Nitrogen Fertilizer Replacement Value of the Liquid Fraction of Separated Livestock Slurries Applied to Potatoes and Silage Maize

Separation of livestock slurries followed by reverse osmosis yields mineral concentrates (MCs) in which almost all nitrogen (N) is ammonium (NH₄)-N. The ability of MCs to substitute calcium ammonium nitrate (CAN), a common conventional mineral N fertilizer, was tested in two trials on a silty loam soil (ware potatoes, 2009 and 2010) and four trials on sandy soils (starch potatoes, 2009 and 2010; silage maize in 2010 and 2011). The N fertilizer replacement value (NFRV) of spring-injected MCs ranged from 72 to 84%, slightly less than their share of ammonium-N (90–100%). The fate of N that was apparently unavailable to crops was not fully disclosed, but there were indications that ammonia loss may have played a role.     

不同初始pH对猪粪水酸化贮存过程及氮素损失的影响

为减少猪粪水贮存过程中氮素损失,提高还田安全性,采用酸化贮存技术,以磷酸为酸化剂,比较了不同初始pH对猪粪水酸化贮存过程及氮素损失的影响。结果表明：试验用猪粪水中重金属浓度大小顺序为：Cu>Pb>Zn>Cd>As,贮存后重金属浓度均降低,符合《农用沼液：GB/T 40750-2021》标准,但贮存180 d后猪粪水氮素损失率达68.55%,贮存后猪粪水中氮素以氨氮为主,占比达51.73%;酸化pH与酸化剂用量的相关性公式为：y=-3.3113x + 22.999,R2=0.985;酸化贮存大幅减少了猪粪水氮素损失,损失率较CK降低了5.98-62.77个百分点,且贮存后氨氮占总氮占比大幅提高24个百分点以上,保氮效果与pH呈反比;磷酸酸化提高了猪粪水总磷和水溶性磷浓度,增加幅度与磷酸用量呈正比;酸化贮存后猪粪水EC、Cd和Pb浓度偏高,抑制根和茎生长,其负面效应与贮存pH呈反比;酸化贮存降低了猪粪水Cu浓度,Cu浓度与pH呈正比,对As和Zn的作用无明显规律。综上所述,建议将猪粪水pH调至6.0后贮存,酸化剂成本为13.89元·吨-1。     

水氮处理对玉米根区水氮迁移和利用的影响

为研究灌水和施氮位置对玉米根区水氮迁移和利用的影响,通过春玉米水氮同区、异区隔沟灌溉试验,研究了不同水氮处理根区土壤水氮迁移和水氮利用规律。结果表明同区低水处理和异区高水处理收获时根区土壤硝态氮残留量较大,同区高水处理更容易导致硝态氮的淋失。异区高氮低水处理的籽粒产量最大为9953kg/hm2,并且水分利用效率也最高,为6.70kg/m3,比同区高氮高水处理的水分利用效率提高72.68%。高水处理的水分利用效率小于低水处理的水分利用效率;高氮处理玉米的氮素累积总量大于低氮处理的氮素累积总量,作物的氮素累积总量和施氮量呈正相关;其中异区高氮低水的氮素累积总量最大,同区低氮高水处理的最小。最佳的水氮耦合处理是异区高氮低水。     

沼液农用对土壤氮素形态影响的整合分析

通过研究沼液施用对农田土壤氮素形态影响,为沼液农田可持续利用提供数据支撑。在中国知网和Web of Science文献数据库中,以“沼液”和“氮”为     

沼液处理方式及资源化研究进展

该文综述了国内外厌氧发酵概况,以及沼液性质和国内外处理工艺的发展情况,并针对沼液成分的分析,从资源化利用的角度,对沼液回用的现实意义和限制条件进行讨论,综合分析了沼液在微藻养殖应用的优势和前景,论述了沼液作为肥料的农业应用价值和可行性.沼液的处理处置和资源化利用不仅仅是对水资源的保护,也可推进资源型和节约型社会建设,实...     

