氮肥运筹方式对油菜产量、氮肥利用率及氮素淋失的影响（简报）

通过盆栽模拟试验研究了不同氮肥运筹方式对油菜产量、氮肥利用率、氮素淋失及氮素平衡的影响。试验设5个处理：不施氮肥（CK），氮肥全部基施（TJ），氮肥60%基施、40%做越冬肥追施（TJD），氮肥60%基施、40%做薹肥追施（TJT），氮肥60%基施、20%做越冬肥、20%做薹肥追施（TJDT）。研究结果表明，氮肥分期施用可明显增加油菜产量，提高氮肥利用率，其中以TJDT处理效果最佳，与TJ处理相比，TJDT处理的产量、氮肥农学利用率及表观利用率分别提高了17.6%、2.1 kg&;#8226;kg-1氮和4.9%。同时，TJDT处理的氮素淋失量也最小。氮素平衡计算结果表明，不同时期追施氮肥对氮素平衡影响不大，但是均比氮肥集中做基肥施用(TJ)的表观损失明显减小。尽管油菜收获后，各施氮处理土壤氮素均有盈余，但分期施肥盈余量明显高于TJ。研究表明在油菜生产中，氮肥分期施用既能提高油菜籽的产量和氮肥的利用效率，又可获得较好的环境效应。     

控释氮肥对东北春玉米产量及土壤-作物体系内氮素平衡的影响

采用定位试验开展控释氮肥对春玉米产量及氮素在土壤-作物体系内平衡研究。结果表明,100%控释氮肥基施与100%普通速效氮肥基施比较,平均增产5.1%,玉米地上部氮素吸收总量平均增加6.6%,氮肥表观利用率平均提高2.4个百分点,氮肥农学效率平均提高2.0 kg/kg,土壤-作物体系内氮素盈余-10.2 kg/hm~2。60%控释氮肥与40%速效氮肥混合一次性施用与普通速效氮肥40%基施+60%追施比较,平均增产7.3%,玉米地上部氮素吸收总量平均增加8.8%,氮肥表观利用率平均提高6.8个百分点,氮肥农学效率平均提高3.0 kg/kg,土壤-作物体系内氮素盈余-17.7 kg/hm~2。75%控释氮肥基施与75%速效氮肥基施比较,平均增产7.5%,玉米地上部氮素吸收总量平均增加6.7%,氮肥表观利用率平均提高7.0个百分点,氮肥农学效率平均提高3.8 kg/kg,土壤-作物体系内氮素盈余-14.9 kg/hm~2。     

缓释尿素对滴灌玉米农田土壤无机氮及产量的影响

通过研究不同基施比例的缓释尿素与滴灌玉米土壤氮素供应、氮素吸收利用以及农田氮素平衡的相互关系,明确缓释尿素在滴灌玉米上作基肥施用并探讨其施用的适宜基施比例。结果表明,基施缓释尿素对比普通尿素增加了土壤硝态氮和铵态氮含量,缓释尿素处理土壤无机氮积累量表现为富集现象,不施氮处理则表现为负积累效应;土壤氮素含量随基施比例的增加而降低。玉米产量、氮肥利用率和农学效率随缓释尿素基施比例的增大表现为先增加后降低的趋势,土壤氮素表观损失量和氮素盈余量随基施比例的增大均先降后增。以缓释尿素50%作基肥的玉米产量及氮肥利用率较高,土壤氮素表观损失量较低。     

控释氮肥用量对早熟油菜产量及氮素吸收利用的影响?

为控释氮肥在双季稻区早熟油菜生产上大面积应用提供依据，研究控释氮肥用量对早熟油菜产量及氮素吸收利用的影响，以早熟常规油菜“1358”为材料，于2012-2013年在江西省油菜主产县(市)设置6个田间试验，调查控释氮肥用量对早熟油菜产量、产油量及氮素吸收利用的影响。结果表明，控释氮肥施肥效应与普通氮肥施肥效应均有随施氮量的增加而增产的趋势。等量控释氮肥一次性基施比普通尿素分次施用增产，甚至控释氮肥适量降低也能达到普通氮肥合理施用量的产量水平，同时提高了氮肥利用率。在180kg/hm2施氮水平下，控释氮肥一次性基施较普通尿素分底施60%，苗期施20%和抽薹期施20%共3次施用显著增产，油菜籽粒增产7.64％，产油量提高8.30％，氮肥利用率增加2.27个百分点。双季稻区早熟油菜控释氮肥施用量150kg/hm2可以达到普通氮肥180 kg/hm2用量的产量效果。     

