不同缓控释氮肥对高羊茅草坪生长及氮素挥发的影响

 通过田间试验,研究了氮释放期为３０和６０ｄ的树脂包膜尿素（ＰＣＵ３０、ＰＣＵ６０）,硫包衣尿素（ＳＣＵ）,抑制剂型缓释尿素（ＵＩ）和普通尿素（Ｕ）对高羊茅草坪生长、氮素吸收及氮素挥发的影响。结果表明,在全年施氮量２６０ｋｇ／ｈｍ^２ 的情况下,ＰＣＵ３０、ＰＣＵ６０和ＳＣＵ 一年分春秋２次施用可以满足高羊茅草坪正常生长需要,其草屑累积量和氮素吸收量显著高于普通尿素一年４ 次施用处理;氮素气态损失方面,ＵＩ处理的氨挥发损失氮量高达４４．４２ｋｇ／ｈｍ^２,显著高于其他施氮处理,其Ｎ_２Ｏ 排放氮量为６．４６ｋｇ／ｈｍ^２,显著低于其他施氮处理;ＰＣＵ３０、ＰＣＵ６０、ＳＣＵ 处理的氨挥发量和Ｎ_２Ｏ 排放氮量分别为１７．６７,１３．５９,１８．５４ｋｇ／ｈｍ^２ 和８．１４,６．９２ ,９．９１ｋｇ／ｈｍ^２,显著低于Ｕ处 理。综合考虑各种因素,建议高羊茅草坪一年分春秋２次施用树脂包膜尿素ＰＣＵ６０较为适宜,可有效提高肥料利用率、降低氮素挥发损失,环境效益明显。     

几种缓释肥的氮释放特性以及对草坪草生长的影响

实验室内采用水浸泡法对尿素、3种缓效肥和山西省农业科学院土壤肥料研究所研制(自研草坪肥)的缓效肥的初期溶出率和微分溶出率进行了测定.其中尿素的初期溶出率为22.75%,超出了国际上公认的缓/控释肥的初期溶出率小于15%的指标,而微分溶出率为0.22%,也小于国际上公认的缓/控释肥的微分溶出率(0.25%～2.5%)指标.其他几种缓释肥的初期溶出率为8.73%～14.42%,微分溶出率为0.30%～2.11%,符合国际上公认的缓/控释肥的初期溶出率和微分溶出率指标.田间试验比较和研究了尿素、3种缓效肥和山西省农业科学院土壤肥料研究所研制的缓效肥对草坪草的干草产量和养分含量的影响,尿素和包衣尿素处理的草坪草的生长量前期较高,后期产草量较低,呈马鞍型.其他处理的草坪草干草产量则比较平缓,肥料的氮释放特性与草坪草生长趋势相同.不同肥料处理对草坪草的中量、微量元素含量有一定的影响.     

芽前除草剂和氮肥联合施用对纯雌野牛草草坪建植的影响

采用大田试验方法,研究了芽前除草剂氨氟乐灵和氮肥尿素对纯雌野牛草(Buchloe dactyloides)草坪建植的影响。第一次杂草调查结果表明氨氟乐灵处理显著降低野牛草分株的移苗死亡率、对草坪建植初期杂草封杀显著有效,虽然第二次杂草调查结果欠佳,但氨氟乐灵对杂草仍有一定的控制效果,推荐使用浓度在600～1 200 g·hm^-2。其次,氨氟乐灵和尿素的结合处理提高了纯雌野牛草草坪的生物量、盖度以及降低了杂草总数量和杂草物种数,双因素方差分析结果表明氨氟乐灵相较于尿素对纯雌野牛草草坪建植的影响更大。最后,通过聚类分析发现氨氟乐灵和尿素结合处理中A3B2和A2B3的效果相近且最优。     

速效氮肥和缓释肥混施对早熟禾草坪的影响

按氮肥对植物产生效果的快慢可分为速效氮肥和缓释氮肥。速效氮肥能很快改善草坪质量，但用量太高时不但会灼烧草坪，而且还会使营养成分大量淋失。而施用量太低，有可能满足不了草坪生长发育的需要，而且必须经常施用，需要大量的人力、物力。缓效肥料又称长效肥料、迟效肥料，     

