Nitrogen Fertilizer Replacement Value of Concentrated Liquid Fraction of Separated Pig Slurry Applied to Grassland

Seven grassland experiments on sandy and clay soils were performed during a period of 4 years to estimate the nitrogen (N) fertilizer replacement value (NFRV) of concentrated liquid fractions of separated pig slurry (mineral concentrate: MC). The risk of nitrate leaching when applying MC was compared to when applying mineral fertilizers. Grassland yields in 2009–2012 fertilized with MC were compared with grassland fertilized with two mineral fertilizers: granulated calcium ammonium nitrate and liquid ammonium nitrate (LAN). The mineral fertilizers comprised 50% nitrate-N and 50% ammonium-N, and MC comprised 95–100% ammonium-N. Treatment application rates included zero N and three incremental rates of N fertilization. The liquid fertilizers were shallow injected (0–5 cm). The NFRV of MCs was 75% on sandy and 58% on clay soil with granulated ammonium nitrate as reference, and 89% on sandy and 92% on clay soil with LAN as reference. Risk of nitrate leaching after application of MC, measured in residual soil mineral N post-growing season and N in the upper groundwater in the following spring, was equal to that for mineral fertilizers.     

Application of Fresh and Treated Pig Slurries and a Novel Organic-Mineral Fertilizer in Maize Crop

Lysimeter experiments were carried out during two growing seasons to compare the effect of untreated, digested, codigested, and a novel organic-mineral fertilizer, synthesized with pig slurry by a new-generation technology, on nitrogen (N) and phosphorus (P) leaching when compared with mineral fertilizer at typical rates for maize (Zea mays L.) production in Mediterranean soil. Relationships between application rates and type of fertilizer on maize crop yield, N uptake, and N and P leaching were investigated to assess the efficacy of these fertilizers in Mediterranean areas. Results showed a positive effect of the use of treated slurries, high N uptake of maize plants, and dry-matter production that was crucial for keeping N leaching loads at minimum. Then, not only in terms of production, but also in terms of N conservation in soil and in environmental water quality, slurries showed a better performance than inorganic or the organic-mineral fertilizer.     

Effects of short‐term nitrogen supply from livestock manures and cover crops on silage maize production and nitrate leaching

Resource use efficiency requires a correct appreciation of the nitrogen (N) fertilizer replacement value (NFRV, percentage of total N applied) of manures. We assessed the NFRVs of the liquid fraction originating from separated pig slurry (MC), untreated pig slurry (PS), untreated cattle slurry (CS), the solid fraction from separated pig slurry (SF) and solid farmyard manure from cattle (FYM) in two consecutive years in silage maize grown on a sandy soil. Maize yields responded positively to each of these N sources applied at rates up to 150 kg of mineral fertilizer equivalents per ha per year (i.e. NFRV × total N rate). The observed NFRVs, relative to calcium ammonium nitrate fertilizer, amounted to 78% for MC, 82% for PS, 79% for CS, 56% for SF and 34% for FYM when averaged over both years. NFRVs were positively related to the ammonium‐N share in the total N content. Rye cover crop establishment after the harvest of maize reduced nitrate concentrations of the upper groundwater by, on average, 7.5 mg nitrate‐N/L in the first year and 10.9 mg/L in the second year, relative to a bare soil. Regardless of the presence of a cover crop, nitrate concentrations responded positively to the applied rate of effective N (total N × NFRV) but less to postharvest residual soil mineral N.     

基施缓释肥等氮替代化肥对径流氮素流失和青贮玉米生长的影响

[目的]探究配施两种释放方式不同的缓释氮肥对滇中地区坡耕地径流氮素流失及青贮玉米生长的影响,为滇中坡耕地水土保持提供理论依据和支持。[方法]通过研究自然降雨条件下的径流槽模拟试验,在等氮条件下设置普通尿素(CK),40%添加了硝化抑制剂的速溶诺泰克^?21+60%普通尿素(处理I)和40%包膜缓释氮肥聚谷氨酸增效3代+60%普通尿素(处理Ⅱ)3个处理。[结果]生育期内各处理氮素流失呈先上升后下降的趋势,其中CK流失量最高,处理I和处理Ⅱ较CK有显著减少,总氮流失量分别下降了29.95%和16.77%,硝态氮分别减少了14.55%和6.53%,铵态氮分别减少了16.08%,8.24%。尿素配施缓释氮肥能够有效提高土壤全氮和铵态氮含量,减少硝态氮含量。处理I,Ⅱ较CK相比土壤全氮含量增加了3.25%和0.87%,铵态氮含量分别显著增加了30.57%,25.70%;较CK相比,处理I、处理Ⅱ硝态氮含量分别减少了22.49%和16.61%。[结论]3个处理间青贮玉米的产量无显著性差异,但配施缓释肥可以在保证土壤肥力和满足青贮玉米正常生长需求的同时减少坡耕地径流养分流失,其中...     

