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991.
Changes of yields, nitrogen uptake on the zero plots and nitrogen balances are discussed in the course of the decades at the Static Fertilization Experiment exemplary. 1991-2000 yields of cereals on the fertilized plots were nearly 200% in comparison to 1906-1915. At potatoes and sugar beets increase of yields was smaller. In the middle of all crops 52kg/ha nitrogen were taken up on the unfertilized plots in the years 1959-2000. Since there is a balance in the soil this nitrogen can only derived from the air. On the PK plots the atmogenic nitrogen input is 6kg/ha still higher. Crops with a long vegetation period like winter wheat and sugar beets take up more atmogenic nitrogen than such with a shorter vegetation period like summer barley and potatoes. The atmogenic nitrogen input per day of vegetation period is between 0,24 (winter wheat) and 0,38 (sugar beet)kg/ha and day. Nitrogen balances of the more important variants show that nitrogen uptake is higher than nitrogen input for a long time. In comparison of the decades 1961-1970 and 1991-2000 the best effect is in the case of mineral fertilization alone, also at increasing nitrogen input at the end of the century. The reason is the optimal control of nitrogen amount and time of application. In contrast organic fertilization and nitrogen release from the organic matter you can't control with the result of more unfavourable balances. 相似文献
992.
Gisa-Wilhelmine Rathke Martin Körschens Wulf Diepenbrock 《Archives of Agronomy and Soil Science》2013,59(5):423-433
Data of the "Static Fertilisation Experiment Bad Lauchstädt" were used to identify the effect of different fertiliser application on yield, various energetic parameters as well as on carbon and nitrogen balance of the long-term trial in a selected time period (1991-2000). The fertiliser regimes considered, are neither mineral fertiliser nor farmyard manure (without/without), mineral NPK and no farmyard manure (NPK/without), no mineral fertiliser and 10t ha m 1 a m 1 farmyard manure (without/10), mineral NPK and 10t ha m 1 a m 1 farmyard manure (NPK/10), no mineral fertiliser and 15t ha m 1 a m 1 farmyard manure (without/15), as well as mineral NPK and 15t ha m 1 a m 1 farmyard manure (NPK/15). The farmyard manure was only applicated to root crops. The crop rotation included sugar beets, spring barley, potatoes and winter wheat. In most cases, the treatment NPK/10 yielded in the most favourable results whereas the treatment without/without was the most unfavourable one. Sugar beets were - followed by winter wheat - the most profitable crops, potatoes the most unfavourable one. The fossil energy input was highly variable; it ranged from 4.1 to 24.3GJ ha m 1 a m 1 depending on fertiliser regime and crop. The total yield (based on main products and by-products) varied from 2.1 to 20.1t dry matter ha m 1 a m 1 , corresponding to an energy output between 3.4 and 33.6GJ ha m 1 a m 1 . The energetic parameters energy gain (net energy output) and energy intensity ranged form 25.5 to 315GJ ha m 1 a m 1 and from 143 to 1824MJ GE m 1 , respectively. The carbon balances resulted the highest C gain with the exclusive mineral fertilisation (NPK/without), followed from the treatment NPK/10. The same applies for the nitrogen balances. 相似文献
993.
Tomas Losak Jaroslav Hlusek Jiri Martinec Jiri Jandak Monika Szostkova Radek Filipcik 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(6):543-550
Abstract Due to continuous single nitrogen fertilization, we hypothesized a built-up deficiency of micronutrients in crops that would limit plant growth and crop quality. In 2-year field experiments using urea-N fertilized grain maize (Zea mays L.), hybrid KWS 2376 at 0, 120 and 240 kg N ha?1 crop uptake of Zn, Mn, Cu and Fe was studied at DC 32, DC 61 and in the grain harvested. Micronutrient contents at DC 32 stage – 1st node (aboveground phytomass) and DC 61 – flowering (ear leaf) were all at levels indicative of adequate micronutrient supply to the crop. At both sampling occasions the Fe:Zn and Fe:Mn ratios were adequate implying that Fe did not inhibit the uptake of Zn and Mn. The application of nitrogen increased the Fe content at the 1st sampling in both years; in the second year the same was also the case for the Zn content. Nitrogen nutrition increased the contents of Mn and Fe at the 2nd sampling only in year 2; in the other treatments no changes were observed in the micronutrient contents. Micronutrient correlations in the grain were discovered between Zn and Mn contents and between Fe and Mn contents. In the second year the highest N-rate significantly increased the Fe and Zn content of the grain compared with the lower rates of nitrogen fertilization. Grain yields were not affected by the rate of nitrogen and ranged between 13.65 and 14.34 t ha?1 (1st year) and between 13.68 and 14.18 t ha?1 (2nd year). Nitrogen fertilization did not reduce the content of micronutrients in the plant or grain of maize. It is evident that the continuous single use of N fertilization so far has not resulted in a micronutrient deficiency of the plants limiting the nutrient density of the grain or reducing its quality. 相似文献
994.
