不同阶段施用氮肥对大豆氮吸收及固氮的影响

以两种不同基因型的大豆品种为试材，研究不同阶段施用氮肥对大豆吸氮及固氮的影响。试验结果表明，氮肥的施用时间对大豆氮吸收、根瘤干重及固氮，具有重要影响。仅施２５ｋｇ／ｈｍ２的启动氮，两个大豆品种都获得了最高的根瘤干重和固氮率。在开花期或种于形成初期，再追施５０ｋｇ／ｈｍ２氮，两个大豆品种都获得了最高的氮吸收总量和固氮总量。大豆的根瘤干重与固氮率呈线型正相关。     

不同氮肥管理对毛豆共生固氮及产量的影响

以两个不同基因型毛豆品种为试材，研究不同的氮肥管理对毛豆产量及其共生固氮的影响，结果表明，氮肥的施用时间对毛豆的产量及固氮量具有显著的影响，二对复叶始期（Ｖ１．５），每公顷追施５０公斤尿素和在种子形成中期（Ｒ４．５）每公顷再追施２５公斤尿素，两个品种都获得了最高的饱荚产量及最大的固氮量。四对复叶期（Ｖ４），土壤中的速效氮含量与毛豆的固氮率呈正相关，但在开花期和种荚形成期表现为显著的负相关。每公顷仅施２５公斤尿素不能满足毛豆丰产及最大限度利用其共生固氮的需要。     

大豆的最佳氮肥施用时期研究

以３种不同基因型大豆品种为试材，研究大豆根瘤形成始期（二片复叶Ｖ２）和大豆生殖生长期间施用氮肥，对大豆生长，结瘤及产量的影响。试验结果表明，大豆营养生长阶段的最佳追肥时间为根瘤形成始期；面在豆生殖生长期间的最佳追肥时间为大豆开花期。     

长期施肥对大豆生长状况及产量的影响

以海伦农田生态系统国家野外科学观测研究站长期定位试验为平台,选择了5个不同施肥处理,包括无肥(CK),单施氮肥(N),氮肥+有机肥(N+OM),氮、磷、钾配合施用(NPK),氮、磷、钾+有机肥(NPK+OM),研究了连续27年不同施肥处理对大豆生长和产量的影响。结果表明:长期施用有机肥能够明显增加大豆株高和荚数,并且能增加植株的生长速度,氮磷钾肥配合施用能增加大豆根瘤干重和根瘤数,而有机肥对根瘤的作用不显著。与单施化肥和无肥相比,施用有机肥处理大豆的根冠比较小,说明有机肥能够促进地上部干物质的积累。长期施肥对大豆产量构成因子的影响表现为:NPK+OM>NPK>N+OM>N>CK,大豆产量也表现出相似趋势,说明有机肥的施用能够改善大豆的产量性状,同时氮肥配施有机肥的大豆产量低于氮、磷、钾平衡施肥的处理,说明在东北黑土区有机肥不能代替磷钾肥施用。     

淹水大豆的生长与固氮研究

试验于1989年7月至10月在泰国清迈大学农学院多熟制研究中心的农业试验场进行。在淹水栽培与常规栽培条件下,对二个大豆品种SJ5和NW1的生长与产量、根瘤生长与固氮率和固氮量及其对增施每公顷50kg氮素肥料的反应进行测定。结果表明,淹水能促进根瘤生长,增加固氮率、比常规栽培法多固定氮素44％以上。但是淹水栽培法对干物质和产量的增加并不显著。增施氮肥能防止淹水初期的植株落黄现象,但抑制根瘤生长和固氮。     

不同供N方式对大豆生长和结瘤固氮的影响

采用框栽试验方法对比研究了不同供N方式对大豆生长和结瘤同氮的影响.结果表明:持续供N和非持续供N对大豆生长有不同的影响,在苗期,非持续供N与持续供N相比,对大豆生长有较大的促进作用,而在仡期以后则是持续供N对大豆生长的促进作用较大;持续供N和非持续供N对大豆结瘤同氮的影响不同,大豆根瘤数量表现为非持续供N＞持续供N＞无N,表明氮肥的持续施用对大豆根瘤的形成和生长有抑制作用,不利于大豆根瘤的生长发育;不论何种方式供N对大豆同氮酶活性和豆血红蛋白含量均有抑制作用,使固氮酶活性和豆血红蛋白含量显著降低,而且氮肥的持续施用对固氮酶活性和豆血红蛋白含量的抑制要显著高于非持续供N,表现为持续供N＜非持续供N＜无N,因此,氮肥的持续施用使大豆的同氮效率降低.     

