• Authors:
    • Tadesse, T.
    • Narumalani, S.
    • Wardlow, B. D.
    • Swain, S.
    • Callahan, K.
  • Source: GIScience & Remote Sensing
  • Volume: 48
  • Issue: 3
  • Year: 2011
  • Summary: Eight-day composite Terra-MODIS cumulative LST and NDVI timeseries data were used to analyze the responses of crop and grassland cover types to drought in Nebraska. Four hundred ninety 1 km pixels that included irrigated and non-irrigated corn and soybeans and three grassland cover types were selected across the state of Nebraska. Statistical analyses revealed that the majority of the land cover pixels experienced significantly higher daytime and nighttime LSTs and lower NDVI during the drought-year growing season ( p
  • Authors:
    • Farran, M.
    • Nimah, M.
    • Yau, S. K.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 12
  • Year: 2011
  • Summary: In rainfed Mediterranean areas, early sowings which lead to early growth and maturity to escape terminal heat and drought usually give higher grain yield than late sowings in years when rains come early. We test the hypothesis that early sowing coupled with a small amount of irrigation to ensure earlier emergence increases grain yield significantly, while improving irrigation water productivity. Replicated field experiments were conducted for 4 years in the semi-arid central Bekaa Valley of Lebanon. Barley was sown early, and half of the plots were irrigated with 25-30 mm of water immediately after sowing (EI). Half of the plots also received irrigation around heading stage (LI). Besides yields, other agronomic data were collected throughout crop growth, and the supplemental irrigation water use efficiency (WUE SI) was calculated. Our results confirm the hypothesis that in Mediterranean areas early sowing followed immediately with a small amount of irrigation increases barley grain yield significantly. Farmers in the region should seriously consider practicing this technique as it produces a higher WUE SI than irrigation at the heading stage.
  • Authors:
    • You, L. Z.
    • Zhao, J. S.
    • Ringler, C.
    • Yang, Y. C. E.
    • Cai, X. M.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 8
  • Year: 2011
  • Summary: Agricultural water productivity (WP) has been recognized as an important indicator of agricultural water management. This study assesses the WP for irrigated (WPI) and rainfed (WPR) crops in the Yellow River Basin (YRB) in China. WPI and WPR are calculated for major crops (corn, wheat, rice, and soybean) using experimental, statistical and empirically estimated data. The spatial variability of WPI and WRR is analyzed with regard to water and energy factors. Results show that although irrigated corn and soybean yields are significantly higher than rainfed yields in different regions of the YRB, WPI is slightly lower than WPR for these two crops. This can be explained by the seasonal coincidence of precipitation and solar energy patterns in the YRB. However, as expected, irrigation stabilizes crop production per unit of water consumption over space. WPI and WPR vary spatially from upstream to downstream in the YRB as a result of varying climate and water supply conditions. The water factor has stronger effects on both crop yield and WP than the energy factor in the upper and middle basin, whereas energy matters more in the lower basin. Moreover, WP in terms of crop yield is compared to that in terms of agricultural GDP and the results are not consistent. This paper contributes to the WP studies by a basin context, a comparison between WPI and WPR, a comparison of WP in terms of crop yield and economic value, and insights on the water and energy factors on WP. Moreover, policy implications based on the WP analysis are provided.
  • Authors:
    • Ebert, W.
    • Olson, R.
    • Demchik, M.
  • Source: Agroforestry: A Profitable Land Use. Proceedings of the 12th North American Agroforestry Conference, Athens, Georgia, USA, 4-9 June 2011
  • Year: 2011
  • Summary: In fall of 2006, a 2-acre hayfield on a tree farm in central Wisconsin was laid out into 10-foot wide terraces/swales along contour lines. The beds were strip sprayed with glyphosate and a two-bottom plow was used to create swales. A total of 2400 linear feet of planting bed were created. Each terrace was planted to 2-3 rows of plants, with trees on 20-ft spacing and shrubs interplanted at 5-8 foot spacing. This will create a multi-layer canopy with crops from each layer. Over 40 species/varieties were planted on the site in the spring of 2007 (240 trees, 480 shrubs, and 250 perennials). The entire site was electrically fenced. Plants were mulched with either wood chips or fabric mulch and treatments of drip-irrigation or no irrigation were applied to the plants. After three growing seasons, no difference was found between treatments. The swales and mulching was adequate to ensure survival and growth without the need of supplemental irrigation. Growth and fruiting of individual species as well as other observations will be discussed in this presentation.
  • Authors:
    • Dadhwal, K. S.
    • Sharma, N. K.
    • Ghosh, B. N.
