• Authors:
    • Scheer,Clemens
    • Grace,Peter R.
    • Rowlings,David W.
    • Payero,Jose
  • Source: Plant and Soil
  • Volume: 359
  • Issue: 1-2
  • Year: 2012
  • Summary: Irrigation management affects soil water dynamics as well as the soil microbial carbon and nitrogen turnover and potentially the biosphere-atmosphere exchange of greenhouse gasses (GHG). We present a study on the effect of three irrigation treatments on the emissions of nitrous oxide (N2O) from irrigated wheat on black vertisols in South-Eastern Queensland, Australia. Soil N2O fluxes from wheat were monitored over one season with a fully automated system that measured emissions on a sub-daily basis. Measurements were taken from 3 subplots for each treatment within a randomized split-plot design. Highest N2O emissions occurred after rainfall or irrigation and the amount of irrigation water applied was found to influence the magnitude of these "emission pulses". Daily N2O emissions varied from -0.74 to 20.46 g N2O-N ha(-1) day(-1) resulting in seasonal losses ranging from 0.43 to 0.75 kg N2O-N ha(-1) season (-aEuro parts per thousand 1) for the different irrigation treatments. Emission factors (EF = proportion of N fertilizer emitted as N2O) over the wheat cropping season, uncorrected for background emissions, ranged from 0.2 to 0.4 % of total N applied for the different treatments. Highest seasonal N2O emissions were observed in the treatment with the highest irrigation intensity; however, the N2O intensity (N2O emission per crop yield) was highest in the treatment with the lowest irrigation intensity. Our data suggest that timing and amount of irrigation can effectively be used to reduce N2O losses from irrigated agricultural systems; however, in order to develop sustainable mitigation strategies the N2O intensity of a cropping system is an important concept that needs to be taken into account.
  • Authors:
    • Finlay, L. A.
    • Hulugalle, N. R.
    • Weaver, T. B.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 27
  • Issue: 2
  • Year: 2012
  • Summary: Cover crops in minimum or no-tilled systems are usually killed by applying one or more herbicides, thus significantly increasing costs. Applying herbicides at lower rates with mechanical interventions that do not disturb or bury cover crop residues can, however, reduce costs. Our objective was to develop a management system with the above-mentioned features for prostrate cover crops on permanent beds in an irrigated Vertisol. The implement developed consisted of a toolbar to which were attached spring-loaded pairs of parallel coulter discs, one set of nozzles between the individual coulter discs that directed a contact herbicide to the bed surfaces to kill the cover crop and a second set of nozzles located to direct the cheaper glyphosate to the furrow to kill weeds. The management system killed a prostrate cover crop with less trafficking, reduced the use of more toxic herbicides, carbon footprint, labor and risk to operators. Maximum depth of compaction was more but average increase was less than that with the boom sprayer control.
  • Authors:
    • Khairy, A. I. H.
    • Idris, A. E.
    • Ibrahim, Y. M.
  • Source: Advances in Environmental Biology
  • Volume: 6
  • Issue: 1
  • Year: 2012
  • Summary: The evaluation of Rhodes grass ( Chloris gayana Kunth) as intercropped with alfalfa ( Medicago sativa L.) was assessed under different intercropping ratios at Shambat, Sudan. A completely randomized block design with three replications was used. Different Rhodes grass growth characters and the yield characters of the intercropping were measured. The significance of intercropping was resulted in plant height and leaf area of Rhodes grass. The fresh yield of intercropping was also higher and significant than monocropping ratios. Thus, the experiment showed the positive effect of Alfalfa on Rhodes grass characters when they intercropped with each others. The highest yield of intercropping ratios than monocropping and the superior of treatment D (50% Rhodes grass+50% Alfalfa) over other treatments used in the study was evident.
  • Authors:
    • Iqbal, K.
    • Khurshid, W.
    • Hassan, I.
