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1.
不同施肥条件下北方夏玉米农田土壤氨挥发研究 总被引：6，自引：0，他引：6
通过用间歇密闭室抽气法对不同施肥方式下的夏玉米田间土壤氨挥发进行了研究.结果表明:基肥与追肥氨挥发一共持续了15d与11d,基肥时期氨挥发累积量在2.970 ～4.123kg· hm-2之间,占施肥量的0.81～ 1.65％;追肥时期累积量在6.240～8.347kg·hm-2之间,占施肥量的3.1 ～4.6％.不同施肥处理氨挥发的总量范围在2.914 ～3.920kg·hm1之间,占施肥量的2.3～3.0％;垄作覆膜是降低氨挥发损失的有效施肥方式;而追肥条件下,有机物料还田、施用复合肥和添加尿酶抑制剂会增加氨挥发强度.本次试验结果表明,即使在碱性土壤上,在严格的控制条件和良好的施肥管理条件下,氨挥发损失量仅占总施肥量的约1～2％. 相似文献
2.
施肥对油菜及田间杂草物质养分积累的影响 总被引：2，自引：0，他引：2
在大田试验条件下,研究了不同施肥处理对油菜和田间杂草物质养分积累的影响,以期为油菜田杂草的生态防控提供理论依据。结果表明,氮磷钾硼配施(NPKB)处理油菜产量最高,为1 487.1 kg/hm2,其次是缺K(NPB)处理(1 431.2 kg/hm2),缺P(NKB)和缺N(PKB)处理油菜产量均很低,分别为836.4 kg/hm2和407.7 kg/hm2,油菜干物质累积量的变化趋势与产量的一致。缺P处理杂草的干物质累积量最高,为2 751.0 kg/hm2,其次是缺N(1 669.8 kg/hm2)和缺K处理(1 029.4 kg/hm2),NPKB处理的干物质累积量最低,仅为738.8 kg/hm2。施肥对植物养分含量有一定影响,缺P处理油菜N含量最高(2.06%),但P含量最低(0.22%);而缺N处理油菜N含量最低(0.89%),但P含量最高(0.32%);施肥对油菜K含量的影响不显著。缺N处理杂草P含量最高(0.50%),NPKB处理杂草K含量最高(3.39%),而其他各处理的N、P、K含量没有明显差别。NPKB处理和缺K处理油菜的养分累积量远大于杂草,缺N条件下杂草的养分累积量明显大于油菜,缺P处理杂草的N累积量低于油菜,而P和K的累积量都显著大于油菜。 相似文献
3.
有机无机肥配施对宁夏引黄灌区露地菜田土壤氨挥发的影响 总被引：5，自引：0，他引：5
为了探讨宁夏引黄灌区露地菜田土壤氨挥发损失特征,于2013年5—9月在该区域露地花椰菜-大白菜轮作体系下,采用田间小区试验,研究了不同有机无机肥配施对土壤氨挥发速率、氨挥发损失通量及其损失率的影响。结果表明:露地花椰菜和大白菜基肥后,不同有机无机肥配施处理下土壤氨挥发损失高峰通常出现在第1~4天,而追肥后提前到1~2天,在高量施氮处理下,氨挥发延续时间在10天以上;花椰菜季大多数施肥处理的氨挥发损失发生在追肥阶段(占总氨挥发损失通量的50.2%~60.3%,单施有机肥和低氮处理除外),大白菜季各处理的氨挥发损失主要在基肥阶段(占总氨挥发损失通量的57.0%~73.6%);露地花椰菜基肥和追肥后,不同施肥处理下土壤氨挥发最大速率分别在0.79~4.56、1.00~5.34 kg·hm-2·d-1之间,而露地大白菜季分别为3.49~13.09、1.54~7.03 kg·hm-2·d-1;不同有机无机肥配施下,花椰菜和大白菜全生育期内土壤氨挥发损失通量分别为5.15~35.82、11.11~70.60 kg·hm-2,其随总施氮量的增加而增加;花椰菜和大白菜季不同施肥处理的土壤氨挥发损失率分别为4.02%~4.87%和2.54%~10.55%,其化肥贡献率分别为62.0%~100.0%和85.5%~100.0%,且化肥贡献率随化学氮肥用量的增加而增加。因此,在同等施用有机肥的情况下,合理降低化肥氮用量是减少该地区露地菜田土壤氨挥发损失的重要措施。 相似文献
4.