畜禽养殖粪水酸化贮存及氮素减损增效研究进展

畜禽粪水酸化贮存能够有效调控粪水贮存中微生物、环境与氮素间的作用关系,实现粪水氮素的减损增效,是一种具有广泛应用前景的关键技术。该研究系统综述了粪水酸化贮存中氮素的迁移转化机理,比较评价了常见酸化剂和不同酸化贮存工艺的应用效果,分析了酸化贮存技术对粪水氮素减损增效的影响。梳理总结得到：粪水酸化存储中氮素的迁移转化机制主要包括有机氮矿化、铵态氮固持、无机氮转化的抑制及硝化3个关键环节,可以依靠改变微生物作用和化学平衡状态实现氮素的减损;与其他酸化工艺相比,长期酸化工艺具有酸化效果更加稳定、应用范围较为广泛等优势;粪水酸化技术能够大幅降低NH3排放,以及部分N2O的排放,进而提高粪肥还田后土壤肥效,但不合理的酸化贮存技术及施用方式也会降低粪水肥效,甚至引起二次污染;未来应重点从氮素迁移转化路径的定量分析、复合酸化剂的开发、粪肥施用效果及风险的评估应对等方面进行深入研究。     

黑龙港低平原高产田小麦追肥研究

在严重干旱的 1999～ 2 0 0 0年 ,采用 3个品种 ,3个追肥量 ,3个追肥时期和 3次重复的完全组合设计 ,对大运河以东黑龙港低平原区高产田小麦春季追氮时期和追氮量进行了系统研究。结果表明 :春季追肥时期宜晚 ,第一次肥水在 4叶 1心到 5叶 1心期为好 ,追肥量以尿素 75kg/hm2 为高限 ,甚至可以考虑不追肥。     

冬小麦—夏玉米轮作周期内碱解氮、硝态氮时空变化及施氮安全值的研究

利用 3年 6季氮肥试验研究了冬小麦—夏玉米轮作制度下 ,冀东褐土剖面碱解氮、NO-3 -N含量时空迁移变化和土壤氮素安全值指标。结果表明 ,土壤碱解氮自上而下依次递减 ,NO-3 -N呈“V”字型变化 ,二者均与施肥水平及植株生长状况密切相关 ,在 2 0～ 40cm区域出现碱解氮亏缺区 ,N2处理较为明显。N2处理的地下水NO-3 -N含量已超标 ,建议高产条件下土壤环境投氮安全值为 42 0～ 450kghm- 2 较为适宜     

沼肥对大豆产量、品质、养分和土壤化学性质的影响

为探讨沼肥在大豆上的合理施用技术,采用田间试验,研究沼肥对大豆产量、品质、养分吸收利用及土壤化学性质的影响。结果表明：与习惯施肥处理相比,100%沼渣、30%沼渣＋化肥、20%沼渣＋化肥处理的大豆产量分别增加1.02%,10.48%,0.16%;大豆粗脂肪含量分别增加2.31%,2.70%,5.07%;磷肥利用率分别增加5.04%,23.39%,8.60%;土壤有机质含量分别升高13.39%,3.68%,0.50%;20-80 cm土层内土壤硝态氮、铵态氮含量降低幅度分别在13.70%～61.56%,15.98%～70.10%之间。说明试验条件下,无论沼渣单施还是沼渣与化肥配施均可提高大豆粗脂肪含量、磷肥利用率、土壤有机质含量,降低氮素的流失。     

4种畜禽粪便厌氧发酵产甲烷特性研究

本文采用玻璃厌氧发酵罐研究了猪粪、牛粪、鸡粪和鸭粪在室温下发酵20 d过程中产甲烷气量及其受物料特性影响的规律, 为动物废弃物的资源化利用提供指导。研究表明, 在同等条件下猪粪、牛粪、鸡粪和鸭粪经过20 d的厌氧发酵后, 总产气量从大到小排序为牛粪>鸭粪>猪粪>鸡粪, 分别为2 649 mL、2 515 mL、1 964 mL、1 278 mL; 与总产气量排序相似, 上述粪便厌氧发酵总固体物质降解产气率分别为47.60 mL·g^-1、45.23 mL·g^-1、37.27 mL·g^-1和33.49 mL·g^-1。猪粪在厌氧发酵过程中易发生酸化, 第10 d发酵液 pH降到5.62, 从而导致产气量下降; 鸡粪在厌氧发酵过程中铵态氮含量过高, 发酵液铵态氮含量在前5 d就快速增长, 第15 d达到最大值3 604 mg·L^-1, 从而抑制产气。可见, 源于物料自身的pH和铵态氮含量变化是影响畜禽粪便发酵液厌氧产气的重要因素。     

