• Authors:
    • Chernchom, P.
    • Wetayaprasit, P.
    • Somboonsuke, B.
    • Pacheerat, K.
  • Source: Kasetsart Journal, Social Sciences
  • Volume: 32
  • Issue: 2
  • Year: 2011
  • Summary: The rubber agroforestry system is an alternative agriculture practice for rubber smallholders to enhance the ecological integrity and crop diversity. The data collection for the study of diversification of smallholding rubber agroforestry system (SRAS) included 300 rubber farms of 21 systems in the south, east, and northeast of Thailand. The project results revealed that there are a multitude of 21 rubber farming systems in Thailand. These systems can be classified into three main types: (1) the intercropping rubber-food crop system, growing short-lived plants, for example, pineapple, chili, banana, rice, sweet potato, long bean and corn, for a rubber period, no longer than 36 months; (2) the rubber-fruit crop system, growing multicrop within the rubber area during the rubber productive period. The most common fruit crops that have been grown in Thailand are guava, gnetum, long kong, salacca, mangosteen, durian, and levistona, etc., and (3) the rubber-timber species system, normally yielding higher income to rubber smallholders since the sales of both rubber and wood products are at the same time and this is coupled with the presently high value of wood. The important timber varieties in the rubber area are neem and teak. As for profitability of Smallholding Rubber Agro forestry System (SRAS), it was noted that pineapple, chili, salacca, and gnetum are highly profitable. However, in the rubber-pineapple system which yields the highest income, the cost of investment is the highest too, when compared to the rubber-gnetum system which requires minimal input and low cost of production and management. The main conditions for decision-making in the rubber intercropping system are as follows: (1) farm household labor requirement, (2) knowledge and experience, (3) extension and policy implication, (4) marketing opportunity, (5) consistent capability of local communities, and (6) land topography and sustainability. For SRAS development strategy in the southern Thailand, improvement should be made on pricing and marketing of agroforestry products, appropriate technology for higher productivity, greater farm efficiency and risk reduction at farm level, and more synchronized co-ordination among stakeholder agencies at the regional level.
  • Authors:
    • Gawronska-Kulesza, A.
    • Suwara, I.
  • Source: Fragmenta Agronomica
  • Volume: 28
  • Issue: 2
  • Year: 2011
  • Summary: Soil structure is one of the most important factors affecting soil fertility. In the structure-forming process the main role is played by organic matter and biological processes occurring in soil. The role of plants largely depends on their influence on the content of organic matter in the soil. The favourable influence of continuous pasture and red clover on formation of the granular structure are commonly known. The aim of these studies was to determine the effect of annual plants grown in narrow (spring barley, winter rye, winter oilseed rape, white mustard) and wide row-spacing (potato, maize) on the structure of light soil. The plants were cultivated in four-year crop rotation: potatoes (or maize) - spring barley - oilseed winter rape (or white mustard) - winter rye. In a permanent fertilization experiment at yczyn near Warsaw established in 1960 soil crumb composition and water resistance were investigated in years 1994-1997. The field was situated on lessive soil, the upper layer of which constitutes light loamy sand on boulder loam. The soil for studies was taken from the arable layer of 0-20 cm. The cultivated plants significantly influenced soil structure and water resistance of soil aggregates. The soil from plots in which winter plants were grown in narrow row-spacing (winter oilseed rape, winter rye) was characterised by the best structure. The highest water resistance of aggregates was formed on these plots. Potato and maize, grown in wide row-spacing had the worst influence on the soil crumb composition and water resistance of aggregates. Their action on the soil started relatively late, what had an effect on the formation of water resistance of aggregates. Plants shading the soil well over the year favour the increase in water resistance of aggregates and those shading poorly like potatoes and maize - its decrease.
  • Authors:
    • Halloran, J. M.
    • Olanya, O. M.
    • Griffin, T. S.
    • Honeycutt, C. W.
    • Larkin, R. P.
    • He, Z.
