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11.
Fertilizer trees, the nitrogen-fixing legumes, such as gliricidia (Gliricidia sepium) and tephrosia (Tephrosia spp.) have been used to improve soil fertility for higher crop yields in nitrogen deficient soils. Many studies have focused on how these fertilizer trees improve maize yield, but there has been a dearth of information on the effect of fertilizer tree species on cotton growth and yield. A study was undertaken for two cropping seasons (2012/13 and 2013/14) with the objective of assessing IRM 81 cotton growth and yield responses to tephrosia and/or gliricidia biomass with or without inorganic fertilizer application. Boll opening significantly varied (P < 0.0001) with treatments and early boll opening was observed in plots where only inorganic fertilizer was applied. Higher lint yield (mean of 1397 kg/ha) was obtained in the second cropping season than in the first cropping season (480 kg/ha) and the application of gliricidia biomass with fertilizer gave the highest lint yield (2121 kg/ha). The lowest lint and seed yields were obtained from plots where tephrosia biomass only was applied. It is concluded that the use of gliricidia biomass with inorganic fertilizer improved cotton yields. The high amount of gliricidia biomass (due to prolific coppicing) applied contributed to higher cotton lint yields with reduced rates of inorganic fertilizer application, making gliricidia-cotton intercropping a cost-effective option to smallholder farmers.  相似文献   
12.
The production of paprika (Capsicum annum L.) under small-scale farm conditions in southern Africa is constrained by low soil fertility and lack of appropriate cultivars. The objective of this study was to determine the growth responses and fruit yields of six cultivars of paprika to organic and inorganic nutrient sources. The study was conducted in 2007 and 2008 at Chitedze Agricultural Research Station in Malawi. A combination of six paprika cultivars and four nutrient sources, namely (1) organic input from Gliricidia, (Gliricidia sepium) biomass, (2) inorganic fertilizer, (3) integrated nutrient input (Gliricidia biomass + inorganic fertilizer), and (4) control (no nutrient input) were compared. Each combination was replicated five times. A split-plot design was used where nutrient sources formed the main plot and cultivars the sub-plots. Plant height differed due to nutrient source in 2007 and 2008, while differences due to cultivar were minor. The control plots produced the shortest plants (height < 50 cm), while plots receiving the integrated nutrient input produced the tallest plants (height > 60 cm). Numbers of branches and fruits per plant differed due to nutrient source and cultivar during most of the study period. Plants receiving either organic inputs (Gliricidia biomass) alone or the integrated nutrient input alone had significantly higher stem, leaf and fruit weight compared with the control. Average fruit yield was lower in control plots than in plots receiving the organic input alone or the integrated nutrient input. Among cultivars, Papri-King, Papri-Supreme and Papri-Queen produced higher dry fruit yield. The ASTA and RAL colour rating was within the internationally accepted range for fruit from the treatments.  相似文献   
13.
Agroforestry Tree Seed Production and Supply Systems in Malawi   总被引:1,自引:1,他引:0  
A sustainable agroforestry tree germplasm supply system is vital to resource-constrained smallholder farmers who depend on agroforestry to improve the productivity of their farm enterprises. Successful adoption of agroforestry hinges on the development of a sustainable agroforestry tree germplasm supply system. This paper reviews the agroforestry tree seed supply system in Malawi, with a view to determining its sustainability and quality. Currently, more than 90% of the documented agroforestry tree seed distributed to farmers is produced by smallholder farmers collected mainly from scattered farmland trees, the remainder being produced from seed orchards and seed stands owned or controlled by research organizations. Three organizations—namely the Land Resources Centre (LRC), National Tree Seed Centre (NTSC) of the Forestry Research Institute of Malawi (FRIM) and the World Agroforestry Centre (ICRAF)—were identified as major procurers of agroforestry tree seed produced by smallholder farmers. Agroforestry germplasm is distributed to farmers by non-governmental organizations (NGOs) and government agricultural and forestry extension departments. The procurement and distribution of germplasm to farmers is in general effective. The major challenge to sustainability of agroforestry tree germplasm distribution in Malawi is dependence on donor funding. The agroforestry tree seed system is, to some extent, sustainable with regards to production, although the genetic quality of the germplasm is low. Germplasm storage facilities at national level are available and possibly adequate, but knowledge and information on effective low-cost tree germplasm storage systems at household level are limited. Sustainability could be enhanced by strengthening of grass-root organizations involved in tree seed production to institutionalize the distribution through farmer–farmer exchange. There is also a need to support the development, promotion and adoption of low-cost tree germplasm storage facilities by smallholder farmers.  相似文献   
14.
