• Authors:
    • Todorova, R.
  • Source: Rasteniev'dni Nauki
  • Volume: 46
  • Issue: 4
  • Year: 2009
  • Summary: As a result of long research work on genetic improvement of soybean, new varieties have been developed and rich germplasm has been obtained. Classic breeding methods of hybridization and experimental mutagenesis were used. Our studies were directed to obtaining of varieties with high productive potential and resistance to biotic and abiotic stress, as well as to increase of crude protein and crude fat content. The candidate variety Rosa was presented for testing in the system of EAVTFISC (Executive Agency for Variety Testing, Field Inspection and Seed Control). In our competition variety trials it possessed high productive potential under irrigated and nonirrigated conditions and showed resistance to the diseases of bacteriosis and mildew.
  • Authors:
    • Chen, P.
    • Gbur, E. E.
    • Popp, J. H.
    • Brye, K. R.
    • Verkler, T. L.
    • Amuri, N.
  • Source: Journal of Sustainable Agriculture
  • Volume: 33
  • Issue: 7
  • Year: 2009
  • Summary: Soil, water, and air quality can be positively impacted by alternative crop residue management practices that return residue to the soil. Double-crop production systems, particularly those with a grass included in the rotation, rely on successful residue management practices. Soil quality and overall soil tilth are often low in regions with a long history of intensely cultivated, row-crop production, such as in the Mississippi River Delta region of the mid-South. Therefore, the objective of this study was to evaluate the effects of alternative residue (i.e., tillage, residue burning, and residue level) and water management practices on soil properties, soybean [ Glycine max (L.) Merr.] production, and net economic returns, over two consecutive rotations in a wheat ( Triticum aestivum L.) - soybean double-crop system in the Mississippi River Δ region of eastern Arkansas. Initiated in 2001, this study reports results from years 4 and 5 of the experiment. Residue management effects were inconsistent among soil properties and years, and differences were generally agronomically non-significant. Averaged across irrigation treatments, soybean yield was unaffected by tillage, burning, and residue level either year. Within the non-irrigated treatment, conventionally tilled (CT) soybean yield was 38% greater ( p
  • Authors:
    • Zhang, M. H.
    • Zhang, L. X.
    • Zhang, J. Q.
    • Watson, C.
  • Source: Acta Agronomica Sinica
  • Volume: 35
  • Issue: 2
  • Year: 2009
  • Summary: A study was conducted in Stoneville, Mississippi, USA, under irrigated conditions to develop predictive models, using a simple and effective model technique which can allow producers to predict soyabean growth and development stages in their fields. The models were constructed using 4-year field data (1998-2001) and validated with the fifth year data (2002). Potential factors affecting stages of soyabean growth and development were considered for developing the models. Affecting factors, such as weeds, insects, diseases and drought stress, were controlled optimally to simplify the modelling procedures. In addition, stepwise regression (SR) analysis, artificial neural networks (ANN), and interpolation approaches were used to construct the models. The modelling of soyabean growth and development processes was separated into 2 distinct periods: vegetative growth stage (V-stage) and reproductive growth stage (R-stage). The models included 10 V-stages (up to V8) and 8 R-stages. In the V-stages models, PD (planting date) and mean relative time-span for planting to a particular stage were the only significant parameters, whereas in R-stage models, PD and MG (maturity group) were significant. The models obtained accurate predictions were only using PD, MG and mean relative time-span from planting to a particular stage. The ANN method provided the greatest accuracy in predicting phenological events, indicating that the ANN method can be effectively applied in crop modelling.
  • Authors:
    • Zhu, W. W.
  • Source: Guizhou Agricultural Sciences
  • Issue: 6
  • Year: 2009
  • Summary: The results from analyzing the comparative superiority of main agricultural products in Hunan province by using the comparative superiority index method show that the agricultural products with obvious comparative superiority are rice, cotton, soybean, tobacco and tea, which depend on their large-scale superiority, and the agricultural products with inferior position are maize, sorghum and wheat. The market competitive power is weak because the efficiency superiority of various agricultural products is not obvious essentially. The paper puts forward the measures including maintaining the market superiority of the agricultural products with obvious comparative superiority and improving the quality of the agricultural products with significant comparative inferiority to overall promote the market competitive power of Hunan province's agricultural products.
  • Authors:
    • Andresen, D.
    • Das, S.
    • Miller, M.
    • Lauwo, S.
    • Staggenborg, S.
    • Jin, W.
    • Bulatewicz, T.
    • Peterson, J.
    • Steward, D. R.
    • Welch, S. M.