  • Source: Phytopathology
  • Volume: 101
  • Issue: 1
  • Year: 2011
  • Summary: Four different potato cropping systems, designed to address specific management goals of soil conservation, soil improvement, disease suppression, and a status quo standard rotation control, were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics. The status quo system (SQ) consisted of barley under-seeded with red clover followed by potato (2-year). The soil-conserving system (SC) featured an additional year of forage grass and reduced tillage (3-year, barley/timothy-timothy-potato). The soil-improving system (SI) added yearly compost amendments to the SC rotation, and the disease-suppressive system (DS) featured diverse crops with known disease-suppressive capability (3-year, mustard/rapeseed-sudangrass/rye-potato). Each system was also compared with a continuous potato control (PP) and evaluated under both irrigated and nonirrigated conditions. Data collected over three potato seasons following full rotation cycles demonstrated that all rotations reduced stem canker (10 to 50%) relative to PP. The SQ, SC, and DS systems reduced black scurf (18 to 58%) relative to PP; ST reduced scurf under nonirri2ated but not irrigated conditions; and scurf was lower in DS than all other systems. The SQ. SC, and DS systems also reduced common scab (15 to 45%), and scab was lower in DS than all other systems. Irrigation increased black scurf and common scab but also resulted in higher yields for most rotations. SI produced the highest yields under nonirrigated conditions, and DS produced high yields and low disease under both irrigation regimes. Each cropping system resulted in distinctive changes in soil microbial community characteristics as represented by microbial populations, substrate utilization, and fatty acid methyl-ester (FAME) profiles. SI tended to increase soil moisture, microbial populations, and activity, as well result in higher proportions of monounsaturated FAMEs and the FAME biomarker for mycorrhizae (16:1 omega 6c) relative to most other rotations. DS resulted in moderate microbial populations and activity but higher substrate richness and diversity in substrate utilization profiles. DS also resulted in relatively higher proportions of FAME biomarkers for fungi (18:2 omega 6c), actinomycetes, and gram-positive bacteria than most other systems, whereas PP resulted in the lowest microbial populations and activity; substrate richness and diversity; proportions of monounsaturated and polyunsaturated FAME classes; and fungal, mycorrhizae, and actinomycete FAME biomarkers of all cropping systems. Overall, soil water, soil quality, and soilborne diseases were all important factors affecting productivity, and cropping systems addressing these constraints improved production. Cropping system approaches will need to balance these factors to achieve sustainable production and disease management.
  • Authors:
    • Pecchioni, N.
    • Perata, P.
    • Milc, J.
    • Meriggi, P.
    • Arru, L.
    • Caffagni, A.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 42
  • Issue: 6
  • Year: 2011
  • Summary: Iodine is an essential microelement for human health, and the recommended daily allowance (RDA) of such element should range from 40 to 200 g day -1. Because of the low iodine contents in vegetables, cereals, and many other foods, iodine deficiency disorder (IDD) is one of the most widespread nutrient-deficiency diseases in the world. Therefore, investigations of I uptake in plants with the aim of fortifying them can help reach the important health and social objective of IDD elimination. This study was conducted to determine the effects of the absorption of iodine from two different chemical forms - potassium iodide (I -) and potassium iodate (IO -3) - in a wide range of wild and cultivated plant species. Pot plants were irrigated with different concentrations of I - or IO -3, namely 0.05% and 0.1% (w/v) I - and 0.05%, 0.1%, 0.2%, and 0.5% (w/v) IO -3. Inhibiting effects on plant growth were observed after adding these amounts of iodine to the irrigation water. Plants were able to tolerate high levels of iodine as IO -3 better than I - in the root environment. Among cultivated species, barley ( Hordeum vulgare L.) showed the lowest biomass reductions due to iodine toxicity and maize ( Zea mays L.) together with tobacco ( Nicotiana tabacum L.) showed the greatest. After the screening, cultivated tomato and potato were shown to be good targets for a fortification-rate study among the species screened. When fed with 0.05% iodine salts, potato ( Solanum tuberosum L.) tubers and tomato ( Solanum lycopersicum L.) fruits absorbed iodine up to 272 and 527 g/100 g fresh weight (FW) from IO -3 and 1,875 and 3,900 g/100 g FW from I -. These uptake levels were well more than the RDA of 150 g day -1 for adults. Moreover, the agronomic efficiency of iodine accumulation of potato tubers and tomato fruits was calculated. Both plant organs showed greater accumulation efficiency for given units of iodine from iodide than from iodate. This accumulation efficiency decreased in both potato tubers and tomato fruits at iodine concentrations greater than 0.05% for iodide and at respectively 0.2% and 0.1% for iodate. On the basis of the uptake curve, it was finally possible to calculate the doses of supply in the irrigation water of iodine as iodate (0.028% for potato and 0.014% for tomato) as well as of iodide (0.004% for potato and 0.002% for tomato) to reach the 150 g day -1 RDA for adults in 100 g of such vegetables, to efficiently control IDD, although these results still need to be validated.
  • Authors:
    • McSorley, R.