Fertilizer tree technologies such as intercropping, relay cropping, improved fallows and biomass transfer have been promoted as sustainable, low-input alternative or complimentary inputs to inorganic fertilizers in Malawi. However, research into the long term effects of their adoption on household food security and poverty reduction is limited. This study examined whether these technologies contribute to rural household of subsistence farmers in terms of food security and livelihoods improvement in two districts of Malawi. The study shows that fertilizer tree technologies increase crop production and provide additional income to households through sources such as sale of agroforestry tree seed and fuelwood. The choice of the technologies is driven by the size of the land holdings and more benefits are associated with large land holdings. While fertilizer tree technologies contribute to the reduction in hunger months, this is usually compromised at the household level by the inability to achieve livelihood security, absorb and cope with shocks and overall improved welfare.  相似文献   
15.
16.
The objective of the study was to determine the relationship between phenols and graft incompatibility in Uapaca kirkiana. Phenol quantification and identification were carried out using Folin-Ciocalteau reagent procedure, fluorescence microscopy and reverse phase high performance liquid chromatograph (RP-HPLC) above, below and at the graft union. Results showed no vascular cambium continuity above the scion/stock unions. Significant differences in total soluble phenols and cell wall bound phenols were obtained. Fluorescence microscope indicated the presence of flavonoids and other polymers above the union. The RP-HPLC identified ferulic acid as a major phenol component found in U. kirkiana plant cells and responsible for wood discolouration. High phenol concentrations were obtained in less compatible combinations than in compatible combinations. High peaks of ρ-coumaric acid were obtained above the union. It is concluded that phenols, especially ρ-coumaric acids and flavonoids caused poor callus formation at the union, and hence implicated in graft incompatibility.  相似文献   
17.
Tropical Animal Health and Production - Systematic assessment and documentation of extensive livestock production systems are necessary to design or review breeding programs, extension services,...  相似文献   
18.
Water availability is a major constraint to crop production in sub-Saharan Africa (SSA) where agriculture is predominantly rain-fed. This study aimed to investigate the effect of the nitrogen-fixing legume tree Leucaena (Leucaena leucocephala) and inorganic fertilizer on rain use efficiency (RUE), a robust measure of productivity and land degradation, in three long-term (11-12 years) experiments conducted in Zambia and Nigeria. On the two Zambian sites, sole maize (Zea mays) grown continuously (for 11-12 years) with the recommended fertilizer achieved the highest RUE (3.9-4.6 kg ha−1 mm−1) followed by maize intercropped with Leucaena (2.5-3.4 kg ha−1 mm−1). This translated to 192-383% increase in RUE over the control (maize grown without nutrient inputs), which is the de facto resource-poor farmers’ practice. RUE was more stable in fully fertilized sole maize on the first Zambian site and not statistically different from the maize-Leucaena associations on the second site. On the Nigerian site, RUE was higher in maize planted between Leucaena hedgerows supplemented with 50% of the recommended fertilizer (3.9 kg ha−1 mm−1), maize grown between Leucaena hedgerows without fertilizer (3.0 kg ha−1 mm−1) and sole maize receiving the recommended fertilizer (2.8 kg ha−1 mm−1), which translated to increases in RUE of 202%, 139% and 85%, respectively, over the control. RUE was more stable in the maize grown between Leucaena hedgerows than in the fully fertilized maize. On all sites RUE was least stable in the control. Yield stability in the maize-Leucaena association was not significantly different from the fully fertilized maize on the Zambian sites. On the Nigerian site, maize yields were more stable in maize grown in Leucaena hedgerows than in fully fertilized sole maize. Supplementation of maize grown in Leucaena hedgerows with 50% of the recommended fertilizers resulted in greater yield stability. It is concluded that intercropping cereals with legume trees and supplementation with inorganic fertilizer can increase rain use efficiency and yield stability in rain-fed agriculture in SSA.  相似文献   
19.