氮肥对大豆不同类型品种结瘤固氮影响的差异性研究

本研究选用生育期和蛋白质含量不同的六个夏大豆品种，在磷钾肥基础上施用三个氮肥水平（０、６、１２ｋｇ氮／亩）。结果表明：施氨抑制结瘤，氮肥越多抑制越严重；抑制作用主要在盛花期前，至鼓粒期有的品种受抑制作用较小；对固氮的抑制在不同品种间存在明显差异，品种豫豆８号表现出较耐氮。酰脲相对丰度与根瘤干重极显著正相关，六叶期、盛花期和鼓粒期两者的相关系数分别为ｒ＿ａ＝０．９５４５、ｒ＿ｂ＝０．８０２５、ｒ＿ｃ＝０．６５３１，Ｐ＜０．０１。酰脲的相对丰度反映了品种的固氮差异和不同氮肥水平下固氮的变化。     

酸性土施用石灰对甘蔗产量和品质的影响

在酸性土壤条件下,甘蔗分蘖期每公顷施用石灰３００ｋｇ和６００ｋｇ,可有效地促进甘蔗对Ｍｇ的吸收,使甘蔗生长中期叶绿素ａ含量和叶绿素ａ／ｂ比值提高,每公顷减少施尿素２２５ｋｇ、４５０ｋｇ,仍获得与每公顷施用７５０ｋｇ尿素的产量相若,而且提高蔗糖分     

氮肥施用量对不同大豆品种产量及品质的影响

以5个不同生态类型的大豆品种为试验材料，分别施用3个不同水平的氮肥，研究种肥对5个不同基因型大豆品种产量及品质的影响。研究表明，在草甸黑钙土上施用氮肥，对大豆的产量和品质均有显著影响，且对不同品种的影响各不相同。就产量而言，增施氮肥提高了晚熟品种黑农37和早熟品种东农44的产量，降低了中熟品种东农48和东农53的产量；就品质而言，增施氮肥提高了绥农14籽粒中蛋白质含量，降低了其余4个品种籽粒中蛋白质含量，提高了黑农37籽粒中油分含量，降低了绥农14和东农48籽粒中油分含量。     

氮和根瘤菌交互作用对大豆生长、结瘤及产量的影响

采用根瘤菌拌种,以氮素及根瘤菌为试验因素设置处理,随机区组设计,研究了氮和根瘤菌交互作用对大豆根瘤生长及大豆产量和品质的影响。结果表明,接入的根瘤菌能有效的增加大豆植株的结瘤数量,而施入大量的氮肥则产生抑制作用。根瘤菌的接入对大豆R3期生物量的积累产生一定的促进作用。在接入根瘤菌的条件下,施入氮肥单个根瘤体积增大;不施入氮肥,单个根瘤体积变小。产量构成因子综合作用的结果使得接种根瘤菌与施入氮肥相比,更能提高大豆的产量。     

在接种和施氮胁迫下应用综合等级指数对大豆种质固氮的评价

在根瘤菌接种和施氮胁迫下,应用综合等级指数对田间种植的东北40个大豆品种(系)固氮能力进行了评价。高N(80kg)/ha)抑制大豆结瘤固氮;低N(40kg/ha)接种产量最高。评价了对氮反应为耐氮和氮敏感的大豆种质和对接种反应亲合力高、低的大豆种质。     

Effect of N fertilizer top-dressing at various reproductive stages on growth,N2 fixation and yield of three soybean (Glycine max (L.) Merr.) genotypes

Soybean (Glycine max (L.) Merr.) is one of the most important food and cash crops in China and a key protein source for the farmers in northern China. Previous experiments in both the field and greenhouse have shown that N₂ fixation alone cannot meet the N requirement for maximizing soybean yield, and that N top-dressing at the flowering stage was more efficient than N top-dressing at the vegetative stages. However, the effect of N fertilizer application at other reproductive stages of soybean is unknown. Thus, a field experiment was conducted to study the effects of N applications at various reproductive stages on growth, N₂ fixation and yield of three soybean genotypes. The results showed that starter N at 25 kg ha⁻¹ resulted in minimum yield, total N accumulation and total amount of N₂ fixed in all three genotypes. N top-dressing at 50 kg ha⁻¹ at either the V2 or R1 stages, significantly increased N accumulation, yield and total amount of N₂ fixed in all three genotypes. However, N top-dressing at the same rate at either the R3 or R5 stage did not show this positive effect in any of the three genotypes. Thus, the best timing for N top-dressing during reproduction is at the flowering stage, which increased seed yield by 21% for Wuyin 9, 27% for You 91-19, and 26% for Jufeng, respectively, compared to the treatment without N top-dressing.     

THE EFFECT OF NITROGENOUS FERTILIZER ON THE RATE OF GROWTH OF ITALIAN RYEGRASS.

Residual response to an initial application of nitrogen was measured in 3 years and was found to be quite large, e.g. a response of 8 Ib DM per extra Ib N at the first harvest, when applying 125 Ib N/ac (140 kg/ha) rather than‘75 Ib (84 kg/ha) and allowing 6 weeks' growth, was increased to 21 Ib DM when yield from residual cuts was taken into account. Response was large in relation to the amount of N estimated to have been left behind after the first harvest. Marginal recovery of N, already quite high at the first harvest, was increased to a little over 90% when yield from residual cuts was taken into account Recovery, however, was lower than this when 10 weeks' growth was allowed before the first harvest, and it seems that, in this case, some N may have been lost from the system. A supplementary experiment suggested that the residual effect of N on DM yield could be obscured to some extent by fresh applications of N.     