氮肥运筹对夏玉米氮素利用及土壤无机氮时空变异的影响

研究不同施氮量及基肥追肥比例对土壤无机氮时空分布及玉米氮肥利用效率的影响。结果表明,不同施氮量和基追比显著影响土壤剖面硝态氮含量。各施氮处理不同生育期0～60 cm土层硝态氮含量均显著高于不施氮肥处理,且随施氮量的增加土壤中硝态氮含量增加。夏玉米生长季土壤铵态氮含量较低,且时空变化不明显。玉米氮素农学效率（NAE）、氮素利用效率（NUE）随施氮量的增加显著降低;氮素表观回收率（NRE）有相同的变化趋势,但差异不显著;氮素收获指数（NHI）随施氮量的增加显著增大。相同施氮水平下,“50%基肥+50%大喇叭口肥基追比”的NAE、NUE、NHI和玉米产量显著高于其他处理。因此,在玉米生产中应避免播种时一次性大量施用氮肥,增加后期施氮比例可显著提高氮肥利用效率和玉米产量。     

不同氮肥运筹对东北春玉米氮素吸收和土壤氮素平衡的影响

在吉林省榆树市粮食高产示范区,以先玉335为试验材料,通过田间试验研究不同氮肥运筹对春玉米的生长、产量及土壤氮素平衡的影响。结果表明,适宜氮肥运筹方式能显著提高玉米产量,施氮量200 kg/hm2,全部用作基肥不追肥(基追比1∶0)处理前期氮素供应过量,导致氮素向子粒转运量减少,过多保留在营养体中,致使产量和氮素利用效率相对其他处理较低;氮肥1/5基施,2/5拔节期追施,2/5大喇叭口期追施(基追比为1∶2∶2)的处理有较高的氮肥农学利用率、氮肥利用率和氮肥偏生产力。玉米生育期田间氮肥的表观损失主要由一次性过量施肥造成,增大拔节后追肥比例增加了收获后土壤的无机氮残留。对氮肥的调控应结合作物养分不同阶段需求及土壤养分供应,达到玉米高产和提高氮肥利用效率,减少氮肥损失对环境带来的危害。     

氮肥运筹对水稻产量及氮素利用率的影响

以北方超级稻沈农265为材料,研究了氮肥运筹对水稻产量形成及氮素利用率的影响.结果表明:施纯氮210kg/hm2,且基蘖肥与穗粒肥比为6∶4时,由于单位面积有效穗数较其他处理提高2.4％～21.1％,致使产量提高3.3％～20.2％;同一基蘖肥与穗粒肥施用比例下,随施氮量的增加,沈农265的总吸氮量呈上升趋势,而氮素利用率有下降趋势;不同施氮量条件下,穗粒肥比例增加有利于总吸氮量和氮素利用率的提高;适宜施氮量和基蘖肥与穗粒肥比例,能为水稻整个生育期提供比较平衡的氮素供应,提高氮肥利用效率,协调产量构成因素,从而提高产量,节本增效.     

苗期渍水对直播冬油菜产量和农学利用率的影响及油菜在不同氮肥施用下的响应

在轻简化施肥背景下，为减少渍害损失，解决长江流域冬油菜产区生产面临的重要问题，开展氮肥施用 对油菜渍害的缓解作用研究。设置三因素田间试验，分别为不同氮肥用量（0、60、120、180、240和300 kg N/hm2）、氮 肥类型（油菜专用控释尿素和普通尿素）和水分处理（苗期渍水和正常排水），测定各处理产量和氮肥农学利用率， 明确苗期渍水对不同氮素供应水平油菜的影响，并比较油菜专用控释尿素一次性施用和普通尿素分次施用下油菜 对苗期渍水的响应。结果表明，直播冬油菜产量随氮肥施用量增加而提高，至240 kg N/hm2时不再增加。油菜专用 控释尿素一次性施用，在氮肥用量为60～180 kg N/hm2时产量高于普通尿素分次施用；在氮肥用量为240～300 kg N/hm2时，两种氮肥类型产量基本相当。氮肥施用通过增加收获密度、单株角果数和每角粒数提高产量。苗期渍水 导致直播冬油菜产量损失1.1%～41.9%，随氮肥用量增加，渍水引起的产量损失率呈先增加后降低趋势。0～60 kg N/hm2处理时，渍水使收获密度显著降低（降幅达29.4%~45.0%），单株角果数增加；施氮量为120~180 kg N/hm2时， 渍水导致收获密度和单株角果数分别降低19.5%~33.7%和1.4%~17.7%；施氮高于180 kg N/hm2时，收获密度和单 株角果数降幅减小（降幅分别为5%~30.9%和3.6%~9.5%）。普通尿素分次施用和油菜专用控释尿素一次性施用， 分别在施氮量为120和180 kg N/hm2时产量损失率最高，分别达29.8%和41.9%。相同氮肥用量下油菜专用控释尿 素一次性施用的产量损失率大于普通尿素分次施用。渍水显著降低氮肥农学利用率，降幅为8.4%～51.9%，施氮充 足（240～300 kg N/hm2）时氮肥农学利用率降幅低于氮素用量较低处理（120～180 kg N/hm2），油菜专用控释尿素一 次施用处理的农学利用率平均降幅（36.5%）高于普通尿素分次施用（17.3%）。综上可知，苗期渍水时，油菜专用控 释尿素一次施用，会加重油菜受渍影响；土壤氮素供应能力较低时，渍害逆境解除后，适量追施速效氮肥可有效缓 解产量损失，实现油菜稳产。     