不同缓释氮肥对冷季型草坪生长特性及品质的影响

通过大田试验研究速效肥(尿素)与3种缓释氮肥(SUD、IBDU、MU)对冷季型混播草坪草叶绿素含量、密度、生长速度、质地的影响,结果表明:施肥7 d后,尿素处理叶绿素含量与CK相比增加了42.9%,SUD、IBDU、MU处理与CK相比分别增加了34.7%,34.7%和32.7%,施肥60 d后,尿素处理叶绿素含量与CK相比增加28.5%,SUD、IBDU、MU处理与CK相比分别增加了44.5%,38.0%和32.5%;SUD缓释氮肥使草坪密度增加达122.2%,最差的MU缓释氮肥草坪密度为68.9%,均好于尿素42.5%;施肥后60 d,SUD处理草坪草盖度达到98%,尿素处理为94%,CK为87%。参照综合外观质量法对各处理草坪进行评价,CK、尿素、SUD、IBUD、MU得分分别为14、18、21、20、19。CK处理草坪评价为"差",SUD处理草坪评价为"良好",其余均评价为"中等"。     

不同氮肥和基质类型对匍匐翦股颖草坪质量的影响

为了更好地了解不同氮肥和基质类型对高尔夫果岭草坪质量的影响,在温室里模拟果岭用PVC管建造4种基质类型的匍匐翦股颖Agrostis stolonifera cv.Prenncross草坪,出苗后施用Hoagland和Arnon营养液培育至成坪,成坪后选用速效氮尿素和控释肥丁异叉双缩脲进行氮肥类型处理。试验结果表明,基质类型对匍匐翦股颖的生长和坪用质量有着显著影响并表现出阶段性差异。4种基质类型的草坪成坪速度快慢顺序为：土壤基质>改良沙基质>半改良沙基质>纯沙基质,这也是表层有机质累积量的大小顺序;外观质量高低为：改良沙基质>半改良沙基质>纯沙基质>土壤基质;在播种建坪的初期施用速效氮肥有助于匍匐翦股颖的生长和快速成坪;缓释氮肥释放速率慢,更符合草坪成熟后对氮的需求规律。缓释氮肥起效慢,应在草坪逐渐成熟时与速效氮肥搭配施用。     

应用N~(15)研究桑园氮素平衡的初步结果

<正> 随着蚕业生产的发展,桑园氮肥施用量迅速增加,研究氮肥施入土壤后的氮素平衡状况,对于了解氮肥的增产效果,提高氮肥的利用率及制订合理施肥技术措施都是极为重要的。氮肥施入土壤后,一部分被桑树吸收,一部分残留在土壤中,一部分则通过不同途径而损失(如氮素的硝化淋失,反硝化作用损失及氨的挥发等)。这几个部分构成了桑园的“氮素平衡”。气候、土壤、耕作和栽培技术,以及氮肥的种类,施肥时间和施肥方法等因素,都对氮肥的氮素平衡状况产生显著的影响。因此,吸收、残留、损失的三部分氮素占施入氮素总量的比例也会有很大     

浅谈牛尿素中毒的防治

<正>尿素是一种农业速效氮肥,含氮量46%,在畜牧生产中反刍动物瘤胃内的微生物可将尿素的非蛋白氨转化蛋白质,因此利用尿素加入日粮中其作为蛋白质补充饲料,但其促生长量与中毒剂量较为     