菏泽地区夏大豆亩产200kg的栽培措施研究

1986～1990年我们进行了夏大豆品种、密度、施肥、灌水等主要栽培措施与综合丰产的研究与应用,认为菏泽地区夏播大豆由于可供其生长的时期相对较短,以选用生育期100天左右,株形紧凑的品种,适当增加密度,较易获得每亩200kg以上的稳定产量。栽培措施要点是:以增加群体密度、采用氮磷配合施用;有机肥、无机肥与微肥配合施用,以提高光合与固氮能力,并使植株生长稳健、营养与生殖生长协调,促进养分向生殖器官输送。花荚期叶面施肥与结荚、鼓粒期迂旱浇水,延长叶片与根瘤的功能期,使养分充分运入籽粒,以提高粒重,充分发挥大粒品种籽粒的养分贮藏功能。     

The effects of nitrogen and iron fertilization on growth,yield and fertilizer use efficiency of soybean in a Mediterranean-type soil

Poor seed yield of soybean in Mediterranean-type environments may result from insufficient iron (Fe) uptake and poor biological nitrogen (N) fixation due to high bicarbonate and pH in soils. This study was conducted to evaluate the effects of N and Fe fertilization on growth and yield of double cropped soybean (cv. SA 88, MG III) in a Mediterranean-type environment in Turkey during 2003 and 2004. The soil of the experimental plots was a Vertisol with 176 g CaCO₃ kg⁻¹ and pH 7.7 and 17 g organic matter kg⁻¹ soil. Soybean seeds were inoculated prior to planting with commercial peat inoculants. N fertilizer rates were 0, 40, 80, and 120 kg N ha⁻¹ of which half was applied before planting and the other half at full blooming stage (R2). Fe fertilizer rates were 0, 200 and 400 g Fe EDTA (5.5% Fe and 2% EDTA) ha⁻¹. It was sprayed as two equal portions at two trifoliate (V2) and at five trifoliate stages (V5). Plants were sampled at flower initiation (R1), at full pod (R4) and at full seed (R6) stages. Application of starter N increased biomass and leaf area index at R1 stage whereas Fe fertilization did not affect early growth parameters. N application continued to have a positive effect on growth parameters at later stages and on seed yield. Fe fertilization increased growth parameters at R4 and R6 stages, and final seed yield in both years. This study demonstrated an interactive effect of N and Fe fertilization on growth and yield of soybean in the soil having high bicarbonate and pH. There was a positive interaction between N and Fe at the N rates up to 80 kg N ha⁻¹. However, further increase in N rate produced a negative interaction. Fertilization of soybean with 80 kg N ha⁻¹ and 400 g Fe ha⁻¹ resulted in the highest seed yield in both years. We concluded that application of starter and top dressed N in combination with two split FeEDTA fertilization can be beneficial to improve early growth and final yield of inoculated soybean in Mediterranean-type soils.     

THE EFFECT OF NITROGENOUS FERTILIZER ON THE RATE OF GROWTH OF ITALIAN RYEGRASS

In an experiment described earlier (13), the N content of Italian ryegrass in spring reached a high value one or two weeks after applying N and then fell quickly at first and then more slowly. After 10 weeks average N content (in DM) was 0.6% from an application of 25 lh N/ac (28 kg/ha), 0.9% from 75 lb N (84 kg/ha), and 12% from 125 lb N (140 kgJha). Nitrate-N content fell more abruptly and tben remained fairly constant. Percentage nitrate–N (in DM) fell below 0.10% during the second week after an application of 25 lb NJac, during the third week after 75 lb N, and during the fifth week after recciriag 125 lb N. The yield of N increased during the first 5 or 6 weeks, remained fairly constant for 3–5 weeks, and then hegan to fall. During the ninth and tenth weeks, the crop lost an average of 9 lb N/ac per week (10 kg/ha) after an application of 75 Ib N/ac and 12 lb N/ac per week (13 kg/ha) after 125 Ib N.     

施氮水平对7S亚基缺失大豆根系形态和结瘤固氮的影响

为有效推广功能型大豆7S亚基缺失品种,以7S亚基缺失大豆品系东富2号为研究对象,设置4种施氮水平(纯N),N0(0 mg·kg~(-1))、N1(25 mg·kg~(-1))、N2(50 mg·kg~(-1))、N3(75 mg·kg~(-1)),采用桶栽法研究大豆根系形态和结瘤固氮对不同施氮水平的响应。结果表明:N1(25 mg·kg~(-1))水平下根系干重加大,根冠比增大,根瘤固氮潜力高,单株产量较高。N2(50 mg·kg~(-1))水平下根长、根表面积、根体积在生育后期增长较快,根系干重较大,根冠比低,固氮酶活性最高,单株籽粒产量最高。N3(75 mg·kg~(-1))水平下植株干重较大,无效生长较多,根瘤数少,固氮潜力和根冠比低,单株产量不高。综合籽粒产量和根系特性指标,功能型大豆7S亚基缺失品系东富2号的适宜施肥量为25~50 mg·kg~(-1)。