• Authors:
    • Ramakrishna, A.
    • Bourke, R.
  • Source: ACIAR Technical Reports Series
  • Issue: 71
  • Year: 2009
  • Summary: Sweetpotato was introduced into Papua New Guinea (PNG) from eastern Indonesia about 300 years ago and now dominates agricultural production in the PNG highlands. The environments in which it is grown in the highlands are briefly reviewed. The main components of the agricultural systems in which it is grown are noted, including type of fallow vegetation cleared for cultivation, fallow period, cropping period before fallow, intercropping, seasonality, soil fertility maintenance techniques, mounding and drainage. The importance of the crop in highlanders' diets and agricultural systems is briefly reviewed, as is the crop's role as pig fodder and the quantity sold in fresh food markets. Some possible future trends for sweetpotato in the highlands conclude the paper.
  • Authors:
    • Garcia, R.
    • Dornelles, M.
    • Lima, A.
    • Coelho, F.
    • Lima, E.
  • Source: Revista Ceres
  • Volume: 56
  • Issue: 6
  • Year: 2009
  • Summary: The objective of this work was to evaluate a number of soybean agronomic characteristics in green manuring succession with two types of residue management. An experiment arranged in a complete randomized block design with four repetitions distributed in a split-plot scheme was carried out in Campos dos Goytacazes-RJ, in the agricultural year 2001/2002. The plots consisted of two managements (with and without clipping) and the subplots consisted of the cover species (black oat, millet, forage sorghum, teosinte, forage radish, dwarf velvet bean, white lupin, pigeonpea, and spontaneous vegetation). In the treatment without clipping, the mean grain yield of soybean in succession with black oat and spontaneous vegetation was 50% higher than the succession with dwarf velvet bean, millet, pigeonpea and forage sorghum. However, in the treatment with clipping, the mean grain yield in succession with millet, teosinte and spontaneous vegetation was 79% higher than the succession with lupin and dwarf velvet bean. The management of millet with mechanical clipping resulted in the increase of 1.154 kg ha -1 of soybean compared wih the treatment without management.
  • Authors:
    • Ratsch, R.
    • Taraken, I.
  • Source: ACIAR Technical Reports Series
  • Issue: 71
  • Year: 2009
  • Summary: This paper explains the concept of composted mounding, which is used to cultivate sweetpotato/kaukau ( Ipomoea batatas) in many locations in Enga province and parts of Southern Highlands and Western Highlands provinces of Papua New Guinea (PNG). It draws both from published literature and recent findings on sweetpotato cultivation in the PNG highlands. The practice of composted mounding allows permanent land use and intercropping, and facilitates successive multiple harvests of sweetpotato tubers and other vegetables. It counteracts the risks of frosts and soil-borne pests and diseases, and reduces soil erosion. It offsets the inherent soil-fertility problems associated with the dominant volcanic ash soils in the mounding zone of the PNG highlands. The method utilises locally available organic materials such as garden debris, weeds, grasses and farmyard manure as compost. Numerous agronomic trials have been conducted to evaluate the effects of composted mounding on sweetpotato yield. However, further research is needed on the decomposition process to assess the beneficial effects of mounding in terms of reduced risk of frost, and pest and disease damage, and to evaluate the benefits of using ever-greater rates of compost in the light of the extra costs of collecting the compost material.
  • Authors:
    • Monteiro, J. E. B. A.
  • Source: Agrometeorologia dos cultivos: o fator meteorológico na produção agrícola
  • Year: 2009
  • Summary: This book brings together a broad base of information on 32 major Brazilian agricultural crops and their relations with climate. The focus of the book is not on the methodologies and applications of agrometeorology per se, but rather restricts its focus to crops and traits that determine yield as a function of the environment. The crops included are rice, castor oil, sunflowers, pineapples, soyabeans, triticale, maize, potatoes, barley, peanuts, oats, onions, canola, wheat, cotton, beans, sugarcane, Pinus, black wattle ( Acacia mearnsii), tropical and temperate grapes, coconuts, citrus, bananas, sisal, cocoa, coffee, apples, Jatropha, Eucalyptus and the fodder plants Cynodon, Brachiaria and Panicum. The contents of the book are divided into three main parts, I. Introduction, II. Temporary crops and III. Permanent crops, with each chapter within parts II and III dedicated to a particular crop, and covering: (1) the main features of farming and phenology; (2) agrometeorological productivity constraints - water availability, temperature, solar radiation, photoperiod and wind; and (3) adverse events - hail and rainstorms, droughts and dry spells, winds and gales, frost, and too much rain and over-prolonged drought. The book was organized by the National Institute of Meteorology and had the collaboration of 105 researchers from 37 Brazilian institutions (federal and state), research centres, institutes and universities.