  • Source: Indian Journal of Soil Conservation
  • Volume: 39
  • Issue: 3
  • Year: 2011
  • Summary: Agricultural land use coupled with cropping system and integrated nutrient management (INM) can enhance crop yields, water productivity, improve soil health and income to the farmers. To test this hypothesis, four technologies namely rainfed; (i) maize+cowpea (1:2)-wheat, (ii) maizewheat+mustard (9:1), (iii) irrigated, paddy-wheat, paddy (System of rice intensification, SRI) - wheat and (iv) maize-potato-onion with INM to each crop rotations were experimented and demonstrated on farmer's fields in the agroclimatic zone of valley land of north-west Himalayas (Agro-ecological 14) in the districts of Dehradun (Uftarakhand) and Sirmour (Himachal pradesh) during 2007-09. Two years pooled data indicated that maize-potato-onion rotation rendered highest maize equivalent yield (18762 kg ha -1) among all the cropping system, followed by paddy wheat (10789 kg ha -1) and maize-wheat+mustard intercropping system (4826 kg ha -1). Of the two rainfed systems, maize-wheat+mustard gave slightly higher (1.5%) maize equivalent yield than maize- + cowpea-wheat sequence whereas under limited irrigation condition, maize-potato-onion exhibited significantly higher (73.9%) maize equivalent yield than paddy-wheat system. Results also revealed that on an average, yield, water use efficiency (WUE) and net return increased to the tune of 40.7, 44.7 and 89.9%, respectively on adoption of technology in the farmer's field over conventional farming irrespective of crop rotations. Water use in system of rice intensification (SRI) with INM technology was 80-90 mm less than fanners practice. On adoption of INM technology, the soil quality index (SQI) improved from 11.9 to 18.8% exhibiting highest in maize-potato-onion and lowest in paddy-wheat system. It is inferred that maize-potato-onion under limited irrigation treatment and maize-wheat+mustard under rainfed conditions are the best management options for maximizing water productivity, net return and soil quality.
  • Authors:
    • Williams, J. D.
    • Long, D. S.
  • Source: Crop Management
  • Issue: March
  • Year: 2011
  • Summary: In the intermediate annual precipitation zone (14 to 18 inches) of northeastern Oregon, there is interest in increasing the intensity of cropping with spring crops. Mechanical tillage remains popular for seedbed preparation and weed control, but contributes to environmental problems and high labor and fuel cost. No-tillage (NT) crop production can reduce on site and off site problems and has lower labor and fuel costs, but soil-borne disease and weed control problems can limit yields. We compared crop yields, production costs, and economic returns of an intensive, four-year crop production rotation under two management systems: (i) minimum tillage (MT) with cultivation by chiseling, sweeping, and rod weeding; and (ii) NT with chemical weed control. The rotation was fallow-winter wheat-dry spring pea-winter wheat in which a spring broadleaf crop is included to aid in the control of winter annual weeds and reduce host pathogen levels of soil-borne cereal diseases. Four year averages of wheat yields in the NT treatment were equal to or greater than those in the MT treatment whereas dry green pea production was roughly equal in each treatment. Crop productivity differed significantly in each phase of the rotation in descending order from winter wheat following fallow [4,578 lb/acre (76 bu/acre)], winter wheat following dry spring pea [3,548 lb/acre (59 bu/acre)], to dry spring pea (1,505 lb/acre). Partial budget analysis shows that NT is substantially less costly than MT in terms of labor and fuel, potentially making NT economically viable for intensive cropping systems in the intermediate precipitation dryland region of northeastern Oregon.
  • Authors:
    • Zhang, Y. Q.
    • Yang, .L W.
  • Source: Scientia Agricultura Sinica
  • Volume: 44
  • Issue: 11
  • Year: 2011
  • Summary: Objective: The study was to explore the geometric characteristics, spatial and temporal distributive patterns of root systems of spring wheat, millet, grain sorghum, and broomcorn millet. Method: Experimental methods employed were pot culture, soil column culture, chain link mesh box cultivation and field investigation. Result: Differences in root system characteristic patterns of the four cereal crops: Number of seminal root and secondary root was different, maximum striking depth of root systems was different which usually followed the order of grain sorghum > millet > spring wheat > broomcorn millet, maximum root extension was different, maximum root extension often showed an order of grain sorghum > broomcorn millet > millet > spring wheat. The basilar 1-3 node of millet, broomcorn millet and grain sorghum formed 1st round to 3rd round support root after tasselling, while spring wheat did not have support root commonly. Temporal distributive patterns of the four cereal crops in the experiment: root systems of millet, broomcorn millet and spring wheat grew downward gradually along with developing stage, root length and root weight increased persistently, the increase of root length and root weight showed slow-fast-slow patterns. The growth patterns of root weight and total root length of the four cereal crops accorded with S-type growth curve, while the increase per day for root length and root weight of grain sorghum was far larger than that of millet and broomcorn millet. Spatial distributive patterns of the four cereal crops in the experiment: in seedling stage root systems of the four cereal crops grew downward mainly; in each soil layer the absolute root amount increased gradually; root length and root dry weight mostly distributed in the soil layer of 0-40 cm depth; root systems hardly distributed in the soil layer of below 40 cm. Therefore, spatial patterns of the four cereal crops showed a clear T-shape. At jointing stage, root systems kept on growing downward, and the root amount in different soil layers increased distinctly. The spring wheat root weight enhanced notably, and spring wheat root length distribution showed 8-shape approximately. Patterns for root length and weight of the other three crops still showed a T-shape. At heading stage, the root length distributive patterns in different depth soil of millet, broomcorn millet and grain sorghum turned into 8-shape approximately, while the root length distributive patterns in different depths of soil of spring wheat showed an egg-shape. So, the root length of the four cereal crops in the experiment at late heading stage had superiority in middle and bottom soil layer. The vertical distribution of root weight of millet, broomcorn millet, grain sorghum followed the exponential equation y=A.e -bx , but different crops had different b values. The total root length distributive patterns of the four cereal crops in different soil depths at early stage followed the exponential equation y=A.e -bx , but at late stage it followed the multinomial y= ax3+ bx2+ cx+ d. Conclusion: The similarities in spatial distributive patterns of the root systems of the four cereal crops were positive, which provided a theoretical basis for root regulation for cultivation.
