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1.
丁培俊  邢有忠 《草业科学》1994,11(1):1-7,22
针对甘南州半农半牧区歇地占地面积30%-40%的突出问题,在广泛调查的基础上,利用卓尼县阿子滩乡歇地种植一年生豆科牧草进行作物轮作试验。结果,种植当年获得了明显的效益,次年轮作作物后除燕麦根茬处理减产外,豆科牧草轮作根茬处理的产作物产量与对照相同作物持平并略有增产,增产幅度因牧草种类不同而别。但增产增收的总趋势始终是豌豆>箭舌豌豆>混播箭舌豌豆和燕麦>对照(歇地)。  相似文献   

2.
为了加强对青海省饲草料产业发展的技术支撑,改善其饲草种植、草产品加工结构,解决其农牧交错带、牧区单一饲草种类连作造成的饲草产量低、营养质量差及饲草加工产品结构单一的问题,本文介绍了青海省饲草轮作模式:"禾本科饲草+豆科饲草"轮作、"豆科饲草+禾本科作物"轮作、"禾本科饲草+豆科作物"轮作、"禾本科、豆科饲草+经济作物"轮作、"燕麦+豆科饲草"混播、"燕麦+豆科饲草"混播、"农作物+饲草"复种和饲草加工模式:青干草加工、青贮饲草加工、草颗粒和草块加工、专用饲料加工,通过这些模式,使青海省形成轮作模式多样性、饲草产品多元化的产业经营格局,从而提高饲草质量和产量,增加农牧民收入,发展草原畜牧业综合生产能力。  相似文献   

3.
土壤磷状况与苜蓿施磷肥必要性探讨   总被引:1,自引:0,他引:1  
苜蓿既是重要的饲料作物,又是草田轮作的最佳草种。山西省1986年种植苜蓿面积已达156万商。苜蓿适于石灰性土壤,需钙磷又较多,而石灰性土壤磷含量、形态及施磷肥的动态变化,都对苜蓿产量、品质以及后茬施磷肥迫切性有着重要影响。因此种植苜蓿必须依土壤磷状况,做到合理施磷肥,才能跺持苜蓿优质高产,并为后茬作物丰产创造有利条件。  相似文献   

4.
为研究不同暖季型饲草轮作多花黑麦草对牧草产量及品质的影响,以墨西哥玉米、青贮玉米、甜高粱、高丹草、东非狼尾草和多花黑麦草为试验材料,分析测定土壤养分、牧草产量、生长速率及营养品质的变化规律。结果表明,不同暖季型饲草种植影响土壤养分含量,种植高丹草后,土壤全氮、速效磷和速效钾含量最高。轮作能够延长牧草的供草时间、提高牧草总产量,5种轮作模式分别提高了单作暖季型饲草产量,高丹草和东非狼尾草轮作多花黑麦草增产幅度较大,甜高粱轮作多花黑麦草总产量最高。不同前作对多花黑麦草生长速率影响存在明显差异,其中高丹草收割后复种多花黑麦草的生长速率最快,墨西哥玉米收割后复种最慢。墨西哥玉米粗蛋白含量最高,青贮玉米中性洗涤纤维、酸性洗涤纤维和粗脂肪含量均最高。一年生暖季型饲草轮作冷季型牧草多花黑麦草,有利于延长全年供草时间及牧草总产量提高。  相似文献   

5.
黄鹏  张恩和  柴强 《草业学报》2001,10(1):86-91
在甘肃秦王川新灌区的大田试验表明,春小麦//蚕豆、春小麦/油菜、春小麦/马铃薯及春小麦//草木樨等4种间套种植模式均能提高农田的生产力;豆料作物与牧草显著地改善耕层的茬口养分特性,草木樨茬口不但速效养分含量高于其他模式,对提高土壤有机质和降低土壤容重也有明显效果。施氮能显著提高各种植模式的综合经济产量,但过量施氮时增产效果又有所下降,且在各茬口的速效磷含量产生较弱的负效应。  相似文献   

