• Authors:
    • Ji, H.
    • Song, T.
    • Han, O.
    • Lee, H.
    • Ju, J.
  • Source: Journal of the Korean Society of Grassland and Forage Science
  • Volume: 31
  • Issue: 4
  • Year: 2011
  • Summary: Soil fertility different depend on application rate of manure and compost for many years. While each crop has different adaptability depend on soil fertility, crop and species or varieties should be chosen depending on the adaptability and productivity. These experiments were carried out to compare the five winter cereal crops for whole crop silage on growth, yield and feed value as affected by soil organic content. The rate of increase on no. of spikes at high fertile soil compared with medium fertile soil was sequently high Samhan (Oat's variety) > Cheongwoo (Wheat) > Gogu (Rye) > Youngyang (Barley) > Shinyoung (Triticale). The rate of decrease at low fertile soil compared with medium fertile soil was sequently high Youngyang > Gogu > Cheongwoo > Shinyoung > Samhan. The triticale was lower variation of no. of spikes as affected by soil organic content than that of other winter cereals. The variations of dry matter yield as affected by soil fertility was higher oat and barley and lower triticale. Forage yield of triticale was higher about 69 percent than that of barley at low fertile soil. Forage yield was the highest in triticale and the lowest in rye in all soil fertility. In high fertile soil, rate of increasing digestible dry matter (DDM) yield compared with medium fertile was high in Samhan and Youngyang. Rate of reduced DDM yield in low fertile soil compared with medium fertile was low in Shinyoung and Cheongwoo.
  • Authors:
    • Kang, U.
    • Park, M.
    • Lee, J.
    • Lee, Y.
    • Oh, I.
    • Cho, H.
    • Ryu, J.
    • Park, C.
    • Seong, K.
    • Jeon, W.
    • Ku, J.
    • Kim, M.
  • Source: Korean Journal of Crop Science / Hanguk Jakmul Hakhoe Chi
  • Volume: 56
  • Issue: 2
  • Year: 2011
  • Summary: To use barley as a green manure crop, this study has been conducted in Suwon, Gyeonggi-do to establish the barley green manure (BGM)-rice cropping system with emphasis on soil incorporation date and BGM density. The nitrogen (N) contents of rye and barley, grass green manure crops, were 1.4-2.4% at early growth stage and decreased rapidly to 0.6-1.0% at late growth stage. The biomass of barley was 449 kg/10 a at heading stage (HS) and increased to 421 kg/10 a at 10 days after heading stage (DAH), 473 kg/10 a at 20 DAH. C/N ratio of BGM was the lowest 26.3 at HS. The N contents of BGM was in the range of 0.9-1.5%, the highest at HS and gradually decreased, and the output of N were 4.3-6.3 kg/10 a. The total amount of nitrogen, phosphorous and potassium of BGM showed the highest level at 10 DAH. Culm length of rice was relatively longer as the BGM application time was delayed. The application of BGM into soil increased plant height of rice by 7.2-7.7 cm as compared to the plants treated with commercial fertilizer at recommended rate, but panicle length of rice showed a similar tendency in both the soil-applied of BGM and commercial fertilizer. N contents of unhulled rice was the highest at HS of BGM and followed by 10 DAH of BGM and 20 DAH of BGM. This trend could also be seen in rice straw. The yield of rice in the soil-applied of BGM was 10-15% lower than in the soil-applied of commercial fertilizer. Based on this study, application of BGM made it possible to save 30-50% of application amount of nitrogen fertilizer for following crops.
  • Authors:
    • Korac, M.
    • Meseldzija, M.
    • Konstantinovic, B.
    • Mandic, N.
