• Authors:
    • Al-Tawaha, A.
    • Al-Ghzawi, A.
    • Al-Ajlouni, M.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 8
  • Issue: 3/4 part 2
  • Year: 2010
  • Summary: Field experiments were conducted in North Part of Jordan to determine the best combination of crop rotations and fertilization levels that would improve the productivity of land and increase barley production under dryland conditions. Six-year field trials were conducted from 1996/1997 to 2001/2002 growing seasons at Ramtha Agricultural Research Station in north Jordan. Treatments effect was independent from each other and it is possible to select the best combination of treatments that give the highest yield. Rotation effect varied across growing seasons. Barley/vetch rotation showed the highest productive rotation. Additionally, barley yield was the same after vetch as after fallow. The application of 30 and 80 kg ha -1 of nitrogen and phosphorus, respectively, resulted in the highest values of fertilizer utilization efficiency.
  • Authors:
    • Afshar, A.
    • Behrooz, M.
    • Aynehband, A.
  • Source: American-Eurasian Journal of Agricultural and Environmental Science
  • Volume: 7
  • Issue: 2
  • Year: 2010
  • Summary: Intercropping system of cereal with legume or some non-legume is a common practice in many developing countries because it may produce higher forage quantity and quality product than monocropping. The objective of this study was to evaluate the effects of mixture system and planting ratios on forage yield and yield components of two intercropping systems including maize:amaranth and maize:mung bean. This field study was conducted during 2008-09 under Mediterranean region in Ahvaz, Iran. The experimental design was split plot with three replications. Our results showed that both intercropping systems at the 75:25 mix-proportion had the highest intercropping dry matter yield. However, regardless of planting ratios, maize:amaranth had the highest intercropping dry matter. But, maize:mungbean at this condition was observed to be the most LER advantages. Furthermore, greater dry matter in maize:amaranth intercropping system mainly was due to higher leaf weight and stem weight values in this mixture than maize:mungbean systems. Means stem and leaf weights were higher in maize:amaranth than maize:mungbean mixture. However, yield of all maize intercropping systems were less that it was in monocropping. The ratio of proportion also seemed to had significantly affect on yield components of both intercropping systems and all crops. Despite of maize dry matter decrease in intercropping system as compared to sole stand, mixing of legume or some pseudocereal in cereal is a suitable alternative to increase the quality of cereal fodders.
  • Authors:
    • Sun, Y.
    • Zhao, Y.
    • Wu, P.
    • Cui, H.
    • Chen, Z.
  • Source: Soil & Tillage Research
  • Volume: 110
  • Issue: 2
  • Year: 2010
  • Summary: Wind erosion near soil surface is one of the major causes of farmland degradation and desertification in arid and semiarid areas. Intercropping wheat and potato can effectively reduce wind erosion, soil desertification and degradation. In this paper, a quantitative research on effective resistance width to wind erosion for the wheat and potato intercropping farmland was performed using several 8-channel wind speed samplers and a movable wind tunnel. As can be seen from the test results, the effective width to control wind erosion for conventional tillage strips on wheat and potato intercropping farmland was lower than or equal to 5 m as the wind speed at 2 m height was 6-7 m.s -1. Moreover, the effective width to control wind erosion of conservation tillage strips on wheat and potato intercropping farmland should be greater than or equal to 5.5 m. Therefore, wheat and potato intercropping with suitable strip width is a cropping mode that not only protects farmland soil from wind erosion to the utmost but also satisfies the requirements of regional planting structure.
  • Authors:
    • Andrew, J.
    • Gazey, C.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Symposium 4.1.2 Management and protection of receiving environments
  • Year: 2010
  • Summary: Surface application of agricultural lime to treat acidity in the soil profile delivers multiple benefits to the broadcare dryland farming systems in Western Australia. Soil pH measured in 2009 to a depth of 40-50 cm was increased by applications of lime applied in 1991 and 2000. The ameliorated soil pH profile, which meets the Wheatbelt Natural Resource Management 2025 resource targets (Avon Catchment Council 2005) (designed to remove acidity as a constraint to productive agriculture), has provided multiple benefits in terms of increased productivity, increased crop competitiveness, reduced weed burden, reduced risk of soil erosion by wind due to increased biomass cover and potentially reduced off-site effects which result from decreased water use efficiency on profiles with low pH. Current annual losses due to soil acidity for the WA wheatbelt are estimated at between $300-400 million or around 9% of the total crop. The treated soil profile in this trial returned $175/ha benefit from increased wheat yield in 2008 and $225/ha benefit from increased barley grain yield in 2009.