ABSTRACT Two cultivars of pea: ‘PS210713’ (‘PS’), sensitive to iron deficiency, and ‘Marveille de Kelvedon’ (‘MK’), tolerant, were cultivated in controlled climatic conditions during one month, on a nutrient solution containing either nitrate (NO3 ?, 4 mM) or ammonium (NH4 +, 4 mM) and in the presence of bicarbonate (10 mM). The effects of these nitrogen forms on the growth and the mineral nutrition, and especially iron nutrition are analyzed. The reduction of growth by bicarbonate was approximately 30% in case of NO3 ? nutrition in the two cultivars, whereas in ammoniacal treatment the reduction is only 6% and 18% respectively in ‘PS’ and ‘MK’ cultivars. In presence of bicarbonate, the plant growth is not stimulated by NO3 ?relatively to its growth on ammoniacal medium, as often noticed when plants are cultivated on medium without bicarbonate: In presence of this compound, the biomass production of plant pea, was not influenced by the nitrogen forms. The nitric source led to a ferric chlorosis in the sensitive cultivar plants whereas any chlorosis was noted when ammoniacal source was applied. On the other hand, nitric nitrogen form decreased the nitrogen feeding of plants and increased the potassium one, while the effect of the ammoniacal nitrogen form on these nutrients was quite the inverse. In addition, the later increased the allocation of iron towards shoots. Besides, with this nitrogen source there was not accumulation of nitrate in the plant tissues. In nitric feeding case, the nitrate is mainly accumulated in the roots of the two cultivars. It is noticeable that the sensitive cultivar (‘PS’) accumulates three times more nitrate than the tolerant one (‘MK’). On the level of the whole plant, the iron and phosphorus nutrition seems unaltered by the nitrogen form. 相似文献
995.
中国玉米化学氮肥利用率的时空变异特征 总被引:3,自引:0,他引:3
玉米生产对我国粮食安全意义重大。化学氮肥施用是保证玉米稳产高产的一个重要条件, 但过量施用也会导致环境问题, 所以化学氮肥的施用量和利用率一直是农业科学领域关注的一个重要课题。本文通过资料搜集、数据整理和分析, 探索中国过去几十年玉米各种植区化学氮肥的当季单位面积施用量(application rate, AR)和回收利用率(recovery efficiency, RE)、农学利用率(agronomic efficiency, AE)、偏生产力(partial factor productivity, PFP)的变异特征。结果表明: 在过去的几十年内, 中国玉米生产中当季AR总体呈增长趋势, 从1970s的93.3 kg·hm-2持续增长至21世纪初的238.2 kg·hm-2; RE和AE都呈下降趋势, 分别从1970s的42.1%和17.0 kg·kg-1下降至21世纪初的26.4%和9.5 kg·kg-1; PFP在各个时期均趋于稳定, 维持在40.0 kg·kg-1左右。在全国各玉米种植区内, 北方春播玉米区的AR各时期均较其他各区低且增速缓慢, AE和RE则偏高; 黄淮海平原春、夏播玉米区的AR增速同全国平均增速基本持平, 较全国略高, AE和RE较全国平均水平低。另外, 本研究还证实平衡施肥、使用氮高效品种以及优化农业管理等举措可成为提高我国氮肥利用率、减少资源浪费和减轻环境污染的有效途径。 相似文献
996.
玉米杂交种正红2号群体结构与密肥优化方案的研究 总被引:1,自引:2,他引:1
采用两因素五水平裂区试验设计方法,研究了种植密度和施氮量对玉米新杂交种正红2号的产量及其群体结构的影响,建立了优化栽培模型。结果表明,正红2号产量在7500kg/hm2以上的高产栽培技术方案为:种植密度为58542.2~75474.3株/hm2,施氮量为188.50~336.50kg/hm2。 相似文献
997.
不同形态氮素对甜菜生长发育的影响 总被引:2,自引:0,他引:2
论述了不同形态氮素对甜菜硝酸还原酶活性、谷氨酰胺合成酶活性及蔗糖合成酶活性的影响,并在影响生理生化过程的基础上,对氮素形态和甜菜生长发育及产质量的相关性进行了分析,提出了不同形态氮素配合施用是提高甜菜保护酶系统活性及其抗逆性的有效途径。 相似文献
998.
999.
1000.
玉米苗期氮素吸收利用效率差异及聚类分析 总被引:3,自引:0,他引:3
采用循环营养液培养法,研究安徽省23个玉米主推品种苗期吸收与积累氮素的差异.结果表明,在常氮(5 mmol/L)和高氮(45 mmol/L)水平下,玉米茎叶干重、总干重、叶面积、茎叶氮累积量和整株氮累积量的变异系数分别在0.34~0.58和0.35~0.51;其中,常氮和高氮条件下茎叶干重、总干重、叶面积、茎叶氮累积量和整株氮累积量呈极显著正相关(P<0.01),其相关系数分别在0.529~0.998和0.821~0.995.以玉米茎叶干重、总干重、叶面积、茎叶氮累积量和整株氮累积量为玉米苗期氮高效评价指标,玉米苗期氮效率综合值在常氮和高氮水平下分别在0.199~1.113和0.216~1.128,其中,浚单20在常氮和高氮条件下的氮效率综合值均大于0.90,且聚类分析中均在第一类群,为氮高效品种. 相似文献