均采用人工撒施;CUM:氮肥类型为尿素,按基肥﹕分蘖肥﹕穗肥=5﹕3﹕2施用,基肥在插秧时机械侧深施,分蘖肥和穗肥采用人工撒施;CRUB:氮肥类型为控释尿素,按基肥﹕分蘖肥﹕穗肥=5﹕3﹕2施用,基肥、分蘖肥和穗肥均采用人工撒施;CRUM:氮肥类型为控释尿素,按基肥﹕分蘖肥﹕穗肥=5﹕3﹕2施用,基肥在插秧时机械侧深施,分蘖肥和穗肥采用人工撒施。每个处理重复3次,小区面积为60 m2。22017年和2018年纯氮用量分别为150 kg·hm-2和180 kg·hm-2;所有小区P2O5(过磷酸钙,P2O5≥12%)用量分别为45 kg·hm-2和60 kg·hm-2,全部作基肥;K2O(钾肥为氯化钾,K2O≥60%)用量均为180 kg·hm-2,按照基肥﹕穗肥=1﹕1施用。全部磷肥和50%钾肥作基肥于插秧前1 d撒施,50%钾肥作穗肥在主茎倒3叶期撒施;50%氮肥作基肥(CUB和CRUB于移栽前1 d撒施,CUM和CRUM在插秧时机械侧深施),30%氮肥作分蘖肥在移栽后第7天撒施,20%氮肥作穗肥在主茎倒3叶期撒施。小区间筑高30 cm、宽30 cm的田埂,并覆塑料膜,独立排灌。
试验于2017年7月8日、2018年5月20日采用基质进行钵形毯状育秧(9寸秧盘),每盘播种量为105 g芽谷,出苗后适时浇水培育壮秧。2017年7月25日、2018年6月24日采用侧深施肥插秧机栽插施肥,插秧同时通过机械臂在窄行秧苗侧面(5±0.5)cm处开沟施肥,沟深(5.5±0.5)cm,泥土回填覆盖肥料,机插规格为宽行33 cm,窄行17 cm,株距20 cm,每穴栽插3—4苗。所有小区前期浅水勤灌,待田间分蘖数达到预期穗数的80%时排水晒田7 d,孕穗至成熟期采用干湿交替灌溉,收获前7 d停止灌水;病虫和杂草防控同当地一般大田栽培。
1.4 测定项目及方法
1.4.1 叶片SPAD值 在穗分化期、齐穗期,每个小区选取30个代表性叶片(穗分化期选择顶上第1完全展开叶,齐穗期选择完全展开的剑叶),用SPAD-502PLUS叶绿素仪测定。1.4.2 干物质重 在穗分化期、齐穗期和成熟期,每个小区按照平均分蘖数选取代表性植株3丛,分叶、茎(含叶鞘)和穗(齐穗期和成熟期),105℃杀青30 min,80℃烘干至恒重,称量干重。
1.4.3 叶、茎和穗部氮含量 利用1.4.2的干样磨碎成粉(过80目筛),采用浓H2SO4+H2O2消煮(420℃,消解2 h),用全自动凯氏定氮仪(KjeltecTM 8400,FOSS公司生产)测定氮含量。
1.4.4 收获与计产 收获前,每个小区调查30丛的有效穗,按照平均穗数取6丛代表性植株,调查结实率、每穗粒数、千粒重等产量构成指标;选取15 m2人工脱粒,晒干后换算成标准含水量13.5%进行计产,每处理重复3次。
1.4.5 参数计算
营养器官干物质输出量(t·hm-2)=齐穗期营养器官干重-成熟期营养器官干重;
营养器官干物质转运率(%)= 营养器官干物质输出量/齐穗期营养器官干重×100;
茎叶氮素表观转移量(kg·hm-2)=齐穗期茎叶氮素积累量-成熟期茎叶氮素积累量[18];
茎叶氮素表观转移率(%)=茎叶氮素表观转移量/齐穗期茎叶氮素积累量×100[18];
茎叶转移的氮对籽粒氮的贡献率(%)=茎叶氮素表观转移量/成熟期籽粒中氮素积累量×100[18];
茎鞘(叶片)氮素转移量(kg·hm-2)=齐穗期茎鞘(叶片)氮素积累量-成熟期茎鞘(叶片)氮素积累量[18];
茎鞘(叶片)氮素转移率(%)=茎鞘(叶片)氮素转移量/齐穗期茎鞘(叶片)氮素积累量×100[18];
氮素干物质生产效率(kg·kg-1)=成熟期地上部干物质积累量/成熟期地上部氮素积累量[29,30];
氮素稻谷生产效率(kg·kg-1)=籽粒产量/成熟期地上部氮素积累量[29,30];
氮肥吸收利用率(%)=(成熟期施氮区地上部氮素积累量-成熟期不施氮区地上部氮素积累量)/施氮量×100%[11, 16];
氮肥农学效率(kg·kg-1)=(施氮区籽粒产量-不施氮区籽粒产量)/施氮量[11, 16]。
1.5 数据分析
采用DPS 7.05软件进行试验数据统计分析,用最小显著差法LSD检验平均数(P<0.05),用OriginPro 2017软件制图。2 结果
2.1 产量和产量构成因素
施氮方式能够显著影响水稻产量及产量构成因素(表2)。施用控释尿素比尿素平均增产3.72%(2017年)和3.32%(2018年),侧深施肥比人工撒施平均增产5.67%(2017年)和6.80%(2018年),控释尿素侧深施处理(CRUM)比尿素人工撒施处理(CUB)增产9.67%(2017年)和10.41%(2018年)。2年籽粒产量均表现为CRUM>CUM>CRUB>CUB>N0。Table 2
表2
表2机械侧深施氮对水稻产量及产量构成的影响
Table 2
年份 Year | 处理 Treatment | 籽粒产量 Grain yield (t·hm-2) | 有效穗数 Effective panicle number (104·hm-2) | 颖花总量 Total amount of spikelet (106·hm-2) | 每穗实粒数 Number of filled grains per panicle | 结实率 Seed-setting rate (%) | 千粒重 1000-grain weight (g) |
---|---|---|---|---|---|---|---|
2017 | N0 | 5.42d | 201.11e | 310.16d | 114.79abc | 74.40a | 24.29b |
CUB | 6.62c | 269.44d | 426.85c | 116.88ab | 73.74a | 25.15ab | |
CUM | 7.08ab | 293.89b | 482.25a | 120.54a | 73.50a | 24.53ab | |
CRUB | 6.95b | 285.00c | 456.48b | 113.56bc | 70.86b | 24.89ab | |
CRUM | 7.26a | 316.11a | 496.51a | 109.72c | 69.86b | 25.48a | |
2018 | N0 | 7.04c | 228.25c | 426.43d | 155.98b | 83.67c | 23.30b |
CUB | 9.13b | 287.97b | 544.79c | 162.45ab | 85.95a | 23.33b | |
CUM | 9.87a | 330.37a | 636.86ab | 163.42ab | 84.78b | 24.06a | |
CRUB | 9.55ab | 319.77a | 602.54b | 162.19ab | 86.03a | 24.14a | |
CRUM | 10.08a | 328.97a | 668.32a | 170.54a | 83.91c | 24.17a |
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与撒施相比,机械侧深施肥可以显著提高水稻的有效穗数和颖花总量,其中颖花总量以CRUM处理最高。机械侧深施肥处理的结实率低于撒施处理,2018年尤其显著。各施氮处理间千粒重差异较小。综上所述,机械侧深施肥处理CRUM和CUM产量较高的主要原因是具有更高的有效穗数和颖花总量。
2.2 叶片SPAD值
施肥方式能够显著影响水稻穗分化期、齐穗期叶片的SPAD值(表3)。在穗分化期,叶片SPAD值为CRUM>CRUB>CUM>CUB,CUM处理和CRUB处理无显著差异。在齐穗期,CRUM处理叶片SPAD值显著高于CUB处理,而CUM、CRUB和CRUM处理之间叶片SPAD值无显著差异。Table 3
表3
表3机械侧深施氮对水稻叶片SPAD值的影响
Table 3
年份 Year | 处理 Treatment | SPAD | |
---|---|---|---|
穗分化期 Panicle initiation stage | 齐穗期 Full heading stage | ||
2017 | N0 | 37.80d | 40.55c |
CUB | 39.59c | 43.06b | |
CUM | 41.03b | 43.68ab | |
CRUB | 41.97b | 44.59a | |
CRUM | 44.11a | 44.73a | |
2018 | N0 | 38.13d | 39.04c |
CUB | 40.30c | 40.74b | |
CUM | 41.47bc | 41.77ab | |
CRUB | 42.20b | 41.34ab | |
CRUM | 43.90a | 42.21a |
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2.3 干物质积累、转运和收获指数
施肥方式能够显著影响水稻干物质积累和营养器官干物质转运(表4)。穗分化期、齐穗期和成熟期,干物质积累量均表现为控释尿素显著高于尿素,侧深施肥显著高于人工撒施。与尿素相比,控释尿素穗分化期、齐穗期、成熟期干物质积累量分别增加12.55%、10.60%、3.22%(2017年)和3.91%、1.22%、8.77%(2018年)。与人工撒施相比,机械侧深施肥穗分化期、齐穗期、成熟期干物质积累量分别增加14.72%、10.33%、8.08%(2017年)和28.61%、9.78%、6.89%(2018年),营养器官干物质转运量分别增加7.69%(2017年)和30.47%(2018年)。与CUB处理相比,CRUM处理穗分化期、齐穗期和成熟期干物质积累量分别增加29.52%、22.21%、11.57%(2017年)和33.91%、11.07%、16.33%(2018年),营养器官干物质转运量分别增加44.54%(2017年)和26.05%(2018年)。CRUM处理收获指数均低于其他施氮处理。综上所述,机械侧深施氮提高水稻干物质积累量和灌浆期营养器官干物质输出量,进而获得高产。Table 4
表4
表4机械侧深施氮对水稻干物质积累、转运和收获指数的影响
Table 4
年份 Year | 处理 Treatment | 干物质积累量 Dry matter accumulation (t·hm-2) | 齐穗后干物质积累所占比例RDMA-FHM (%) | 营养器官干物质输出量 DME (t·hm-2) | 营养器官干物质转运率 TRDV (%) | 收获指数 Harvest index (%) | |||
---|---|---|---|---|---|---|---|---|---|
穗分化期 PI | 齐穗期 FH | 齐穗—成熟 FTM | 成熟期 MS | ||||||
2017 | N0 | 1.77d | 6.06d | 4.21c | 10.26d | 40.84a | 1.11c | 22.91ab | 52.91ab |
CUB | 2.27c | 7.34c | 5.19ab | 12.53c | 41.43a | 1.19bc | 20.09ab | 52.89ab | |
CUM | 2.67b | 8.22b | 5.36a | 13.58a | 39.38ab | 1.22bc | 18.25b | 52.12ab | |
CRUB | 2.62b | 8.24b | 4.73b | 12.97b | 36.44bc | 1.54ab | 23.23ab | 53.64a | |
CRUM | 2.94a | 8.97a | 5.02ab | 13.98a | 35.85c | 1.72a | 24.20a | 51.93b | |
2018 | N0 | 4.42c | 9.59c | 4.10c | 13.69d | 29.92a | 1.98c | 25.56a | 51.51a |
CUB | 5.22b | 12.56b | 4.89bc | 17.45c | 27.82a | 2.38b | 23.01ab | 52.32a | |
CUM | 6.81a | 13.67a | 5.15b | 18.81b | 27.19a | 2.78a | 25.27a | 52.46a | |
CRUB | 5.51b | 12.60b | 6.54a | 19.14b | 34.09a | 2.05bc | 19.52b | 49.89a | |
CRUM | 6.99a | 13.95a | 6.36a | 20.30a | 31.11a | 3.00a | 26.70a | 49.73 a |
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2.4 氮素积累和分配
施用氮肥可以显著提高水稻穗分化期、齐穗期和成熟期的氮素吸收总量(图1)。在穗分化期、齐穗期和成熟期,控释尿素的氮素吸收总量显著高于尿素,侧深施氮的氮素吸收总量显著高于人工撒施。在成熟期,水稻穗部氮素分配比例达到68.63%—82.30%(2017年)、67.93%—71.83%(2018年)。相比其他3个施氮处理,CRUM处理成熟期茎叶鞘(含叶鞘)中氮素积累量最高,因此,该处理稻草还田腐解后能够为下季作物生长提供更多的氮素。图1
![](https://www.chinaagrisci.com/article/2019/0578-1752/0578-1752-52-23-4228/thumbnail/img_1.png)