  • Source: Hydrology & Earth System Sciences
  • Volume: 13
  • Issue: 8
  • Year: 2009
  • Summary: Near-term consumption of groundwater for irrigated agriculture in the High Plains Aquifer supports a dynamic bio-socio-economic system, all parts of which will be impacted by a future transition to sustainable usage that matches natural recharge rates. Plants are the foundation of this system and so generic plant models suitable for coupling to representations of other component processes (hydrologic, economic, etc.) are key elements of needed stakeholder decision support systems. This study explores utilization of the Environmental Policy Integrated Climate (EPIC) model to serve in this role. Calibration required many facilities of a fully deployed decision support system: geo-referenced databases of crop (corn, sorghum, alfalfa, and soybean), soil, weather, and water-use data (4931 well-years), interfacing heterogeneous software components, and massively parallel processing (3.8*10 9 model runs). Bootstrap probability distributions for ten model parameters were obtained for each crop by entropy maximization via the genetic algorithm. The relative errors in yield and water estimates based on the parameters are analyzed by crop, the level of aggregation (county- or well-level), and the degree of independence between the data set used for estimation and the data being predicted.
  • Authors:
    • Fonseca, A. F. da
    • Alleoni, L. R. F.
    • Caires, E. F.
    • Churka, S.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 40
  • Issue: 17/18
  • Year: 2009
  • Summary: No-till (NT) system with crop rotation is one of the most effective strategies to improve agricultural sustainability in tropical and subtropical regions. To control soil acidity in NT, lime is broadcast on the surface without incorporation. The increase in soil pH due to surface liming may decrease zinc (Zn) availability and its uptake by crops. A field experiment was performed in Paran State, Brazil, on a loamy, kaolinitic, thermic Typic Hapludox to evaluate Zn bioavailability in a NT system after surface liming and re-liming. Dolomitic lime was surface applied on the main plots in July 1993 at the rates of 0, 2, 4, and 6 Mg ha -1. In June 2000, the main plots were divided in two subplots to study of the effect of surface re-liming at the rates of 0 and 3 Mg ha -1. The cropping sequence was soybean [ Glycine max (L.) Merrill] (2001-2 and 2002-3), wheat ( Triticum aestivum L.) (2003), soybean (2003-4), corn ( Zea mays L.) (2004-5), and soybean (2005-6). Soil samples were collected at the following depths: 0-0.05, 0.05-0.10, and 0.10-0.20 m, 10 years after surface liming and 3 years after surface re-liming. Soil Zn levels were extracted by four extractants: (i) 0.005 mol L -1 diethylenetriaminepentaacetic acid (DTPA)+0.1 mol L -1 triethanolamine (TEA)+0.01 mol L -1 calcium chloride (CaCl 2) solution at pH 7.3 (DTPA-TEA), (ii) 0.1 mol L -1 hydrochloric acid (HCl) solution, (iii) Mehlich 1 solution, and (iv) Mehlich 3 solution. Zinc concentrations in leaves and grains of soybean, wheat, and corn were also determined. Soil pH (0.01 mol L -1 CaCl 2 suspension) varied from 4.4 to 6.1, at the 0- to 0.05-m depth, from 4.2 to 5.3 at the 0.05- to 0.10-m depth, and from 4.2 to 4.8 at the 0.10- to 0.20-m depth, after liming and re-liming. Zinc concentrations evaluated by DTPA-TEA, 0.1 mol L -1 HCl, Mehlich 1, and Mehlich 3 solutions were not changed as a result of lime rate application. Re-liming increased Zn concentrations extracted by 0.1 mol L -1 HCl at 0-0.05 m deep and by DTPA-TEA at 0.05-0.10 m deep. Surface-applied lime promoted a decrease in Zn concentrations of the crops, mainly in grains, because of increased soil pH at the surface layers. Regardless of the liming treatments, levels of Zn were sufficient to soybean, wheat, and corn nutrition under NT.
  • Authors:
    • Hedtcke, J. L.
    • Posner, J. L.
    • Chavas, J. P.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 2
  • Year: 2009
  • Summary: This article, the second in a series looking at the Wisconsin Integrated Cropping Systems Trial (WICST), reports on the profitability of six conventional and organic systems, with a focus on net returns and associated risk exposure. Several pricing scenarios were compared to evaluate the impact of government programs and organic price premiums. When net return estimates are made using only neighboring elevator prices (no government programs or organic price premiums), we found that the no-till corn-soybean system [ Zea mays L. and Glycine max (L.) Merr.] was the most profitable grain system, and management intensive rotational grazing (MIRG) the most profitable forage system. When government programs and organic price premiums are included, returns increased by 85 to 110% for the organic grain system corn-soybean-wheat+red clover ( Triticum aestivum L.+ Trifolium pratense L.) and 35 to 40% for the organic forage system [companion seeded alfalfa with oat+field pea ( Medicago sativa L., Avena sativa L., and Pisum sativum L.), hay, and then corn]. This places both organic systems with higher returns than any of the Midwestern standards of no-till corn-soybean, continuous corn, or intensive alfalfa production. Also, the results indicate how risk exposure varied across systems. Interestingly, taking risk into consideration did not drastically affect the ranking among those systems. Our analysis shows that, under the market scenarios that prevailed between 1993 and 2006, intensive rotational grazing and organic grain and forage systems were the most profitable systems on highly productive land in southern Wisconsin.