  • Source: Nematropica
  • Volume: 41
  • Issue: 2
  • Year: 2011
  • Summary: Studies that utilized rotation crops for management of root-knot nematodes in the southeastern United States were examined to evaluate the overall performance of rotation crops. In general, nematode-susceptible crops that followed effective rotation crops produced yields and supported nematode numbers similar to those obtained on crops treated with most standard nematicides. Fumigation with methyl bromide was an exception, and resulted in low nematode numbers up to the end of the susceptible target crop, whereas nematode numbers recovered following rotation crops. Performance of rotation crops was similar to clean fallow in most studies, and there was little evidence that rotation crops could suppress nematode numbers below levels obtained after clean fallow. Large reductions in nematode numbers often were achieved following rotation crops. In sites with relatively low initial population levels before rotation crops were used, effective rotation crops sometimes maintained relatively low nematode numbers through the following susceptible target crop, and nematode recovery was not observed until the second year of the rotation sequences. Where practical, very long rotations such as bahiagrass pastures were often effective in preventing increase in nematode numbers on subsequent susceptible crops. Rehabilitation of heavily infested sites is difficult, could require several years of rotation crops, and the benefit gained may last only through one susceptible crop.
  • Authors:
    • Mueller, T.
    • Schulz, R.
    • Moeller, K.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 89
  • Issue: 2
  • Year: 2011
  • Summary: An increasing number of biogas plants (BGPs) based on digestion of dedicated energy crops have been implemented in Germany. The objectives of this study were to assess the changes in (1) the acreage of different crops (silage maize, cereals, etc.) related to the setup of the BGP, (2) nutrient flows and budgets (N, P, K) due to the implementation of the BGPs, and (3) to assess the effluent N in the overall crop N supply. Data from 14 farmers before the setup of the BGPs were compared with data after implementation. Due to the setup of the BGPs, the acreage of silage maize greatly increased and there were significant negative effects on the weighted soil humus budgets, no effects on the weighted mean N and P budgets, and a negative trend regarding the K budgets. Results concerning the N release from organic manuring to maize crops showed that one third of the farmers considerably over-fertilize maize, indicating an underestimation of short- and long-term N supply of manure N. The implementation of centralized BGPs established very intensive nutrient cycles and, in the long-term higher risks of nutrient losses and environmental pollution are expected. One very effective measure to compensate for negative effects on the soil humus budgets and nitrate leaching is an enlargement of cover cropping, which will also offer economic revenue by providing aboveground biomass for digestion. If the amounts of effluents returned to a single farm or field are not adapted to the nutrient composition of the substrates delivered to the BGP, large nutrient imbalances can result. An effective measure to get a better allocation of the available nutrients is a solid-liquid separation of the effluents, enabling a more targeted allocation of the nutrients.
  • Authors:
    • Buckley, K. E.
    • Moulin, A. P.
    • Volkmar, K.
  • Source: Canadian Journal of Soil Science
  • Volume: 91
  • Issue: 4
  • Year: 2011
  • Summary: The potential for adverse effects on soil quality and erosion in pinto bean-potato rotations is significant due to low levels of residue input to the soil following potatoes or beans, and the effect of tillage on soil structure, particularly in sandy-textured soils typical of the potato-growing area of Manitoba. Soil quality is reduced by low inputs of residue and carbon commensurate with an increase in the proportion of small and unstable aggregates susceptible to erosion. Furthermore N and P concentrations at the soil surface may be affected by various management options including fall cover crops, application of straw and the use of composted manure. In a study conducted at Carberry, MB, from 2000 to 2006, KCI-extractible NO(3)-N and Olsen P were determined in the fall prior to seeding in each year of the study. Water-soluble P, determined in the fall of 2005 for selected treatments, increased with application of compost. Soil organic C, total N and the proportion of erodible (
  • Authors:
    • Miah, M. N. A.
    • Paul, G. C.
    • Siddique, M. A. B.
    • Amanullah, A. S. M.
  • Source: Pakistan Sugar Journal
  • Volume: 26
  • Issue: 3
  • Year: 2011
  • Summary: An experiment was conducted at Regional Sugarcane Research Station (RSRS). Thakurgaon during 2005-06 and 2006-07 cropping seasons to asses effects of different levels of irrigation and split application of N-K fertilizers in sugarcane (var. Isd 36) intercropped with potato (var. Diamond). The intercrop, potato received recommended fertilizer as usual. Application of Urea and Potash (N-K fertilizers) in two splits (B 1) produced highest number of tiller, millable cane and also highest yield in both levels of irrigation in both years. Though the difference was not significant over B 2 and B 3. But irrigation level A 1 (Six light irrigation with 65 mm effective rainfall) had significant difference over A 2 (five comparatively deep irrigation with same effective rainfall). Highest number of tiller (215.3*10 3 ha -1), millable cane (114.7*10 3 ha -1) and cane yield (109.9 t ha -1) were produced by the treatment B 1 under A 1 level of irrigation in the crop year 2006-07. Hence split application of N-K fertilizers with two equal splits applied at plantation and at 145 days after plantation and also light irrigation, 6 to 7 number with total amount of 460-500 mm including effective rainfall may be preferred for loamy and sandy loam soils.
