Unused fertiliser nitrogen in arable soils—its contribution to nitrate leaching

Nitrate present in arable soils in autumn is at risk to leaching during the following winter. To see whether unused nitrogen fertiliser was a major source of this nitrate, ¹⁵N-labelled fertiliser was applied to 11 winter wheat crops at rates of between 47 and 234 kg N ha^?1in spring. The experiments were on three contrasting soil types in south-east England. On average, 17′% of the N from spring-applied labelled fertiliser remained in the 0–23 cm soil layer at harvest (range, 7–36%) but only a small proportion was in inorganic forms (ammonium + nitrate). This was never more than 5 kg N ha^?1and averaged only 1·3% of the fertiliser N applied (range, 0·4–3·6 %). Between 79 and 98% of the inorganic N in soils at harvest was unlabelled, being derived from the mineralisation of organic N rather than from unused fertiliser. The amount of unlabelled N was much greater where wheat was grown after ploughing up grass or grass/clover leys than where it was grown in all-arable rotations. When wheat was grown without N fertiliser, soil inorganic N content at harvest was no lower than in plots given fertiliser at rates up to 234 kg N ha^?1. This work indicates that, for soil growing winter wheat, almost all of the nitrate at risk to leaching over the winter period comes from mineralisation of organic N, not from unused fertiliser applied in spring. Consequently, even a drastic reduction in N fertiliser use would have little effect on nitrate leaching.     

垂直深旋耕配施改土物料改良酸性土壤并提高烟草种植效益研究

为实现酸性土壤改良与土壤培肥同步、表层土与表下层土壤改良同步的目的,运用垂直深旋耕与无机、有机、生物等多物料综合协同改良酸性土壤,采用双因素裂区设计,试验设垂直深旋耕和传统耕作方式,以及石灰、石灰+绿肥、石灰+绿肥+酸性生物有机肥、石灰+绿肥+碱性生物有机肥等改土物料组合,研究了耕作方式和改土物料及其互作对植烟土壤理化...     

Regular applications of poultry litter to a sandy arable soil: effects on nitrate leaching and nitrogen balance

Intensive poultry units often have insufficient land for spreading manure at agronomically and environmentally acceptable rates. This experiment measured the effects of annual applications, at several rates, on nitrate-N leaching and the soil–crop N balance on a sandy soil. Poultry litter from a broiler unit was applied each autumn 1992–1995. Total loadings on the main experiment area (instrumented with ceramic and Teflon water samplers at 1·0 and 1·5 m, and monolith lysimeters, 1·5 m deep) were 0, 60 and 150 t ha⁻¹. Additional plots (not instrumented) received 30, 90 or 120 t ha⁻¹. There was good agreement in the nitrate-N concentrations measured by the Teflon and ceramic water samplers and the lysimeters; all three methods gave acceptable measurements of nitrate leaching on structureless sandy soils. Autumn applications of poultry manure should be avoided: leaching was much greater than when delayed into December. At rates of broiler litter which supplied more N than the crop required (generally above 10 t ha⁻¹ each year), nitrate-N leaching losses were large; at the largest application rate (akin to a disposal, rather than a planned fertiliser strategy), concentrations peaked at c 500 mg litre⁻¹ N. Despite the movement of dissolved organic carbon to 1 m depth, the N concentration profiles measured by the water samplers did not provide clear evidence of subsoil denitrification. A nitrogen balance sheet, based on available N applied (as either fertiliser or manure) with some adjustment for mineralisation of the manure's organic fraction (10% annually) and for volatilisation (15%) was strongly correlated with soil mineral N each spring. © 1998 Society of Chemical Industry.     

The influence of nitrogen fertilizer on grain quality in winter wheat

Between 1966 and 1969, 44 experiments on winter wheat tested 5 rates of N applied as spring top dressings of NH₄NO₃. At almost every site increasing the rate of N applied, decreased grain size and increased the N content of the grain. There was a marked effect of season: the sunniest season, 1969, produced the largest grain and the lowest mean N content; the season with the least soil moisture deficit, 1968, produced the highest mean N content. There was no relationship between N content and the variety of wheat or soil type. The N content of grain grown without N fertiliser was highly significantly related to reserves of available N in the soil. i.e. to the rate of fertilizer N required for maximum grain yield, determined by experiment. By using this relationship, the fertilizer N requirement at 20 sites with nil N plots was calculated and was found to compare favourably with the ADAS N Index prediction method based largely on previous cropping. Grain density was determined on three sites in 1967; with increasing rates of N, grain density increased slightly.     

