• 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:
    • Darshana
    • Pandey, A.
    • Pandey, R. P.
    • Ostrowski, M.
  • Source: Irrigation and Drainage
  • Volume: 61
  • Issue: 2
  • Year: 2012
  • Summary: In this study, simulation and optimization models were assembled for the optimization of irrigation systems and their operation. The simulation model CROPWAT was used for estimation of the crop water requirement, time and depth. The evolutionary algorithm (GANetXL) was used for the optimal planning of cropping pattern, maximization of net benefits and minimization of irrigation water requirements for the study area of Holeta catchment, Ethiopia. The study area encompasses three command areas, i.e. farm A, farm B and Tsedey State Farm, and five different type of crops, i.e. potato, tomato, apple, peach and winter wheat. The simulation results of the CROPWAT model illustrated that crop water requirement for apple was highest (993 mm), followed by peach (908 mm), tomato (470 mm), potato (443 mm) and wheat (294 mm). The study reveals that fruit crops have more crop water requirements than cereals. The results of the GANetXL show that when the cropped area and water allocated was varied between extreme values, 23% of water can be saved. The total benefit from the study area can be enhanced by USD 34 ha -1 and can be helpful in improving the economic conditions of the farmers.
  • Authors:
    • Gonzalez, B.
    • Rodriguez, E.
    • Campos, M.
  • Source: Bulletin of Insectology
  • Volume: 65
  • Issue: 1
  • Year: 2012
  • Summary: The use of cover crops is the most effective method to combat soil degradation due to erosion in olive cropping in Spain. Within the framework of Integrated Pest Management (IPM), a compelling question is how cover crops would affect elements of the olive-agroecosystem such as natural enemies. Accordingly, the objective of this study was to examine the effects of cereal cover cropping on natural enemy communities in olive groves. Samples of the anthropod communities were collected in olive groves under tillage and cover cropping systems at five different locations in the same province. Cereal cover crops significantly increased the abundance of parasitoids in the olive canopy, especially Ageniaspis fuscicollis Dalman (Hymenoptera Encyrtidae) a parasitoid of the olive moth Prays oleae Bernard (Lepidoptera Yponomeutidae), the most common insect pest of olive trees. However, parasitoid abundance and structure depended on olive grove location suggesting the importance of crop surroundings in parasitoid community dynamics. Predators numbers were slightly higher in tilled olive groves but no significant differences were found between the two soil management systems.
  • Authors:
    • Wu, Z. B.
    • Shi, Y. J.
    • Song, F. H.
    • Yishake, H.
    • Yu, T.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 49
  • Issue: 1
  • Year: 2012
  • Summary: Objective: The spatial distribution characteristics of jujube tree fine roots in the jujube-cotton intercorpping were analyzed in order to provide the basic documents for constructing the model of water uptake by roots, and for determining the width of jujube protection and improving irrigation and fertilization technology. Method: Root excavation was used and a soil sample for each side of the live root was picked, cleaned, dried, sorted, scanned. Specialized software was used to measure and analyze the root length and other indicators. Result: (1) In the vertical direction, jujube trees fine roots are mainly distributed in the soil layer of 0-120 cm, accounting for 87.09% of the total; (2) in the horizontal direction, they are mainly distributed in the range of 0-150 cm between the jujube trees, accounting for 83.67% of the total amount; (3) according to the distribution of cotton roots, jujube and cotton roots are mainly distributed in the range of 0-150 cm between the jujube trees at the depth of 0-80 cm of the soil layer. Conclusion: Establishment of protection for root growth of the jujube trees played an extremely important role in the relief of the water and nutrient competition between cotton and jujube trees, but the width of protection setting is still worthy of further consideration, which would be involved in the comprehensive judgments of jujube tree age, crown, etc. In view of the present test situation, the zone of fertilization to jujube trees should be within the range of 100-150 cm without changing the test protection.
  • Authors:
    • Nieder, R.
    • Ma, W. Q.
    • Roelcke, M.
    • Heimann, L.
    • Gao, Z. L.