缓释肥等氮替代尿素对坡耕地径流氮素流失和青贮玉米生长的影响

为比较单施尿素与尿素和缓释肥配施对云南坡耕地径流氮流失、土壤养分及青贮饲用玉米生长的影响作用。通过自然降雨下的径流槽试验,在等氮条件下按云南常规施肥量设置单施尿素(CK)、添加硝化抑制剂速溶诺泰克^®21等氮替代40%的尿素+60%普通尿素(处理I)和聚谷氨酸增效3代等氮替代40%的尿素+60%普通尿素(处理Ⅱ)3个处理。结果表明:生育期内尿素配施缓释肥的处理I和处理Ⅱ与单施尿素CK处理相比,总氮、铵态氮和硝态氮流失浓度削减量最高分别为2.59,1.60,1.42 mg/L和1.61,1.38,1.25 mg/L;累计流失量与CK相比,处理I、处理Ⅱ的总氮、铵态氮和硝态氮累计流失量分别削减18.56%,16.19%,24.31%和10.75%,8.73%,17.08%。在青贮玉米生育期内,配施缓释肥处理土壤较CK处理铵态氮含量分别显著提高13.94%~45.04%和9.63%~22.39%,硝态氮含量分别显著降低3.70%~29.91%,8.61%~12.55%,土壤微生物生物量氮含量分别显著提高22.13%~31.76%,11.80%~22.81%。尿素配施缓释肥也可以显著提高青贮玉米产量和植株氮吸收量,并通过显著提高植株粗蛋白和粗脂肪含量,降低粗灰分和洗涤纤维含量来提高其品质性状。相关性分析可知,径流氮流失与土壤氮含量、青贮玉米产量和植株吸氮量呈负相关关系,土壤氮素与产量和植株氮吸收均呈正相关关系,产量与植株氮吸收呈极显著正相关关系。综上所述,与单施尿素相比,尿素配施缓释氮肥能够减缓土壤氮素的硝化过程,显著增强土壤的固氮能力,维持土壤高氮素水平,进而提高青贮饲用玉米的产量和品质,为红壤坡耕地青贮玉米种植的施肥提供科学理论依据。     

玉米施肥新技术及影响施肥效果的因素

参考了90年代以来我国玉米施肥技术研究的新成果,针对近年来玉米生产对施肥技术提出的新要求,介绍了新的施肥技术和改善施肥效果需要考虑的各影响因素等。     

华北平原玉米种植中施入氮肥的去向研究

为了定量研究玉米氮肥利用特性以及肥料氮的去向,设计了~(15) N标记微区控制试验,设置3个施氮水平:不施氮肥(对照)、低氮处理(120kg N/hm~2)和高氮处理(240kg N/hm~2)。结果表明:土壤中残留~(15) N量随施氮量增加而显著增加(P0.05)。在空间分布上,总体呈现出随土壤深度先下降后上升的趋势,高氮处理和低氮处理~(15) N累积量均以40—60cm和60—80cm土层最多,这两层残留~(15) N总量分别占总投入量的37.55%和18.99%。与对照相比,施氮处理均显著提高了玉米地上、地下生物量和籽粒产量以及各部分吸氮量。虽然高氮处理较低氮处理施氮量增加了1倍,但籽粒产量仅增加0.14倍。氮肥农学效率与氮肥表观利用率随着施氮量增加而显著降低。高氮处理和低氮处理中玉米对~(15) N标记氮肥的利用率分别为28.86%和31.15%,土壤氮残留率分别为50.42%和36.52%,当季进入地下水的比率分别为4.27%和0.68%,其他损失率分别为16.45%和32.33%。研究结果表明,施氮量为120kg/hm~2可有效增加玉米产量,同时提高氮肥利用率,减少土壤氮累积,减小氮肥施用产生的环境污染风险。     

