• Authors:
    • Garcia, T. S.
    • Giannico, G. R.
    • Mueller-Warrant, G. W.
    • Griffith, S. M.
    • Whittaker, G. W.
    • Banowetz, G. M.
    • Pfender, W. F.
  • Source: Journal of Soil and Water Conservation
  • Volume: 67
  • Issue: 3
  • Year: 2012
  • Summary: Agricultural practices, including tillage, fertilization, and residue management, can affect surface runoff, soil erosion, and nutrient cycling. These processes, in turn, may adversely affect (1) quality of aquatic resources as habitat for amphibians, fish, and invertebrates, (2) costs of treating surface and ground water to meet drinking water standards, and (3) large-scale biogeochemistry. This study characterized the surface water sources of nitrogen (N) (total, nitrate [NO 3-], ammonium [NH 4+], and dissolved organic N) and sediment active within 40 subbasins of the Calapooia River Basin in western Oregon in monthly samples over three cropping years. The subbasins included both independent and nested drainages, with wide ranges in tree cover, agricultural practices, slopes, and soils. Sediment and N form concentrations were tested against weather and agricultural practice variables. Subbasin land use ranged from 96% forest to 100% agriculture. Average slopes varied from 1.3% to 18.9%, and surface water quality ranged from 0.5 to 43 mg L -1 (ppm) total N maxima and 29 to 249 mg L -1 suspended sediment maxima. Total N during the winter was positively related to percentage landcover of seven common agricultural crops (nongrass seed summer annuals, established seed crops of perennial ryegrass [ Lolium perenne L.], tall fescue [ Schedonorus phoenix {Scop.} Holub], orchardgrass [ Dactylis glomerata L.], clover [ Trifolium spp.], and newly planted stands of perennial ryegrass and clover) and negatively related to cover by trees and one seed crop, Italian (annual) ryegrass ( Lolium multiflorum). Results for NO 3- and total N were highly similar. Sediment concentrations were most strongly related to rainfall totals during periods of 4 and 14 days prior to sampling, with smaller effects of soil disturbance. Fourier analysis of total N over time identified four prominent groups of subbasins: those with (1) low, (2) medium, and (3) high impacts of N (up to 2, 8, and 21 mg L -1, respectively) and a strong cyclical signal peaking in December and (4) those with very high impact of N (up to 43 mg L -1) and a weak time series signal. Preponderance of N in streams draining agriculturally dominated subbasins was in the form of the NO 3- ion, implying mineralization of N that had been incorporated within plant tissue following its initial application in the spring as urea-based fertilizer. Since mineralization is driven by seasonal rainfall and temperature patterns, changes in agronomic practices designed to reduce prompt runoff of fertilizer are unlikely to achieve to more than ~24% reduction in N export to streams.
  • Authors:
    • Roger-Estrade, J.
    • Basch, G.
    • Moreno, F.
    • Soane, B. D.
    • Ball, B. C.
    • Arvidsson, J.
  • Source: Soil & Tillage Research
  • Volume: 118
  • Year: 2012
  • Summary: Recent literature on no-till is reviewed with particular emphasis on research on commercial uptake and environmental concerns in northern, western and south-western Europe. Increased interest in no-till, and minimum or reduced tillage, results from changes in the economic circumstances of crop production, the opportunity to increase the area of more profitable autumn-sown crops and increased concern about environmental damage associated with soil inversion by ploughing. Highly contrasting soil and climate types within and between these regions exert a strong influence on the success of no-till. While no-till may often result in crop yields which equal or exceed those obtained after ploughing, modest reductions in yield may be tolerated if production costs are lower than with ploughing. The relative costs of fuel and herbicides have changed appreciably in recent years making no-till more attractive commercially. While effective weed control is an essential aspect of no-till, current herbicide technology may not yet fully achieve this. In northern regions no-till usually allows earlier drilling of winter-sown crops but will give lower soil temperature and higher moisture content in spring, causing delayed drilling of spring-sown crops. No-till soils have greater bulk density and bearing capacity than ploughed soils with a pronounced vertical orientation of macroporosity allowing penetration of roots and water, especially in view of the increased population of deep-burrowing earthworms. Particular care must be taken with no-till to minimise soil damage at harvest and to ensure the even distribution of crop residues prior to drilling. Reduced erosion and runoff after adoption of no-till are widely observed and are of particular importance in southwestern Europe. No-till reduces losses of phosphorus in runoff and, in some cases, reduces the loss of nitrate through leaching. Emissions of greenhouse gases CO 2 and N 2O from no-till soils are highly variable and depend on complex interactions of soil properties. Emission of CO 2 from fuel during machinery usage is always appreciably reduced with no-till. Increased soil organic carbon in surface layers of no-till soils is widely found but may not be associated with increased carbon sequestration throughout the profile. The evaluation of the relative carbon balance for no-till and ploughing depends upon complex inter-relationships between soil and climate factors which are as yet poorly understood. Adoption of no-till could be encouraged by government financial assistance in recognition of environmental benefits, although future restrictions on the use of herbicides may be a deterrent. Opportunities for further research on no-till are outlined.