  • Authors:
    • Garcia-Oliva, F.
    • Prat, C.
    • Medina-Orozco, L.
    • Mendoza, M. E.
    • Bravo-Espinosa, M.
    • Lopez-Granados, E.
  • Source: Land Degradation & Development
  • Volume: 20
  • Issue: 6
  • Year: 2009
  • Summary: In the Transmexican Volcanic Belt a traditional fallow system is practiced, called "ano y vez" (AV), which does not benefit soil conservation due to its low level of nutrient recycling and because soil protection is poor during the cultivation year. The objective of the present work was to measure runoff and soil and nutrient losses during three annual cycles (2002-2004) in Central Mexico under AV rotation and two alternative systems: improved traditional (IT) and traditional organic (TO). Soil losses in the three systems were moderate (
  • Authors:
    • Gerpen, J. H. van
    • Kinney, A. J.
    • Schweiger, B.
    • Tat, M.
    • Tenopir, P.
    • LaVallee, B. J.
    • Graef, G.
    • Clemente, T. E.
  • Source: Plant Biotechnology Journal
  • Volume: 7
  • Issue: 5
  • Year: 2009
  • Summary: Phenotypic characterization of soybean event 335-13, which possesses oil with an increased oleic acid content (>85%) and reduced palmitic acid content (
  • Authors:
    • Place, F.
    • Ajayi, O. C.
    • Akinnifesi, F. K.
    • Sileshi, G.
  • Source: Plant and Soil
  • Volume: 307
  • Issue: 1-2
  • Year: 2008
  • Summary: A number of studies have tested the effect of woody and herbaceous legumes on soil fertility and maize yields in sub-Saharan Africa. However, their effects on maize productivity are much debated because results have been variable. A meta-analysis was conducted with the aim of evaluating the evidence in support of yield benefits from woody and herbaceous green manure legumes. A total of 94 peer-reviewed publications from West, East and southern Africa qualified for inclusion in the analysis. Maize yield from herbaceous green manure legumes (54 publications), non-coppicing legumes (48 publications), coppicing woody legumes (10 publications), natural fallows (29 publications), and fully fertilized monoculture maize (52 publications) were compared. Mixed linear modelling using yield differences (D) and response ratios (RR) indicated that the response to legumes is positive. The mean yield increase (D) over unfertilized maize was highest (2.3 t ha-1) and least variable (CV=70%) in fully fertilized maize, while it was lowest (0.3 t ha-1) and most variable (CV=229%) in natural fallows. The increase in yield over unfertilized maize was 1.6 t ha-1 with coppicing woody legumes, 1.3 t ha-1 with non-coppicing woody legumes and 0.8 t ha-1 with herbaceous green manure legumes. Doubling and tripling of yields relative to the control (RR > 2) was recorded in coppicing species (67% of the cases), non-coppicing legumes (45% of the cases), herbaceous green manure legumes (16% of the cases) and natural fallows (19% of the cases). However, doubling or tripling of yields occurred only in low and medium potential sites. Amending post-fallow plots with 50% of the recommended fertilizer dose further increased yields by over 25% indicating that legume rotations may play an important role in reducing fertilizer requirements. Except with the natural fallow, the 95% confidence intervals of D and RR were higher than 1 and 0, respectively indicating significant and positive response to treatments. Therefore, it is concluded that the global maize yield response to legumes is significantly positive and higher than unfertilized maize and natural vegetation fallows.
  • Authors:
    • Koch, B.
    • Siwe, R. N.