图1机械侧深施氮对水稻氮素吸收、分配的影响
柱上不同小写字母表示不同施肥方式地上部氮素吸收总量间差异显著(P<0.05)
Fig. 1Effects of mechanized side deep placement of nitrogen fertilizer on nitrogen uptake and distribution of rice
Different lowercase letters on bars indicate significant differences at P<0.05 on total nitrogen uptake in aboveground among different fertilization treatments
2.5 茎叶氮素转移量、氮素转移率及贡献率
施氮方式对水稻茎叶氮素表观转移量(TNT)、茎叶氮素表观转移率(TNTE)和茎叶转移的氮对籽粒氮的贡献率(NCR)有显著影响(表5)。撒施条件下,与尿素相比,施用控释尿素可以显著提高茎鞘氮素转移量(SNT)和叶片氮素转移量(LNT),进而提高TNT。CUM处理的TNT显著高于CUB处理,而CRUB处理和CRUM处理间TNTE、NCR无显著差异。所有施氮处理中,CRUM处理的TNT最高,但是其TNTE却较低。可见,CRUM处理灌浆结实期茎叶鞘等营养器官氮素向籽粒转移量增加,进而能够避免稻株贪青陡长。Table 5
表5
表5机械侧深施氮对水稻氮素转移的影响
Table 5
年份 Year | 试验处理 Treatment | 茎叶氮素表观 转移量 TNT (kg·hm-2) | 茎叶氮素表观 转移率 TNTE (%) | 茎叶转移的氮对籽粒氮的贡献率 NCR (%) | 茎鞘Stem-sheath | 叶 Leaf | ||
---|---|---|---|---|---|---|---|---|
SNT (kg·hm-2) | SNTE (%) | LNT (kg·hm-2) | LNTE (%) | |||||
2017 | N0 | 40.18d | 74.93a | 64.56b | 16.06c | 69.67a | 24.12d | 78.92a |
CUB | 49.01c | 63.77b | 56.96c | 18.65c | 57.56b | 30.36c | 68.20b | |
CUM | 57.50b | 61.87bc | 60.59b | 22.31b | 53.04c | 35.19b | 69.12b | |
CRUB | 68.97a | 63.11bc | 70.90a | 25.66a | 54.46bc | 43.31a | 69.61b | |
CRUM | 74.62a | 61.46c | 72.99a | 27.13a | 51.98c | 47.49a | 68.62b | |
2018 | N0 | 32.50b | 52.36a | 53.25a | 16.84ab | 48.02a | 15.66b | 58.03a |
CUB | 27.60c | 35.21c | 30.60b | 11.74c | 26.13b | 15.86b | 47.55b | |
CUM | 38.54a | 40.12b | 33.45b | 19.71a | 34.55b | 18.82a | 48.42b | |
CRUB | 33.24b | 37.65bc | 30.35b | 15.16bc | 30.00b | 18.08ab | 47.75b | |
CRUM | 39.51a | 39.43bc | 28.41b | 19.70a | 33.29b | 19.81a | 48.26b |
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2.6 氮素利用
施肥方式能够显著影响水稻氮素利用(表6)。与尿素相比,控释尿素的氮肥吸收利用率(NRE)提高32.07%—46.00%,氮肥农学效率(NAE)提高12.74%—17.79%。与人工撒施相比,机械侧深施可以显著提高水稻氮肥利用率,2017年和2018年NRE分别增加17.91%—43.14%和53.80%—54.10%;NAE分别增加19.61%—37.39%和21.11%—35.11%。与CUB处理相比,2017年CUM、CRUB、CRUM处理NRE和NAE分别增加43.14%、62.86%、92.12%和37.39%、27.33%、52.30%,2018年CUM、CRUB、CRUM处理NRE和NAE分别增加54.10%、32.22%、103.36%和35.11%、19.88%、45.18%。可见,控释尿素机械侧深施处理(CRUM)是提高水稻NRE和NAE的最佳施肥方式。Table 6
表6
表6机械侧深施氮对水稻氮素利用的影响
Table 6
年份 Year | 处理 Treatment | 氮素干物质生产率 N dry matter production efficiency (kg·kg-1) | 氮素稻谷生产率 N grain production efficiency (kg·kg-1) | 氮肥吸收利用率 N recovery efficiency (%) | 氮肥农学效率 N agronomic use efficiency (kg·kg-1) |
---|---|---|---|---|---|
2017 | N0 | 135.69a | 71.64a | — | — |
CUB | 109.97b | 58.17b | 25.50d | 8.05c | |
CUM | 104.21c | 54.31c | 36.50c | 11.06b | |
CRUB | 94.11d | 50.47d | 41.53b | 10.25b | |
CRUM | 93.76d | 48.67d | 48.97a | 12.26a | |
2018 | N0 | 95.07a | 69.61a | — | — |
CUB | 80.15b | 58.05b | 31.22c | 11.62b | |
CUM | 73.08bc | 52.67c | 48.11b | 15.70a | |
CRUB | 71.92cd | 54.46bc | 41.28b | 13.93ab | |
CRUM | 64.89d | 46.85d | 63.49a | 16.87a |
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3 讨论
3.1 控释尿素对产量形成和氮素利用的影响
充足的干物质积累是水稻高产的重要前提,干物质生产积累能力较高的水稻群体都具有适宜的叶片SPAD值;等量施氮条件下,施用控/释尿素能够提高水稻光合势、光合速率、叶面积指数和干物质积累量,最终提高水稻产量[14-15, 19, 31]。本研究表明,中稻生长季CRUB处理穗分化期叶片SPAD值和成熟期干物质积累量均显著高于CUB处理,而CRUB和CUB处理、CUM和CRUB处理、CUM和CRUM处理籽粒产量无显著差异;晚稻生长季,控释尿素的穗分化期叶片SPAD值均显著高于尿素,CRUB处理籽粒产量和成熟期干物质积累量均显著高于CUB处理,而CUM和CRUB处理、CUM和CRUM处理籽粒产量无显著差异,CUM和CRUM处理成熟期干物质积累量也无显著差异(表2—表4)。水稻是以分蘖夺取高产的作物,充足的有效穗数是高产的前提,施用控释氮肥能够影响最高分蘖数和成穗率等产量构成因素[14-15, 19]。水稻产量首先取决于有效穗数,在此基础上依靠较高每穗粒数、结实率和千粒重;然而氮肥类型对水稻分蘖形成有显著的影响,也会影响到水稻穗粒数和千粒重。彭玉等[32]研究认为控释尿素可以显著提高水稻有效穗数、千粒重,提高稻谷产量。本研究表明,中稻生长季CRUB处理有效穗数和颖花总量均显著高于CUB处理,而CUM和CRUB处理、CUM和CRUM处理之间无显著差异;晚稻生长季,控释尿素的有效穗数显著高于尿素,CRUB处理颖花总量显著高于CUB处理,CUM处理有效穗数和颖花总量均显著高于CRUB处理,CUM和CRUM处理之间颖花总量无显著差异(表2)。综上所述,撒施条件下控释尿素的增产效果优于尿素,尿素侧深施用可以延长其肥效,进而提高籽粒产量。氮肥施入灌溉稻田,大部分通过氨挥发、反硝化作用、表面流失及渗漏等途径损失,一部分被土壤固定,一部分被水稻吸收利用。改用控释氮肥、改良施肥方式、减少氮素损失是促进稻株吸收利用氮素和提高氮肥利用效率的捷径[2, 14-15, 18]。本研究表明,与尿素相比,控释尿素的稻株氮素吸收量显著增加(图1),氮肥吸收利用率提高32.07%—46.00%,氮肥农学效率提高12.74%—17.79%(表6),其主要原因是控释尿素氮素在水稻生长中前期养分释放期更长,水稻茎叶等营养器官生长旺盛,稻株吸收积累更多氮素,灌浆结实期茎叶(含叶鞘)具有更高的氮素表观转移总量,氮素养分高效转入籽粒(表5)。此外,控释尿素的养分释放速率会受温度的影响,2018年中稻季移栽施肥后60 d内的平均气温低于2017年晚稻季,有利于延长该季控释尿素(25℃释放期为60 d)养分释放周期;2018年中稻季水稻生育期比2017年晚稻季更长,稻株养分吸收与氮肥养分释放更加匹配,进一步提高该季控释尿素处理的氮肥吸收利用率。
3.2 侧深施氮对产量形成和氮素利用的影响
水稻生育前期充足的干物质积累量是水稻获得高产的关键,齐穗期积累充足的干物质量是高产水稻群体的重要特征;生育后期适当延长叶片功能期,可以进一步提高水稻产量。侧深施氮也可以明显提高水稻生育前期干物质积累量,提高水稻有效穗数、结实率和稻谷产量[23],本研究结果与之基本一致(表1和表4)。此外,与尿素人工撒施相比,尿素采用机械化深施处理穗分化期、齐穗期叶片SPAD值提高2.90%—3.64%、1.44%—2.53%,产量最终增加6.95%—8.11%;与控释尿素人工撒施相比,控释尿素采用机械侧深施处理穗分化期、齐穗期叶片SPAD值提高4.03%—5.10%、0.31%—2.10%,产量最终增加4.46%—5.55%(表2—3)。控释尿素机械侧深施到根区土壤中,水稻生育中后期氮素持续释放,维持稻株生长不脱肥,充足的氮素营养可以提高水稻光合生产能力,促进“源”—茎叶(含叶鞘)干物质积累更加充足,灌浆结实期茎叶(含叶鞘)中更多物质被转运到籽粒(表4),进而促进籽粒灌浆,增加稻谷产量。本研究还表明,尿素采用机械侧深施可以显著增加有效穗数和颖花总量;尿素机械侧深施处理(CUM)与控释尿素撒施处理(CRUB)产量间无明显差异(表2),其主要原因是尿素机械侧深施用也能够降低氮素损失率[24-25, 33],促进稻株吸收氮素(图1),进而提高物质生产能力;CUM和CRUB处理穗分化期和齐穗期叶片SPAD值均无显著差异,灌浆结实期的物质生产能力相近,最终稻谷产量无明显差异。此外,CRUM处理的有效穗数和产量均高于CUM和CRUB处理,其主要原因是机械侧深施控释尿素前期氮素直接释放到根区土壤,能够快速供给根系吸收,分蘖期撒施的控释尿素也能够为返青后的秧苗提供足量氮素,促进分蘖早生快发;控释尿素在水稻生育中后期持续释放氮素[34],延长叶片功能期,减少无效分蘖,提高成穗率,促使灌浆期叶片物质生产高效进行,籽粒灌浆流畅,茎叶鞘物质转移充足,结实率和千粒重无显著下降,最终获得高产高效。此外,机械侧深施肥的氮素干物质生产率和氮素稻谷生产率均低于撒施(表6),表明机械侧深施肥方式能够促进稻株从外界环境吸收更多氮素进入氮代谢环节,但氮代谢和碳代谢(碳水化合物合成)改善不同步[30],植株一定程度上表现出“氮素冗余吸收”。我国水稻生产中氮肥以尿素、碳铵等速效氮肥为主,施肥方式通常为撒施、表层浅施,如此施入稻田的氮肥很快溶入水体,具有很强的流动性[1, 17, 18-19],极容易通过挥发、渗漏、径流等途径损失。刘晓伟等[27]研究认为根区一次施尿素可以明显提高施肥点周围土壤中铵态氮含量,增强根区土壤氮素供应能力,提高水稻氮肥利用效率;此外,也有研究证实尿素深施能够减弱氮素损失途径,进而提高氮素利用效率[9, 22, 24, 35-36]。孙浩燕等[20-21, 31]研究还认为适宜的浅层施肥促使速效养分主要分布于土壤上层,有利于秧苗根系生长,促进秧苗吸收氮素等养分,提高秧苗养分含量,促进水稻秧苗的生长发育,增加养分积累量,最终提高氮素等养分资源利用效率。本研究中,与人工撒施相比较,控释尿素或尿素采用机械侧深施后水稻整个生育阶段氮素吸收量以及氮肥利用效率均大幅提高,氮肥吸收利用率和氮肥农学效率增幅达到17.91%—54.10%和19.61%—37.39%(表6),其主要原因为:(1)插秧时机械臂将尿素、控释尿素精确送达水稻根区附近(秧苗侧面(5.0±0.5)cm,深度为(5.5±0.5)cm的区域),水稻返青后根系能够更快、更足地吸收氮素养分(硝态氮和铵态氮为主要氮源);(2)机械侧深施还能减少氮素通过NH3、NO2-、N2O和NO等途径的损失量,提高土壤供氮能力;(3)控释尿素(25℃释放期为60 d)养分释放曲线与水稻需氮较为吻合,保证根区氮素有效供应,且控释尿素缓慢释放氮素的特性也能进一步减少氮素损失量[9, 24, 28, 35-36]。综上可得,控释尿素或尿素机械侧深施既减轻水稻施肥劳动强度,又节本增效,对推进水稻产业全程机械化生产具有重要实践意义。
4 结论