  • Authors:
    • Weeks, C.
    • Cordingley, N.
    • Flower, K. C.
    • Ward, P. R.
    • Micin, S. F.
  • Source: Field Crops Research
  • Volume: 132
  • Year: 2012
  • Summary: Modern conservation agriculture practices aim to maintain year-round ground cover in order to maximise soil protection from extremes of temperature and minimise erosion risk. However, in Mediterranean-style environments with hot dry summer periods, maintaining ground cover can be difficult, as these periods are generally too arid for plant growth. In this research, we investigated the use of cover crops, grown solely to increase ground cover and not harvested for grain or biomass, in a Mediterranean climate. Specifically, we examined the impact of cover crops and residue retention on evapotranspiration, both over the summer fallow period and during the winter and spring crop growth period, and on deep drainage from subsequent crops, on two contrasting soil types in south-western Australia. The impact of cover crops on weed populations and nitrogen dynamics is described in a companion paper. In contrast to previously published research, cover crops and residue retention were found to have limited impact on total evaporation during the summer and autumn period, although there were occasional short-term impacts on the rate of evaporation shortly after rainfall. There was also limited evidence of changes in evaporation during early crop growth. Drainage from crops grown after cover crops was not consistently different to drainage from crops grown after conventional crops. The inclusion of cover crops in farming systems in regions with a Mediterranean climate is unlikely to have major impacts on the water balance, but may still increase overall sustainability of the farming system.
  • Authors:
    • Tunali, M.
    • Carpici, E.
  • Source: Journal of Food Agriculture and Environment
  • Volume: 10
  • Issue: 2 part 2
  • Year: 2012
  • Summary: The current research was conducted to evaluate the forage yield and quality of stands of common vetch ( Vicia sativa L.) in various combinations with annual cereals such as oat ( Avena sativa L.), barley ( Hordeum vulgare L.) and wheat ( Triticum aestivum L.). Mixture rates were formulated using three combinations of common vetch-cereal (75:25, 50:50 and 25:75) under rainfed conditions in the southern Marmara Region, Turkey, during the 2009-2010 and 2010-2011 growing seasons. The field trials were arranged in a randomized block design with three replications. The averages of the two-year findings indicated that the highest dry matter was determined at pure oat stands, followed by common vetch-oat mixtures at ratios of 50:50 and 75:25. The highest crude protein yield was obtained from pure common vetch and common vetch-oat (75:25) stands. A common vetch-oat mixture at 75:25 can be recommended for experimental and similar ecologies because of its higher dry matter and crude protein yields.
  • Authors:
    • Sanja, V.
    • Branko, M.
    • Aleksandar, M.
    • Dura, K.
    • Nenad, D.