  • Authors:
    • Xue, X.
    • Chen, G.
    • Hu, Y.
    • Ren, C.
    • Eneji, A.
    • Islam, M.
  • Source: Journal of Agriculture, Biotechnology and Ecology
  • Volume: 3
  • Issue: 3
  • Year: 2010
  • Summary: Oat is an important grain and forage crop and is now being cultivated as a promising forage crop in northern China. Increased land degradation and shortage of forage resources for animal production over-winter have accentuated the need for alternative cropping systems in arid regions of northern China (
  • Authors:
    • Harbaoui, Y.
    • Jeddi, F.
    • Sahli, A.
    • Rezig, M.
  • Source: Options Mediterraneennes. Serie A, Seminaires Mediterraneens
  • Issue: 95
  • Year: 2010
  • Summary: The adoption of intercropping systems in the irrigated perimeters can constitute an "agronomic way" to increase the added value by used m 3 of water. The objective of this research was to evaluate the efficacy of intercropping potatoes with green bean compared to monoculture potatoes. Intercropped potatoes showed no significant reduction in yield when compared to monoculture potatoes. Green beans yields were reduced when concurrently intercropped. The relative yield total (RYT), a measure of intercropping productivity, was 1.55 indicating that it would require 55% more land for separate monoculture plantings of potatoes and beans to produce a yield equivalent to the intercropping system. On the other hand, the intercropping system engendered an increase in the water and in the radiation use efficiencies (WUE MST and RUE MST) from 8.69 kg/m 3 to 10.15 kg/m 3 and from 4.47 g/MJ to 4.77 g/MJ, respectively. Finally, a linear relation between the accumulated absorbed radiation and the accumulated evapotranspiration was able to be revealed. Intercropping potatoes with green beans increases output per unit area and enables growers to take full advantage of the available natural resources.
  • Authors:
    • Yifru, A.
    • Taye, B.
  • Source: World Journal of Agricultural Sciences
  • Volume: 6
  • Issue: 5
  • Year: 2010
  • Summary: A study to examine soil fertility status was conducted in the highlands of Southeast Ethiopia situated within latitude 0707′N and longitude 4010′E at altitude 2200 m to 2400 m above sea level. Twenty five farmers who are knowledgeable about soils of the area are purposively selected to provide insight into different soil fertility management practices. Local methods used to identify different soils and to assess the fertility status. Farmers used soil color, texture, water holding capacity, fertilizer requirement (inherent fertility) and workability as a criteria to identify different soil types. However, soil color and texture were commonly used by farmers to describe soil quality. Farmers preferred black and clay soils to white and sandy soils due to their high water holding capacity and inherent fertility. Besides, soil samples were randomly collected from the farmer's field under continuous cereal production systems. The study made up thirty-two sites and each site covered 400 m 2 sampling area. Composite samples of surface and subsurface soils were collected using special auger from three depths (0-10, 10-20, 20-30 cm). The laboratory analysis result indicated the soils are low in cation exchange capacity, low to medium in organic matter, slightly acidic to neutral, very high in base saturation, low to medium in exchangeable bases and moderate in both total nitrogen and available phosphorus. These soils are low to moderate in fertility that requires quite reasonable management. As a summary, the combined effect of both qualitative (local indicators of soil fertility) and quantitative (technical indicators of soil fertility) information would result in better assessment of soil fertility pattern and soil fertility management strategies to ensure food security program.
  • Authors:
    • Towett, B. K.
    • Ogola, J. B. O.
    • Kinyua, M. G.
    • Gottschalk, K.
    • Kimurto, P. K.
