Journal of Agriculture and Rural Development in the Tropics and Subtropics (JARTS)
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Effect of Neem Kernel Cake Powder (NKCP) on Fusarium Wilt of Tomato when Used as Soil Amendment
Get PDFA study was conducted to investigate effect of Neem Kernel Cake Powder (NKCP) at 1.75, 3.5 and 7g rates on development of tomato Fusarium wilt in 1997 at the National Horticultural Research Center, Thika, Kenya. Inoculum density of Fusarium oxysporum f.sp. lycopersici (Sacc.) was two 14mm - diameter disks per planting hole taken from 10 day old cultures growing on PDA. Plant performance was based on shoot height and weight; stem diameter; number and weight of tomato fruits. Disease assessment was based on wilt index of shoots and length of discolouration of vascular tissues. Performance of plants grown in NKCP amended and non-amended soils was significantly (p=0.05) different (33.3 - 93.3%). Disease severity based on the wilt index (0.53-2.87) and length of discoloured vascular tissues (7.4cm - 25.62cm) differed significantly (p=0.05) among treatments
Phosphorus Uptake and Balance in a Soyabean-Maize Rotation in the Moist Savanna of West Africa
Get PDFThis study investigated the effect of maturity class on phosphorus (P) balance in a soyabean-maize rotation in the West African moist savanna.F our soyabean varieties of different maturity classes were grown with or without P fertilizer followed by a maize crop. Soyabean stover P content averaged 1.77 kg ha−1 compared with 5.13 kg ha−1 in the grain. The late soyabean variety TGx1670-1F accumulated a significantly higher P in the grain (6.56 kg ha−1), and stover (2.57 kg ha−1) than the others. While P harvest index averaged 79%, P application increased grain P by 63-81% and stover P by 100% or more. When either soyabean grain or grain+stover was exported, P balance was negative and was not statistically different for varieties when no P was applied. At 30 or 60 kg P ha−1, P balance was negative but significantly lower in TGx1670-1F compared with other varieties. In creasing P rate applied to soyabean significantly (p 0.01) increased maize grain P by 35-66% in the second year. When P was exported only in soyabean grain, cumulative P balances after maize grain harvest (with no P or 30 kg ha−1 applied previous year) were not significantly different for previous soyabean crops. At 60 kg ha−1, however, P balance in previous TGx1670-1F plot was significantly lower than for other varieties. A further export of soyabean stover reduced P balance. Significant residual P effect was observed emphasizing the need to focus P fertilizer application in the cropping system rather than on the single crop. Also with more P in soyabean grain, a reduction in the extent of P depletion will be achieved by returning soyabean stover to the field after threshing
Determinants of Land Contracts and Efficiency in Ethiopia: The Case of Libokemkem District of Amhara Region
Get PDFThe land policy reform that took place in the 1990s in northern Ethiopia has resulted in various forms of land contracts and efficiency. As a policy measure, sale of land is officially prohibited while leasing and inheritance are allowed in one form or another. This paper attempts to assess the efficiency of the different forms of tenure arrangements emerging in Libokemkem district of the Amhara region, northern Ethiopia, and their implication for land tenure policies. With the help of maximum likelihood estimates the effect of various factors on total operated fields was examined. The maximum likelihood result indicates that oxen ownership, family size, age, and total income determine the total cultivated land. It was also shown that choice of crops (tef and wheat) resulted in positive estimates indicating that crop types determine the land area operated. Choice of tenure arrangement on the other hand depends on livestock units, large family size and food shortages, and access to markets. This finding calls for a kind of intervention, which can support operation of informal land markets to be more efficient than the prevailing situation
Response of Sesbania Green Manuring and Mungbean Residue Incorporation on Microbial Activities for Sustainability of a Rice-Wheat Cropping System