  • Authors:
    • Lee, G. J.
    • Abdel-Haleem, H.
    • Boerma, R. H.
  • Source: Theoretical and Applied Genetics
  • Volume: 122
  • Issue: 5
  • Year: 2011
  • Summary: Drought stress adversely affects soybean at various developmental stages, which collectively results in yield reduction. Unpredictable rainfall has been reported to contribute about 36% to variation of yield difference between the rain-fed and irrigated fields. Among the drought resistance mechanisms, drought avoidance in genotypes with fibrous roots was recognized to be associated with drought resistance in soybean. Plant introduction PI416937 was shown to possess fibrous roots and has been used as a parent in breeding programs to improve soybean productivity. Little information is available on relative contribution and chromosomal location of quantitative trait loci (QTL) conditioning fibrous roots in soybean. To identify the genomic locations and genetic bases of this trait, a recombinant inbred line population was derived from a cross between PI416937 and 'Benning'. To detect associated QTLs, phenotypic data were collected and analyzed for 2 years under rain-fed field conditions. The selective genotyping approach was used to reduce the costs and work associated with conducting the QTL analysis. A total of five QTLs were identified on chromosomes Gm01 (Satt383), Gm03 (Satt339), Gm04 (Sct_191), Gm08 (Satt429), and Gm20 (Sat_299), and together explained 51% of the variation in root score. Detected QTLs were co-localized with QTLs related to root morphology, suggesting that fibrous roots QTL may be associated with other morpho-physiological traits and seed yield in soybean. Genetic dissection of the fibrous roots trait at the individual marker loci will allow for marker-assisted selection to develop soybean genotypes with enhanced levels of fibrous roots.
  • Authors:
    • Bandici, G. E.
    • Ardelean, I.
  • Source: Analele Universităţii din Oradea, Fascicula ProtecÅ£ia Mediului
  • Volume: 17
  • Year: 2011
  • Summary: The paper based on the research carried out during 2008-2010 in the long term trial placed in 1990 on the preluvosoil from Oradea. Three kind of crop rotation (wheat - monocrop; wheat - maize; wheat - maize - soybean) were studied in unirrigated and irrigated conditions. The smallest content of the protein from wheat grains were registered in the wheat monocrop both nonirrigated and irrigated variant. In the wheat-maize and wheat-maize-soybean crop rotation the values registered were significant statistically bigger than in wheat monocrop. Irrigation determined the decrease of the protein content.
  • Authors:
    • Yawson, D. O.
    • Obiri, S.
    • Yengoh, G. T.
    • Odoi, J. O.
    • Armah, F. A.
    • Afrifa, E. K. A.
  • Source: Mitigation and Adaptation Strategies for Global Change
  • Volume: 16
  • Issue: 3
  • Year: 2011
  • Summary: Desertification, climate variability and food security are closely linked through drought, land cover changes, and climate and biological feedbacks. In Ghana, only few studies have documented these linkages. To establish this link the study provides historical and predicted climatic changes for two drought sensitive agro-ecological zones in Ghana and further determines how these changes have influenced crop production within the two zones. This objective was attained via Markov chain and Fuzzy modelling. Results from the Markov chain model point to the fact that the Guinea savanna agro-ecological zone has experienced delayed rains from 1960 to 2008 while the Sudan savanna agro-ecological zone had slightly earlier rains for the same period. Results of Fuzzy Modelling indicate that very suitable and moderately suitable croplands for millet and sorghum production are evenly distributed within the two agro-ecological zones. For Ghana to adapt to climate change and thereby achieve food security, it is important to pursue strategies such as expansion of irrigated agricultural areas, improvement of crop water productivity in rain-fed agriculture, crop improvement and specialisation, and improvement in indigenous technology. It is also important to encourage farmers in the Sudan and Guinea Savanna zones to focus on the production of cereals and legumes (e.g. sorghum, millet and soybeans) as the edaphic and climatic factors favour these crops and will give the farmers a competitive advantage. It may be necessary to consider the development of the study area as the main production and supply source of selected cereals and legumes for the entire country in order to free lands in other regions for the production of crops highly suitable for those regions on the basis of their edaphic and climatic conditions.