8 pages, Commercial, Industrial and agricultural wastes are major soil pollutants, which contain inorganic, organic compounds and heavy metals. When these heavy metals accumulate in agricultural lands, they adversely affect on growth and physiology of crops ultimately causing decrease in food productivity. In this experiment maize was used to investigate the effects of heavy metals on plant physiology and growth. Maize is cultivated throughout the world for its importance as cereal. It is the third most important cereal crop, following wheat and rice. Maize is a significant food source for humans providing essential minerals, vitamins, carotene and ascorbic acid. Apart from its importance as a cereal source, it also serves as important raw material for various products such as syrup, starch and oil. Various concentrations of Cr and Mn were applied individually as well as in combination to examine their effects on growth and physiology of maize. Analysis of recorded data showed that the treatment 0.5 mM MnCl2 + 0.25 mM CrCl3 had the most harmful effect and caused significant decrease in height, number of leaves and chlorophyll 'a' and 'b' in the stems and leaves. While less harmful effects were seen when heavy metals were applied individually such as 0.25 mM CrCl3, 0.25 mM MnCl2 and 0.5 mM MnCl2 as these treatments did not significantly impact on height, leaf area and chlorophyll content in stems and leaves. So, from these results it can be concluded that. when chromium was applied separately, it had minimal impact on plant physiology and growth, but in combination with manganese, it severely affected on maize plants. Similarly, a small concentration of manganese alone did not affect plant growth, but combined with chromium, it negatively impacted photosynthetic pigments and growth traits.
International: International Program for Agricultural Knowledge Systems (INTERPAKS), Office of International Agriculture, University of Illinois, Urbana-Champaign.
Location:
Agricultural Communications Documentation Center, Funk Library, University of Illinois Document Number: D07288
INTERPAKS, Examines the nature and extent of different extension services available to farmers in Punjab state (1974-5) as well as the impact of extension inputs on productivity in agriculture. The design of the study was multi-stage stratified random sampling with weights assigned to different items of extension input (mass media, visits by extension officers, visits to extension agencies, training). On the average, each farmer visited the extension agencies 5.8 times a year, was visited 9.42 times, only 22% of farmers received training, 28% purchased daily newspapers, 86% listened to radio programs for the rural population, and 68% visited the university. Production function analysis was conducted both with and without extension inputs. The regression coefficient of the extension input was found to be 0.18 which was significant at the 5% level.
Agricultural Communications Documentation Center, Funk Library, University of Illinois Box: 93 Document Number: C06992
Notes:
AGRICOLA IND 90047157; Paper presented at the 1988 Winter Meeting of the American Society of Agricultural Engineers, December 13-16, 1988, Chicago, IL., St. Joseph, MI: American Society of Agricultural Engineers, 1988. 36 p. (Microfiche Collection fiche no. 88-1606), A key to the adoption of spatially variable or site specific farming methods will be the ability to examine and analyze information. Geographic Information Systems (GIS) are computerized systems designed to manage mapped data. A survey of microcomputer based GIS was performed. Nineteen GIS systems were summarized. (original)
12 pages, Conservation Agriculture (CA) has been widely promoted as a pathway to sustainably intensify agriculture in sub-Saharan Africa (SSA). Yet despite decades of promotion, CA uptake in SSA remains sparse with only few analyses of its impacts on farming and rural livelihoods. This study, which focuses on areas in Central Malawi considered to have a relatively high uptake of CA, uses analyses of satellite images, field observations, interviews with farmers, extension workers and other people involved in CA promotion, as well as a household survey, to investigate how CA has been adapted. We find that the three CA principles – (1) continuous minimum tillage, e.g. no-ridging, (2) permanent ground cover, and (3) crop rotation/intercropping – were not practiced as intended. First, one-third of non-ridged land was tilled during the growing season, and half was again ridged in the following season. Second, unless crop residues were added, the soil’s surface of non-ridged plots was usually bare at planting, causing weed control problems, and an increased risk of erosion. Most farmers added large volumes of crop residues to their non-ridged plots. They collected these from the surrounding fields, but this practice severely restricted the size of these plots. Third, crop rotation/intercropping was practiced less when farmers stopped ridging. Thus overall, very few farmers practised all of the three CA principles simultaneously. CA promotion appeared to only increase yields on plots where mulch was added, but this practice is not scalable. CA promotiondoes not seem to have provided substantial benefits for overall farm productivity, labour-savings or soil cons