    • Hou, Y.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 92
  • Issue: 3
  • Year: 2012
  • Summary: An in-depth understanding of nutrient management variability on the regional scale is urgently required due to rapid changes in cropping patterns and farmers' resource use in peri-urban areas of China. The soil surface nitrogen (N) balances of cereal, orchard and vegetable systems were studied over a 2-year period on smallholder fields in a representative peri-urban area of Beijing. Positive soil surface N balances were obtained across all three cropping systems. The mean annual N surplus of the vegetable system was 1,575 kg N ha(-1) year(-1), or approximately 3 times the corresponding values in the cereal (531 kg N ha(-1) year(-1)) and orchard systems (519 kg N ha(-1) year(-1)). In the vegetable system, animal manure (1,443 kg N ha(-1) year(-1) on average) was the major source of N input (65 % of the total N input) and the factor with strongest impact on the N surplus. In the cereal system, however, about 74 % of the total N input originated from mineral fertilizer application which was the major contributor to the N surplus, while in the orchard system, the N surplus was strongly and positively correlated with both mineral fertilizer and animal manure applications. Furthermore, within each cropping system, N fertilization, crop yields and N balances showed large variations among different smallholder fields, especially in orchard and vegetable systems. This study highlights that differences in farming practices within or among cropping systems should be taken into account when calculating nutrient balances and designing strategies of integrated nutrient management on a regional scale.
  • Authors:
    • Infante Amate, J.
    • Bernard, C.
    • Vanwalleghem, T.
    • Toloza, A.
    • Chhem-Kieth, S.
    • Mabit, L.
    • Gonzalez de Molina, M.
    • Gomez, J. A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 159
  • Year: 2012
  • Summary: Soil degradation is a major agrienvironmental issue under Mediterranean climatic conditions. To assess soil erosion magnitude under orchard plantation, soils in an undisturbed area - located within an archaeological protected site in southern Spain - were analysed to establish its physicochemical status, the initial 137Cs fallout and the natural level of radioactivity taking into account the content of naturally occurring radionuclides (NOR). The vertical profiles of NOR mass activities confirmed its non-disturbance. 90% of the 137Cs content was concentrated in the top 20 cm and the physicochemical parameters confirmed as well the undisturbed status of the site. The base-line level of 137Cs was established at 1925250 Bq m -2 with a coefficient of variation of 23% and an allowable error of 11%. This 137Cs background was used to assess soil erosion magnitude in a close orchard field using the 137Cs method. The maximum erosion rates reached 19 t -1 ha -1 yr -1 and a sediment delivery ratio of 29% was evaluated, both values confirming an unsustainable soil loss magnitude due to the combination of water and tillage erosion processes since the 1950s. The radium equivalent activity and the absorbed dose rate results highlighted a difference between eroded and deposition sectors in the cultivated field confirming that these parameters could be used to some extend to assess pedologic processes.
  • Authors:
    • Hastings, A.
    • Sim, S.
    • King, H.
    • Keller, E.
    • Canals, L. M. I.
    • Flynn, H. C.
    • Wang, S.
    • Smith, P.
  • Source: Global Change Biology
  • Volume: 18
  • Issue: 5
  • Year: 2012
  • Summary: Many assessments of product carbon footprint (PCF) for agricultural products omit emissions arising from land-use change (LUC). In this study, we developed a framework based on IPCC national greenhouse gas inventory methodologies to assess the impacts of LUC from crop production using oil palm, soybean and oilseed rape as examples. Using ecological zone, climate and soil types fromnatural the top 20 producing countries, calculated emissions for transitions from vegetation to cropland on mineral soils under typical management ranged from -4.5 to 29.4 t CO2-eq ha-1 yr-1 over 20 years for oil palm and 1.247.5 t CO2-eq ha-1 yr-1 over 20 years for soybeans. Oilseed rape showed similar results to soybeans, but with lower maximum values because it is mainly grown in areas with lower C stocks. GHG emissions from other land-use transitions were between 62% and 95% lower than those from natural vegetation for the arable crops, while conversions to oil palm were a sink for C. LUC emissions were considered on a national basis and also expressed per-tonne-of-oil-produced. Weighted global averages indicate that, depending on the land-use transition, oil crop production on newly converted land contributes between -3.1 and 7.0 t CO2-eq t oil production-1 yr-1 for palm oil, 11.950.6 t CO2-eq t oil production-1 yr-1 for soybean oil, and 7.731.4 t CO2-eq t oil production-1 yr-1 for rapeseed oil. Assumptions made about crop and LUC distribution within countries contributed up to 66% error around the global averages for natural vegetation conversions. Uncertainty around biomass and soil C stocks were also examined. Finer resolution data and information (particularly on land management and yield) could improve reliability of the estimates but the framework can be used in all global regions and represents an important step forward for including LUC emissions in PCFs.
  • Authors:
    • James, A.
    • Solah, V.
    • Biswas, W.
    • Gunady, M.