氮肥运筹对农大108产量、氮肥利用率及土壤氮素平衡的影响

以农大108为试材,通过田间试验研究不同氮肥运筹方式对春玉米干物质积累、子粒产量、氮肥利用率及土壤氮素平衡的影响。结果表明,氮肥不同运筹方式增产效果差异显著,其中,1/3氮肥底施、2/3氮肥两次追肥(N3)处理增产效果最好,其次是1/4氮肥底施、3/4氮肥3次追肥(N4)处理,氮肥全部作底肥(N1)处理增产效果最小。分次施肥有利于子粒粗蛋白含量、子粒蛋白质产量以及氮肥利用率的提高;随着施肥次数的增加,子粒粗蛋白含量、子粒蛋白质产量以及氮肥利用率均呈上升趋势,以N4处理最佳,其次是N3处理。氮肥不同运筹方式氮素表观损失量差异显著,N1处理其表观损失量最高,N3处理最低。因此,N3处理有效促进了植株对氮素的吸收利用,显著增加了产量和子粒蛋白质产量,降低了氮素表观损失量,是最佳氮肥运筹方式。     

氮肥用量对油菜产量及氮素利用效率的影响

通过大田试验研究了氮肥用量对油菜产量、养分含量、养分累积量及氮肥利用效率的影响。结果表明，与不施氮相比，施氮肥75、150和225kg/hm2平均分别增产41.9%、70.3%和66.2%，籽粒含氮量分别提高9.1%、14.2%和13.1%，植株地上部氮素总累积量分别增加59.6%、111.6%和108.0%。施氮促进油菜生长发育，显著提高油菜对氮素的吸收、累积和籽粒需氮量，但氮肥农学利用率、偏生产力和表观利用率均随氮肥用量的增加显著下降。氮肥用量在150kg/hm2时，能较好地协调油菜较高产量水平与合理氮肥利用率的统一。     

氮肥后移对花生氮代谢相关酶活性、氮素利用效率及产量的影响

本研究以农花5号为试材,在施氮肥总量一致的条件下,设3个不同施用时期处理：基施氮肥135 kg·hm^-2（T1）、基施氮肥67.5 kg·hm^-2+苗期追肥67.5 kg·hm^-2（T2）、基施氮肥45 kg·hm^-2＋苗期和开花下针期分别追肥45 kg·hm^-2（T3）、以不施氮肥CK为对照,研究氮肥后移对花生叶片氮代谢相关酶活性、氮素积累量与利用效率、产量及其构成因素的影响。试验结果表明,不同施氮时期处理下,氮代谢相关酶活性和氮素积累量的变化趋势大致相同,但活性和含量的高低因施氮时期的不同发生变化。T3处理能显著提高花生生育后期叶片的硝酸还原酶、谷氨酰胺合成酶和谷氨酸脱氢酶的活性;花生生育后期植株总氮素积累量、根系和荚果氮素积累量以T3处理最高,但各施肥处理间差异不显著;氮肥农学利用率和氮肥偏生产力亦以T3处理最高,且差异达到显著水平（P＜0.05）;T3处理产量最高,为5361.11 kg·hm^-2,比CK 、T1和T2处理分别增产20.79%、3.27%和5.66%。从产量构成因素分析,T3处理产量的提高主要依赖于花生的单株果重和饱果率的提高。     