  • Source: Herbologia
  • Volume: 12
  • Issue: 1
  • Year: 2011
  • Summary: Soil surface contains huge amount of seed of different weed species. By examination of weed seed distribution in the soil, it can be predicted which weeds will occur under different crops and to what extent. Detailed data analysis enables determination of timely soil tillage, as well as herbicide use. In the period 2008-2010, the weed seed bank was studied in different localities on the territory of Vojvodina (Krivaja, Ratkovo, Zmajevo, Bac, and Despotovo). Soil samples were collected from fields under different crops (soybean, sugar beet, maize, clover and sunflower). The sampling was performed diagonally in four replications from several arable depth layers of 0-10, 10-20 and 20-30 cm. Each sample was sieved through the system of cooper sieves of different diameter, according to the method of Conn (1987). After extraction from the samples, weed seeds were determined (Skender et. al., 1998; Kronaveter and Boar, 1994) and abundance of weed seed per m 2 was established for all three studied soil layers. The most abundant weed species in the weed seed bank under all studied crops were: Amaranthus retroflexus, Chenopodium album, Datura stramonium, Polygonum lapathifolium and Solanum nigrum, while less abundant were seeds of: Echinochloa cruss-galli, Euphorbia helioscopia, Sinapis arvensis, Sorghum halepense and Stachys annua. The highest abundance of weed seed was found at locality Zmajevo under sunflower crop in the soil layer of 0-10 cm, in the amount of 8.487 seeds per m 2. At locality Krivaja, under soybean crop, the highest number of seeds was recorded in layers of 10-20 and 20-30, in the amount of 9.252 and 10.609 seeds per m 2, respectively. The results were statistically processed and it was calculated that the highest coefficient of variance, i.e. the maximum deviation between number of seeds of weed species per soil layers was 40.53% at locality Despotovo.
  • Authors:
    • Liu, Y.
    • Ma, L.
    • Li, X.
  • Source: Acta Phytophylacica Sinica
  • Volume: 38
  • Issue: 3
  • Year: 2011
  • Summary: In order to fully understand the regular pattern of the population dynamics of Lithocolletis ringoniella Matsumura in the apple production region of the Loess Plateau, the distribution pattern and the ecological niche index were determined and the clustering analysis was conducted to describe the dynamic change of L. ringoniella population. The results showed that the leaf insect spot caused by L. ringoniella was visible in June; the number of the insect increased in July, with the damage symptom severe in August; and the quantity of the population number was in surge in September and October. The relative abundance of the temporal sequence was in a strong rising trend since August. Population distribution in the crown was uniform in early July and aggregative after that. The spatial distribution among the vertical positions of the tree crown showed significant difference, population number following the order of lower > middle > upper parts, whereas distribution among horizontal directions had no significant difference. The general distribution within the crown appeared in cluster, with individuals attractive to each other. The ecological niche occupation of this pest in vertical and horizontal directions as well as in temporal sequences are 0.179, 0.371 and 0.594, respectively. The resource utilization rate in the lower part of the crown reached 53.73% and almost nothing utilized in the upper part, indicating a more horizontal expansion potential. Viewing from the four directions, the maximum utilization of resources was in the north and east, up to 27.90% and 21.66% respectively. The ecological niche overlap index of L. ringoniella with hawthorn spider mite in vertical and horizontal directions reached 92.65 and 64.95, respectively, in addition to temporal sequence to be 66.36, indicating that hawthorn spider mite is the most intense space-temporal competitor for the limited resources of apple's crown leaves. The dominance degree index of L. ringoniella in the young apple orchard in different intercropping patterns increased over time since August and largest increase happened in the middle of August. The highest dominance degree index was found in soybean-apple intercropping pattern and the lowest index with sweet potato-apple intercropping pattern. The index fluctuated in the orchard with weeds unwell-managed.
  • Authors:
    • Osetrov, D.