Nodulation and Symbiotic Nitrogen Fixation of Cowpea Genotypes as Affected by Fertilizer Nitrogen

Abstract

Intercropping with legumes and non‐legumes is commonly practiced in many parts of the world to maximize productivity per unit area of land. In India, cowpea [Vigna unguiculate (L.) Walp] is a popular pulse legume component of intercropping farming systems. Often, however, potential production is compromised, particularly in high fertilizer input systems, because legume component competes with the non‐legume component of the system for nitrogen (N) in the soil. An experiment was conducted in order to identify lines of cowpea that could obtain the majority of their nitrogen requirements from symbiotic fixation of atmospheric nitrogen rather than from uptake of soil nitrogen. Twenty‐nine genotypes of cowpea were screened for tolerance to (applied) nitrogen in soil in field condition. The parameters used to appraise tolerance were extent of root nodulation, the amount of nitrogen fixed, nitrate reductase activity (NR) in roots and nodules, and nitrite content of roots and nodules. There were two nitrogen treatments applied as urea, 40 kg N per ha (N40), and 120 kg N per ha (N120). There were three genotypes whose nitrogen‐fixing effectiveness was apparently unimpaired by applications of nitrogen to the soil. Genotype EC‐170442‐3 nodulated and fixed atmospheric nitrogen satisfactorily at higher levels of applied nitrogen. At N40, genotypes EC‐244390 and EC‐240900 formed a great abundance of large nodules effective in nitrogen fixation; even at N120, EC‐240900 had better symbioses than the majority of the 29 cowpea lines originally screened. These three genotypes are deemed worthy of further examination for their suitability for intercropping systems. How this might be achieved is discussed.     

不同施肥措施对玉米根际土壤微生物数量及养分含量的影响

通过田间试验,研究了不同施肥措施对根际土壤微生物数量及养分含量的影响。结果表明:(1)施肥显著提高了根际土壤微生物数量。在玉米生育期内土壤细菌和放线菌数量平均数量表现为MNP(有机肥+N+P)>M(有机肥)>NP(N+P)>CK(对照),与CK相比,MNP、M和NP处理细菌数量分别提高了302.82%、183.96%和136.23%,而放线菌数量则分别提高了93.97%%、62.64%和54.28%。土壤真菌平均数量表现为MNP>NP>CK>M,其中MNP和NP分别比CK提高了33.74%和29.08,而M则比CK降低了8.39%。土壤好气性固氮细菌平均数量表现为MNP>NP>M>CK,MNP、M和NP分别比CK提高了55.46%、24.63%和40.87%。(2)在玉米收获期土壤有机质和各营养指标含量均比播种期降低,不同施肥处理土壤有机质含量在播种期和收获期均表现为M>MNP>CK>NP,而土壤全氮、全磷、全钾、碱解氮和速效磷含量在播种期表现为MNP>NP>M>CK,在收获期表现则不尽一致。(3)土壤细菌、放线菌和固氮菌数量均与土壤全氮、全磷和碱解氮含量之间有显著正相关关系(P<0.05),土壤真菌数量与土壤有机质及各养分含量之间相关性较差。     

控释氮肥比例对土壤氮含量和玉米氮素吸收利用的影响

通过大田试验,研究相同氮肥施用量的条件下,不同比例控释尿素与普通尿素混合施用对土壤氮含量、玉米植株氮素吸收利用及产量的影响。结果表明:施氮显著提高了0-20,20-40cm耕层土壤碱解氮和全氮含量。全施普通尿素时,一次施肥可提高前期土壤氮含量,而2次施肥则有利于提高后期土壤氮含量;与普通尿素施肥相比,掺混一定比例的控释尿素一次性底施可显著提高各生育时期耕层土壤含氮量。适宜比例的控释尿素与普通尿素掺混施用可在一定程度上增加玉米中后期的氮素积累量,提高氮肥表观利用率、氮肥农学效率和肥料贡献率以及玉米功能叶关键酶活性,在相同氮肥水平下,其一次性底施的效果甚至超过普通尿素2次施用。随控释尿素比例的增加,玉米产量呈先增后减趋势,以75%控释尿素+25%普通尿素处理产量最高,比普通尿素一次施增产12.09%(2014年)和21.58%(2015年),比普通尿素2次施肥增产8.27%(2014年)和14.19%(2015年)。因此,普通尿素掺混75%比例的控释尿素进行一次底施,不仅能够协调在整个玉米生育期土壤对氮素的供应,实现玉米的有效增产,而且还能够减少施肥次数和劳力投入。     