  • Source: Journal of Agricultural Research
  • Volume: 50
  • Issue: 1
  • Year: 2012
  • Summary: A study was conducted during the year 2009 to find out the factors responsible for decline in guava ( Psidium guajava) yield. For this purpose three districts Sheikhupura, Kasur and Faisalabad, Pakistan were selected being core area for guava cultivation. To examine impact of various inputs on guava production, the Cobb-Douglas production function model was used. Factors which caused decline in guava yield were found to be physical beating of flowers, excessive intercropping and number of sprays. The physical beating of flowers (-0.317 coefficient value) and intercropping (-0.200) proved as two major depressing factors. Intercropping in both summer and winter seasons went in a long way in depressing yields. Flower shedding by beating with clubs proved to be more significant (-0.317). It was found that productivity decline can be arrested as well as be reversed with adequate number of irrigations, proper use of fertilizers and adopting good management measures.
  • Authors:
    • Jensen, C. R.
    • Jacobsen, S. -E
    • Liu, F.
  • Source: Field Crops Research
  • Volume: 128
  • Year: 2012
  • Summary: The aim of the present review is to highlight the possibilities of a sustainable crop production in the arid Mediterranean region, which is predicted to suffer from increasingly severe droughts in the future due to climate changes, in addition to increased problems with soil salinity and increased temperatures. Annual rainfall in the region varies between 300 and 1000 mm, covering arid, semi-arid and wet ecosystems. As stress factors often act together, it is important sometimes to focus on multiple stresses affecting the crop, instead of looking at the individual stress separated from the rest. The rainfed farming systems are the most important in the Mediterranean countries. The question is if we can overcome mild to medium level of abiotic stresses by agronomic means. It might be done by using different crops of increased drought and salinity tolerance, and utilizing their stress adaptation mechanisms to optimize crop productivity. However supplemental irrigation used as deficit irrigation has the potential to overcome periods of low rainfall or high temperatures. It is suggested that improvements in crop production may arise from several strategies such as early sowing enabled by minimum tillage, increased use of organic manure, and an efficient weed control. Further, crop rotations will play an important role in improving weed control, minimizing disease risk, and increasing nitrogen availability. Introduction of drought and salt tolerant crop species as quinoa, amaranth and Andean lupin may result in more resilient crop rotations and high value cash crop products. Genotypic increases may arise from selection for early vigour, deep roots, increased transpiration efficiency, improved disease resistance, and high assimilate storage and remobilization. A range of crop and management strategies might be combined for a specific target environment in order to optimize crop productivity. These combinations can then be used as a guidance to future decision support systems for crop production at limited water supply under arid Mediterranean conditions. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Nariya, J. N.
    • Khanpara, M. D.
    • Butani, A. M.
    • Kapadiya, H. J.
  • Source: Journal of Cotton Research and Development
  • Volume: 26
  • Issue: 1
  • Year: 2012
  • Summary: FLD's with participation of farmers' in production technology was conducted in seven districts of Saurashtra. Thirty four, 50 and 50 farmers were selected for FLD's during 2005-2006, 2006-2007 and 2007-2008, respectively. Varietal, fertilizer, irrigation and inter cropping components were conducted in FLD's. Results indicated that 8.83 per cent average seed cotton yield was increased over improved varieties. In fertilizer components, there was no effect of DAP on seed cotton yield, however without DAP clearly showed the average saving of Rs. 1743/ha. The reduction of 3.98 per cent seed cotton yield was recorded in alternate furrow irrigation, but the cost of cultivation of Rs. 3370/ha was decreased as compared to local practices. In inter cropping practices, 10.13 per cent seed cotton yield was increased over local practices. Overall results clearly indicated that an additional net return of Rs. 5130, 3831, 1002 and 859 was recorded in improved varities, intercropping, irrigation and fertilizer components, respectively. Looking to the over all of three years average results with four improved production technologies of FLD's, recorded a increase of 4.6 per cent in seed cotton yield, reduced by 3.12 per cent in cost of cultivation and increased net return of 9.95 per cent with a net profit of 3371 Rs/ha during three years of cropping season.
  • Authors:
    • Rocha, H. S.
    • Souza, A. P. de
    • Carvalho, D. F. de
    • Lima, M. E. de
    • Guerra, J. G. M.