6.
不同轮作模式对后茬作物小麦产量及生理指标的影响   总被引:1,自引:0,他引:1  
本研究在前茬作物分别是种植4年的苜蓿田,玉米田,大豆田的情况下,研究了3种轮作模式(苜蓿-小麦;大豆-小麦;玉米-小麦)对其后茬作物小麦产量(籽粒产量、出籽率、地上部生物量)与小麦的生理指标(叶色值、叶面积指数、净光合速率、蒸腾速率、硝酸还原酶活性)之间的影响。结果表明:苜蓿-小麦轮作模式下比玉米、大豆轮作小麦模式会显著提高后茬作物小麦产量,而后2种模式在产量上差异不显著。苜蓿-小麦轮作模式显著改善小麦旗叶叶色值、叶面积指数,提高了小麦在灌浆期和成熟期的净光合速率、降低了在孕穗期的蒸腾速率;苜蓿-小麦轮作模式显著提高了小麦生长在整个生长期间的硝酸还原酶活性。说明此种轮作模式有利于改善后茬作物小麦对氮肥的利用率、提高其产量。  相似文献   

7.
针对阴山北麓农牧交错带马铃薯种植面积不断增加,冬春季节地表大面积裸露、表土疏松,与同期风大风多、降水稀少的自然特点叠加,导致土壤风蚀日趋严重的现状,在多年带状留茬间作轮作技术研究的基础上,研究集成生物篱网营建技术。研究发现,在大面积种植马铃薯田块间隔插入易留茬作物后.与残茬带间隔分布的不同带田宽度间作裸地在宽度小于8.4m时,土壤风蚀量与大面积裸地相比有效降低;当宽度大于10.0m后,土壤风蚀量呈直线上升趋势,但在带状留茬间作农田中隔3~5带将适宜北方旱地种植的油用向日葵按照1m(3行)的带田宽度或驼绒藜按照1m(2行)的带田宽度插入.利用油用向日葵秆或驼绒藜与作物留茬带的双重防护,可以使残茬对裸露地带的保护作用从8.4m宽增加到15.0m宽.解决了部分地块宽度大于8.4m后风蚀量加大的问题。  相似文献   

8.
不同轮作模式对后茬作物小麦产量及生理指标的影响   总被引:1,自引:0,他引:1  
本研究在前茬作物分别是种植4年的苜蓿田,玉米田,大豆田的情况下,研究了3种轮作模式(苜蓿-小麦;大豆-小麦;玉米-小麦)对其后茬作物小麦产量(籽粒产量、出籽率、地上部生物量)与小麦的生理指标(叶色值、叶面积指数、净光合速率、蒸腾速率、硝酸还原酶活性)之间的影响。结果表明:苜蓿-小麦轮作模式下比玉米、大豆轮作小麦模式会显著提高后茬作物小麦产量,而后2种模式在产量上差异不显著。苜蓿-小麦轮作模式显著改善小麦旗叶叶色值、叶面积指数,提高了小麦在灌浆期和成熟期的净光合速率、降低了在孕穗期的蒸腾速率;苜蓿-小麦轮作模式显著提高了小麦生长在整个生长期间的硝酸还原酶活性。说明此种轮作模式有利于改善后茬作物小麦对氮肥的利用率、提高其产量。  相似文献   

9.
我国草田轮作的研究历史及现状   总被引:4,自引:1,他引:3  
草田轮作是提高作物产量和改良土壤性状、实现土地可持续生产的重要措施。我国的草田轮作从魏晋南北朝开始就有记载。近年来的研究主要集中在草田轮作潜力及重要性、轮作效益、轮作模式及对土壤影响等方面。草田轮作既提高了粮食产量,又为家畜提供了充足的饲料,促进了养分循环,是实现农牧民增收及我国生态、经济和社会可持续发展的有效途径。  相似文献   

10.
农作物秸秆的综合利用   总被引:5,自引:0,他引:5  
秸秆直接还田。近年来已得到广泛宣传、推广,其中包括秸秆粉碎还田、粉碎灭茬还田、整株还田、根茬粉碎还田。这种方式重在改善土壤的团粒结构和理化性状。秸秆翻人土中后,在分解过程中矿质化,释放养分;同时进行腐殖质化,从而改善了土壤的结构及保水、吸水、粘结、透气、保温等性状,提高了土壤本身调节水、肥、温、气的能力。土壤有机质含量增加,养分结构趋于合理,容重降低,土质疏松、通透性提高,犁耕比阻减少。  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

13.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

14.
15.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

16.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

17.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

18.
19.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

20.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

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