  • Authors:
    • Madar, R.
    • Cosma, C.
    • Vuşcan, A.
    • Samuel, A. D.
    • Jurcă, A.
    • Ciobanu, G.
    • Domuta, C.
    • Ciobanu, C.
    • Albu, R.
    • Şandor, M.
  • Source: Bulletin of the University of Agricultural Sciences & Veterinary Medicine Cluj-Napoca
  • Volume: 66
  • Issue: 1
  • Year: 2009
  • Summary: The paper based on the research carried out during 2005-2008 in the long term trial placed in 1990 on the preluvosoil from Oradea. The monoculture of maize, maize-wheat and maize-soybean-wheat crop rotations were studied in unirrigated and irrigated conditions. The crop rotation of six years (oat+clover-clover-maize-wheat-maize-sunflower) was studied in unirrigated conditions. The research emphasized that the monoculture is the most responsible for the pest multiplication. In maize monoculture the larvae number on the roots was ranged between 4.91-8.23 and root attack degree in IOWA scale (with marks from 1 to 6 in which maximum attack is 6), had values between 3.84 and 5.62 and the frequent of attacked plants with the symptom "goose neck" ranged between 16,4% and 31.2% and larval aggressiveness being higher in the case of favorable soil moisture in irrigated condition. The maize rotation with other plants interrupts the biologic pest cycle. The results obtained emphasize that later maize sowing alongside by the utilizing of lower plant thickness level contribute to prevention of pest multiplication, while earlier sowing at high thickness favor the larvae developing.
  • Authors:
    • Knighton, R. E.
    • Casey, F. X. M.
    • Derby, N. E.
  • Source: Vadose Zone Journal
  • Volume: 8
  • Issue: 2
  • Year: 2009
  • Summary: Proper N management for agricultural production is critical to minimize groundwater contamination with NO 3. For 18 yr, research was conducted to observe NO 3-N concentrations in the vadose zone, groundwater, and subsurface drainage under sprinkler-irrigated, primarily corn ( Zea mays L.) production. Potato ( Solanum tuberosum L.) and soybean [ Glycine max (L.) Merr.] were also grown intermittently on the site. The lysimeter leachate NO 3-N concentration increased to 156 mg L -1 under corn production within 1 yr after the initiation of irrigation (at the onset of the study), then decreased to
  • Authors:
    • Tarau, D.
    • Borza, I.
    • Dicu, D.
  • Source: Research Journal of Agricultural Science
  • Volume: 41
  • Issue: 2
  • Year: 2009
  • Summary: This study was conducted on a cambic chernozem in the Banat-Crisana Plain (Romania) to determine the quantitative and qualitative influence of tillage and fertilizer modifications made on the agroecosystem level on wheat, maize and soyabeans. The treatments include with and without deep soil working, conventional and no-tillage, and with (P1, N 80P 80K 80; P2, N 160P 80K 80) and without fertilizer application. Wheat was sown in 17 October 2007 and harvested in 28 June 2008. Maize was sown in 20 April 2008 and harvested in 27 Septerm 2008. Soyabean was sown 22 April 2008 and harvested in 11 October 2008. The field under the no-till system was maintained with more weeding than the conventional tillage. In terms of the evolution of soil humidity, more uniform values were obtained in the soil profile of the no-till system, while a low increase in soil water content was observed in the fields with deep working of soil. For wheat, the highest yield (4579 kg/ha) was obtained from the no-till system without deep working of the soil with P2 treatment, while the lowest yield (3475 kg/ha) was obtained from the conventional tillage system with deep soil working without fertilizer. For maize, the highest yield (5749 kg/ha) was obtained under the no-till system without deep working of soil with P2 treatment, while the lowest yield (3415 kg/ha) in classic system with deep work of soil without fertilizer. For soyabeans, the highest yield (1988 kg/ha) was obtained from the conventional tillage system without deep working of soil with P2 treatment, while the lowest (880 kg/ha) was obtained from the no-till system with deep working of soil without fertilizer treatment.