  • Source: African Journal of Biotechnology
  • Volume: 11
  • Issue: 30
  • Year: 2012
  • Summary: The winter-sowing genotypes of common vetch ( Vicia sativa L.) are very susceptible to lodging and therefore are sown in mixtures with small grains that serve as supporting crops. In order to determine an optimum ratio of vetch and wheat ( Triticum aestivum L.) components in their mixture, a four-year trial (autumn 2005 to spring 2009) was carried out, aiming at the yield and quality of winter vetch haylage. The sowing rate of winter vetch was 120 kg ha -1, while the sowing rate of winter wheat was 0, 15, 20, 25 and 30 kg ha -1. An increased proportion of the cereal in its mixture with vetch significantly decreased the stand lodging, have a positive influence on forage yield, but haylage quality is of a poorer quality. Quality characteristics such as crude protein and lignin content, total digestible nutrients, dry matter intake and relative feed value were highest in monoculture common vetch followed by mixture with the lowest rate of wheat. Neutral detergent fiber content was positively affected by intercropping. There were no significant differences among treatments for acid detergent fiber content, digestible dry matter and net energy for lactation. The most favorable balance between the haylage yield and quality, as well as the highest crude protein yield (1482 kg ha -1), was achieved with the mixture of 120 kg ha -1 of the vetch seed and 15 kg ha -1 of wheat.
  • Authors:
    • Pannacci, E.
    • Onofri, A.
    • Graziani, F.
    • Tei, F.
    • Guiducci, M.
  • Source: European Journal of Agronomy
  • Volume: 39
  • Year: 2012
  • Summary: Long-term effects of organic (ORG) and conventional low-input (CONV) farming systems on size and composition of weed seedbank were assessed in 2007 in central Italy, in an on-farm experiment set up in 1996. In this experiment, six rotations (R1-R6) were considered, basically consisting on the same crop sequence with different starting points, i.e. (1) legume crop (soybean/field bean/common pea), (2) vegetable crop (pepper/melon), (3) winter cereal (soft/durum wheat), (4) summer cereal (maize) (5) industrial vegetable (processing tomato), (6) winter cereal (soft/durum wheat). All rotations were established both in ORG and in CONV, in strict adherence to EU regulations (ORG: EU reg. 2092/91; CONV: EU reg. 2078/92). Intercrops with green manuring purposes were included in ORG, while weed control was performed mechanically in ORG and chemically/mechanically in CONV. Weed seedbank was determined on 10 soil samples (0-0.30 m depth) in each plot and seeds were directly extracted, identified and counted. In all rotations, the adoption of ORG resulted in a significant increase in weed seedbank density, particularly in the case of summer weed species ( Portulaca oleracea L., Amaranthus retroflexus L. and Chenopodium album L.), which are more competitive and difficult to control in summer crops under organic farming systems in the Mediterranean climates. Small differences between ORG and CONV were found in terms of number of weed species (23 in ORG and 20 in CONV, on average), but the index of diversity in CONV was on average higher than in ORG. Furthermore, the most dominant weeds in CONV represented a lower percentage of total seedbank (40%, 23% and 5%, respectively, for P. oleracea, A. retroflexus and C. album in CONV and 56%, 32% and 4% for the same three weeds in ORG). These results confirm that the wider availability of effective weed control methods in integrated low-input farming systems (CONV) is helpful to maintain a low seedbank size, with a lower dominance structure. However, the adoption of ORG systems based on long rotation cycles, very competitive crops and accurate weed control, especially at the beginning of the ORG management, may be sustainable in the long run, in terms of potential weed infestation levels.
  • Authors:
    • Jamshidi, K.
  • Source: Desert
  • Volume: 16
  • Issue: 2
  • Year: 2012
  • Summary: In order to evaluate the yield, yield components and protein contents of two wheat cultivars (Zarrin and Gaspard) in sole cropping and intercropping systems,an experiment was conducted using replacement serious technique and different combinations of intercropping with high plant density and optimal of each cultivar. A factorial experiment was conducted in the form of randomized complete block design (RCBD) with three replications at the research farm of Agriculture Faculty of University of Zanjan at 2008-2009. The results showed that planting patterns has significant effect (alpha=0.01) on grain yield, the average number of grain per spike and protein content of each cultivar. The effect of plant density levels on grain yield of Zarrin cultivar was significant (alpha=0.01). The results indicated that the highest grain yield (9611 kg ha -1) was obtained from 2:2 ratios of (50% Zarrin+50% Gaspard) cultivars in plant density of 400 seed per m 2 which had Land Equivalent Ratio (LER) above 1.79. Land equivalent Ratio Index(LER) calculation showed that all intercrops had advantage compare to sole cropping system.
  • Authors:
    • Ercoli, L.
    • Masoni, A.
    • Mariotti, M.
    • Arduini, I.