  • Source: Revista Brasileira de Engenharia Agrícola e Ambiental
  • Volume: 16
  • Issue: 6
  • Year: 2012
  • Summary: This study was carried out in the municipality of Seropedica-RJ, in order to determine, under organic farming and no tillage system, the yield of eggplants under different irrigation depths and cropping systems (intercropped with legumes and alone). The experimental design was in randomized blocks in a split plot design with four replications. The plots were characterized by the treatments corresponding to different water depths (40, 70, 100, 120% ETc), and the sub plots, the intercropping systems with cowpea and eggplant alone. Cropping systems did not influence the final yield of eggplant. However, considering the different irrigation depths, the highest commercial yield (65.41 Mg ha -1) was obtained for a total depth of 690.04 mm (106.8% ETc). The lower applied depth provided lower quality of fruit compared with that observed in the higher depths. The rate of fruit discard was 3 and 14%, respectively, for the higher and lower depths of irrigation.
  • Authors:
    • Rajput, T. B. S.
    • Sarangi, A.
    • Singh, M.
    • Abedinpour, M.
    • Pathak, H.
    • Ahmad, T.
  • Source: Agricultural Water Management
  • Volume: 110
  • Year: 2012
  • Summary: Crop growth simulation models of varying complexity have been developed for predicting the effects of soil, water and nutrients on grain and biomass yields and water productivity of different crops. These models are calibrated and validated for a given region using the data generated from field experiments. In this study, a water-driven crop model AquaCrop, developed by FAO was calibrated and validated for maize crop under varying irrigation and nitrogen regimes. The experiment was conducted at the research farm of the Water Technology Centre, IARI, New Delhi during kharif 2009 and 2010. Calibration was done using the data of 2009 and validation with the data of 2010. Irrigation applications comprised rainfed, i.e. no irrigation (W 1) irrigation at 50% of field capacity (FC) (W 2) at 75% FC (W 3) and full irrigation (W 4). Nitrogen application levels were no nitrogen (N 1), 75 kg ha -1 (N 2) and 150 kg ha -1 (N 3). Model efficiency ( E), coefficient of determination ( R2), Root Mean Square error (RMSE) and Mean Absolute Error (MAE) were used to test the model performance. The model was calibrated for simulating maize grain and biomass yield for all treatment levels with the prediction error statistics 0.95
  • Authors:
    • Al-Amoud, A. I.
    • Alabdulkader, A. M.
    • Awad, F. S.
  • Source: Agricultural Economics – Czech
  • Volume: 58
  • Issue: 2
  • Year: 2012
  • Summary: A mathematical sector model has been formulated to optimize the cropping pattern in Saudi Arabia aiming at maximizing the net annual return of the agricultural sector in the country and ensuring the efficient allocation of the scarce water resources and arable land among the competing crops. The results showed the potential for Saudi Arabia to optimize its cropping pattern and to generate an estimated net return equivalent to about 2.42 billion US$ per year. The optimized cropping pattern in Saudi Arabia has been coupled with about 53% saving in water use and about 48% reduction in the arable land use compared to the base-year cropping pattern. Comparable weights was given to different crop groups by allocating about 48.4%, 35.4%, 13.1%, and 3.2% to grow cereals, fruits, forages, and vegetables, respectively. These findings are in line with the national strategy to rationalize the cultivation of water-intensive crops in favour of highly water-efficient crops.
  • Authors:
    • Taha, A. S.
    • Muneer, S. E.
    • Alzahrani, K. H.
    • Baig, M. B.
  • Source: JAPS, Journal of Animal and Plant Sciences
  • Volume: 22
  • Issue: 1
  • Year: 2012
  • Summary: Fresh water is one of the most important and scarcest natural resources around the globe. In Saudi Arabia fresh water shortage for different uses represents one of the main challenges hindering development efforts in the country. As such there is a need to pursue a water demand management policy which should include any measure or initiative that will result in reduction of water usage and/or water demand. This study is intended to explore the potential of proper cropping pattern as a water demand management tool to enhance water and food security in Saudi Arabia. Secondary data were obtained from the ministry of Agriculture and Ministry of Electricity and Water. The analyses revealed that existing cropping pattern did not benefit from the relative advantage of different regions in producing different crops. Thus, there is a great potential for enhancing food and water security in Saudi Arabia through altering existing cropping pattern by encouraging production of different crops in the regions that have clear relative advantage in their production i.e. give the highest productivity. For example production of cereals could be concentrated in Jouf and Tabuk areas, while vegetables production in the eastern region and Asser area.