Effects of husbandry treatments on nitrogen concentration of grain and related yields in winter-wheat experiments made in South-East England

Experiments by Rothamsted staff over 20 years show that N (protein) concentration in wheat grain is influenced considerably by several husbandry treatments other than total fertiliser N. Even small differences can be of practical importance if values lie close to the minimum standard for bread wheat. In 15 experiments which tested timing of fertiliser N, an extra 60 kg ha^?1 would have been needed in autumn to increase grain-N concentration by 0.1% on average, but only 43 kg in early and 30 kg in late spring. The response to autumn N was similar in a ley-arable rotation experiment Fertiliser N applied to a previous potato crop gave a grain-N% increase equivalent to a quarter of the fresh application on a silty clay loam soil but none on a sandy loam. Cumulative annual dressings of farmyard manure benefited grain-N% as did residues from FYM applied to a previous potato crop, which gave increases equivalent to those from 16 kg ha^?1 of fresh fertiliser N. In ley-arable rotation experiments, wheat after arable cropping did not reach bread-quality standard with the largest amount of fertiliser N (150 kg ha^?1), but after lucerne N% values exceeded the threshold value of 2.14% N with all rates. Benefits from lucerne and a grass-clover ley were still considerable when wheat was grown as a second test crop after potatoes. Yield responses to these husbandry treatments tended to be small and positive, except that in the presence of larger dosager of fertiliser N farmyard manure sometimes caused a depression.     

兰州拉面专用粉对春小麦品质的要求——Ⅱ小麦籽粒面筋蛋白组成含量与品质的关系

共选用30份春小麦材料,参照Singh等[1]和Verbruggen等[2]方法,提取出不同材料的面筋蛋白、高分子量麦谷蛋白亚基(HMW-GS)和低分子量麦谷蛋白亚基(LMW-GS)。通过测定各蛋白组分的含量及比例,同时结合不同材料的理化品质、面团流变学特性以及拉面食用品质进行多元相关分析,结果表明:麦谷蛋白含量与小麦籽粒蛋白含量、湿面筋含量、面筋指数、干面筋含量呈显著正相关;与面团弹性、延伸性以及面团筋力也呈显著正相关;与拉面食用韧性、粘性以及总评分呈显著正相关。HMW-GS含量与小麦湿面筋和干面筋含量呈显著正相关;与面筋指数呈显著负相关。在面团品质方面,HMW-GS含量与面团韧性呈显著正相关,而与LMW-GS与面团延伸性和面团筋力为显著正相关。HMW-GS含量与拉面最终评分呈显著负相关,相反LMW-GS与拉面最终评分呈显著正相关。     

Effect of nitrogen and manure fertilizer on grain quality,baking and rheological properties of wheat grown in sandy soil

Winter wheat was grown under various nitrogen (N) fertilizer regimes (with/without manure application) under calcareous sandy soils, control wheat being grown without fertilization. Six levels of N fertilizer were applied. The technological and baking characteristics of the wheat were closely related to N and nitrogen + manure (NM) fertilization. Contents of protein increased with increase in fertilization level, which also improved the rheological properties of dough and baking quality. N fertilization increased farinograph stability time, which increased with increasing flour protein content. NM fertilization affected protein content as well as farinograph stability time and farinograph maximum viscosity, thereby affecting the relationship between these properties. The increase in bread volume due to fertilizers was more noticeable with NM than with N. Application of 60 t ha^?1 manure along with 200 kg ha^?1 N onwards improved technological properties of flour in comparison with wheat grown with the basic N fertilizer only. Copyright © 2005 Society of Chemical Industry     

Use of nitrification inhibitors to improve recovery of mineralised nitrogen by winter wheat

Nitrification inhibitors were applied in September 1980, after ploughing of a grass ley, to prevent formation of NO_3-N which could be lost by leaching and denitrification. Laboratory tests indicated that nitrapyrin or etridiazole at 1 μg g soil^?1 and dicyandiamide (DCD) at 10 μg g^?1 could inhibit nitrification by approximately 40%, compared with untreated soil, for 10 weeks at 10°C. In the field, nitrapyrin, etridiazole and DCD had little effect on NH₄ and NO₃ levels in the soil throughout autumn and winter. In April uptake of mineralised N by wheat was greater in plots treated with DCD (but not with nitrapyrin or etridiazole) than in untreated plots. Spring fertiliser N applications (35 or 70 kg N ha^?1) increased ear numbers, as did the two rates of all inhibitors except etridiazole. At harvest, grain and straw yields were increased by both rates of DCD with and without fertiliser N in spring, but there were no consistent increases from nitrapyrin or etridiazole. The mean increases in N uptake by wheat grain plus straw were 12 and 15% for 5 and 20 kg ha^?1 DCD respectively. DCD could be of use in preventing losses of NO₃-N, particularly in situations where large amounts of N may be mineralised during autumn and would be liable to loss prior to crop uptake.     