秋施不同缓释氮肥对坪用草地早熟禾抗寒性影响的研究

秋季对草地早熟禾(Poa pratensis L.)草坪施用MU(亚甲基脲)、IBDU(亚异丁基二脲)、SUD1(大颗粒尿素+硝化抑制剂)、SUD2(大颗粒尿素+硝化抑制剂)、SUDT₂(大颗粒尿素+2种硝化抑制剂)、木质素肥和有机氮肥7种不同类型的缓释氮肥,以及速效氮肥尿素,于冬季不同时期,测定与抗寒性相关的过氧化氢酶(CAT)活性和可溶性蛋白质(SP)、可溶性糖(WSS)、游离脯氨酸(Pro)、丙二醛(MDA)含量,以探查缓释氮肥对草坪草抗寒性的影响。结果表明:与不施氮的对照相比,秋季施氮肥有助于提高草地早熟禾的抗寒性;7种缓释氮肥的抗寒性效应较尿素更为全面和显著,均增强了CAT活性,提高了Pro,SP和WSS含量,降低了MDA含量。MU,IBDU,SUD1,SUD2,SUDT₂和木质素肥6种缓释氮肥对5种生理生化指标的影响基本相同,但MU和IDBU对MDA活性的影响较低(P<0.05);有机肥除了对CAT,Pro和SP的影响较小外(P<0.05),对MDA和WSS的影响与缓释氮肥具有相同效果,因此,秋施有机氮肥也是提高草地早熟禾抗寒性的有效措施。根据Fuzzy数学隶属函数综合评判法计算的缓释氮肥抗寒性数值,8种肥料对抗寒性影响的大小排序为SUDT₂>SUD2>IBDU>木质素肥>SUD1>MU>有机肥>尿素(速效肥),也可按其对抗寒性影响的大小分为高、中、低3组,SUD2和SUDT₂为高效组,有机肥和MU属于低效组,其余为中效组。     

紫花苜蓿草地氨挥发损失的原位研究

采用密闭通气法研究了紫花苜蓿草地原位氨挥发损失。结果表明,紫花苜蓿(Med icago sativa L)草地分枝期、现蕾期和开花期昼夜都有氨挥发损失;连作苜蓿草地分枝期、现蕾期和开花期的昼夜平均氨挥发速率分别为54.3、111.6和181.9μg/(m²·h);连作苜蓿草地的昼夜氨挥发速率随着生育期的推移迅速增加;施P 26.2 kg/hm²可以降低连作苜蓿草地的氨挥发损失;轮作苜蓿草地分枝期、现蕾期和开花期的昼夜平均氨挥发速率分别为49.2、346.5和149.1μg/(m²·h);轮作改变了氨挥发速率的变化规律,现蕾期比连作高2.1倍,开花期比连作低18.0%。     

Instrumentation for Evaluating Differences in Ammonia Volatilization from Broiler Litter and Cake

Greater understanding of the mechanisms affecting NH₃ volatilization from reused broiler bedding is needed to determine pathways for mitigating NH₃ emissions. A chamber acid trap (CAT) system was developed to provide an improved laboratory method for determining NH₃ volatilization from litter or cake samples and for assessing treatment technologies to decrease NH₃ losses from poultry litter. The CAT system offers precision control of air flow rate through sample chambers as well as straightforward, precise determination of the amount of N volatilized. This article outlines the basic setup of the CAT system. The system can be utilized and modified for researching specific mechanisms involving physical, chemical, or biological treatments affecting NH₃ volatilization from litter or cake.     

Effect of Various Litter Amendments on Ammonia Volatilization and Nitrogen Content of Poultry Litter

Ammonia volatilization from poultry manure contributes to atmospheric N pollution, negatively affects poultry performance, and decreases the fertilizer value of manure. The objective of this study was to evaluate the effects of alum [Al₂(SO₄)₃·14H₂ O], liquid alum, high acid alum (A7), aluminum chloride (AlCl₃·6H₂ O), fly ash, Poultry Litter Treatment (PLT), and Poultry Guard (PG) litter amendments on NH₃ volatilization and N contents in litter. Two laboratory studies were conducted for 42 d each. The treatments in experiment 1, which were mixed in the upper 1 cm of litter, were 4 g of alum, 8 g of alum, 8.66 g of liquid alum, 17.3 g of liquid alum, 11.2 g of A7, 22.4 g of A7, 4 g of PG, 4 g of PLT, 4 g of fly ash, and 4 g of AlCl₃/100 g of litter. The treatments for experiment 2 were identical to experiment 1, except the fly ash treatment was dropped and an additional 4 g of alum/100 g of litter treatment was added, which was incorporated totally within the litter. The various rates of dry alum, liquid alum, and A7 significantly decreased NH₃ volatilization compared with the controls, with reductions ranging from 77 to 96% for experiment 1 and from 78 to 96% for experiment 2, respectively. Poultry Litter Treatment decreased NH₃ volatilization by 76 and 87% for experiment 1 and 2, respectively. Aluminum chloride decreased NH₃ volatilization by 48 and 92% for experiment 1 and 2, respectively. Litter treated with alum, liquid alum, A7, PLT, and AlCl₃ had a lower pH and a greater N content than the controls in experiment 1 and 2. In contrast, PG and fly ash resulted in a greater pH and were ineffective in decreasing NH₃ volatilization and increasing N contents in experiment 1. However, in experiment 2, PG was effective in reducting NH₃ loss. In this study, the decreased NH₃ volatilization was chiefly associated with reduction in litter pH.     