控释尿素替代尿素、机械侧深施替代传统撒施都能够显著增加水稻干物质积累量,增加有效穗数,提高水稻氮素吸收量,提高灌浆结实期茎叶氮素表观转移量和干物质转移量,同步提高水稻产量和氮肥吸收利用率。与尿素相比,控释尿素产量增加3.32%—3.72%,氮肥吸收利用率(NRE)提高32.07%—46.00%,氮肥农学效率(NAE)提高12.74%—17.79%。与传统撒施相比,机械侧深施产量增加4.46%—8.11%,NRE提高17.91%—54.10%,NAE提高19.61%—37.39%。与尿素撒施相比,控释尿素侧深施用产量增加9.67%—10.41%,NRE提高92.04%—103.36%,NAE提高45.18%—52.30%。可见,控释尿素侧深施用既能减轻水稻生产施肥劳作强度,又能增产增效,值得大面积推广应用。参考文献 原文顺序
文献年度倒序
文中引用次数倒序
被引期刊影响因子
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DOI:10.3864/j.issn.0578-1752.2014.07.004URL [本文引用: 1]
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Rice planting mechanization is a difficult point of the whole-course mechanized development in crop production in China. Based on the reviewing of development situation of rice planting mechanization in China, the high-yielding rules and cultivation techniques of three mechanized planting methods were highlighted and illustrated. (1) Growth characteristics and high-yielding rules of blanket-seedling mechanical transplanting rice grown in floppy disks were generalized systematically. Firstly, population photosynthesis and matter production at the middle and later period were improved by developing appropriate dynamics of stems and tillers and LAI. Secondly, it was the emphasis to increase the effective and efficient biomass accumulation in the middle period, and matter production after heading and the final biological yield. Thirdly, the sufficient population spikelets were composed of enough panicles and larger spike harmoniously, with normal seed-setting rate and 1000-grain weight at the same time. Moreover, the supporting cultivation techniques for high yield were as follows. ① Nursing standardized seedlings for providing biological basis of building starting point of high-yielding population. ② Precise mechanical planting was conducive to the formation of high-yielding population. ③ Promoting tillers growth earlier in the early period could make sure of suitable stems and tillers for high yield slightly before the critical leaf-age for productive tillers. ④ Field draining earlier and lighter, with an appropriate number of peak seedling (1.4-1.5 folds of expected panicle number), could create conditions for reapplying fertilizer of strong stalk and spikelet promotion as early as possible. ⑤ Committed to optimize the growth in the middle period and increase the effective and efficient biomass accumulation, a right amount of population stems and tillers with strong stalk and large panicle was beneficial to constitute a high-efficiency photosynthetic layer. ⑥ Strengthening material production and accumulation for increasing the enrichment of population sink. (2) Many advantages of the high-yielding cultivation of pot-seedling mechanical transplanting rice were also introduced systematically, such as nursing elder seedlings with soil bowl, almost no damage to machine-transplanting precisely, achieving designed basic seedling of high-yielding cultivation accurately, forming an appropriate number of population stems and tillers with strong stalk and large panicle, improving ventilation and light conditions of population, strengthening the resistance to lodging, coordinating source-sink, strengthening strong photosynthetic production in the middle and later periods, making full use of temperature and solar radiation, creating (super) high yield stably and annual yield in the multiple cropping rotation systems, etc. And the key agronomic techniques for high-yielding cultivation of pot-seedling mechanical transplanting rice were as below. ① Nursing age-lengthening seedlings precisely; ② Precise quantitative mechanical planting; ③ Reapplying tillering fertilizer and spikelet- promoting fertilizer appropriately. (3) Characteristics of growth and yield formation of mechanical drilling rice were reviewed, presented with its supporting techniques including determined planting areas reasonably, selecting large-panicle varieties with appropriate growth duration and strong lodging, mechanical sowing earlier and extremely, chemical weed control and fertilizer management. Simultaneously, the existed main problems in the process of rice planting mechanization in China were analyzed further. According to China’s national conditions, the cultivation model raising nurturing standardized seedlings professionally and mechanical transplanting precisely as well as stable high-yielding-high-efficiency agronomic techniques should be the basic direction of mechanized cultivation for the majority of the localities. And mechanical seeding could be applied in several areas with abundant heat of rice season. Then the corresponding research and development (R & D) focuses for mechanized planting of rice were referred. ① High-yielding cultivation of blanket-seedling mechanical transplanting rice should be classified as the main direction of mechanization in the major rice producing areas so as to R & D further. There were several focal points such as enhanced flexibility of blanket-seedling age and seedling quality, straw machine-returning and land preparation and seedling planting precisely, promoting earlier and stably in the field, cultivating a right amount of population stems and tillers with strong stalk and large panicle and increasing population sink. ② Reducing equipment costs, improving operating efficiency and building stable (super) high-yielding-high-efficiency agronomy techniques were the research priorities of pot-seedling mechanical transplanting rice. ③ However, for the mechanical drilling rice, attention should be focused on improving the quality of previous straw machine-returning and land preparation through efficient mechanical operations, and mechanical precise direct seeding and early germinating for achieving expected seedlings. Finally, the technology integration and demonstration of the whole-process mechanized models under the local main mechanized cultivation methods should be done well in accordance with their characteristics in each main region of rice.