  • Authors:
    • Vinnichek, L.
    • Ivanov, A.
  • Source: Mezhdunarodnyi Sel'skokhozyaistvennyi Zhurnal
  • Issue: 5
  • Year: 2011
  • Summary: In Russia's Penza Oblast', cereal grain crops account for 58.1% of receipts from crop sales, sugarbeets account for 26.9%, and oil bearing crops 5.8%. Penza Oblast' can be divided into four different zones, each of which is characterized by different patterns of crop production. These zones are: (1) Vadinskii-Mokshanskii, comprising 12 raiony (administrative districts) in the Central and North Western parts of the oblast'; (2) Belinskii-Serdobskii, comprising seven raiony in the South and South West of the oblast'; (3) Nikol'skii-Gorodishchenskii, comprising three raiony in the North East of the oblast'; and (4) Kuznetskii-Lopatinskii, comprising five raiony in the South East and East of the oblast'. Zone (1) is characterized by average productivity soils, and includes 48.8% of the total land area used for cereal grain production in the oblast', 50.6% of land used for sugarbeet production, and 23.6% of land used for sunflower cultivation. Zone (2) has the highest productivity soils in the oblast', and accounts for 35.0% of the total land area used for cereal grain production in the oblast' and 49.4% of land used for sugarbeet cultivation in the oblast'. The fertility of most soils in zone (3) is poor, resulting in low productivity. Zone (3) accounts for just 4.0% of the total land area used for cereal grain production in the oblast', and technical crop production in this zone is almost nonexistent. Zone (4) accounts for 12.1% of the total land area used for cereal grain production in the oblast' and 31.5% of land used for sunflower cultivation. Sugarbeets are not grown in zone (4) because of the distance from sugar refineries. The zones in which crop production is most profitable are zones (1) and (2), which are also characterized by the highest degree of diversification. Overall, the most economically efficient crop types produced in the Oblast' are potatoes and sunflowers. Recommendations for the future development of different types of crop production in have been formulated on the basis of analysis of natural and economic factors existing in different parts of the oblast'. The recommendations relate to the cultivation of different cereal grain crops (including winter and summer wheat, barley, buckwheat, maize, rye and oats), legume crops (peas and lentils), sugarbeets, oil bearing crops (sunflowers, rape and camelina), potatoes, and other vegetables in the four different zones.
  • Authors:
    • Leifert, C.
    • Critchley, C. N. R.
    • Eyre, M. D.
    • Wilcockson, S. J.
  • Source: European Journal of Agronomy
  • Volume: 34
  • Issue: 3
  • Year: 2011
  • Summary: A survey of 128 plots, in 2008, of a trial where the effects of crop protection can be separated from those of fertility management, generated weed cover data within six crops (winter wheat, winter barley, spring barley, potatoes, cabbages and a grass/clover ley). The effects of the 2008 crop types, of the two preceding crops and of organic and conventional crop protection and fertility management, were assessed using mixed-effects models and constrained ordination. Cover data for 22 weed species and for monocotyledon, dicotyledon, annual, perennial and total weed cover were used. Cover of 15 weed species, and of the five weed groups, was significantly affected by 2008 crops, with cover highest in spring beans and cabbage. Nine and four weed species 2008 cover were significantly related to crops grown in 2007 and 2006 respectively, as were dicotyledon, annual and total weed cover, but not monocotyledon or perennial cover. Cover of 15 species, and the five groups, was significantly higher in plots with organic crop protection, but only eight species and annuals were significantly affected by fertility management. Crop:crop protection produced the most significant interactions with most cover in organically managed plots. Five species, perennials and total weed cover produced significant three-factor models. The greatest weed cover was in organic crop protected but conventionally fertilised spring barley and the least in totally conventional winter barley. Other factors such as crop density and mechanical weeding also affected 2008 weed cover. The ordination indicated that most of the 22 species were strongly associated with crops from all three years. The sequence of crops in the rotation had a profound effect on weed cover. Where three spring-sown, difficult to weed, crops were grown in sequence (spring beans, potatoes and vegetables, spring barley) weed cover increased. However, cover was limited in grass/clover and some cereal plots with different preceding crops. Models predicting weed cover may need to take into account crop sequences within crop rotations, as well as the more usual management inputs. (C) 2011 Elsevier B.V. All rights reserved.