不同施肥条件下甘肃夏玉米农田灌淤土土壤氨挥发研究 总被引：2，自引：0，他引：2
通过间歇密闭室抽气法对不同施肥方式下甘肃农田灌淤土土壤氨挥发,以及不同施肥方式对玉米生长发育与氮素平衡的影响进行了研究。结果表明,基肥与追肥氨挥发分别持续了15 d与11 d,基肥时期氨挥发累积量在2.970~4.123 kg·hm~(-2)之间,占施肥量的0.81%~1.65%;追肥时期累积量在6.240~8.347 kg·hm~(-2)之间,占施肥量的3.1%~4.6%;覆膜+尿素施肥条件下农田氨挥发损失较小,氮肥利用率高,千粒重比常规施肥高出3.6%~11.9%;产量比常规施肥高出24.98%~36.73%;降低氮盈余量40.46~68.67 kg·hm~(-2)。综上所述,覆膜施肥(尿素深施/表施灌水)能降低土壤氨挥发损失,促进夏玉米生长发育及产量,增加生产效益,农业面源污染小。因此,可以在甘肃灌淤土玉米种植区进行大面积推广使用。 相似文献
5.
不同施氮量和施氮方式下田间氨挥发损失及其影响因素 总被引：18，自引：1，他引：17
为明确干旱、半干旱区农田氨挥发损失规律及其影响因素,采用通气法研究黄淮海平原地区河南封丘国家农业生态实验站冬小麦季不同施氮量与不同施氮方式下基、追肥施用后的土壤氨挥发损失情况,同时测定了表层土壤(0~5 cm)的NH+4-N浓度、pH值和温度等氨挥发影响因素的动态变化。结果表明:肥料氮素的氨挥发损失主要发生在施肥后的1周内。不同施氮方式下土壤氨挥发速率、氨挥发累积量及其占施氮量的比率均随施氮量的增大而增大。氮肥在土壤中的深度对氨挥发有显著影响,基肥时期除150 kg/hm2施N量外,氨挥发累积量沟施法明显大于传统施氮法;追肥期不同施氮量均为传统施氮法大于沟施法。传统施氮法在整个冬小麦季节氨挥发损失累积量占施N量的4.78%~6.72%,沟施法为4.31%~11.24%。相关分析显示,施肥后表层土壤NH+4-N浓度与氨挥发速率呈正相关关系,而pH值则与其呈负相关关系。另外,气温、降雨气候条件对氨挥发速率也有一定程度的影响。 相似文献
6.
对山东省烟台市丘陵冬小麦进行覆盖施肥试验研究,结果表明:覆盖和施有机肥能有效的促进丘陵冬小麦的生长发育、干物质积累和产量的提高.施有机肥较不施有机肥处理单株次生根、分蘖数和株高分别增加0.85～2.51条/株、0.22～1.52个/株和0.46～4.23 cm,干物质增加0.03～1.15 g/株,且均差异显著;覆膜和盖草处理的单株次生根、分蘖数和株高也显著高于裸地,分别增加0.25～3.36条/株、0.23～0.9个/株和0.27～3.57 cm,干物质增加0.02～0.74 g/株.在本试验条件下,施有机肥(22 500 kg/hm2)、化肥(碳酸氢氨990 kg/hm2,过磷酸钙815 kg/hm2,氯化钾228 kg/hm2)和覆膜或盖草处理组合的干物质积累量最高,产量与其它处理相比差异极显著,但覆膜和盖草处理之间的产量差异不显著.因此认为盖草、施用有机肥和适宜数量的化肥是丘陵冬小麦保水增产的有效措施,值得在冬小麦生产上推广应用. 相似文献
7.
本试验在片麻岩新成山地土壤上,设置0(CK)、N 120kg/hm2(N120)、N 225 kg/hm2(N225)、N 300kg/hm2(N300)4个施氮水平,布置田间微区试验,小区面积为10m2,研究了尿素不同施用量对旱地谷子生长及土壤硝态氮时空分布的影响。定位试验第二年的结果表明:在该试验条件下,N120处理谷子产量达到最高为4.76 kg/10m2,之后提高施肥量N225和N300处理的谷子产量并没有显著增加;从0~60 cm土壤剖面中硝态氮时空分布的差异可以看出:在施肥20 d后,N120、N225和N300处理NO3--N含量在0~40 cm土层显著增加,其中N225和N300处理NO3--N已经下移到40~60 cm土层。施肥80 d后,各施肥处理的硝态氮有一部分已经移出60 cm土层。到施肥96 d(谷子收获),N120、N225和N300处理比CK处理土壤剖面中NO3--N含量显著增加,且氮肥用量越高,土壤中NO3--N含量越高。 相似文献
8.
在膜下滴灌棉田,随灌水设置0,90,180,270,360 kg/hm2共5个N肥用量处理,观测不同N用量下棉花生长和干物质积累情况,尝试建立推荐施肥决策支持系统.结果表明:N 270 1g/hm2处理最好,施肥模型为y=3271.82 14.46x-0.0312x2(R=0.9604*),y籽棉产量,x滴灌棉田施N量. 相似文献
9.