蚯蚓引入垂直流-水平潜流湿地混流系统处理沼液的效果

为了避免或减少人工湿地处理厌氧发酵液发生堵塞,并提高系统处理效果,该试验将蚯蚓引入到垂直流湿地系统中,并与水平潜流湿地构成混流系统,用来处理厌氧发酵液。结果表明:采用蚯蚓垂直流湿地-水平潜流湿地混流系统处理厌氧发酵液,在进水平均有机负荷达1.82 kg/(m~2·d),水力负荷10、20 cm/d的条件下,对化学需氧量、总磷、总悬浮固体的去除率达到了90%以上,氨氮去除率达80%以上,总氮去除率也维持在60%以上。提高水力负荷对污染物的消减量更有优势,水平潜流湿地对总氮的消减优于蚯蚓生态湿地。2种水力负荷下,混流湿地出水化学需氧量、氨氮、总磷、总悬浮固体均能达到《畜禽养殖业污染物排放标准》要求。蚯蚓使混流系统对化学需氧量、氨氮、总凯氏氮的去除分别提高了2%、12%、4%,同时具有同步处理污水污泥,缓解湿地堵塞的效果,处理水质基本达标,处理污泥的成本也大大降低,因此具有很大应用潜力。     

猪场处理废水施用对机插水稻产量形成和氮素利用的影响

为研究规模化猪场处理废水在机插水稻的施用技术,在大田条件下,以迟熟中粳水稻品种淮稻5号为材料,采用模拟机插秧移栽方式,设计不同施肥处理,研究施用猪场废水对机插水稻产量形成和氮素吸收利用的影响。结果表明,在分蘖期配施相同量尿素条件下,拔节期总茎蘖数和有效茎蘖数与基施废水用量关系不密切,抽穗期、成熟期叶片SPAD值、干物质积累量、植株含氮量和吸氮量总体上随穗期废水施用量增加而提高,4个指标皆表现为高量废水配施尿素处理与常规施肥处理无显著差异,但显著高于不配施尿素的高量废水处理。废水配施尿素各处理氮素收获指数变化范围为0.64~0.69,除穗期施用低量废水处理外,其它处理显著高于常规施肥处理。各废水配施尿素处理氮素籽粒生产效率变化范围为61.37~66.94 kg/kg,以高量废水配施尿素处理最低。大多数废水与尿素配施处理能够获得与常规施肥持平或较高的产量,以水稻生长季施用废水210 m3/hm~2分蘖期配施尿素187.5 kg/hm~2处理产量最高,比常规施肥处理增加10.84%。     

外来植物入侵对乡土植物土壤氮素及其代谢酶活性的影响

[目的]探究外来植物入侵对乡土植物土壤氮素及其代谢酶活性的影响的微生物学机制,为中国入侵植物的有效防治和生态管理提供科学依据.[方法]采用田间小区控制试验,通过连续5 a的观测,研究了4种外来入侵植物(独行菜、紫茎泽兰、小飞蓬和黄顶菊)和乡土植物矮牵牛(对照)土壤氮素、酶活性及微生物学特征.[结果]①植物入侵降低了叶片...     

Potential loss of nutrients from different rearing strategies for fattening pigs on pasture

Nutrient load and distribution on pasture were investigated with fattening pigs that: (1) spent a proportion of or their entire life on pasture; (2) were fed either restrictively or ad libitum; and (3) were weaned at different times of the year. N and P retention in pigs decreased the longer they were kept on pasture. The contents of soil inorganic N and exchangeable K were significantly raised compared with the soil outside the enclosures but with no differences between treatments. Pig grazing did not affect extractable soil P. Regular moving of huts, feeding and water troughs was effective in ensuring that nutrients were more evenly distributed on the paddocks. Grass cover, as determined by spectral reflectance, was not related to the experimental treatments but only to the time of year. During spring and summer, grass was present in parts of the paddocks, whereas during autumn and winter, the pigs kept grass cover below 10%. Fattening pigs on pasture carry a high risk of nutrient loss and it is concluded that the most environmentally acceptable way of keeping them on pasture involves a combination of reduced dietary N intake, reduced stocking rate and seasonal rather than round the year production.     