稳定氮肥用量对夏玉米产量和氮肥利用率的影响

通过大田小区试验,研究了稳定氮肥不同用量对夏玉米产量、养分累积量、氮肥利用效率及经济效益的影响。结果表明,与不施稳定氮肥相比,稳定氮肥施氮量90、150、210 kg·hm-2和270 kg·hm-2分别增产36.7%、62.1%、76.6%和81.9%,地上部氮素总累积量分别增加39.0%、60.3%、79.0%和113.4%,经济效益分别增加36.1%、61.2%、72.7%和77.1%;与农民习惯施用氮肥相比,高量稳定氮肥用量210 kg·hm-2和270 kg·hm-2分别增产7.3%和10.5%,地上部氮素总累积量分别增加3.2%和23.0%,经济效益分别增加9.7%和11.4%。施用稳定氮肥促进夏玉米对氮素的吸收累积,高量210 kg·hm-2和270kg·hm-2处理较习惯施氮提高总吸氮量。施用稳定氮肥各处理氮肥表观利用率和农学效率显著高于农民习惯施氮,偏生产力高于农民习惯施氮,生理效率除270 kg·hm-2处理外,高于农民习惯施氮。稳定氮肥施氮量在210 kg·hm-2时,能较好地协调玉米高产与稳定氮肥合理利用的统一。     

秸秆还田下氮肥用量对玉米产量及土壤无机氮的影响

研究连续2年秸秆还田下氮肥用量对玉米产量、氮肥利用率及土壤硝态氮的影响,结果表明,玉米产量随着施氮量的增加逐渐增加,施氮量达到216 kg·hm-2时,产量最高,施氮量超过216 kg·hm-2时产量有降低的趋势。相同施氮处理玉米产量年际变化明显,2010年较2009年产量提高0.69%~4.75%。氮肥利用率、氮肥农学利用率和氮收获指数随着秸秆还田年限的增加,均有不同程度的增加。2年0~100 cm土层土壤硝态氮含量均以施氮240 kg·hm-2最高,且有向土壤深层迁移的趋势,对浅层地下水构成潜在的威胁。与施氮240 kg·hm-2相比,施氮168、192 kg·hm-2和216 kg·hm-2处理0~100 cm土壤无机氮残留量2年平均减少39.87%、35.84%和29.38%。相同施氮处理,0~100 cm土壤无机氮累积量2010年较2009年略有降低。综合考虑玉米产量、氮肥利用率与生态环境效益,该地区最适施氮量200 kg·hm-2左右。     

移栽玉米的氮素诊断及追肥推荐研究

本文通过对不同施氮量与移栽玉米产量的两种模型比较 ,得出线性加平台能较好的模拟产量与施氮量的关系 ,由此得到了最佳施氮量和最佳产量 ,同时确定了玉米植株硝酸盐 ,土壤0～ 30 cm硝酸盐的推荐施氮临界值指标。     

地下水埋深与控肥对夏玉米氮素吸收和产量的影响

为探明地下水埋深与减施氮肥对夏玉米氮素吸收利用及产量的影响,基于大型地中渗透仪,研究了地下水埋深和施氮量对夏玉米氮素利用效率、植株氮素积累量、产量及其形成要素的影响,其中地下水埋深设2 m(G1),3 m(G2)和4 m(G3)3个水平,施氮量设减氮20％处理(240 kg/hm2,N1)、常规施氮处理(300 kg/...     