  • Source: Ekonomika Sel'skokhozyaistvennykh i Pererabatyvayushchikh Predpriyatii
  • Issue: 4
  • Year: 2011
  • Summary: In 2006-2009, total annual production of food and feed grain crops in Russia's Volgograd Oblast' averaged 3 652 300 tonnes, of which the main food crops (winter and spring wheat, rye, buckwheat and millet) accounted for 85.8%, the main feed crops (barley, oats, cereal maize and legumes) 14.1%, and other food and feed crops 0.1%. In 2001-2005, the region's total annual production of food and feed grain crops averaged 3 075 500 tonnes, of which the main food crops accounted for 78.9%, the main feed crops 21.1%, and other food and feed crops 0.0%. Total production of food grains, increased significantly (29.1%) between the 2001-2005 and 2006-2009 periods, with this growth largely attributable to higher harvests of winter wheat (up 50.1%). Total production of feed grains fell by 20.4% between the 2001-2005 and 2006-2009 periods, with harvests of barley, oats and legumes falling by 45.9%, 34.8% and 37.2% respectively, although cereal maize output more than quadrupled. On average in the 2006-2009 period, 1 755 000 tonnes/year of cereal grains were exported outside the region, and 112 000 tonnes/year were imported. Analysis of actual consumption of cereal grains in Volgograd Oblast' shows that total regional consumption averaged 1 919 000 tonnes/year in 2006-2009, of which 19.3% was used for seeds, 62.1% for animal feeds, 13.0% for food purposes, and 2.4% for other industrial processing, with 3.2% losses. A very similar usage pattern was recorded in 2001-2005. It is anticipated that demand for feed grains will rise as a result of implementation of government agricultural policies aimed at stimulating animal production, including the priority national programme "Development of the agro-industrial complex". While 62.1% of cereal grains consumed in Volgograd Oblast' in 2006-2009 were used in animal feeds (1 191 000 tonnes/year), feed crops accounted for only 14.1% of the region's cereal grain output (515 200 tonnes/year). Consequently many enterprises in the animal production segment were forced to use significant volumes of food grains, particularly wheat, for production of animal feeds. This pushes up the price of feeds, and also causes imbalances in the nutrient composition of feeds. Production of food grains in Volgograd Oblast' significantly exceeds demand, and the percentage of total cereal grain production accounted for by food grains is continuing to rise. However the region's food industry still suffers from shortages of some types of cereal grain. In order to correct the problems that have been identified with regard to cereal grains production in Volgograd Oblast', a strategy based on formation of clusters of cereal grain producers, processors and end users is recommended. Recommendations for improvements to the structure of cereal grain production in the region are also presented. These include significant increases in volumes of production of feed crops, in particular oats, maize, legumes and triticale.
  • Authors:
    • Walter-Shea, E. A.
    • Singh, R. K.
    • Irmak, A.
    • Verma, S. B.
    • Suyker, A. E.
  • Source: Transactions of the American Society of Agricultural and Biological Engineers and Papers in Natural Resources. Paper 334.
  • Volume: 54
  • Issue: 1
  • Year: 2011
  • Summary: We evaluated the performance of four models for estimating soil heat flux density (G) in maize (Zea mays L.) and soybean (Glycine max L.) fields under different irrigation methods (center-pivot irrigated fields at Mead, Nebraska, and subsurface drip irrigated field at Clay Center, Nebraska) and rainfed conditions at Mead. The model estimates were compared against measurements made during growing seasons of 2003, 2004, and 2005 at Mead and during 2005, 2006, and 2007 at Clay Center. We observed a strong relationship between the G and net radiation (R n) ratio (G/R n) and the normalized difference vegetation index (NDVI). When a significant portion of the ground was bare soil, G/R n ranged from 0.15 to 0.30 and decreased with increasing NDVI. In contrast to the NDVI progression, the G/R n ratio decreased with crop growth and development. The G/R n ratio for subsurface drip irrigated crops was smaller than for the center-pivot irrigated crops. The seasonal average G was 13.1%, 15.2%, 10.9%, and 12.8% of R n for irrigated maize, rainfed maize, irrigated soybean, and rainfed soybean, respectively. Statistical analyses of the performance of the four models showed a wide range of variation in G estimation. The root mean square error (RMSE) of predictions ranged from 15 to 81.3 W m -2. Based on the wide range of RMSE, it is recommended that local calibration of the models should be carried out for remote estimation of soil heat flux.
  • Authors:
    • Verma, S. B.
    • Vanegas, D. X.
    • Xiao, X. M.
    • Kalfas, J. L.
    • Suyker, A. E.