水土流失区马尾松垦复施肥与混交固氮植物措施对比分析

水土流失区马尾松“老头林”采用一般的垦复施肥措施,对促进马尾松生长有显著效果,但施肥作用只能持续3年左右。而采用混交固氮树种杨梅、胡枝子的措施,随着固氮植物固氮能力及生物生长量的增加,土壤养分状况、土壤结构等得到不断改善,马尾松高生长量也在逐步上升,效果十分显著,且作用持久。     

Potassium and Nitrogen Distribution Pattern and Growth of Flue-Cured Tobacco Seedlings Influenced by Nitrogen Form and Calcium Carbonate in Hydroponic Culture

ABSTRACT

Grape tomatoes (Solanum lycopersicon L. var. cerasiform) have recently gained in popularity among consumers because they can be eaten without being cut, they are deep red in color, and their flavor is intense and pleasant. Current nitrogen (N) fertilization recommendations were developed for determinate tomato varieties that have a 3-month long growing season, whereas that of the indeterminate grape cultivars may be up to six months. ‘Tami G’ grape tomatoes were grown on a Lakeland fine sand at the North Florida Research and Education Center—Suwannee Valley, near Live Oak, FL in Springs 2005 and 2006 using standard plasticulture practices under 0%, 33%, 66%, 100%, 133%, and 166% of the current recommended N rate for round tomato (224 kg/ha). Due to a longer growing season in 2006, plants received an additional three weekly injections of 22 kg/ha of N each in the 100% rate, that were also proportionally applied to the other treatments. Tomatoes were transplanted March 24, 2005 and April 4, 2006 and harvested, weighed and graded five (2005) and seven (2006) times. Season marketable yield (SMY) responses to N rates were quadratic (both years P < 0.01) and highest SMY (40,340 and 36,873 kg/ha) occurred with 314 and 280 kg/ha of N in 2005 and 2006, respectively. Fruit soluble solids concentrations ranged from 6.25 to 7.5, and 7.0 to 8.3° Brix in 2005 and 2006, respectively, and were not significantly affected by N rate. These results suggest that N fertilization for grape tomato grown in Spring with plasticulture could be done by incorporating 56 kg/ha of N in the bed, followed by daily rates ranging from 0.5 to 3.5 kg/ha/day. Because the length of the growing season for grape tomato may vary, emphasis should be placed on daily N rates and irrigation management, rather than on seasonal N rate.     

双氰胺在不同温度下对碱性土尿素氮转化的影响

[目的]为了提高氮素的利用效率,减少NO_3~-—N淋溶污染,本试验研究了硝化抑制剂双氰胺(DCD)对碱性土壤中氮素转化的影响,为氮素的合理高效利用,增加作物产量提供参考。[方法]采用实验室人工气候箱培养法,研究双氰胺在15,25和35℃不同温度下对山西省晋城市菜园土(碱性)的pH值、氨挥发量及NH_4~+—N和NO_3~-—N转化的影响。[结果]在碱性土壤中施加双氰胺后,其pH值高于对照,且pH值随土壤温度的升高而升高;同时碱性土壤中氨挥发量也随温度升高而增大,每升高10℃,氮素以氨气形式损失的增加率约为6.90%;而土壤NO_3~-—N量却随温度的升高有所下降,其变化趋势与土壤NH_4~+—N量变化相反,此外温度的升高可导致NH_4~+—N含量峰值的出现时间提前,每增加10℃提前约为1周左右。双氰胺的施加可减少了NH_4~+—N转化为NO_3~-—N的量。[结论]双氰胺的施加可减少碱性土壤中氮素转化为NO_3~-—N所带来的淋溶污染问题,且随温度的升高pH值、氨挥发量和NH_4~+—N量增加。