DOI:10.3864/j.issn.0578-1752.2014.07.004URL [本文引用: 1]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Rice planting mechanization is a difficult point of the whole-course mechanized development in crop production in China. Based on the reviewing of development situation of rice planting mechanization in China, the high-yielding rules and cultivation techniques of three mechanized planting methods were highlighted and illustrated. (1) Growth characteristics and high-yielding rules of blanket-seedling mechanical transplanting rice grown in floppy disks were generalized systematically. Firstly, population photosynthesis and matter production at the middle and later period were improved by developing appropriate dynamics of stems and tillers and LAI. Secondly, it was the emphasis to increase the effective and efficient biomass accumulation in the middle period, and matter production after heading and the final biological yield. Thirdly, the sufficient population spikelets were composed of enough panicles and larger spike harmoniously, with normal seed-setting rate and 1000-grain weight at the same time. Moreover, the supporting cultivation techniques for high yield were as follows. ① Nursing standardized seedlings for providing biological basis of building starting point of high-yielding population. ② Precise mechanical planting was conducive to the formation of high-yielding population. ③ Promoting tillers growth earlier in the early period could make sure of suitable stems and tillers for high yield slightly before the critical leaf-age for productive tillers. ④ Field draining earlier and lighter, with an appropriate number of peak seedling (1.4-1.5 folds of expected panicle number), could create conditions for reapplying fertilizer of strong stalk and spikelet promotion as early as possible. ⑤ Committed to optimize the growth in the middle period and increase the effective and efficient biomass accumulation, a right amount of population stems and tillers with strong stalk and large panicle was beneficial to constitute a high-efficiency photosynthetic layer. ⑥ Strengthening material production and accumulation for increasing the enrichment of population sink. (2) Many advantages of the high-yielding cultivation of pot-seedling mechanical transplanting rice were also introduced systematically, such as nursing elder seedlings with soil bowl, almost no damage to machine-transplanting precisely, achieving designed basic seedling of high-yielding cultivation accurately, forming an appropriate number of population stems and tillers with strong stalk and large panicle, improving ventilation and light conditions of population, strengthening the resistance to lodging, coordinating source-sink, strengthening strong photosynthetic production in the middle and later periods, making full use of temperature and solar radiation, creating (super) high yield stably and annual yield in the multiple cropping rotation systems, etc. And the key agronomic techniques for high-yielding cultivation of pot-seedling mechanical transplanting rice were as below. ① Nursing age-lengthening seedlings precisely; ② Precise quantitative mechanical planting; ③ Reapplying tillering fertilizer and spikelet- promoting fertilizer appropriately. (3) Characteristics of growth and yield formation of mechanical drilling rice were reviewed, presented with its supporting techniques including determined planting areas reasonably, selecting large-panicle varieties with appropriate growth duration and strong lodging, mechanical sowing earlier and extremely, chemical weed control and fertilizer management. Simultaneously, the existed main problems in the process of rice planting mechanization in China were analyzed further. According to China’s national conditions, the cultivation model raising nurturing standardized seedlings professionally and mechanical transplanting precisely as well as stable high-yielding-high-efficiency agronomic techniques should be the basic direction of mechanized cultivation for the majority of the localities. And mechanical seeding could be applied in several areas with abundant heat of rice season. Then the corresponding research and development (R & D) focuses for mechanized planting of rice were referred. ① High-yielding cultivation of blanket-seedling mechanical transplanting rice should be classified as the main direction of mechanization in the major rice producing areas so as to R & D further. There were several focal points such as enhanced flexibility of blanket-seedling age and seedling quality, straw machine-returning and land preparation and seedling planting precisely, promoting earlier and stably in the field, cultivating a right amount of population stems and tillers with strong stalk and large panicle and increasing population sink. ② Reducing equipment costs, improving operating efficiency and building stable (super) high-yielding-high-efficiency agronomy techniques were the research priorities of pot-seedling mechanical transplanting rice. ③ However, for the mechanical drilling rice, attention should be focused on improving the quality of previous straw machine-returning and land preparation through efficient mechanical operations, and mechanical precise direct seeding and early germinating for achieving expected seedlings. Finally, the technology integration and demonstration of the whole-process mechanized models under the local main mechanized cultivation methods should be done well in accordance with their characteristics in each main region of rice.