Get PDFThe microbial population and its biomass and nitrogenase activity in plant roots under sandy-clay-loam soil conditions where the plant residues of Sesbania rostrata and mungbean (Vigna radiata) were incorporated were significantly higher than that obtained from summer fallow. The increases in yield of rice and wheat and the total nitrogen content in shoot and grain was also perceptible by the application of green manuring. The results highlight the importance of green manuring in rice-wheat cropping systems under tropical sandy-clay-loam soil conditions of India
Crop Performance and Yield of Groundnut, Sesame and Roselle in an Agroforesty Cropping System with Acacia senegal in North Kordofan (Sudan)
Get PDFCrop performance and yield of groundnut (Arachis hypogea), sesame (Sesamum indicum) and roselle (Hibiscus sabdariffa) were investigated in an intercropping system with Acacia senegal and compared with sole cropping. The study was conducted in North Kordofan (Sudan) on loamy sand. Experimental design was a randomized complete block with split plots.Crop performance and crop yield of groundnut, sesame and roselle were significantly (p 0.05) reduced in the intercropping system compared to sole cropping. However, yield reduction in groundnut (53%) was much higher than in sesame (6%) and roselle (14%). The reduction in yield of the intercropping plots could be due to the high tree density, which results in water and light competition between the trees and the agricultural crops
Improving On-farm Water Management - A Never-ending Challenge
Get PDFMost on-farm water management (OFWM) problems are not new.They have been a threat to agriculture in many countries around the globe in the last few decades. However, these problems have now grown larger and there is increasing public demand for the development and management of land and water to be ecologically sustainable as well as economic.As there is a close interrelationship between land use and water resources, farmers need to be aware of this interrelationship and adjust their OFWM e.orts in order to address the issues.In their management e.orts, they need to consider both the on-site and the o.-site e.ects. This paper highlights holistic approaches in water management as being indispensable in the future.Present and future water-utilisation problems can only be solved on the basis of an intersectoral participatory approach to water management conducted at the level of the respective catchment area.In the context of this approach, farmers need to realise that they are part of an integral whole. The paper also lists a range of present and future challenges facing farmers, extensionists, researchers, etc.in relation to OFWM e.orts.Among the challenges are: the e.ects of the increasing competition for freshwater resources; the increasing in.uence of non-agricultural factors on farmers’ land use decisions; the fragmentation of the labour process and its e.ects on farming skills; the information requirements of farmers; the participatory dissemination of information on OFWM; the process of changing permanently the agrarian structure; and the establishment of criteria of good and bad OFWM
Development of organic matter in soils of natural phytocoenoses and agrocoenoses
Get PDFThe brown mountain carbonate soils covering the “yadiere” (hills) in the Gissarska valley of Tadzhikistan have relatively high humus portions. The humus content in the upper layers of sedentary soils was found to range from 2.70 to 3.18 per cent. However, in eroded soils the humus content declines from 1.35-0.83 per cent to levels as low as 0.57-0.75 per cent. The decrease of humus substances in erodible soils is mainly dependent on their slope exposure. Soils on sites sloping to north revealed the highest humus content whilst soils on east and west slopes and, in particular, on south slopes were found to have the lowest humus content. Sprinkler irrigation applied to soils on sloping sites, following grass seeding, was found to result in swift growth and in the evolution of a natural flora what, in turn, induced intensive humus build-up. The humus content of the covering layer increased by 0.98 per cent, that in eroded soils markedly less. The increased humus content primarily leads to humic acid enrichment, this effect causing a wider SGK:SFK ratio. Following grass seeding on these soils a marked increase in the content of dissolved and R2O3-bound humic acids can be observed
The Thermal Conductivity: An Alternative Method for the Measurement of Soil Compaction
