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71.
ABSTRACT

Soil fertility in many parts of the north?western Himalayan region (NWHR) has declined owing to accelerated nutrient mining under existing crop regime. Therefore, this study aimed to assess effect of the predominant horticulture?based land uses on soil fertility and health in mid and high hills of NWHR. Soil samples (0?20 cm) were collected, analyzed for different soil chemical attributes (pH, electrical conductivity, organic C, available primary-, secondary-, and micro-nutrients), and compared across five key land uses: perennial grass (PG), peach orchard (PO), apple orchard (AO), field vegetable farming (VF), and protected vegetable farming (PV). Soils of the investigated land uses were neutral to near neutral in soil reaction (6.3?6.8) except field vegetable and protected vegetable farming. Amount of soil organic C and labile organic C was significantly higher (p ≤ 0.05) in soils of apple orchards (18.6 g kg?1 and 687.3 mg kg?1, respectively) and peach orchards (20.4 g kg?1 and 731.3 mg kg?1, respectively) over others. An abrupt and significant increase in Olsen-P was recorded in soils of field vegetable farming (17.1 mg kg?1) and protected vegetable farming (13.0 mg kg?1), which shifted their nutrient index (NI) of P in to high category (≥ 2.33). The concentration of mineralizable-N in soil was statistically at par in soils under perennial grass and fruit orchards, while protected vegetable farming showed maximum soil mineralizable-N content (115.5 mg kg?1) and NI of nitrogen (1.83). The NI was in high category (≥ 2.33) for copper, iron, and manganese in majority of the land uses. In view of the results, temperate fruit?tree based land uses are benign in up?keeping soil fertility and soil health, and needs promotion on large scale. Additionally, policies to create incentives for the build-up of soil organic matter and replenishment of the depleted soil macro and micro nutrients in vegetable-farmed lands are warranted.  相似文献   
72.
Ecological studies on earthworms were conducted in a Kumaun Himalayan pasture soil. The C:N ratio in the soil declined with increasing depth. A combination of hand-sorting and formalin application was used to sample the earthworms. Three species, Amynthas alexandri, A. diffringens (Megascolecidae), and Eisenia fetida (Lumbricidae) were found. Of the 13310 individuals collected, 99.9% were A. alexandri. The maximum density (138.8 m-2) and biomass (25.2 g m-2) were recorded in the wet season. More than 60% of the total earthworm numbers and biomass were recorded at 0–10 cm in depth. The mean yearly ratio of clitellate to aclitellate worms was 1:7.3.  相似文献   
73.
74.
Forests provide a source of livelihood to all classes of rural people, especially in tribal dominated areas. With the advent of joint forest management concepts and commercial earning prospects from non-timber forest products (NTFPs), it was expected that forests would be best preserved by the villagers who depend on them for a substantial part of their livelihoods. However, in the case of the Ranibundh block in the Bankura district, it was observed that the predominance of private agencies in marketing channels of NTFPs, together with risk of eviction, loss of customary right to access forest resources, low employment prospects, and lack of training about proper management of NTFPs have led to the failure in motivating the forest dwellers to prevent degradation of forest resources. It is suggested that government agencies, producer institutions, non-governmental organizations (NGOs), and other strong institutional entities can promote forest preservation when complemented by the granting of forest rights to rural people, the extension of training facilities, and alternative employment prospects.  相似文献   
75.
Panicum maximum (guinea grass) is a model crop for apomixis and polyploidy studies. It is predominantly tetraploid (2n?=?32) and is characterized by gametophytic apomixis, Panicum-type apospory and pseudogamous endosperm development. The three components of apomixis, viz. apomeiosis, parthenogenesis and functional endosperm development, can be uncoupled in this crop. An exhaustive single progenitor-derived ploidy series comprising of 32 accessions representing 3x, 4x, 5x, 6x, 7x, 8x, 9x and 11x cytotypes was utilized in present study to understand ploidy effects on expression of apospory as well on uncoupled components in two phases of progeny formation i.e. in matured ovules (using embryo-sac analysis) and in matured self-pollinated seeds (using Flow Cytometric Seed Screen method). Rise in ploidy enhanced the formation of sexual embryo-sacs (ES) thereby increasing the frequency of facultative accessions at higher ploidy level. Our results suggested that the eventual phenotype depends on relative doses of apospory and sexual factors in the genome. Ploidy level was also found affecting the penetrance and expressivity of uncoupled apomixis components. Formation of BIII hybrids (3n) appeared to be more stabilised and less affected by the ploidy change, however, formation of M1 (1n) progenies increased with the rise in ploidy. Ploidy effects on traits such as occurrence of multiple ES, autonomous endosperm development, and twin embryos were also studied. Flexibility of guinea grass to tolerate excessive genome burden and successful formation of seeds overcoming endosperm balance number and endosperm imprinting constraints is also discussed.  相似文献   
76.