Effect of sources of nitrogen on yield and nitrogen absorption of potatoes

In tests with sources of N, (NH₄)₂SO₄, when banded in the soil, usually resulted in highest tuber yield. Yields with Nitroform and sulfur-coated urea were similar to each other, and somewhat less than those from urea. Application of Aqua Humus, a humic acid derivative, in addition to several sources of N, had no significant effect on yields. Nitrogen absorption was highest from (NH₄)₂SO₄, as measured by NO₃ content of the petioles or total N absorption by the entire plant. There was little difference in N absorption from Nitroform and sulfurcoated urea. These materials did not result in increased N absorption by plants during late growth. In Kern County experiments, about 80% of the N from (NH₄)₂SO₄ and urea had nitrified and leached from the fertilizer band by 40 days after application. At 80 days after application, half of the N from Nitroform was still in place. In an experiment at Davis on a heavier soil, Nitroform had a slower rate of N release than sulfur-coated urea, followed in order by (NH₄)₂SO₄ and urea.     

氮素水平对油菜根茎叶氮素输出 及角果中氮素积累的影响

通过测定不同施N条件下油菜各器官的N素含量,研究了油菜后期根、茎枝、叶片等营养器官中N素的 输出和角果中N素的积累。其主要结果如下: (1)根、茎枝、叶片中N素积累量的变化呈先增后减的趋势,一般在 开花期前后达最大值;角果中N素总量随角果的生长逐渐增加。增施N肥明显增加各器官的N素积累量,推迟最 大值出现的时间。(2)根系、茎枝、叶片中的N素向外输出的比例随施N量的增加而下降,分别占其最大值的20% ～35%、35%～65%、55%～70%。(3)角果中的N素有30%左右来自叶片中N素的再利用,受施肥量的变化影响 较小; 35% ～10%来自茎枝的N素的再利用,随施N量的增加而减少;来自根系中N素的再利用不足5%;来自开 花后从土壤中吸收的N素约为30% ～60% ,随施N量的增加而增加。     

外源褪黑素对高氮下大豆氮代谢及生长发育的影响

过量的氮素供应会对大豆体内氮代谢及生长发育水平产生一系列的不良影响。因此，探索相应的补救措施具有十分重要的科学与实践意义。为此，本试验针对外源褪黑素对高氮环境下大豆氮代谢活动及整体生长发育的调控作用开展相关研究，分别采用7.5 mmol·L-1（对照组）和15 mmol·L-1（高氮组）的铵态氮作为唯一氮源，于大豆V3期进行100 μmol·L-1褪黑素的喷施处理。研究结果表明，外源褪黑素提高了高氮环境下大豆根系及根瘤的发育水平，并通过增强氮同化过程中谷氨酰胺合成酶等关键酶的活性，提高了氮代谢水平。此外，褪黑素还诱导了叶肉细胞内抗氧化酶活性的进一步升高，降低了膜脂过氧化程度，使光合等碳代谢能力也得到了相应的缓解。因此，褪黑素的施用有利于高氮环境下大豆碳、氮代谢平衡的恢复，进而促进各部分干物质的积累，缓解高氮对大豆生长发育的不利影响。     

施N水平对油菜杂交种及其亲本氮素利用效率的影响

通过测定不同施N水平下油菜杂交种及其亲本各器官的干物重和含N量，研究了施N水平对油菜杂交种及其亲本氮素利用效率的影响，结果表明：①油菜的氮素干物质生产效率（NUEp）、氮素籽粒生产效率（NUEg）以及氮素收获指数（NHI）均随施N水平的增加而显著降低。②不施氮肥条件下杂交种的NUEp和NUEg与其亲本相近，在施氮量为240和360Kg/hm2条件下显著高于其亲本。③杂交种的NHI在不施N肥和360Kg/hm2条件下与其亲本相近，而施N量为120、240 Kg/hm2时显著高于其亲本。④NUEg比NUEp和NHI更适合作为反映油菜N素效率高低的指标。     

Effect of fertilizer nitrogen source and cattle slurry on herbage production and nitrogen utilization