2001～2003年连续3a在西吉县吉强镇酸刺村科技扶贫示范区旱地上,采用三因素四水平14处理最优回归设计,对西吉县4种主栽农作物小麦、豌豆、地膜玉米、马铃薯进行了平衡施肥专题试验研究。结果表明在降雨量350～400mm的半干旱地区,上述4种农作物的最优施肥组合分别为施纯N120kg/hm2、P2O590kg/hm2、K2O30kg/hm2;N45kg/hm2、P2O5180kg/hm2、K2O40kg/hm2;N270kg/hm2、P2O5120kg/hm2、K2O60kg/hm2;N225kg/hm2、P2O572kg/hm2、K2O80kg/hm2。 相似文献
10.
中苜2号苜蓿高产配方施肥的研究 总被引：1，自引：0，他引：1
为解决苜蓿规模化技术研发滞后于产业发展等关键性问题,采用测土配方施肥试验,结合理论优化模型和计算机模拟寻优技术,筛选出高产苜蓿的最佳土肥配比技术.结果表明:田间测产与4种模型筛选出,经济效益最佳施肥组合为:当P肥31.70kg/hm2(Ca(H2PO4)2·2H2O为159 kg/hm2)、K肥86.05kg/hm2(K2SO4为172 kg/hm2)、N肥73.08kg/hm2(CO(NH2)2为159 kg/hm2)时,产量为12348.66 kg/hm2,肥料投资较低(1171.8 元/hm2),与最高肥料投资相比低386.3元/hm2,产投比为21.08. 相似文献
11.
温室集雨与集雨水高效利用研究 总被引：5，自引：0，他引：5
在半干旱偏旱区设置了清除土表杂草、红沙覆盖、废膜覆盖和日光温室棚面4种不同的集流面处理,结合日光温室秋冬茬黄瓜、番茄不同灌水量试验,通过水的转化效率探讨不同集流面的使用价值和提高水转化效益的适宜灌水量.结果表明:温室棚面的年产流率最高为85.4%,其次为废膜集流面45.4%,清除土表杂草集流面的年产流率仅有8.2%.从单方水集流费用看,清除土表杂草>红沙集流面>废膜集流面>日光温室棚面,平均集流费用为2.18元/m3,单座温室棚面(450 m2)集流面加上温室间隔区废膜集雨(600 m2),集雨水总量可达到197 m3,能够满足温室一茬黄瓜和一茬番茄的需水量. 相似文献
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14.
Peter A. Duffield 《Pest management science》1977,8(3):279-283
The new pyrethroid, permethrin, previously shown to have high activity against textile pests, was successfully applied to wool from a conventional dye bath. The stability of permethrin to boiling aqueous conditions and to some textile testing regimes was shown to be satisfactory, although some loss on prolonged boiling did occur. Industrial trials made on both wool and wool/nylon blends are described. 相似文献
15.
Abstract Seven new granular herbicides were evaluated in Taiwan for the control of weeds in broadcast flooded rice. In general, herbicides applied early (6 days after seeding) gave better weed control but caused more crop damage than when applied late (12 days after seeding). Benthiocarb applied at 6 days after seeding, when most weeds were at the one to two leaf stage, was highly selective in controlling broad-leaved weeds and sedges with no sustained injury to rice. Butachlor failed to control broad-leaved weeds at the two to three leaf stage. The initial toxicities of C-288 (dimethatryn plus piperophos, 1:4) piperophos (C-19490), and CRD 71.6388 were too severe to warrant their use in direct-seeded flooded rice in Taiwan. Among the herbicides tested, thiochlormethyl and molinate and thiochlormethyl when applied late, were the most selective. When applied 12 days after seeding or at the three to four leaf stage of weeds, both treatments provided excellent control of weeds without causing any crop injury. 相似文献
16.