Effect of aluminum chloride and dietary phytase on relative ammonia losses from swine manure

Ammonia (NH3) losses from swine manure contribute to odor problems, decrease animal productivity, and increase the risk of acid rain deposition. This study was conducted to determine whether aluminum chloride (AlCl3) or dietary manipulation with phytase could decrease relative NH3 losses from swine manure. Twenty-four pens of nursery pigs were used in two trials, and the pigs were fed normal or phytase-supplemented (500 IU/kg) diets. Aluminum chloride was added to manure pits (1.9 x 1.2 x 0.5 m) under each pen at 0, 0.25, 0.50, or 0.75% (vol:vol) of final manure volume. Manure pH and NH3 losses (measured by relative NH3 flux) were determined twice weekly. The addition of AlCl3 at 0.75% decreased (P < 0.05) manure pH from 7.48 to 6.69. Phytase decreased (P < 0.05) manure pH to 7.07 compared with 7.12 in the normal diet manure. Aluminum chloride administered at 0.75% without phytase reduced (P < 0.05) relative NH3 losses 52% for the entire 6-wk period. Relative NH3 losses were decreased (P < 0.05) from 109 mg of NH3/(m2 x h) in pens containing pigs fed the normal diet without AlCl3 to 81 mg of NH3/(m2 x h) in pens housing pigs administered the phytase diet, a 26% reduction. When the phytase diet and 0.75% AlCl3 additions were used in combination, relative NH3 losses were reduced (P < 0.05) by 60% compared with pens of pigs fed the control diet without AlCl3. Decreases in manure pH were likely responsible for the observed reduction in NH3 losses. Multiple regression was performed with relative rates of NH3 losses as the dependent variable and rate of AlCl3 addition, diet, and manure pH as independent variables. The model was tested using a stepwise regression (P < 0.001), and results indicated that the most important factors determining NH3 losses were manure pH and diet. However, the contribution of AlCl3 cannot be discounted. When manure pH was regressed against AlCl3 and dietary phytase, AlCl3 levels accounted for 64% of the variation in manure pH (P < 0.001). Dietary manipulation with phytase and application of AlCl3 to manure are promising management practices for the reduction of NH3 from swine facilities.     

保水剂施用层次对草坪生长及土壤水肥的影响

本研究利用多年生黑麦草草坪,探究保水剂在土壤中的最佳施放层次,以提高草坪土壤的水肥利用率。实验将保水剂分别施放在土壤表层以下0,5,10和15 cm处,采用正常浇水和大淋浇水两种不同灌水方式,定期观测黑麦草生长速度、土壤体积含水量、淋溶液养分淋失量、土壤养分变化以及草坪外观质量等指标。实验结果表明,黑麦草草坪7.5 cm浅层和20 cm深层土壤体积含水量、养分持有能力、草坪密度均受不同层次施用保水剂影响,保水剂在深层和浅层施用都能发挥保水作用,提高草坪肥料持有能力。土壤表层以下5 cm施用保水剂对土壤水分的保持能力最强,对N和P的保持能力最好,草坪密度最大,为施用保水剂的最佳层次。     