[本文引用: 2]
[本文引用: 2]
[本文引用: 1]
[本文引用: 1]
[本文引用: 2]
[本文引用: 2]
DOI:10.3864/j.issn.0578-1752.2014.17.009URL [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
【Objective】This study is the first to make a large-scale assessment of the effect of the application of enhanced efficiency nitrogen fertilizers (EENF) on rice yield and plant N uptake quantitatively to provide a scientific basis for evaluating the economic benefits of EENF and promoting the use of EENF in China.【Method】A total of 48 peer-reviewed studies were collected in Chinese and English books and journals to establish a field experimental database, and a meta-analysis was conducted to quantitatively evaluate the response of rice yield and N uptake to EENF in China and to determine under what conditions EENF are the most effective. 【Result】 The results suggested that, on average, the application of EENF made rice yield and N uptake increase by 7.5% (95% CI: 6.7%-8.4%) and 10.5%(95% CI: 9.5%-11.4%) , respectively. In terms of factors, it was found that soil pH had a significant effect on rice yield and N uptake, which was increased by 10.5% and 18.8% in alkaline soils(pH≥7.5) which are more than that in acidic (pH≤6.5) and neutral soils (pH: 6.5-7.5). Coated slow/controlled release nitrogen fertilizer (CRF) was better than nitrification inhibitors, especially for N uptake, nitrification inhibitor had no effect on it, but CRF made it increase by 17.9% than conventional fertilization; EENF applied as basal fertilization was better than split fertilization, which increased rice yield and N uptake by 4.2% and 7.5% and they were less than as basal fertilization. Besides, mixing EENF with control fertilizer had equal effect, and it was labor-saving; the best practice for N rate was 120-180 kg•hm-2, which increased rice production and N uptake by 6.5% and 12.1%, respectively. At last, the application of EENF in northern China was better than in southern China, because it increased rice yield and N uptake by 3.4% and 3.0% more than in southern China.【Conclusion】The best practice in this study to increase rice yield and plant N uptake is to use EENF, especially the coated slow/controlled release fertilizers (applied into alkaline soil as basal fertilizer) when the total N rate is 120-180 kg•hm-2.Application of nitrification inhibitors, especially 3,4-dimethylpyrazole phosphate (DMPP) is not suitable for paddy fields to increase N uptake in China. It seems that rice planting way (transplant or direct sowing) and fertilization methods of EENF (EENF only or mixed with conventional nitrogen fertilizers) have little difference in improving rice yield and N uptake. It may be better to apply EENF in northern China than southern China.
DOI:10.3864/j.issn.0578-1752.2014.17.009URL [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
【Objective】This study is the first to make a large-scale assessment of the effect of the application of enhanced efficiency nitrogen fertilizers (EENF) on rice yield and plant N uptake quantitatively to provide a scientific basis for evaluating the economic benefits of EENF and promoting the use of EENF in China.【Method】A total of 48 peer-reviewed studies were collected in Chinese and English books and journals to establish a field experimental database, and a meta-analysis was conducted to quantitatively evaluate the response of rice yield and N uptake to EENF in China and to determine under what conditions EENF are the most effective. 【Result】 The results suggested that, on average, the application of EENF made rice yield and N uptake increase by 7.5% (95% CI: 6.7%-8.4%) and 10.5%(95% CI: 9.5%-11.4%) , respectively. In terms of factors, it was found that soil pH had a significant effect on rice yield and N uptake, which was increased by 10.5% and 18.8% in alkaline soils(pH≥7.5) which are more than that in acidic (pH≤6.5) and neutral soils (pH: 6.5-7.5). Coated slow/controlled release nitrogen fertilizer (CRF) was better than nitrification inhibitors, especially for N uptake, nitrification inhibitor had no effect on it, but CRF made it increase by 17.9% than conventional fertilization; EENF applied as basal fertilization was better than split fertilization, which increased rice yield and N uptake by 4.2% and 7.5% and they were less than as basal fertilization. Besides, mixing EENF with control fertilizer had equal effect, and it was labor-saving; the best practice for N rate was 120-180 kg•hm-2, which increased rice production and N uptake by 6.5% and 12.1%, respectively. At last, the application of EENF in northern China was better than in southern China, because it increased rice yield and N uptake by 3.4% and 3.0% more than in southern China.【Conclusion】The best practice in this study to increase rice yield and plant N uptake is to use EENF, especially the coated slow/controlled release fertilizers (applied into alkaline soil as basal fertilizer) when the total N rate is 120-180 kg•hm-2.Application of nitrification inhibitors, especially 3,4-dimethylpyrazole phosphate (DMPP) is not suitable for paddy fields to increase N uptake in China. It seems that rice planting way (transplant or direct sowing) and fertilization methods of EENF (EENF only or mixed with conventional nitrogen fertilizers) have little difference in improving rice yield and N uptake. It may be better to apply EENF in northern China than southern China.
DOI:10.1007/s10705-014-9653-6URL [本文引用: 2]
DOI:10.1016/j.fcr.2015.09.011URL [本文引用: 5]
[本文引用: 3]
[本文引用: 3]
[本文引用: 3]
[本文引用: 3]
URL [本文引用: 1]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
【Objective】Field experiments were carried out to study the optimum substitution of partial mineral-fertilizer- nitrogen (N) by organic-fertilizer-N and to provide a base for the commercial development of mixed organic and mineral fertilizers for rice. 【Method】 Field experiments were done in Changshu city, Jiangsu province under different substitution rates and four N fertilizer rates. 【Result】 Grain yields of 8 242-10 187 kg?hm-2 (4007) and 10 048-11 654 kg?hm-2(Changyou 1) were obtained when 180 kg N?hm-2 was applied with a percentage of organic-fertilizer-N in total N being 15%-30% or 240 kg N?hm-2 with a percentage of organic-fertilizer-N in total N being 10%-20%, which corresponds to application of 1 500-3 000 kg?hm-2 of common compost fertilizer, compared with inorganic nitrogen fertilizer treatment. Compared with inorganic nitrogen fertilizer treatment, a more steady supply of nitrogen could be maintained when certain amounts of organic-fertilizer-N were applied together with inorganic-fertilizer-N. Nitrogen accumulation in 4007 and Changyou 1 were 172.6-256.4 kg?hm-2 and 185.9-235.6 kg?hm-2, respectively, when 180 kg N?hm-2 was applied with a percentage of organic-fertilizer-N in total N being 15%-30% or 240 kg N?hm-2 with a percentage of organic-fertilizer-N in total N being 10%-20%. In these treatments, the highest nitrogen use efficiency was obtained in 4007 (36.6%-48.1%) and Changyou 1 (34.3%-40.0%). 【Conclusion】 Application of mixed mineral-fertilizer-N and organic-fertilizers-N had a better or the same effects on the yields of rice grains and N use efficiency could be significantly increased compared with the single application of mineral nitrogen fertilizer. The best substitution of mineral fertilizer N by organic fertilizer N were 15%-30% or 10%-20% when 180 kg N?hm-2 or 240 kg N?hm-2 was applied in terms of rice fertilization.
URL [本文引用: 1]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
【Objective】Field experiments were carried out to study the optimum substitution of partial mineral-fertilizer- nitrogen (N) by organic-fertilizer-N and to provide a base for the commercial development of mixed organic and mineral fertilizers for rice. 【Method】 Field experiments were done in Changshu city, Jiangsu province under different substitution rates and four N fertilizer rates. 【Result】 Grain yields of 8 242-10 187 kg?hm-2 (4007) and 10 048-11 654 kg?hm-2(Changyou 1) were obtained when 180 kg N?hm-2 was applied with a percentage of organic-fertilizer-N in total N being 15%-30% or 240 kg N?hm-2 with a percentage of organic-fertilizer-N in total N being 10%-20%, which corresponds to application of 1 500-3 000 kg?hm-2 of common compost fertilizer, compared with inorganic nitrogen fertilizer treatment. Compared with inorganic nitrogen fertilizer treatment, a more steady supply of nitrogen could be maintained when certain amounts of organic-fertilizer-N were applied together with inorganic-fertilizer-N. Nitrogen accumulation in 4007 and Changyou 1 were 172.6-256.4 kg?hm-2 and 185.9-235.6 kg?hm-2, respectively, when 180 kg N?hm-2 was applied with a percentage of organic-fertilizer-N in total N being 15%-30% or 240 kg N?hm-2 with a percentage of organic-fertilizer-N in total N being 10%-20%. In these treatments, the highest nitrogen use efficiency was obtained in 4007 (36.6%-48.1%) and Changyou 1 (34.3%-40.0%). 【Conclusion】 Application of mixed mineral-fertilizer-N and organic-fertilizers-N had a better or the same effects on the yields of rice grains and N use efficiency could be significantly increased compared with the single application of mineral nitrogen fertilizer. The best substitution of mineral fertilizer N by organic fertilizer N were 15%-30% or 10%-20% when 180 kg N?hm-2 or 240 kg N?hm-2 was applied in terms of rice fertilization.
[本文引用: 1]
[本文引用: 1]
URLPMID:12812067 [本文引用: 5]
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Acta Genetica Sinica (AGS) is sponsored by the Genetics Society of China and the Institute of Genetics and Developmental Biology of Chinese Academy of Sciences, and is published by Science Press. The journal is a leading national academic periodical and one of the Chinese key periodicals of natural sciences. Currently, AGS is being indexed by several well-known domestic and international indexing systems, such as the American Chemical Digest (CA), BIOSIS database, Biological Digest (BA), Medical Index and Russian Digest (P [symbol: see text]). Papers in the areas of genetics, developmental biology, cell molecular biology and evolution are regularly published by AGS.