不同类型专用小麦HMW-GS和GMP含量与面筋含量的关系

高分子质量谷蛋白质亚基(HMW-GS)是决定小麦加工品质的重要因子,以25个小麦品种为材料,采用SDS-PAGE电泳方法研究亚基组成、各位点(Glu-A1、Glu-B1、Glu-D1)亚基积累量、谷蛋白大聚合体(GMP)含量及其与面筋含量的关系.研究结果表明:低蛋白小麦品种HMW-GS组成主要以"N、7+8/7+9、2+12"亚基组合为主,高蛋白小麦品种HMW-GS组成则主要以"1、7+8/7+9、5+10"亚基组合为主,中等蛋白小麦品种兼有以上两种类型亚基组合;亚基组成相同的小麦,籽粒GMP含量和蛋白质含量仍有较大差异.相关分析表明,HMW-GS亚基总积累量与籽粒蛋白质含量和GMP含量呈极显著正相关,与干、湿面筋含量成正相关;GMP含量与干、湿面筋含量、蛋白质含量均呈极显著正相关,说明小麦品质类型虽与HMW-GS组成有关,但亚基积累强度不同可能是导致籽粒品质类型差异的重要因素之一.     

The effects of cattle slurry and inorganic fertiliser nitrogen on the yield and mineral composition of forage maize. results of preliminary experiment

Four rates of cow slurry (0, 35, 70 and 105 t/ha) and inorganic nitrogen (0, 40, 80 and 120 kg/ha) were applied in a factorial arrangement to forage maize plots on a sandy loam soil (Hurst Series). The response of maize DM yield to inorganic N was small above 40 kg N/ha. Slurry alone gave satisfactory yields and up to 70 t/ha improved the response to inorganic N. Slurry at 105 t/ha tended to delay crop maturity and reduced yields when more than 40 kg inorganic N/ha was applied. The percentage N, P and K in the soil before drilling and in the crop at the silage stage were positively related to the amount of slurry applied. Appreciable amounts of P, K and Mg remained in a “plant available” state in the soil after the maize harvest.     

Agronomic Factors Related to the Quality of Wheat for the Starch Industry. Part II: Nitrogen Fertilisation and Overall Conclusions

In the N.W.-European wheat growing system high levels of nitrogen fertiliser are applied. Especially late nitrogen applications are thought to increase the amount of soluble proteins, leading to extra losses and wastage. On the other hand, protein content is the most important factor determining gluten yield. The effects of fertilisation on processing quality have been investigated using a pilot separator. Samples from fertilisation trials show a high correlation between gluten yield and protein content of the flour. This relation is variety dependent, due to differences in water-soluble proteins. For both varieties the percentage of water-soluble proteins appeared to decrease with increasing N-fertilisation levels. At low protein contents of the flour the coagulation of the gluten is adversely influenced. Using soft bread wheats, this may cause severe difficulties during separation. At high fertilisation levels the amount of solubles in the waste water increased slightly. - A review on research results is made, showing the criteria for wheat for the starch industry.     

Low carbohydrates bread: Formulation,processing and sensory quality

A low carbohydrate bread formula was prepared using hard red spring wheat flour, soy protein and vital gluten. Soy protein was treated with ethanol and jet-cooked to remove the beany taste. Vital gluten and soy protein blends were prepared and added to the control flour in order to reduce the final starch content by 52%. The ratio of soy protein:vital gluten was adjusted, based on the Farinograph profile of the blend relative to the control flour. AACC Method 10-09, Straight dough, was used for the baking. The amounts of shortening and yeast were increased, to improve the dough consistency and to reduce beany taste, respectively. A blend of 70% gluten and 30% soy protein was added to replace 50% of the control flour. This blend gave a loaf value similar to the control. Overall, the loaf was softer, darker in colour and the grain was more open than the control. Another blend, with 50% soy nuggets and 50% vital gluten, was added to replace 50% of the control flour. This produced a loaf with 35% less volume, darker colour, and a grain similar to the control. The protein content of the final product was 56%, which is much higher than that reported in the literature. Bread with high protein content is more suitable for use in low carbohydrate diets than bread formulations currently used.     

