青海高寒草地施肥的研究概况

通过对青海省草地进行施肥改良的综合研究分析，提出了青海地区各类草地施肥的最佳时间，种类及用量，并对现存的问题及应采取的措施提出了自己的观点。     

桑园养分平衡施肥法中肥料的定量研究

针对我省桑园施肥中存在的问题，采用配方施肥中养分平衡施肥理论，经肥效试验后，演算出平原、海涂、山地丘陵地桑园简易的定量用氮公式，按合理的用氮量与氮、磷、钾用肥比例，实施以简化操作、提高肥效为中心的桑园优化施肥技术、在本省进行中试与推广。     

原蚕专用桑园优质高产技术研究：Ⅲ.桑树NPK固定比例长期定位施肥的…

通过桑树ＮＰＫ比例固定长期定位施肥?确立了合理比例用肥及其对桑树生长，各器官的生物合成量，树体的营养生理，土壤肥力等因素的影响。认为不同ＮＰＫ比施肥影响桑叶产质量，从而影响原蚕的饲料生产效率。     

如皋市桑园施肥模式的探讨

１ 研究内容１．１ 施肥品种研究 针对我市养蚕布局的调整，夏伐后两次施速效肥改为一次重施速效肥，但由于高沙土地区保肥能力差，到８月份桑树中下部叶片开始老化，９月份出现封顶，造成中秋小蚕采不到适宜叶，大蚕用叶质量下降。为此，我们根据夏秋季气温高，有机肥易腐熟，养分易于释放，但与速效肥相比，肥效持久，有利８、９月份桑树养分供给这一原理，６月份在施速效肥的基础上，增施有机肥，改变了过去夏伐肥以速效肥为主的传统做法（见表１）。１．２施肥时间研究 在施肥品种改进的基础上，由于有机肥肥效持久，而对夏秋季施肥时间…     

干旱条件下桑园几种施肥方法的比较试验

<正>1994年6～9月份,我县境内持续高温干旱,全县8.3万亩桑园,约有4.6万亩不同程度地遭受了旱害。这给桑园施肥工作带来了很大难度。因为在干旱条件下,如进行常规的土壤施肥,肥料中的养分分解释放慢,养分赖以到达根系表面的质流作用、扩散作用弱,肥效极差。为了寻求干旱条件下桑园理想的施肥方法,我们在组织抗旱的同时,进行了根外追肥、带水施肥、灌根施肥的比较试验。现将试验结果整理如下:     

不同产茧水平桑园施肥现状及土壤肥力的调查

通过8户不同产茧水平农户施肥情况及其桑园土壤肥力的调查与分析，明确了目前桑园施肥存在的主要问题，为指导蚕农进行科学施肥提供了依据。     

天山北坡高寒草甸和山地草原氮磷配方施肥的研究

应用二元二次施肥数学模型，对天山北坡高寒草甸和山地草原氮磷酸配方施肥进行了回归分析，分别建立了两类型氮磷组合连应方程、得出两类型单位面积最高和最佳产量与相应的关系氮，磷最大和最佳施胜量；氮，磷配施比单施更能提高牧草品质；牧草青绿期比不施肥可延长１５ｄ左右。     

果桑使用有机肥的效果比较

桑树肥料效应田间试验是获得桑树最佳施肥数量、施肥品种、施肥比例、施肥时期、施肥方法的根本途径。本试验按农户习惯性不施用任何肥料与施用有机肥进行试验对比。通过比较在常规施肥的基础上,使用有机肥对桑树结果情况、果实外观、果实品质及叶片性状的影响,进而调查有机肥在果桑园使用的效果。     

模糊聚类分析在桑园土壤养分分级施肥方案中的应用

对某一范围内的土壤养分状况进行分级，从而确定土壤肥力水平高低，从宏观上把握一定范围内的不同土壤肥力水平的各自施肥原则，是实现一定范围内均衡增产、全面增产的重要方法之一。搞好桑园土壤肥力水平高低的分级工作，对于“高产、优质、高效、低耗”地进行桑园生产具有重要意义。本用模糊聚类分析的方法，对四川省三台蚕种场650亩桑园的土壤养分状况进行了分级，并提出了各个级别肥力水平桑园的施肥原则。     

夏秋期不同施肥模式对蚕桑生产的影响

过去,我县蚕农习惯于6月中旬、7月中旬、8月中旬3次“土壤施肥”的夏秋施肥形式(简称A式)。但该种方式常因土壤施肥次数多、工作量大、费时费工(尤其是8月中旬的土壤施肥,因桑树林封行,施肥工作量更大)而不为蚕农所喜爱。现时,因农村劳动力发生转移(蚕农频频外出经商、务工或从事其他产业),蚕桑生产从业人员年龄老化、弱化和部分蚕农怕麻烦、图省事等因素,往往仅在6月中旬重施一次夏伐肥,不施秋肥(简称B式)。这种施肥方式容易造成浪费,更不利于桑树生长和养蚕生产,生产实际中不宜提倡。近年来,我县对夏秋期养蚕布局又进行了调整(不养夏蚕,…     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.