URLPMID:12812067 [本文引用: 5]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Acta Genetica Sinica (AGS) is sponsored by the Genetics Society of China and the Institute of Genetics and Developmental Biology of Chinese Academy of Sciences, and is published by Science Press. The journal is a leading national academic periodical and one of the Chinese key periodicals of natural sciences. Currently, AGS is being indexed by several well-known domestic and international indexing systems, such as the American Chemical Digest (CA), BIOSIS database, Biological Digest (BA), Medical Index and Russian Digest (P [symbol: see text]). Papers in the areas of genetics, developmental biology, cell molecular biology and evolution are regularly published by AGS.
URL [本文引用: 5]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
A2year field experiment with a yellow-clay paddy soil in Zhejiang Province was conducted to study the effects of different planting measures combined with different fertilization practices on rice yield, soil nutrients, microbial biomass C and N and activities of urease, phosphatase, sucrase and hydrogen peroxidase at the maturity stage. Results showed that mechanical transplanting of rice with controlled release bulk blending (BB) fertilizer (BBMT) could achieve a significantly higher mean yield than traditional manual transplanting with traditional fertilizer (TFTM) and direct seeding with controlled release BB fertilizer (BBDS) by 16.3% and 27.0%, respectively. The yield by BBMT was similar to that by traditional manual transplanting with controlled release BB fertilizer (BBTM). Compared with TFTM, BBMT increased the contents of soil totalN, available N, available P and microbial biomass C, and the activities of urease, sucrase and hydrogen peroxidase by 21.5%, 13.6%, 41.2%, 27.1%, 50.0%, 22.5% and 46.2%, respectively. Therefore, BBMT, a simple high-efficiency rice cultivation method with use of a light-weighted mechanical transplanter, should be widely promoted and adopted.
URL [本文引用: 5]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
A2year field experiment with a yellow-clay paddy soil in Zhejiang Province was conducted to study the effects of different planting measures combined with different fertilization practices on rice yield, soil nutrients, microbial biomass C and N and activities of urease, phosphatase, sucrase and hydrogen peroxidase at the maturity stage. Results showed that mechanical transplanting of rice with controlled release bulk blending (BB) fertilizer (BBMT) could achieve a significantly higher mean yield than traditional manual transplanting with traditional fertilizer (TFTM) and direct seeding with controlled release BB fertilizer (BBDS) by 16.3% and 27.0%, respectively. The yield by BBMT was similar to that by traditional manual transplanting with controlled release BB fertilizer (BBTM). Compared with TFTM, BBMT increased the contents of soil totalN, available N, available P and microbial biomass C, and the activities of urease, sucrase and hydrogen peroxidase by 21.5%, 13.6%, 41.2%, 27.1%, 50.0%, 22.5% and 46.2%, respectively. Therefore, BBMT, a simple high-efficiency rice cultivation method with use of a light-weighted mechanical transplanter, should be widely promoted and adopted.
URL [本文引用: 3]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Site-specific N management (SSNM) and real-time N management (RTNM) improves fertilizer-N use efficiency of irrigated rice. This study was conducted to compare the most popular hybrid varieties, three-line hybrid rice-Shanyou63 (SY63) and two-line hybrid rice-Liangyoupei9 (LYP9), in their response to N application and fertilizer-N use efficiency under RTNM and SSNM in field conditions in 2004 and 2005. 【Method】The two varieties were grown under eight and six N treatments in 2004 and 2005, respectively, in Hubei, China. N treatments included a zero-N control, a SSNM and several RTNM with different chlorophyll meter (SPAD) thresholds. 【Result】The results showed that, color of rice leaves had genotypic difference between varieties, the SPAD reading of SY63 had 1.7-2.0 units lower than that of LYP9 while both varieties were under zero or the same fertilizer-N rates. The fertilizer-N rate showed significant exponential correlation with the SPAD threshold based on RTNM for both varieties. The equations for SY63 and LYP9 were, N rate=0.9956 e0.132 SPAD (r2=0.8338**), and N rate=0.1565 e0.173 SPAD (r2=0.9508**), respectively. It was found that, additional fertilizer-N 37.3 kgN.hm-2 was required for SY63 to maintain the same SPAD value in comparison with that of LYP9, when SPAD thresholds were among 36-40 under RTNM. 【Conclusion】When average fertilizer-N rate was around 160 kgN.hm-2, LYP9 showed similar capacity and characteristics on N uptake, N recovery use efficiency, and nitrogen use efficiency based on grain production, in comparison with that of SY63. But LYP9 had greater nitrogen use efficiency based on biomass production, fertilizer-N agronomic use efficiency, in comparison that of SY63 respectively. However, SY63 had greater nitrogen harvest index than that of LYP9. The results also showed that, LYP9 had greater tolerance against lodging than that of SY63 when excessive fertilizer-N applied.
URL [本文引用: 3]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Site-specific N management (SSNM) and real-time N management (RTNM) improves fertilizer-N use efficiency of irrigated rice. This study was conducted to compare the most popular hybrid varieties, three-line hybrid rice-Shanyou63 (SY63) and two-line hybrid rice-Liangyoupei9 (LYP9), in their response to N application and fertilizer-N use efficiency under RTNM and SSNM in field conditions in 2004 and 2005. 【Method】The two varieties were grown under eight and six N treatments in 2004 and 2005, respectively, in Hubei, China. N treatments included a zero-N control, a SSNM and several RTNM with different chlorophyll meter (SPAD) thresholds. 【Result】The results showed that, color of rice leaves had genotypic difference between varieties, the SPAD reading of SY63 had 1.7-2.0 units lower than that of LYP9 while both varieties were under zero or the same fertilizer-N rates. The fertilizer-N rate showed significant exponential correlation with the SPAD threshold based on RTNM for both varieties. The equations for SY63 and LYP9 were, N rate=0.9956 e0.132 SPAD (r2=0.8338**), and N rate=0.1565 e0.173 SPAD (r2=0.9508**), respectively. It was found that, additional fertilizer-N 37.3 kgN.hm-2 was required for SY63 to maintain the same SPAD value in comparison with that of LYP9, when SPAD thresholds were among 36-40 under RTNM. 【Conclusion】When average fertilizer-N rate was around 160 kgN.hm-2, LYP9 showed similar capacity and characteristics on N uptake, N recovery use efficiency, and nitrogen use efficiency based on grain production, in comparison with that of SY63. But LYP9 had greater nitrogen use efficiency based on biomass production, fertilizer-N agronomic use efficiency, in comparison that of SY63 respectively. However, SY63 had greater nitrogen harvest index than that of LYP9. The results also showed that, LYP9 had greater tolerance against lodging than that of SY63 when excessive fertilizer-N applied.
[本文引用: 3]
[本文引用: 3]
DOI:10.13287/j.1001-9332.201801.023URLPMID:29692021 [本文引用: 8]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
With the common urea split application (CU) as the control, a field experiment was conducted to examine the effects of loss-controlled urea by split application (LCUS) and loss-controlled urea by basal application (LCUB) on ammonia volatilization (NH3), nitrogen (N) nutrition status, grain yield and N utilization efficiency in rice plants. The results showed that the ratio of NH3 volatilization loss to total N application were 15.8%, 13.4% and 19.7% under the conditions of CU, LCUS and LCUB treatments, respectively. Compared to CU, LCUS significantly reduced the NH3 emission by 4.4 kg N·hm-2, with a decrease of 18.0%, while the LCUB significantly increased the NH3 emission by 7.2 kg N·hm-2, which increased by 24.7%. Compared to CU, LCUS increased the chlorophyll contents of leaf, the N content and N accumulation of seed and straw and grain yield, and significantly increased the N recovery efficiency by 7.6%, while significantly reduced the amount of N translocation, apparent N translocation rate and the rate of contribution to N in spike, respectively. However, compared to CU, LCUB significantly reduced the chlorophyll contents of leaf, the N content and accumulation of seed and straw as well as N utilization efficiency, but the grain yield, the amount of N translocation, apparent N translocation rate and the rate of contribution to N in spike were not affected. In conclusion, LCUS could maintain stable production, as well as decrease NH3 emission, improve N nutrition status and increase N utilization efficiency in rice plants.