This study was designed to determine the mineral concentration and bioavailability of iron (Fe), phosphorus (P), calcium (Ca) and sodium (Na) of mixtures of Panicum maximum (Panicum) with Lablab purpureus (Lablab), Centrosema pubescens (Centro), Stylosanthes guianensis (Stylo), and Aeschynomene histrix (Histrix) in a fistulated N'Dama steer. The solubility of minerals was determined by an in sacco method by incubating ground samples of these forages in the rumen at 0, 6, 12, 24, 48 and 72 h. The mineral solubility characteristics of the forages were evaluated using the equation PD = a + b (1 − e−ct). The result showed that Panicum intercropped with legumes had better crude protein (CP) (av. 9.22% DM) and ash content (av. 2.22% DM) than sole Panicum which gave 7.63% DM and 1.84% DM for CP and ash contents respectively. The highest value of CP of 23.29% DM and ash content (3.96% DM) was obtained for Lablab. The mineral content values of the intercrop were higher than the sole Panicum. Higher mineral content values were obtained in the sole legumes. Iron solubility values of b and potential degradation (PD) which were 58.71% and 87.92% respectively were for Panicum/Histrix mixtures. Calcium solubility values ranged from 30.0% in Panicum to 46.0% in Panicum/Lablab mixture for b fraction. P solubility ranged from 28.0% and 46.0% for b and PD fractions in Panicum to 43.0% and 71.0% in Panicum/Centro mixture respectively. The solubility of the legumes was higher in Na for b fraction (av. 42.0%) and PD fraction (av. 60.0%). Higher values of b (av. 38.0%) and PD (av. 52.0%) were obtained for the mixtures than for sole Panicum. This study revealed that intercropping Panicum with either of the herbaceous forage legumes used for this experiment would increase the Ca, P, Na and Fe contents of the grass.  相似文献   
20.
The effects of supplementing a basal diet of guineagrass (Panicum maximum cv Ntchisi) (diet 5) with Stylosanthes guianensis (diet 1), Lablab purpureus (diet 2), Aeschynomene histrix (diet 3) and Centrosema pubescens (diet 5) on West African dwarf goats were evaluated. Parameters measured were feed intake, nutrient digestibility and nitrogen balance. Voluntary intake (g/kg W0.75/day) of dry matter (DM) 138.73, crude protein (CP) 25.86, neutral detergent fiber (NDF) (96.29) and acid detergent fiber (ADF) (65.73) of diet 1 were not significantly different (P > 0.05) from the other diets with legume supplements. The feed intake of goats on diet 5 was lower (P < 0.05), having corresponding values of DM (108.21), CP (17.33), NDF (77.68), and ADF (53.55). Weight gain (g/day) differed (P < 0.05) in goats placed on the diets. The lowest weight gain was obtained in diet 5. The digestibilities of DM, CP, ADF and acid detergent lignin (ADL) differed (P < 0.05) in diet 1–5 except for NDF digestibility. Nitrogen balance (g/kg W 0.75/day) ranged from 0.29 in diet 5 to 0.83 in diet 2 (P < 0.05). Similarly, nitrogen retention percentage was highest in diet 2 (35.17), with the lowest value in diet 5 (20.71). It could be concluded that a diet consisting of Panicum maximum with Lablab purpureus supplementation gave the highest performance in weight gain, nitrogen digestibility and nitrogen utilization. However, any of the herbaceous legumes in this study would lead to increased productivity of ruminant livestock.  相似文献   
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