太湖和滇池流域保护地蔬菜氮肥去向研究

为了研究化肥氮在保护地土壤-蔬菜系统中的当季利用与损失,在浙江嘉兴和云南昆明15个点位上进行15N田间微区试验。结果表明,保护地莴苣化肥氮当季利用率为8.32%~14.52%,保护地西芹化肥氮当季利用率为6.34%~13.85%,保护地结球生菜化肥氮当季利用率为11.34%。相同土壤、同一种类蔬菜保护地种植中,随着保护地种植年限的增加,蔬菜对化肥氮当季利用率显著降低。莴苣和西芹吸收化肥氮和土壤氮的比例在不同种植年限保护地土壤上差异不显著。当季蔬菜收获后,0～20 cm土层15N丰度和化肥氮残留量显著高于20 cm以下各土层。在保护地莴苣种植系统中,施入土壤中的化肥氮有18.98%～42.5%损失。在保护地西芹种植系统中,有11.7%~18.9%损失。在保护地生菜种植系统中,施入土壤中的化肥氮有16.0%损失。     

Effect of Water Stress in Maize Crop Production and Nitrogen Fertilizer Fate

ABSTRACT

Maize production is affected by water and nitrogen (N) deficit either separately or joined, but this fact is not completely defined. The aim was to evaluate the fate of N in maize fertilized and subjected to water stress in controlled conditions. A greenhouse experiment was carried out at the University of Buenos Aires campus. The design was a 2 × 2 factorial with four replications. The factors were N: 70 and 140 kg N ha^?1 as labeled urea (¹⁵N), and water: 100% or 50% of the potential evapotranspiration. The harvest of aerial and root biomass was carried out at R1 stage. Nitrogen in plants, soils nitrate, ammonia volatilization, and ¹⁵N percentage were determined. Obtained results only partially agree with previous research. Water stress depressed aerial biomass production independently of N doses. When water was limiting, the uptake of N from fertilizer was independent of N. When water was not limiting, N uptake increased with the higher N doses. Volatilization losses were 3.7 to 7.8% of N applied as fertilizer. Plant N recovers was around 45% of the N applied, except in treatment water stressed with high N rate (19%). Nitrate-N from the fertilizer in the soil at harvest and accumulated N from the fertilizer in plant were lineally related (r² = 0.54; p < 0.001). Important destinations of N were accumulation in plant, volatilization and incorporation into soil organic matter. However, residual nitrate was a main fate in heavily fertilized and water deficit treatment. This process could lead to the eventual nitrate leaching.     

有机资源等氮替代化肥对免耕稻田N2O排放及水稻产量的影响

试验设置两种稻田免耕模式［常规免耕（C）、粉垄免耕（F）］,两种免耕模式下各设置四种施肥方式,绿肥与化肥配施（C3、F3）、蚕沙与化肥配施(C4、F4）,同步设置不施肥的空白对照（C1、F1）,施全量化肥的常规对照（C2、F2）处理,采用分离式静态箱−气象色谱法测定双稻季水稻生育期内稻田N₂O排放通量,并测定水稻收获期干物质量、产量和根冠比等,以探讨集约化稻作下有机氮替代化学氮对稻田N₂O排放及水稻产量的影响,为稻田有机资源与化肥配施提供科学依据。结果表明：（1）有机资源替代化学氮肥能够显著降低稻田N₂O累计排放量。C3、C4、F3、F4的N₂O累计排放量较C2、F2在早稻季分别降低69.1%、86.3%、69.9%和63.4%,晚稻季分别降低7.3%、67.2%、38.5%和60.4%;（2）免耕稻田下绿肥替代化肥利于水稻稳产。粉垄免耕下F3较F2产量提升0.6%～10.0%,F4较F2产量下降1.7%～6.6%;常规免耕下C3较C2产量降低1%～1.1%,C4较C2产量下降1.1%～8.4%。（3）有机资源等氮替代化肥影响水稻根系生长,显著提高植株干物质量、有效穗数和穗粒数。早、晚稻生长季C3、F3的植株干物质量较C2、F2分别提高22.6%和5.4%;有效穗数和穗粒数分别提高6.3%～13.5%和0.3%～6.2%。稻田免耕下两种有机资源替代化学氮肥均能有效降低N₂O排放,粉垄免耕下绿肥替代化学氮肥显著提高水稻干物质量及根系活力,能够维持水稻产量稳定并减少稻田N₂O排放,采用绿肥等氮替代化肥可作为一种集约化稻作可持续生产调控技术。     