  • Source: Journal of Cleaner Production
  • Volume: 28
  • Year: 2012
  • Summary: A life cycle greenhouse gas (GHG) assessment of 1 kJ of strawberries, button mushrooms (Agaricus bisporus), and romaine/cos lettuces (Lactuca sativa) transported to retail outlets in Western Australia (WA) was examined and compared. The study included pre-farm, on-farm, and post-farm emissions. The pre-farm stage included GHG emissions from agricultural machinery and chemical production, and transport of raw materials (spawn, peat, and compost) in mushrooms. The on-farm stage included GHG emissions from agricultural machinery operation, chemical use, water for irrigation, waste generated, as well as electricity and energy consumption. The post-farm stage included transport of produce to Distribution Center (DC), storage in DC, and transport to retail outlets. The 'hotspots' or the stages that emit the highest GHG were determined for strawberries, button mushrooms and romaine/cos lettuces. The results have shown that the life cycle GHG emissions of strawberries and lettuces were higher than mushrooms due to intensive agricultural machinery operations during the on-farm stage. Mushrooms, however have significantly higher GHG emissions during pre-farm stage due to transport of peat, spawn, and compost. (C) 2011 Elsevier Ltd. All rights reserved.
  • Authors:
    • Swartz, H.
    • Proctor, J.
    • Sullivan, J.
    • Harbut, R.
  • Source: Journal of the American Society of Horticultural Science
  • Volume: 137
  • Issue: 3
  • Year: 2012
  • Summary: The net carbon exchange rate (NCER) of Fragaria species, synthetic octoploids [SO (interspecific hybrids)], F-1 (SO X cultivar), and first outcross [OC1 (F-1 X cultivar)] hybrids were evaluated in both field and greenhouse conditions. Plants were grown in a field trial at the Elora Research Station in Ontario, Canada, for one season and then plants were dug and moved into a greenhouse where the trial was repeated during the next season. Single leaf photosynthesis measurements and light response curves were generated at different stages of plant development. Photosynthetic capacity of the species was related to the ecological background of the species with sun-adapted species having higher rates compared with the shade-adapted species. The Fragaria species and introgressed hybrids (F-1 and OC1) had significantly higher NCERs compared with the cultivars with rates 28% and 23% higher, respectively. Species and hybrids also appear to have increased adaptability to both high and low light conditions. These increases in NCER may be a heterotic effect because NCER of the hybrids were consistently higher compared with the midparent values and in some cases, they were higher than the high parent. These results suggest that the introgression of lower-ploidy Fragaria species into the cultivated strawberry (Fragaria Xananassa) may lead to increased NCER and light adaptability.
  • Authors:
    • Villar Sanchez, B.
    • Gonzalez Estrada, A.
    • Livera Munoz, M.
    • Cortes Flores, J. I.
    • Turrent Fernandez, A.
    • Camas Gomez, R.
    • Lopez Martinez, J.
    • Espinoza Paz, N.
    • Cadena Iniguez, P.
  • Source: Revista Mexicana de Ciencias Agricolas
  • Volume: 3
  • Issue: 2
  • Year: 2012
  • Summary: In Chiapas, Mexico, soil erosion is the main problem affecting the sustainability of hillside lands. As a result, yields and incomes are low, and soil quality continues to decrease. With the aim of finding sustainable technological alternatives, an evaluation was performed on the following systems: maize in conservation tillage (MLC); maize in plant barriers (MBMV) and maize alternated with fruit trees (MIAF), in terms of surface runoff, production of sediments and loss of nitrogen and phosphorous from June to November, 2009. The systems were setup in adjacent microbasins, belonging to the basin of river Catarina, Jiquipilas, Chiapas. The soil is a Typic haplustepts, with a slope that varies between 30 and 40%. Out of the total rainfalls, 54% caused soil erosion, 15% of these with rains of over 40 mm 62% of the total erosion. The runoff coefficient and the specific soil degradation were similar and lower in the micro basins; MIAF (12,5.8 t ha -1) and MBMV (13,6.3 t ha -1) than in the microbasin with MLC (19,16.8 t ha -1), respectively. In MIAF, the runoff filter and total cover provided by maize and bean plants during most of the growth season played an important part in obtaining these results, despite this microbasin presenting a greater slope steepness and length. In regards to the nutrients, there was a greater loss of nitrates in the microbasin with the system MBMV, possibly due to the nitrogen contribution by the leftovers of the pruning of Gliricidia sepium. In regard to phosphorous, the system MIAF displayed a greater loss, caused by the yearly phosphoric fertilization performed on the guava trees for three years.