Get PDFFour treatments of tillage were compared by measuring soil thermal conductivity. Bulk density and difference between treatments pointed to the discriminatory capacity of the method. The soil thermal conductivity measure or Electrothermal Method (EM) has demonstrated to be a new and reliable indicator for the compaction state of soil
Land-Use Changes in the Upper Lam Phra Phloeng Watershed, Northeastern Thailand: Characteristics and Driving Forces
Get PDFFor a typical smallholder agricultural area in northeast Thailand, this paper describes the land-use changes, their main driving forces and their consequences over the last forty years -from the conversion of the original forest to the present agricultural land use. The area has a relatively short agricultural history. From the 1960s onward, people started to settle in the area and began to clear-cut the forest to grow subsistence crops, such as upland rice and castor beans.After a relatively short period dominated by subsistence crops, the land use rapidly developed into maize-based cash-crop systems. Maize is still the main crop.Since the beginning of agriculture in the area, the farmers practiced continuous cropping. Shifting cultivation was never practiced. Initially, the soil was not tilled, and dibbling of seeds was exclusively practiced. All soil and crop husbandry practices were carried out manually. Due to the influx of more people, the agricultural land area expanded rapidly. Most of the land remains government property. Only recently, limited land-use rights for the farmers are being issued. With the change of the land-use systems over time, i.e., from upland rice to maize, and from subsistence to more market-oriented farming, the agronomic practices also changed adapting to the requirements of the new crops. The application of inorganic fertilizers, herbicides and pesticides became standard practice. The use of these inputs led to a significant increase in land productivity. However, most farmers do not have su.cient capital to purchase all required inputs fore cultivation and they largely depend on private money lenders and middlemen for input supply at extremely high interest rates. There is a general perception amongst farmers of a considerable soil-fertility decline and that more and more fertilizer needs to be applied to maintain the current yield levels. To realize more sustainable agriculture, land-use technologies need to be adopted at the farm level that increase the e.ciency of nutrient and organic matter cycling and reduce soil-degradation risks. Simultaneously, an enabling environment needs to be developed based on appropriate extension services and adequate credit facilities for the farmers
Bericht über die Sonderausstellung ”Deutschsprachige Lehr- und Handbücher zur Agrarwirtschaft in den Tropen und Subtropen aus 12 Jahrzehnten“ aus den Beständen der Bibliothek des Deutschen Instituts für tropische und subtropische Landwirtschaft (DITSL)
Get PDFAnl¨asslich des Deutschen Tropentages 2002, der hundertjährigen Wiederkehr der Errichtung des ersten Gewächshauses für tropische Nutzppfanzen in Witzenhausen, des Tages der Kulturpflanze und der Kürbismesse präsentierte die Bibliothek des Deutschen Instituts für tropische und subtropische Landwirtschaft (DITSL) im Oktober 2002 eine Sonderausstellung zum Thema ”Deutschsprachige Lehr-und Handbücher zur Agrarwirtschaft in den Tropen und Subtropen“. Die Ausstellung zeigte über 80 der von 1876 bis heute erschienenen deutschsprachigen Lehr-und Handbücher (Anlage 1). Darüber hinaus wurden beispielhaft einige Exemplare der Zeitschrift ”Der Tropenppflanzer“ und ihrer Beihefte ausgestellt. Diese Zeitschrift einschließlich ihrer Beihefte wurde von 1897 bis 1944 vom Kolonial-Wirtschaftlichen Komitee herausgeben. Sie stellte eine wesentliche, oft die einzige fachliche Informationsquelle dar für alle, die sich mit der kolonialen Landwirtschaft befassten. Sie ergänzte und aktualisierte das in den Lehr- und Handbüchern festgehaltene Wissen zur Agrarwirtschaft in den Tropen und Subtropen. Aus Platzmangel konnten die zahlreichen vor allem nach 1955 erschienen Monographien zu speziellen Fragestellungen nicht ausgestellt werden. Dabei hätten es viele durchaus verdient, in einer solchen Ausstellung präsentiert zu werden. Als Beispiel sei die Monographienreihe über wirtschaftlich bedeutende tropische Nutzpflanzen genannt, die von der Firma Ruhrstickstoff herausgegeben wurde. Diese ersetzte bis Ende der 60er Jahre oft die fehlenden aktuellen Lehrbücher