不同氮钾用量对多年生黑麦草草坪的影响

试验阐明了不同氮,钾施用量对多年生黑麦草草坪色泽,密度,均一性及草屑积累量的影响,为草坪的合理营养养护提供了科学的理论依据,研究结果表明,氮肥可明显改善草坪色泽,提高草坪质量,施氮量从３￣１２ｇ／ｍ＾２,可接受的草坪质量持续时间相应为１３￣４８ｄ,多年生黑麦草草屑积累量随施氮量增加而明显增加,草屑积累量与施氮量的关系符合方程：Ｙ＝－０．４４２６Ｘ＾２＋１６．３９２Ｚ＋３９．９２,相关系数Ｒ＾２高达     

不同用量沼肥对高羊茅草坪质量及生长的影响

采用地下渗滤系统,通过盆栽模拟试验研究了不同用量沼肥对高羊茅(Festuca arundinaces Schred.)草坪质量及生长的影响,探索沼肥在草坪上应用的可能性。结果显示:随着沼肥用量的增加,不同处理之间的草坪颜色质量、草屑带出总量、草屑中氮磷养分带出量均存在显著差异(P<0.05)。在相同氮素用量200 kg N·hm^-2下,化肥处理的表现优于沼肥处理,这可能与二者施用方式不同有关。当沼肥用量由200 kg N·hm^-2增加为1400 kg N·hm^-2时,草屑带出总量、草屑中氮、磷养分带出量分别增加了2.0,3.4和2.2倍,表明草坪在消纳利用沼肥方面具有较大的潜力。     

打孔和施肥处理对草地早熟禾草坪质量的影响

对中国农业大学科学园内建植７年的草地早熟禾草坪进行了打孔和施肥８个处理对草坪质量影响的研究,各处理施氮量均为１０ｇ／ｍ＾２。结果表明,打孔改善了颜色和整齐度,对生长速度、分蘖密度、生殖枝数、地下生物量的影响不明显;在肥料的４个处理中,液体肥提高了整齐度;尿素和草坪专用肥能改善草坪颜色;各处理对生长速度、分蘖密度、生殖枝数、地下生物量的影响不明显;在全部８个处理中,打孔＋微肥＋尿素处理较对照未打孔＋尿素处理显著降低了草坪生长速度,各处理在分蘖密度、地下生物量与对照之间差异不显著;打孔＋尿素处理、打孔＋草坪专用肥处理较对照改善了颜色;打孔＋液体肥＋尿素处理、打孔＋微肥＋尿素处理较对照明显改善了整齐度;打孔＋液体肥＋尿素处理较对照显著增加了生殖枝数。打孔＋微肥＋尿素处理效果较好。     

施肥对草地早熟禾草坪质量的影响

本试验是以不同施肥水平对建植四年的草地早熟禾草坪质量指标的影响进行了研究。结果表明,在四种施肥处理中,草地早熟禾的生长速度随着施肥量的增加而提高。施肥改善了草地早熟禾的以不同颜色,但同时降低了草坪的整齐度,加重了病害。综合考虑应采用每次每平米５克氮,３．３克Ｐ２Ｏ５和３．３克Ｋ２Ｏ或１０克氮,６．７克Ｐ２Ｏ５和６．７克Ｋ２Ｏ的施肥水平。其中每次每平米１０克氮,６．７克Ｐ２Ｏ５和６．７克Ｋ２Ｏ的施肥     

菌肥与柠檬酸互作对石灰性土壤生物学特性及草坪质量的影响

在草坪的日常管理中,肥料施用是一个必不可少的环节。在实际生产中,一般通过常规的氮、磷肥施用促进草坪草的生长,达到提高和改善草坪质量的目的,而通过施用微生物肥料和柠檬酸等辅助性肥料来改善土壤微生物环境、提高土壤养分有效性,从而促进草坪的生长方面研究较少。本文研究了柠檬酸和促生菌肥的互作处理对冷季型草坪质量及土壤生物学特性的影响,从而探讨柠檬酸和促生菌肥提高草坪草质量的机理,为草坪的科学管理提供理论依据。研究表明,1)一定量菌肥配合柠檬酸增加了石灰性土壤中微生物数量,尤其是深层土壤放线菌数量,且提高了土壤蔗糖酶和脲酶的活性。2)柠檬酸的施用,显著提高了土壤中有效磷含量。3)在一定量的氮、磷肥施用水平下,柠檬酸和促生菌肥有效提高了草坪质量。