DOI:10.13287/j.1001-9332.201801.023URLPMID:29692021 [本文引用: 8]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
With the common urea split application (CU) as the control, a field experiment was conducted to examine the effects of loss-controlled urea by split application (LCUS) and loss-controlled urea by basal application (LCUB) on ammonia volatilization (NH3), nitrogen (N) nutrition status, grain yield and N utilization efficiency in rice plants. The results showed that the ratio of NH3 volatilization loss to total N application were 15.8%, 13.4% and 19.7% under the conditions of CU, LCUS and LCUB treatments, respectively. Compared to CU, LCUS significantly reduced the NH3 emission by 4.4 kg N·hm-2, with a decrease of 18.0%, while the LCUB significantly increased the NH3 emission by 7.2 kg N·hm-2, which increased by 24.7%. Compared to CU, LCUS increased the chlorophyll contents of leaf, the N content and N accumulation of seed and straw and grain yield, and significantly increased the N recovery efficiency by 7.6%, while significantly reduced the amount of N translocation, apparent N translocation rate and the rate of contribution to N in spike, respectively. However, compared to CU, LCUB significantly reduced the chlorophyll contents of leaf, the N content and accumulation of seed and straw as well as N utilization efficiency, but the grain yield, the amount of N translocation, apparent N translocation rate and the rate of contribution to N in spike were not affected. In conclusion, LCUS could maintain stable production, as well as decrease NH3 emission, improve N nutrition status and increase N utilization efficiency in rice plants.
[本文引用: 4]
[本文引用: 4]
DOI:10.3864/j.issn.0578-1752.2014.12.020URL [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
【Objective】 The aim of the research was to study the effects of different fertilization depths on growth and distribution of rice roots at seedling stage, and to ascertain the importance of fertilizer in shallow soils on the rice growth and thus providing information for appropriate fertilization. 【Method】 The trial was performed at the experimental base of Huazhong Agricultural University. Five treatments were designed, which were no fertilizer and fertilization depths of 1 cm, 5 cm, 10 cm, and 15 cm. According to the growth period of rice, samples were taken on 10, 20, 30 and 40 d after sowing. Several parameters were tested, including root biomasses, morphological index parameters, absorbing surface area and shoot biomasses of rice to assess the effect of different fertilization depths on rice seedling growth.【Result】 The results showed that no significant differences were observed among treatments on 10 d after sowing The root biomass, morphological index parameters and absorbing surface area of 1 cm treatment were significantly higher than those of others on 20 d after sowing. The increment effects were 1 cm>5 cm, 10 cm, 15 cm>CK, and the shoot biomass had same tendency. The biomasses of rice root and shoot of 1 cm treatment were increased by 163.8% and 121.5% compared to those of 5 cm treatment on 30 d after sowing. The shoot biomasses differed among the treatments, the order of which was 1 cm>5 cm>10 cm, 15 cm> CK, and that of 1 cm treatment were 37.6% and 34.6% higher than those of 10 cm and 15 cm treatment, respectively on 40 d after sowing. Additionally, the results of root distribution indicated that 60% of rice roots concentrated in the 0-10 cm soil layer on 40 d after sowing. The root biomass of each soil layer in the fertilization treatments was higher than that of no fertilization treatment. The lower root biomasses of 1 cm treatment were significantly increased, which was 26.1% and 84.0% higher than other treatments in the 10-15 cm and 15-20 cm soil layers, respectively. 【Conclusion】 Different fertilization depths had impacts on the root growth and distribution of rice at seedling stage. During the whole growth period, the root biomass, morphological index parameters and absorbing surface area in 1 cm treatment showed significant advantages compared to other treatments. The 1 cm treatment could improve the root activity, increase the proportion of the lower root and benefit of the root architecture building. In the early rice growth period, the method of appropriate fertilization in shallow soils could significantly promote root growth. The shoot biomass of shallow soil fertilization was more than other treatments, which also responded to the well root growth and distribution of rice.
DOI:10.3864/j.issn.0578-1752.2014.12.020URL [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
【Objective】 The aim of the research was to study the effects of different fertilization depths on growth and distribution of rice roots at seedling stage, and to ascertain the importance of fertilizer in shallow soils on the rice growth and thus providing information for appropriate fertilization. 【Method】 The trial was performed at the experimental base of Huazhong Agricultural University. Five treatments were designed, which were no fertilizer and fertilization depths of 1 cm, 5 cm, 10 cm, and 15 cm. According to the growth period of rice, samples were taken on 10, 20, 30 and 40 d after sowing. Several parameters were tested, including root biomasses, morphological index parameters, absorbing surface area and shoot biomasses of rice to assess the effect of different fertilization depths on rice seedling growth.【Result】 The results showed that no significant differences were observed among treatments on 10 d after sowing The root biomass, morphological index parameters and absorbing surface area of 1 cm treatment were significantly higher than those of others on 20 d after sowing. The increment effects were 1 cm>5 cm, 10 cm, 15 cm>CK, and the shoot biomass had same tendency. The biomasses of rice root and shoot of 1 cm treatment were increased by 163.8% and 121.5% compared to those of 5 cm treatment on 30 d after sowing. The shoot biomasses differed among the treatments, the order of which was 1 cm>5 cm>10 cm, 15 cm> CK, and that of 1 cm treatment were 37.6% and 34.6% higher than those of 10 cm and 15 cm treatment, respectively on 40 d after sowing. Additionally, the results of root distribution indicated that 60% of rice roots concentrated in the 0-10 cm soil layer on 40 d after sowing. The root biomass of each soil layer in the fertilization treatments was higher than that of no fertilization treatment. The lower root biomasses of 1 cm treatment were significantly increased, which was 26.1% and 84.0% higher than other treatments in the 10-15 cm and 15-20 cm soil layers, respectively. 【Conclusion】 Different fertilization depths had impacts on the root growth and distribution of rice at seedling stage. During the whole growth period, the root biomass, morphological index parameters and absorbing surface area in 1 cm treatment showed significant advantages compared to other treatments. The 1 cm treatment could improve the root activity, increase the proportion of the lower root and benefit of the root architecture building. In the early rice growth period, the method of appropriate fertilization in shallow soils could significantly promote root growth. The shoot biomass of shallow soil fertilization was more than other treatments, which also responded to the well root growth and distribution of rice.
[本文引用: 2]
[本文引用: 2]
DOI:10.1016/j.scitotenv.2019.135818URLPMID:31841898 [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Climate change and anthropogenic activities have resulted in increased atmospheric methane (CH4) concentration. Increased nitrogen deposition and precipitation accompanies climate warming and can change soil carbon and nitrogen dynamics and microbial processes and alter CH4 fluxes. To quantify the sink of the vast alpine meadows of the Tibetan Plateau and to examine how precipitation addition (P), warming (W), and nitrogen addition (N) affect CH4 fluxes in alpine meadows, we conducted continuous 3-growing season experiments in an alpine meadow using the static chamber and gas chromatograph method. Soil CH4 samples were collected during the early, peak, and late stages of the growing season from 2015 to 2017. Our results suggested that neither P, W, nor N had an interaction effect on soil CH4 uptake. P significantly increased and decreased the copies number of particulate methane monooxygenase alpha subunit (pmoA) and methyl-coenzyme M reductase alpha subunit (mcrA), respectively. However, P significantly decreased CH4 uptake, particularly under the combined treatment of P and N. Compared with the control, CH4 uptake decreased under P, N, PW, and PN by 50.64%, 6.24%, 39.37%, and 75.06%, respectively, whereas under W and WN CH4 uptake increased by 16.19% and 7.56%, respectively. Soil CH4 uptake was positively correlated with soil temperature and pmoA and negatively correlated with soil moisture and NH4+-N content. CH4 uptake was significantly affected by the sampling period. CH4 uptake was significantly lower rates during peak growing season compared with those during the early and late stages of the growing season. Our results suggest that, (1) CH4 fluxes of alpine grassland ecosystems are more sensitive to P than W or N, and (2) precipitation controls CH4 flux response to increasing nitrogen deposition in alpine meadows on the Tibetan Plateau. Therefore, future research should focus on the response and feedback of CH4 uptake to changes in precipitation.
URL [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
By using a super-high yielding rice variety Dongnong 423 as material, the effect of four kinds of fertilizer application methods was studied based upon the investigation on some characters of growth and development in rice, including tiller number, leaf chlorophyll content, leaf area index, amount of dry matter accumulation in plant, and yield and its components, as well as protein content, amylose content and taste meter value of rice. The four fertilization methods were deep application in the whole growth period (DAF), incorporating into all soil layers (IAF), surface application(SAF) and no fertilization(NF). The DAF treatment could prolong the duration of effective tillering, increase leaf chlorophyll content, leaf area index and amount of dry matter accumulation in plant compared with the other three methods. There were significant differences(P=0.01) in grain yield and rice protein content (DAF>IAF>SAF>NF), and in amylose content and taste meter value of rice(P<0.01)(NF>SAF>IAF>DAF). Under DAF treatment, the grain yield, number of panicles, number of grains per panicle and rice protein content were increased, however, the seed setting rate,1000-grain weight, amylose content and taste meter value of rice were decreased compared with the other three treatments.