  • Source: Agricultural and Forest Meteorology
  • Volume: 151
  • Issue: 12
  • Year: 2011
  • Summary: Information on gross primary production (GPP) of maize croplands is needed for assessing and monitoring maize crop conditions and the carbon cycle. A number of studies have used the eddy covariance technique to measure net ecosystem exchange (NEE) of CO 2 between maize cropland fields and the atmosphere and partitioned NEE data to estimate seasonal dynamics and interannual variation of GPP in maize fields having various crop rotation systems and different water management practices. How to scale up in situ observations from flux tower sites to regional and global scales is a challenging task. In this study, the Vegetation Photosynthesis Model (VPM) and satellite images from the Moderate Resolution Imaging Spectroradiometer (MODIS) are used to estimate seasonal dynamics and interannual variation of GPP during 2001-2005 at five maize cropland sites located in Nebraska and Minnesota of the U.S.A. These sites have different crop rotation systems (continuously maize vs. maize and soybean rotated annually) and different water management practices (irrigation vs. rain-fed). The VPM is based on the concept of light absorption by chlorophyll and is driven by the Enhanced Vegetation Index (EVI) and the Land Surface Water Index (LSWI), photosynthetically active radiation (PAR), and air temperature. The seasonal dynamics of GPP predicted by the VPM agreed well with GPP estimates from eddy covariance flux tower data over the period of 2001-2005. These simulation results clearly demonstrate the potential of the VPM to scale-up GPP estimation of maize cropland, which is relevant to food, biofuel, and feedstock production, as well as food and energy security.
  • Authors:
    • Galusha, T. D.
    • Jackson, D. S.
    • Mason, S. C.
    • Griess, J. K.
    • Pedersen, J. F.
    • Yaseen, M.
  • Source: Crop Science
  • Volume: 51
  • Issue: 4
  • Year: 2011
  • Summary: Grain processors would benefit from information about the production environment and the influences of the sorghum [ Sorghum bicolor (L.) Moench] hybrid on food-grade flour properties. The objective of this study was to determine the effects of environment and hybrid on rapid-visco-analysis (RVA) flour properties of commercially available food-grade sorghum. A randomized complete block experiment was planted in 12 environments, which included the 2004 and 2005 growing seasons and irrigated and dryland water regimes in eastern, central, and west central Nebraska, and a dryland, low-N environment in eastern Nebraska. The environment accounted for 71-85% of the total variation in RVA parameters, while the hybrid accounted for 11-23% and the environment-by-hybrid interaction, 1-3%. Unfortunately, the results of this experiment suggest that it is difficult to predict the effect that environment will have on resulting sorghum-flour parameters. Although of secondary importance in terms of total variation in sorghum-flour RVA properties, the choice of hybrid predictably and significantly contributes to sorghum-starch viscosity properties. Food-grade hybrids were grouped based on viscosity properties into those best suited for dry-mill and alkaline-cooked products (Asgrow Orbit; Sorghum Partners NK1486) and those best suited for porridge, consumable alcohol, and ethanol production (Kelly Green Seeds KG6902; NC+ Hybrids 7W92; Asgrow Eclipse; and Fontanelle W-1000). These results were consistent with those previously reported for grain density.
  • Authors:
    • Mutiibwa, D.
    • Irmak, S.
  • Source: Transactions of the American Society of Agricultural and Biological Engineers
  • Volume: 54
  • Issue: 1
  • Year: 2011
  • Summary: Canopy resistance (r c), which represents the composite diffusive resistance to water vapor transfer from vegetation surfaces to the atmosphere, plays an important role in describing the water vapor and energy fluxes and CO 2 exchange mechanisms and is an essential component of the complex ecophysiological and turbulent transport and evapotranspiration models. While one-step (direct) application of combination-based energy balance models (i.e., Penman-Monteith, PM) requires r c to solve for actual evapotranspiration (ET a), a remaining challenge in practical application of PM-type models is the scaling up of leaf-level stomatal resistance (r s) to r c to represent an integrated resistance from the plant community to quantify field-scale evaporative losses. We validated an integrated approach to scale up r s to the canopy. Through an extensive field campaign, we measured diurnal r s for a subsurface drip-irrigated soybean [ Glycine max (L.) Merr.] canopy and integrated several microclimatic and in-canopy radiation transfer parameters to scale up r s to r c. Using microclimatic and plant factors such as leaf area index for sunlit and shaded leaves, plant height, solar zenith angle, direct and diffuse radiation, and light extinction coefficient, we scaled up soybean r s as a primary function of measured photosynthetic photon flux density (PPFD). We assumed that PPFD is the primary and independent driver