A field plot experiment was carried out on an established grassland sward from 1983–88 inclusive to examine the effects of time of application, chemical form of nitrogen (N) and cattle slurry dry matter (DM) content on yield and efficiency of N use. Four forms of fertilizer N (a semi-organic fertilizer, a combined 2.1:1 (w/w) semi-organic/calcium ammonium nitrate (CAN) fertilizer, CAN and urea, each supplying 300 kg N ha^?1 year^?1, were applied with or without unseparated or separated cattle slurry at 93 and 73 g kg^?1 DM respectively, both supplying approximately 150 kg N ha^?1 year^?1. All fertilizers and slurries were applied in three equal dressings (February/March, May/June and July/August). The efficiency of use of fertilizer and slurry N was evaluated by measuring DM yield, N uptake and apparent recovery of N in herbage at all harvests during each growing season. Fertilizer N application significantly increased (P<0.001) the mean yields of herbage at each harvest in all years. The form of fertilizer N had no significant effect (P>0.05) on first harvest and total herbage yields, nor on N uptakes by herbage at the first harvest in any year. The performance of urea and of CAN was more variable at the second and third harvests relative to that of the semi-organic or combined 2.2:1 (w/w) semi-organic/CAN sources which had similar efficiencies of N use. Lower DM production was associated with reduced uptake of N. Values for mean overall apparent recovery of N ranged from 57.9 ± 2.67% for the semi-organic fertilizer to 50.2±3.05% for CAN. Unseparated cattle slurry and separated cattle slurry produced similar herbage yields and N responses that were lower and more variable than with fertilizer N. The overall mean apparent recovery of N from unseparated cattle slurry was 25.5 ± 5.03% compared to 5.0 ± 4.74% for separated cattle slurry. Efficiency of N use was highest with spring applications and least with mid-season applications. Recoveries ranged from ?29% for separated cattle slurry applied in June 1984 to 56% for unseparated and separated cattle slurry applied in February 1988 and June 1987 respectively. No interactions were recorded between cattle slurry and fertilizer N in terms of DM production or N uptake by herbage. The results of this study support the use of a fertilizer N source, selected on a least-cost basis, in combination with slurry to promote spring herbage production. For subsequent production, N should be supplied in fertilizer form only. The use of urea is risky under low rainfall conditions. Mechanical separation did not improve the efficiency of use of slurry N.     

Influence of applied nitrogen on potato part II: recovery and partitioning of applied nitrogen

Maximizing fertilizer nitrogen (N) uptake efficiency, while maintaining crop productivity may reduce potential nitrate contamination of groundwater. A two-year field investigation was conducted to evaluate the effects of applied N on fertilizer N uptake, uptake efficiency, and total fertilizer N recovery of potato (Solarium tuberosum L. var. Russet Burbank) grown on irrigated sandy soils in Michigan. Nitrogen was applied as₁₅N-depleted ammonium sulfate [(NH₄)₂SO₄] at rates 0, 56, and 112, kg N ha^-1 in a single application at planting or 112 and 168 kg N ha^-1 in split applications during the growing season. Fertilizer N uptake efficiency was relatively unaffected by the N treatments. Fertilizer N uptake efficiency for the whole crop at onset of senescence averaged 52 percent, while values calculated for tubers at harvest were 34 percent. An average of 27 percent of the applied N was present in the soil to a depth of 120 cm after harvest. Approximately 83 percent of this N was found in the 0–30 cm depth. Over 90 percent of the recovered soil N was in the organic form. In this investigation, crop fertilizer N uptake and fertilizer N recovery in soil averaged 63 percent and was largely unaffected by the rate or timing of fertilizer N applications.     

Herbage production and nitrogen recovery from slurry injection and fertilizer nitrogen application

An experiment was carried out during 1986 and 1987 to examine the effects of mid-season slurry injection and fertilizer-nitrogen (N) application on herbage dry matter (DM) yield and N recovery. Cattle and pig slurry were injected at 56 and 112 m³ ha⁻¹ into an established sward. Five rates of fertilizer-N, as calcium ammonium nitrate, ranging from 0 to 120 kg ha⁻¹ in 30-kg increments, were superimposed on these treatments, and in both years DM yield was measured in one cut after 70 d regrowth. Slurry treatments increased herbage DM yields significantly ( P < 0-001). The efficiency of slurry total N compared with calcium ammonium nitrate-N averaged 53% in 1986 and 86% in 1987. The mean apparent recovery of slurry total N in herbage was 55% in 1986 and 40% in 1987. Fertilizer-N application increased ( P < 0.001) the mean yields of herbage in both years but when combined with some of the slurry treatments, DM yields over the five N-levels did not differ significantly, giving rise to interactions in 1986 ( P < 0-001) and 1987 ( P < 001). It is concluded that mid-season injection of slurry can be an effective means of utilizing slurry-N in terms of herbage DM production and consequent N use.