  • Source: Environmental monitoring and assessment
  • Volume: 145
  • Issue: 1-3
  • Year: 2008
  • Summary: The continuous extraction of wood and the conversion of forest to small- and large-scale agricultural parcels is rapidly changing the land cover of the mount Cameroon region. The changes occur at varying spatial scales most often not more than 2ha for the small-scale subsistence farms and above 10ha for the extensive agricultural plantations of cocoa and palm. Given the importance of land use and land cover data in conservation planning, accurate and efficient techniques to provide up-to-date change information are required. A number of techniques for realising the detection of land cover dynamics using remotely sensed imagery have been formulated, tested and assessed with the results varying with respect to the change scenario under investigation, the information required and the imagery applied. In this study the Change Vector Analysis (CVA) technique was implemented on multitemporal multispectral Landsat data from the Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) sensors to monitor the dynamics of forest change in the mount Cameroon region. CVA was applied to multi-temporal data to compare the differences in the time-trajectory of the tasseled cap greenness and brightness for two successive time periods - 1987 and 2002. The tasseled cap was selected as biophysical indicator because it optimises the data viewing capabilities of vegetation, representing the basic types of land cover - vegetation, soil and water. Classes were created arbitrarily to predict the technique's potential in monitoring forest cover changes in the mount Cameroon region. The efficiency of the technique could not be fully assessed due to the inavailability of sufficient ground truth data. Assessment was based on the establishment of an error matrix of change versus no-change. The overall accuracy was 70%. The technique nevertheless demonstrated immense potentials in monitoring forest cover change dynamics especially when complemented with field studies.
  • Authors:
    • Babu, C.
    • Sureshkumar, P.
    • Sivakumar, S.
    • Chandaragiri, K.
    • Thirukumaran, K.
    • Ramesh, S.
    • Umashankar, R.
  • Source: Journal of Ecobiology
  • Volume: 19
  • Issue: 1
  • Year: 2007
  • Summary: Field experiments were carried out at the Tamil Nadu Agricultural University farm, Coimbatore, India, during north-east monsoon seasons of 2000-01 and 2001-02 to design a viable farming system by linking the crop and animal components viz., goat, rabbit and pigeon to sustain crop productivity and profitability and increasing the employment opportunity of dry land farmers. Among the different crops in the farming systems, pearl millet (cumbu) + soyabean grain, maize + cowpea fodder and Cenchrus ciliaris + Stylosanthes scabra fodder system with goat, rabbit and pigeon system were higher economic parameters in the second year than the first year. The economics of the integrated farming system revealed the superiority of pearl millet + soyabean grain, maize + cowpea fodder and C. ciliaris + S. scabra fodder with goat, rabbit and pigeon system in terms of higher total returns of Rs. 162 616 and 206 942, net returns of Rs. 80 924 and 125 250, benefit-cost ratio of 1.99 and 2.53 for every rupee invested and the per day returns (Rs.222 and 343) compared to other systems in first and second year, respectively. It also generated maximum employment opportunity of 490 man-days per year compared to other systems.
  • Authors:
    • Karunanithi, S.
    • Sureshkumar, P.
    • Umashankar, R.
    • Sivakumar, S.
    • Chandaragiri, K.
    • Thirukumaran, K.
    • Ramesh, S.
    • Babu, C.
  • Source: Journal of Ecobiology
  • Volume: 19
  • Issue: 3
  • Year: 2007
  • Summary: Field experiments were carried out at Tamil Nadu Agricultural University farm, Coimbatore (India) during north-east monsoon seasons of 2000-01 and 2001-02, to design a viable farming system by linking the crop and animal components, viz., goat, rabbit and pigeon to sustain the production and productivity of dry land through effective recycling of organic wastes. Results revealed that among the different crops in the farming systems, pearl millet (cumbu)+soyabean grain, maize+cowpea fodder and Cenchrus ciliaris+ Stylosanthes scabra fodder system added higher crop residues of 4250 and 5360 kg ha -1 in the first and second year, respectively. The cumbu+soyabean grain, maize+cowpea fodder and Cenchrus ciliaris+ Stylosanthes scabra fodder system added higher NPK through the residues addition in both the years by recording 31.0, 8.9 and 45.9 kg ha -1; and 39.1, 11.3 and 57.9 kg ha -1 of NPK for the first and second year, respectively. The conventional system (sorghum+cowpea grain) recorded the least amount of NPK addition through the crop residues in both the years. The total organic residues added by the crops+goat+rabbit+pigeon farming system were higher than other system in both the years (9527 and 8170 kg ha -1) and crop+goat+ rabbit+pigeon system added higher total NPK in both the years.