URL [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
By using a super-high yielding rice variety Dongnong 423 as material, the effect of four kinds of fertilizer application methods was studied based upon the investigation on some characters of growth and development in rice, including tiller number, leaf chlorophyll content, leaf area index, amount of dry matter accumulation in plant, and yield and its components, as well as protein content, amylose content and taste meter value of rice. The four fertilization methods were deep application in the whole growth period (DAF), incorporating into all soil layers (IAF), surface application(SAF) and no fertilization(NF). The DAF treatment could prolong the duration of effective tillering, increase leaf chlorophyll content, leaf area index and amount of dry matter accumulation in plant compared with the other three methods. There were significant differences(P=0.01) in grain yield and rice protein content (DAF>IAF>SAF>NF), and in amylose content and taste meter value of rice(P<0.01)(NF>SAF>IAF>DAF). Under DAF treatment, the grain yield, number of panicles, number of grains per panicle and rice protein content were increased, however, the seed setting rate,1000-grain weight, amylose content and taste meter value of rice were decreased compared with the other three treatments.
DOI:10.1038/s41598-017-11772-2URLPMID:28900234 [本文引用: 4]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Ground cover rice production system (GCRPS), i.e., paddy soils being covered by thin plastic films with soil moisture being maintained nearly saturated status, is a promising technology as increased yields are achieved with less irrigation water. However, increased soil aeration and temperature under GCRPS may cause pollution swapping in greenhouse gas (GHG) from CH4 to N2O emissions. A 2-year experiment was performed, taking traditional rice cultivation as a reference, to assess the impacts of N-fertilizer placement methods on CH4, N2O and NO emissions and rice yields under GCRPS. Averaging across all rice seasons and N-fertilizer treatments, the GHG emissions for GCRPS were 1973 kg CO2-eq ha-1 (or 256?kg CO2-eq Mg-1), which is significantly lower than that of traditional cultivation (4186?kg CO2-eq ha-1or 646?kg CO2-eq Mg-1). Furthermore, if urea was placed at a 10-15?cm soil depth instead of broadcasting, the yield-scaled GHG emissions from GCRPS were further reduced from 377 to 222?kg CO2-eq Mg-1, as N2O emissions greatly decreased while yields increased. Urea deep placement also reduced yield-scaled NO emissions by 54%. Therefore, GCRPS with urea deep placement is a climate- and environment-smart management, which allows for maximal rice yields at minimal GHG and NO emissions.
DOI:10.1007/s10705-015-9758-6URL [本文引用: 2]
DOI:10.1039/c9fo01461fURLPMID:31840698 [本文引用: 1]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Consumption of traditional West African pearl millet (Pennisetum glaucum) couscous delayed gastric emptying in our recent human study compared to other starch-based foods (white rice, boiled potatoes, pasta). The objective of this study was to determine whether physical properties of pearl millet couscous affect particle breakdown and starch hydrolysis during simulated gastric digestion to understand the basis of the slow gastric emptying. Starch fine structure and viscosity were analyzed for initial millet and wheat couscous samples by high performance size-exclusion chromatography and the Rapid Visco Analyzer, respectively. Couscous samples were subjected to simulated gastric digestion using the Human Gastric Simulator (HGS), a dynamic model of human gastric digestion. Digesta was collected from the HGS at 30 min intervals over 180 min. Particle size and percent starch hydrolysis of couscous in the digesta were evaluated at each time point. The number of particles per gram of dry mass substantially increased over digestion time for millet couscous (p &lt; 0.05), while changed little for the wheat couscous samples. Millet couscous showed lower starch hydrolysis per unit surface area of particles than wheat couscous (p &lt; 0.05). Slower starch hydrolysis was associated with smaller (p &lt; 0.05) amylose chain length for millet (839-963 DP) than for wheat (1225-1563 DP), which may enable enable a denser packing of millet starch molecules that impedes hydrolysis. We hypothesize that the slow gastric emptying rate of millet couscous observed in humans may be explained by its slow starch hydrolysis property that could activate the ileal brake system, independent of high particle breakdown rate in the stomach.
[本文引用: 2]
[本文引用: 2]
DOI:10.4315/0362-028X.JFP-19-126URLPMID:31841360 [本文引用: 2]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
The purpose of the study was to investigate the influence of management practices on food handler commitment and, ultimately, food safety performance in food manufacturing facilities. Two focus groups, one with six food handlers and the other with six food safety professionals, were used to develop a conceptual model that measured the effect of management practices on food handler commitment and organizational performance. The fitness of the structural model was measured via a survey with 945 respondents from 189 food manufacturing facilities and official food inspectors in the Emirate of Dubai, United Arab Emirates. The study found that training, communication, employee involvement, and organizational management support positively and significantly influenced employee commitment, and employee commitment positively and significantly influenced facilities' food safety performance. These results indicate food handler commitment is a critical factor in the relationship between all of the studied management practices and facilities' food safety performance. The study may have implications for food safety inspectors, enforcement officers, training agencies, and food manufacturing managements to consider human aspects in their work.
[本文引用: 3]
[本文引用: 3]
[本文引用: 3]
[本文引用: 3]
[本文引用: 2]
[本文引用: 2]
DOI:10.11674/zwyf.2013.0503URL [本文引用: 1]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
以杂交中稻F优498为试验材料,采用两因素裂区试验研究4 种氮肥种类(尿素一道清、尿素常规运筹、硫包膜缓释肥、树脂包膜控释肥)在不同移栽秧龄施肥对水稻不同生育期根系形态及籽粒产量的影响。结果表明,在秧苗3叶1心、 5叶1心移栽时水稻在结实期的总根长、根系体积和根系伤流强度比7 叶1 心移栽时高。与施用尿素相比,施用缓/ 控释肥显著增加了根干重、总根长、根系体积和根系伤流强度。在不同移栽秧龄下,施用缓/控释肥均能促进水稻根系生长并向土壤深层分布,保持根系活力。相关分析表明, 水稻籽粒产量与抽穗后的根干重、总根长、根系表面积、伤流强度和10 cm以下的根系分布比例呈显著或极显著正相关。综合根系形态生理与产量表现,5 叶1心移栽、施用树脂包膜控释肥,为本试验的最佳处理。
DOI:10.11674/zwyf.2013.0503URL [本文引用: 1]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
以杂交中稻F优498为试验材料,采用两因素裂区试验研究4 种氮肥种类(尿素一道清、尿素常规运筹、硫包膜缓释肥、树脂包膜控释肥)在不同移栽秧龄施肥对水稻不同生育期根系形态及籽粒产量的影响。结果表明,在秧苗3叶1心、 5叶1心移栽时水稻在结实期的总根长、根系体积和根系伤流强度比7 叶1 心移栽时高。与施用尿素相比,施用缓/ 控释肥显著增加了根干重、总根长、根系体积和根系伤流强度。在不同移栽秧龄下,施用缓/控释肥均能促进水稻根系生长并向土壤深层分布,保持根系活力。相关分析表明, 水稻籽粒产量与抽穗后的根干重、总根长、根系表面积、伤流强度和10 cm以下的根系分布比例呈显著或极显著正相关。综合根系形态生理与产量表现,5 叶1心移栽、施用树脂包膜控释肥,为本试验的最佳处理。
DOI:10.1016/j.fcr.2018.01.015URL [本文引用: 1]
DOI:10.1016/j.scitotenv.2019.135818URLPMID:31841898 [本文引用: 1]
![](https://www.chinaagrisci.com/richhtml/0578-1752/richHtml_jats1_1/images/more.jpg)
Climate change and anthropogenic activities have resulted in increased atmospheric methane (CH4) concentration. Increased nitrogen deposition and precipitation accompanies climate warming and can change soil carbon and nitrogen dynamics and microbial processes and alter CH4 fluxes. To quantify the sink of the vast alpine meadows of the Tibetan Plateau and to examine how precipitation addition (P), warming (W), and nitrogen addition (N) affect CH4 fluxes in alpine meadows, we conducted continuous 3-growing season experiments in an alpine meadow using the static chamber and gas chromatograph method. Soil CH4 samples were collected during the early, peak, and late stages of the growing season from 2015 to 2017. Our results suggested that neither P, W, nor N had an interaction effect on soil CH4 uptake. P significantly increased and decreased the copies number of particulate methane monooxygenase alpha subunit (pmoA) and methyl-coenzyme M reductase alpha subunit (mcrA), respectively. However, P significantly decreased CH4 uptake, particularly under the combined treatment of P and N. Compared with the control, CH4 uptake decreased under P, N, PW, and PN by 50.64%, 6.24%, 39.37%, and 75.06%, respectively, whereas under W and WN CH4 uptake increased by 16.19% and 7.56%, respectively. Soil CH4 uptake was positively correlated with soil temperature and pmoA and negatively correlated with soil moisture and NH4+-N content. CH4 uptake was significantly affected by the sampling period. CH4 uptake was significantly lower rates during peak growing season compared with those during the early and late stages of the growing season. Our results suggest that, (1) CH4 fluxes of alpine grassland ecosystems are more sensitive to P than W or N, and (2) precipitation controls CH4 flux response to increasing nitrogen deposition in alpine meadows on the Tibetan Plateau. Therefore, future research should focus on the response and feedback of CH4 uptake to changes in precipitation.
DOI:10.1007/s10705-016-9799-5URL [本文引用: 2]
DOI:10.3329/sja.v13i2.26577URL [本文引用: 2]