"绿色小麦"的化学组成分析

对彩色小麦中的绿色小麦全粉的基本化学组成,包括蛋白质、脂肪、淀粉、膳食纤维和灰分进行分析,结果表明,除淀粉外,绿色小麦的蛋白质、脂肪、膳食纤维含量均较高,尤其是绿色小麦的蛋白质含量高达17.96%。分析绿色小麦的面筋含量和氨基酸组成,绿色小麦湿面筋含量35%,是高筋粉。与宜兴红麦相比,绿色小麦的单一氨基酸含量均高于红麦,其中半胱氨酸的含量尤其高,是红麦的7倍。采用原子吸收光谱法测定绿色小麦中的Se、Zn、Fe、Cu、Mn、Co、K、Ca、Mg、Na元素,结果表明绿色小麦中的Se、Zn、Mn、K、Mg、Na含量明显高于普通小麦,锌含量为普通小麦的1.7倍,硒含量是普通小麦的2倍。根据结果来看,作为一种新的小麦资源,绿色小麦具有广阔的开发应用前景。     

高温高湿处理对小麦中蛋白质性质的影响

目的：探索高温高湿工艺对小麦及其制品蛋白质性质的影响。方法：分析了经高温高湿工艺处理后小麦粉及其制品的面筋蛋白、麦谷蛋白及麦醇溶蛋白的理化性质、分子性质和超微结构。结果：小麦粉和挂面中蛋白质的水溶性随处理时间的延长而降低;挂面面筋蛋白的持水力优于小麦粉,其中麦谷蛋白的持水能力占主要作用;随着处理时间的延长,小麦蛋白质中相对分子量较大的麦谷蛋白含量增多,而分子量较小的麦醇溶蛋白含量减少。SEM分析发现,热变性使谷蛋白由原来的膜状结构逐渐变成多孔结构,此结构使面筋网络中的孔隙变大,孔隙变大可以更好地包裹淀粉颗粒。结论：高温高湿处理工艺对小麦和面条中的蛋白质性质影响具有差异。小麦粉中的蛋白质持水能力经处理后基本没有变化,而水溶能力则呈下降趋势;面条经高温高湿处理后持水力与水溶力均提高。     

Effect of heating and acidic pH on characteristics of wheat gluten suspension

The effects of different pH treatments with and without heating on the characteristics of wheat gluten suspension was investigated. At pH 1, maximum changes in colour were observed with a concurrent 65% decrease in protein free-thiol content compared to the control gluten. The SDS-Extractability of protein (SDS-EP) chromatogram eluted at lower retention time and the presence of bands at the top lane even during reducing conditions in SDS-PAGE gel suggested complex formation involving bonds other than disulphides. An increase in the free-amino group content and the presence of an additional peak at a higher retention time in the SDS-EP chromatogram was suggestive of hydrolysis. At pH 2 and 3, similar decreases in SDS-EPs and free-thiol content indicated formation of complexes. When heated, the free-thiol content of the dispersions increased compared to the non-heated dispersions indicating disruption of disulphide bonds with changes in gluten structure and size distribution.     

施用麦秸秆对烤烟产质量的影响

在高肥力的土壤上,研究了小麦秸秆还田对烤烟主要农艺性状及产量、品质和病害发生率的影响。结果表明,施N量2kg/667m2和4kg/667m2时,施秸秆的比不施秸秆的烟叶产量分别增加12 2%和13 9%,差异达显著水平;产值分别增加47 65%和39 25%,差异达极显著水平。在不同施N水平下,施秸秆的比不施秸秆的烟株茎围增加,炭疽病和赤星病发生率降低,烟叶中总糖含量提高,烟碱、总氮及蛋白质含量降低。烟叶的香气质、香气量、杂气、劲头和刺激性等有一定程度改善。     

豫北地区小麦籽粒质量及其加工利用潜力研究

为明确豫北地区大田小麦籽粒质量现状,分析区域小麦加工利用潜力,以2008年—2013年在豫北地区按试验设计采集的486份大田小麦样品为材料,分析豫北地区大田小麦籽粒质量现状,探讨小麦加工适用性及加工利用潜力。结果表明,豫北地区大田小麦容重、面团稳定时间较高,湿面筋含量偏低;沉降指数、面团形成时间、弱化度、粉质质量指数年际间变化较大。2008年~2013年豫北地区大田小麦样品有2.88%达到《优质小麦强筋小麦》二等标准。湿面筋含量较低是豫北地区优质小麦比例较低的限制性因素。以湿面筋含量、面团稳定时间同时满足要求作为参考依据,豫北地区大田小麦样品满足不同食品要求的比例依次为面条馒头饺子发酵饼干面包酥性饼干蛋糕、糕点。     