控释氮肥减量施用对春玉米土壤地表径流氮素动态及其损失的影响

在自然降雨条件下的南方丘陵山地典型区域田间径流小区进行定点观测,比较了不施肥处理(T1)、普通尿素处理(T2)、控释氮肥处理(T3~T6)的TN、DN、NO_3~--N和NH_4~+-N的流失浓度变化及其损失负荷特征,为有效控制旱地氮素径流损失从施肥管理角度提供借鉴。结果表明,在168~240kg/hm~2施氮水平变化内,施肥量的增加或减少对径流量的影响不显著(P0.05);与施用普通尿素处理(T2)相比,等氮量的控释氮肥处理(T3)的TN、DN、NO_3~--N和NH_4~+-N的平均流失浓度及损失负荷变化无显著差异(P0.05),当控释氮肥施氮量减少20%时,TN平均流失浓度降低达极显著水平(P0.01)和损失负荷减少达显著水平(P0.05),DN平均流失浓度降低达显著水平(P0.05),损失负荷却始终差异不显著(P0.05);控释肥处理减氮30%的TN损失较T2、T3分别下降39.86%(P0.01)和32.50%(P0.05),较减氮20%处理的效果更好。旱地春玉米种植控释氮肥的施氮量控制在168~192kg/hm~2能够有效减少氮素径流损失,降低环境污染风险。     

长期施用化肥和有机肥下潮土干团聚体有机氮组分特征

依托中国科学院封丘农业生态实验站长期施肥试验,选取不施肥(CK)、单施化肥(NPK)、有机无机肥配施(1/2OM)、有机肥(OM)处理,对比研究27a连续施用化肥和有机肥对土壤机械稳定性团聚体及其有机氮组分的影响。结果表明,长期施用有机肥显著提高了耕层土壤中大于2 mm团聚体的比例,较CK提高了33%,较NPK增加了17%。施肥显著提高耕层团聚体中有机氮含量,以OM处理效果最明显,大于2 mm、2～0.25 mm、小于0.25 mm团聚体中酸解有机氮含量分别为776.4、837.7、625.3 mg·kg~(-1)。各团聚体中有机氮以酸解铵态氮为主,氨基糖态氮最少。长期单施化肥主要提高了大于2 mm团聚体中酸解铵态氮比例,施用有机肥提高了氨基酸态氮和酸解未知态氮含量及分配比例。长期施用有机肥使潮土结构明显改善,有利于耕层团聚体中全氮及有机氮各组分的积累,氨基酸态氮、氨基糖态氮、非酸解有机氮主要赋存于2～0.25 mm团聚体中,而酸解铵态氮和酸解未知态氮在大于2 mm团聚体中分布较多,有效地提高了土壤供氮能力。     

Influence of Nitrogen and Saline Water on the Growth and Partitioning of Mineral Content in Maize

ABSTRACT

Saline irrigation water has a tremendous impact on the yield potential of crops. Distribution of mineral elements in the parts of maize plant in response to saline water and nitrogen (N) nutrition was studied in a pot experiment for six weeks. Plants were irrigated either with tap water or saline water (ECw: 3.2 dSm^?1). Nitrogen was applied at the rate of 0, 50, 100 and 200-kg ha^?1 denoted as N0, N1, N2, and N3, respectively. Plants were separated into leaf, stem and root and analyzed for N, calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K) concentrations. Dry matter production of leaf, stem and root was significantly reduced with saline water. The partitioning of elements in plants was the function of nitrogen and saline water. The N concentration of plant parts varied in the order of leaf > stem > root. A significant decrease in the N content was noted in plants under saline water. The root contained the highest Na content, Ca and Mg were higher in the leaf, whereas K was highest in the stem under saline water. Sodium was highest in the root and the remainder elements were greatest in the stem under tap water. Potassium and Cl were significantly reduced by N level whereas the reverse was true for Ca, Mg and Na content. The Na/K, Na/Ca, and Na/Mg ratios were also higher in salt stressed plant parts due to higher accumulation of Na ion. Among N-fertilizer treatments the Na/Ca and Na/Mg ratios were highest in control whereas Na/K increased with the addition of N. This study indicated that interaction of saline water and nitrogen has mixed effects on the partitioning of mineral elements in maize.