We investigated the influence of season on the rooting behaviour of eight important bamboo species viz., Bambusa balcooa, B.bambos, B. nutans, B. tulda, B. vulgaris, Dendrocalamus giganteus, D.hamiltonii and D. strictus. We collected 2 3 node culm cuttings in three growing seasons viz. spring (March), summer (June) and rainy (August)from superior candidate plus clumps (CPCs) centralized in the germ-plasm garden. Cuttings were placed horizontally in sand and were provided with intermittent misting at regular intervals. Bamboo species exhibited differential rhizogenesis behavior in different seasons. The study reveals significant variation in sprouting and rooting behaviour indifferent bamboo species. B. bambos had maximum rooting (78.89%),followed by B. vulgaris (74.44%). In general, the potential of different bamboo species for rooting was found to be in the order: B. bambos > B.vulgaris > B. balcooa > D. hamiltonii > B. tulda > D. strictus > D.giganteus >B. nutans. The maximum rooting was recorded in spring(56.67%), which was closely followed by summer (54.58%). In winter season, minimum rooting (36.67%) was observed. The interaction effect of species × season was also significant on sprouting and rooting parameters. In B. balcooa, B. nutans, B. vulgaris, D. hamiltonii and D.strictus, cuttings collected in summer season showed maximum sprouting and rooting, whereas, B. bambos, B. tulda and D. giganteus had maximum rooting in spring. The maximum number of roots developed per cutting was observed in B. tulda (43.8) during spring season.  相似文献   
77.
Eupatorium adenophorum (Crofton weed), a native of Central America, has appeared as a major weed in several areas in different parts of the world. Horses that eat this plant are poisoned on prolonged exposure. Toxicity due to consumption of this plant by other grazing animals is not clear. Administration of freeze-dried leaf powder to mice results in hepatotoxicity. Earlier attempts to produce toxicity in rats using the leaves of this plant were not successful. In the present study, administration of oven-dried E. adenophorum leaves collected at the flowering stage elicited hepatotoxicity in rats. The affected animals had a marked increase in the concentration of plasma bilirubin and in the activities of 5-nucleotidase, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase. There were no significant differences in plasma creatinine, urea or total protein values in the affected animals compared to controls. The livers of the affected animals had focal areas of necrosis throughout the parenchyma and hepatocytes showed megalocytosis. The bile ducts were dilated and the epithelium showed degenerative to necrotic changes. The alterations in bilirubin, enzymes and histopathological changes imply cholestasis and liver injury.  相似文献   
78.
79.
Classical swine fever (CSF) is a globally significant disease of swine caused by classical swine fever virus. The virus affects the wild boars and pigs of all age groups, leading to acute, chronic, late-onset or in-apparent course of the disease. The disease causes great economic loss to the piggery industry due to mortality, stunted growth, poor reproductive performance, and by impeding the international trade of pig and pig products. In India, CSF outbreaks are reported from most of the states wherever pig rearing is practiced and more frequently from northeast states. In spite of the highly devastating nature and frequent outbreaks, CSF remained underestimated and neglected for decades in India. The country requires rapid and sensitive diagnostic tests for an early detection of infection to limit the spread of the disease. Also, effective prophylactics are required to help in control and eradication of the disease for the development of the piggery industry. This review looks into the economic impact; epidemiology of CSF highlighting the temporal and spatial occurrence of outbreaks in the last two decades, circulation, and emergence of the virus genotypes in and around the country; and the constraints in the disease control, with the aim to update the knowledge of current status of the disease in India. The article also emphasizes the importance of the disease and the need to develop rapid specific diagnostics and effective measures to eradicate the disease.  相似文献   
80.
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