Field and pot investigations were conducted to determine the effectiveness of pyroxasulfone alone and its combinations with other herbicides against diverse weed flora of wheat (Triticum aestivum L.) including multiple herbicide-resistant (MHR) littleseed canarygrass (Phalaris minor Retz.). Applications of pyroxasulfone 100–127.5 g/ha as pre-emergence (PE) or early post-emergence (EPOE) @ 63.75 g/ha at 21–23 days after sowing (1 day before irrigation) were highly effective for control of grass weeds namely P. minor and wild oat (Avena ludoviciana Dur.). It was poor for control of broad-leaved weeds (Medicago denticulata Willd. and Rumex dentatus L.). However, pyroxasulfone in tank-mix combination with metsulfuron 4 g/ha, triasulfuron 20 g/ha, and pyroxsulam 18 g/ha effectively controlled (96.5%–99.8%) the diverse weed flora and improved the wheat grain yield (69.5%–285.9%) over untreated weedy control. Also, the pre-mix of pyroxasulfone + pendimethalin applied as PE was superior to either of these applied alone for weed control and grain yield. Pyroxasulfone 100–127.5 g/ha had yield gain of 119.6%–125.4% and 10.1%–26% over untreated control and pendimethalin 800–1250 g/ha, respectively. In pot studies, straw burnt ash drastically reduced the pyroxasulfone efficacy against P. minor and A. ludoviciana. Pyroxasulfone was also effective in pot studies for control of MHR P. minor having resistance against acetyl-coA carboxylase (ACCase), acetolactate synthase (ALS), and photosynthesis at the photosystem-II site-A (PS-II) inhibitor herbicides (clodinafop, sulfosulfuron, and isoproturon, respectively). The studies indicate that pyroxasulfone as PE or EPOE can be an alternative grass weed control herbicide in wheat in particular for the control of MHR P. minor. 相似文献
17.
H. J. Miller 《European journal of plant pathology / European Foundation for Plant Pathology》1984,90(1):23-28
The occurrence of low numbers of fluorescing coryneform bacteria located by immunofluorescence microscopy (IF) in heel-end extracts of healthy potatoes was demonstrated to be a normal phenomenon. The number of bacteria found was highly dependent on the antiserum dilution. Bacteria isolated from other healthy potato material also cross-reacted, mostly at low antiserum dilutions compared with homologous isolates or bacteria of the same species, which reacted at a dilution of 11280. Only relatively small differences were found between the antisera tested. Failure to recognize the occurrence of cross-reacting unknown soil bacteria, indicated by the data presented in this paper, can only increase the dangers of incorrect interpretation of IF results.Samenvatting Het optreden van lage aantallen fluorescerende, coryneforme bacteriën gevonden met behulp van immuno fluorescentiemicroscopie in extracten van naveleinden van genzonde aardappelen, bleek een normaal verschijnsel te zijn. Het aantal gevonden bacteriën was sterk afhankelijk van de verdunning van het antiserum. Bacteriën die geïsoleerd werden van ander gezond aardappelmateriaal vertoonden ook kruisreacties, meestal bij lage verdunningen van het antiserum in vergelijking met homologe isolaten of bacteriën van dezelfde soort, die beide nog reageerden bij een verdunning van 11280. Tussen de getoetste antisera bleken slechts geringe onderlinge verschillen te bestaan. De gegevens in dit artikel onderstrepen het gevaar van een onjuiste interpretatie van IF-resultaten, wanneer het voorkomen van kruisreagerende, onbekende bodembacteriën over het hoofd wordt gezien. 相似文献
18.
针对我国北方作物机械化收获模式下,机收后滞留在田间大量秸秆留茬处理问题,结合秸秆整株翻埋技术与秸秆快速腐熟还田技术,设计了秸秆留茬翻埋快速腐熟联合作业机。该机由腐熟剂喷施系统及秸秆留茬翻埋系统两部分组成。通过田间试验表明,秸秆留茬翻埋快速腐熟技术可使翻埋的秸秆留茬快速腐解,7个月后秸秆留茬腐熟率为79.8%,较单一秸秆留茬翻埋作业方式腐熟率提高了18.5%;增加了田间土壤微生物数量,提高了土壤有机质含量;相应配套机具在田间作业时,速度应大于1.46 m/s,悬挂深耕犁耕深应控制在22~29 cm之间。 相似文献
19.
Glasshouse Fumigation with Formaldehyde 总被引：1，自引：1，他引：0
20.
Crop cultivars with allelopathic capability 总被引：12，自引：0，他引：12
Allelopathy has potential in integrated weed management. Crop plants have the capability to produce and exude allelochemicals into their surroundings to suppress the growth of weeds in their vicinity. Selection for superior genotypes with allelopathic potential has been carried out in several field crops, and evidence has accumulated that crop cultivars differ significantly in their ability to inhibit the growth of certain weed species. To date, progress has been made in understanding the genetics of crop allelopathic activity, and successful genetic manipulation of this trait has also been demonstrated. However, much more research needs to be carried out in order to have a thorough understanding of the genetic control of allelopathic activity. Several genes might be involved in regulating the production and exudation of allelochemicals. Concerted efforts using advances in plant biotechnology will help to unveil the genetics of this trait. Once the allelopathic genes have been located, a breeding programme could be initiated to transfer the genes into modern cultivars to enhance their allelopathic activity for weed suppression, thereby reducing over-reliance on herbicides. 相似文献