Effects of tillage and nitrogen fertilisation on triticale grain yield,chemical composition and nutritive value

BACKGROUND: Given the interest in the development of cultivation systems with low agronomic input and environmental impact, the aim of this study was to determine the influence of tillage system (conventional tillage (CT), two‐layer tillage (TT), surface tillage (ST) and minimum tillage (MT)) and nitrogen (N) fertilisation rate (0, 50 and 100 kg ha^?1) on triticale grain and protein yields, chemical composition and nutritive value. RESULTS: There were no significant differences among tillage treatments in grain and protein yields. ST resulted in significantly higher crude protein (CP) and true soluble protein (TSP) contents as well as in vitro crude protein digestibility (CPD). Neutral detergent fibre concentration was significantly higher with ST than with MT, and this led to a small reduction (2 g kg^?1 dry matter (DM)) in in vitro true DM digestibility (IVTDMD). N fertilisation significantly increased grain and protein yields as well as CP, non‐protein nitrogen and TSP contents and CPD. IVTDMD was significantly lower with 0 kg N ha^?1 than with 50 and 100 kg N ha^?1. CONCLUSION: Reducing tillage intensity improved the CP content and CPD of triticale grain. The application of 50 kg N ha^?1 resulted in good grain quality parameters and grain and protein yields. Copyright © 2010 Society of Chemical Industry     

添加赖氨酸和苏氨酸对小麦面筋蛋白降低大鼠同型半胱氨酸效果的影响

目的在小麦面筋蛋白中添加赖氨酸和苏氨酸,探讨两种限制氨基酸在小麦面筋蛋白中降低大鼠血浆高同型半胱氨酸(Hcy)血症的影响。方法 32只健康Wistar大鼠随机分为4组,分别为大豆分离蛋白组(25S)、酪蛋白组(25C)、小麦面筋蛋白组(29G)、赖氨酸+苏氨酸添加组(29GLT)。各组大鼠分别给予不同饲料喂养14 d后处死,采集血液、肝脏等样品,用于测定生化、酶学指标。结果添加赖氨酸和苏氨酸可有效改善大鼠因摄入小麦面筋蛋白导致的体重、血浆中Hcy的降低,可抑制血浆S-腺苷蛋氨酸(SAM)和肝脏甜菜碱高半胱氨酸甲基转移酶(BHMT)活性的升高,但对胱硫醚β-合成酶(CBS)活性无影响。蛋氨酸含量较低的大豆分离蛋白组,血浆中同型半胱氨酸的含量并未降低。结论小麦面筋蛋白对大鼠血浆同型半胱氨酸浓度的影响可能与其氨基酸的组成特点有关。小麦面筋蛋白的高半胱氨酸和低赖氨酸及低苏氨酸的氨基酸组成是小麦面筋蛋白降低同型半胱氨酸水平的可能因素。     

深耕配施有机肥对云南保山植烟土壤肥力的快速提升效应

为研究土壤耕作深度与有机肥对植烟土壤肥力的快速提升效果,设置3种耕作深度（S1：深耕10cm;S2：深耕20cm;S3：深耕30cm）与2种有机肥（OF：商品有机肥;FM：农家肥）的交互试验,研究一个生长季内不同处理对土壤物理结构、养分变化及酶活性的影响。结果表明：（1）耕作深度与有机肥种类对土壤物理特性无显著影响。二者互作可显著提高0~20和20~40cm土层土壤有机质含量。S3FM可显著提高0~20cm土层土壤有机质、全氮和硝态氮含量及20~40cm土层土壤有机质的含量。（2）耕作深度×有机肥种类可显著影响0~20和20~40cm土层脲酶活性。S1FM较S1OF显著提高0~20和20~40 cm土层蔗糖酶活性41.75%和14.29%;当均施用农家肥时,脲酶的活性在耕深30cm达到最高,较其他处理增幅最高达57.89%。（3）土壤肥力质量综合评价表明,S3FM处理0~20和20~40cm土层土壤肥力质量得分均最高,分别为0.58与0.74。可见,农家肥深耕30cm可实现在一个生长季内提升保山植烟土壤肥力质量的目的。