  • Source: Grass and Forage Science
  • Volume: 67
  • Issue: 2
  • Year: 2012
  • Summary: Intercropping (IC) cereals and legumes could be an option for obtaining forage suitable for ensiling and enabling reduced N fertilization. Two experiments were performed in central Italy with durum wheat ( Triticum durum Desf.) and field bean ( Vicia faba L. var. minor) grown for forage production in IC and as sole crops (SC) with different N rates (20 and 50 kg ha -1) and row ratios (1:1 and 2:1 cereal/legume). The aims were to assess (i) whether IC is a feasible option to reduce N fertilization; (ii) the best combination of practices to obtain forage suitable for ensiling; and (iii) competition/facilitation effects exerted by field bean on durum wheat. Results showed IC allowed fertilizer-N reduction and led to improved forage yield with better quality, compared with SC. Land equivalent ratio indicated a high efficiency of the IC, by up to 26% with respect to SC. Field bean was the dominant species of IC, but N fertilization reduced its competitive ability and enhanced that of wheat. In the intercrop fertilized with 50 kg N ha -1, the proportion of the wheat in the herbage (0.34-0.41 of the total dry matter) was sufficient for ensiling of the forage mass. Field bean exerted both competition and facilitation effects on the cereal. N uptake of durum wheat was greater under IC with beans than as wheat SC.
  • Authors:
    • Kizilay, H.
    • Akcaoz, H.
    • Akdemir, S.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 10
  • Issue: 2 part 2
  • Year: 2012
  • Summary: This research examines the energy use patterns and energy input-output analysis of apple production in the Antalya province, which is an important agricultural center in Turkey. Data for the apple production were collected from 90 apple farms by using a face-to-face survey method. The energy input of chemical fertilizer (41.03%), mainly nitrogen, has the biggest share in the total energy inputs followed by electricity (29.21%). The apple production consumed a total of 43,404.31 MJ ha -1. The energy ratio for apple was estimated to be 1.51. The specific energy, energy productivity, energy intensiveness and net energy yield were 1.59 MJ kg -1, 0.63 kg MJ -1, 3.31 MJ TL -1, and 22,103.83 MJ ha -1, respectively. The non-renewable form of energy input was 95.76% of the total energy input used in apple production compared to only 4.01% for the renewable form. The benefit-cost ratio of the cotton production was 1.48.
  • Authors:
    • Bani-Hani, N.
    • Osaili, T.
    • Angor, M.
    • Ajo, R.
    • Al-Rousan, W.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 10
  • Issue: 2 Part 1
  • Year: 2012
  • Summary: The effect of different irrigation levels on the Navel orange fruit quantity and quality was studied in the Jordan Valley through the 2007 and 2008 production seasons. Irrigation treatment consisted of control irrigation at 100% of crop evapotransperation and two deficit irrigation treatments. The latter irrigation treatments consisted of treatment at 75% of control irrigation, and at 50% of control irrigation. Fruits were harvested at five different periods, starting at the beginning of November in both seasons; harvesting took place at two-week intervals. The yield in both seasons of treatment at 75% of control irrigation was not affected significantly (p>0.05) compared with control. Yield of treatment at 75% of control irrigation was 36.1 t ha -1 and 26.17 t ha -1 in 2007 and 2008, respectively. As for control treatment, it was 35.17 and 28.15 t ha -1 for the same seasons. The yield of treatment at 50% of control irrigation was 29.16 t ha -1 for 2007 and 20.43 t ha -1 for 2008, indicating significant reduction (p≤0.05). Total soluble solids, titratable acidity, and their ratio increased when reducing water irrigation. At the same time, juice percent and vitamin C were not nearly significantly different. Yield increased as harvesting progressed up to the third harvesting period (beginning of December) and started to decline by mid December. Fruits harvested at different periods showed a slight increase of juice percentage. Total soluble solids, total soluble solids/titratable acidity, and pH value increased significantly. A decrease of titratable acidity and vitamin C occurred as harvesting approached the third period. The results showed identical trends in both production seasons. From these results, two main conclusions can be obtained. First, the implementation of the 75% deficit irrigation instead of full irrigation would be recommended to save water while sustaining the same quantity and quality of yield. Second, the third harvesting period (beginning of December) is the more profitable harvesting period for Navel oranges at the different irrigation levels.