  • Source: Agricultural Engineering International: CIGR Journal
  • Volume: 12
  • Issue: 3/4
  • Year: 2010
  • Summary: Carrying out field trial-research in dryland areas is usually expensive and costly for most national breeding programmes; hence development of simple crop simulation models for predicting crop performance in actual semi-arid and arid lands (ASALS) would reduce the number of field evaluation trials. This is especially critical in developing countries like Kenya where dry areas is approximately 83% of total land area and annual rainfall in these area is low, unreliable and highly erratic, causing frequent crop failures, food insecurity and famine. This paper used data generated from the rain shelter by measurement of evapotranspiration together with weather variables in Katumani to predict wheat yields in that site. Maximum yield of the wheat genotype considered for genotype Chozi under ideal conditions was 5 t/ha. Total above-ground biomass was obtained and grain yield was to be predicted by the model. Transpiration was estimated from the relationship between total dry matter production and normalised TE (7.8 Pa). The results presented are based on the assumption that all agronomic conditions were optimal and drought stress was the major limiting factor. Predicted grain yield obtained from the conceptual model compares very well with realised yields from actual field experiments with variances of 14%-43% depending on watering regime. This study showed that it is possible to develop simple conceptual model to predict productivity in wheat in semi-arid areas of Kenya to supplement complicated and more sophisticated models like CERES-maize and ECHAM models earlier used in Kenya. The presence of uncontrolled factors in the simulation not accounted for in the estimation and could have contributed to decrease in observed yield need to be included in the model, hence modulation of the equations by introducing these factors may be necessary to reduce variances; thus need to be quantified. To improve the accuracy of prediction and increase wheat production in these areas measures that conserve water and/or make more water available to the crop such as prevention or minimisation of run-off, and rain water harvesting for supplemental irrigation are necessary.
  • Authors:
    • Delve, R. J.
    • Zingore, S.
    • Nyawasha, R. W.
    • Nyamangara, J.
    • Masvaya, E. N.
    • Giller, K. E.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 88
  • Issue: 1
  • Year: 2010
  • Summary: This paper examines a number of agronomic field experiments in different regions of sub-Saharan Africa to assess the associated variability in the efficiencies with which applied and available nutrients are taken up by crops under a wide range of management and environmental conditions. We consider N and P capture efficiencies (NCE and PCE, kg uptake kg(-1) nutrient availability), and N and P recovery efficiencies (NRE and PRE, kg uptake kg(-1) nutrient added). The analyzed cropping systems employed different soil fertility management practices that included (1) N and P mineral fertilizers (as sole or their combinations) (2) cattle manure composted then applied or applied directly to fields through animal corralling, and legume based systems separated into (3) improved fallows/cover crops-cereal sequences, and (4) grain legume-cereal rotations. Crop responses to added nutrients varied widely, which is a logical consequence of the wide diversity in the balance of production resources across regions from arid through wet tropics, coupled with an equally large array of management practices and inter-season variability. The NCE ranged from 0.05 to 0.98 kg kg(-1) for the different systems (NP fertilizers, 0.16-0.98; fallow/cover crops, 0.05-0.75; animal manure, 0.10-0.74 kg kg(-1)), while PCE ranged from 0.09 to 0.71 kg kg(-1), depending on soil conditions. The respective NREs averaged 0.38, 0.23 and 0.25 kg kg(-1). Cases were found where NREs were > 1 for mineral fertilizers or negative when poor quality manure immobilized soil N, while response to P was in many cases poor due to P fixation by soils. Other than good agronomy, it was apparent that flexible systems of fertilization that vary N input according to the current seasonal rainfall pattern offer opportunities for high resource capture and recovery efficiencies in semi-arid areas. We suggest the use of cropping systems modeling approaches to hasten the understanding of Africa's complex cropping systems.
  • Authors:
    • Liu, W. J.
    • Yang, R.
  • Source: Environmental Earth Sciences
  • Volume: 61
  • Issue: 1
  • Year: 2010
  • Summary: In order to assess the extent of groundwater contamination by nitrate (NO 3--N) and to provide information about the deterioration of the groundwater quality in Zhangye Oasis, Northwest China, a study was conducted in this area. The mean value of NO 3--N concentrations in groundwater samples was 10.660.19 mg l -1. NO 3--N concentrations exceeding 10 mg l -1 (the threshold for drinking water set by the World Health Organization) were found in 32.4% of 71 wells, and were 13, 33.3, 52.4 and 50.0% in the groundwater samples from drinking wells, irrigation wells, hand-pumping wells and groundwater table observation wells, respectively. The result showed that the groundwater samples that had NO 3--N concentrations exceeding the threshold for drinking water were mostly collected from a depth of less than 20 m. Groundwater NO 3--N concentrations in areas used for the cultivation of vegetables, seed maize and intercropped maize were significantly higher than those in urban or paddy areas. NO 3--N contamination of groundwater in areas with sandy soil was more severe than in those with loam soil.