of r c; hence, the scaling approach relied heavily on measured PPFD-r s response curves. We present experimental verifications of scaled up r c by evaluating the performance of the scaled up r c values in estimating ET a. In addition, we solved the PM model on an hourly time step using the scaled up r c values and compared the PM-estimated ET a with the Bowen ratio energy balance system (BREBS)-measured ET a. The relationship between r s and PPFD was asymptotic, and r s showed strong dependence to PPFD, as PPFD alone explained 67% to 88% of the variability in r s. Beyond a certain amount of PPFD (400 to 500 mol m -2 s -1), r s became less responsive to PPFD. At smaller PPFD (0 to about 150 mol m -2 s -1) and greater r s (>70 to 80 s m -1) range, r s was very sensitive to PPFD. The r c_min, r c_avg, and r c_max ranged from 42 to 104 s m -1, 69 to 183 s m -1, and 95 to 261 s m -1, respectively, throughout the season. The seasonal average r c_min, r c_avg, and r c_max were 54, 92, and 129 s m -1, respectively. Canopy resistances were higher in early growing season during partial canopy closure, lower during mid-season, and high again in late season due to leaf aging and senescence. The ET a estimates from the PM model using scaled up r c values correlated very well with the BREBS-measured ET a. The average root mean square difference (RMSD) between the BREBS-measured and PM-estimated ET a was 0.08 mm h -1 (r 2=0.91; n=827), and estimates were within 3% of the measured ET a on an hourly basis. On a daily time step, RMSD was 0.64 mm d -1 (r 2=0.86; n=83), and the estimates were within 4% of the measured data. The approach successfully synthesized the whole-canopy resistance for use in PM-type combination-energy balance equations by scaling up from r s using a straightforward model of in-canopy radiation transfer.
  • Authors:
    • Odhiambo, L. O.
    • Irmak, S.
  • Source: Transactions of the American Society of Agricultural and Biological Engineers
  • Volume: 54
  • Issue: 3
  • Year: 2011
  • Summary: Estimation of actual evapotranspiration (ET), especially its partitioning into plant transpiration (T) and soil evaporation (E), in agricultural fields is important for effective soil water management and conservation and for understanding the interactions between ET, T and E with the management practices. Direct field measurements of ET, T, and E rates are difficult and costly; hence, mathematical models are used for estimating them. The objective of this study was to evaluate the practical applicability of the Shuttleworth-Wallace (S-W) model to estimate and partition ET in a subsurface drip-irrigated soybean ( Glycine max L. Merr.) field with partial residue cover. While its performance has been studied for various surfaces, the performance evaluation of the S-W model for such surface has not been carried out. An integrated approach of calculating bulk stomatal resistance (r sc) as a function of soil water content (theta i) was incorporated into the model to allow simulation of T over a range of theta i, and a residue decomposition function was introduced to account for surface residue decay over time to more accurately account for the actual residue cover in field conditions. The model performance was evaluated for different plant growth stages during the 2007 and 2008 growing seasons at the University of Nebraska-Lincoln, South Central Agricultural Laboratory near Clay Center, Nebraska. The sum of estimated T and E was compared to the bowen Ratio Energy Balance System (BREBS)-measured actual ET on a daily time-step. The model was able to capture the trends and magnitudes of measured ET, but its performance differed for various plant physiological growth stages. The root mean square difference (RMSD) values between the model-estimated and measured ET values for the growing season (day after emergence until physiological maturity) were 1.26 and 1.03 mm d -1 for 2007 and 2008, respectively. Best performance was observed during the mid-season during full canopy cover with a two-year average r 2 of 0.87, average RMSD of 0.94 mm d -1, and average mean biased error (MBE) of 0.30 mm d -1. Estimates for both initial and late season growth stages where E was dominant had the least agreement with BREBS measurements. The proportion of T and E in the estimated ET varied with growth stage. The S-W estimated seasonal total ET and BREBS measurements were equal in 2007 (S-W model ET=496 mm and BREBS ET=498 mm), and in 2008 the model underestimated by only 8.2% (S-W model ET=452 mm and BREBS ET=489 mm). While, in general, the model was successful in tracking the trends and magnitude of the BREBS-measured ET, further re-parameterization of the T module of the model can improve its accuracy to estimate ET, especially T, during the initial and late season (before full canopy cover and after physiological maturity) for a subsurface drip-irrigated soybean canopy. Other enhancements needed in the model for improved estimation of the E component include accurate determination of soil surface resistance coefficients and accounting for direct evaporation of intercepted rainfall on the canopy.