• Authors:
    • Németh, T.
    • Kismányoky, A.
    • Lehoczkya, É.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 40
  • Issue: 1/6
  • Year: 2009
  • Summary: The study was carried out in 2006 in Keszthely, on the soil tillage portion of a long-term experiment. In this experiment, a combination of three cultivation methods [no-till drill, disk tillage, conventional tillage (plowed)] and five nitrogen (N) rates (N 0: 0, N 1: 120, N 2:180, N 3: 240, and N 4: 300 kg N ha -1) were assessed. The trial was arranged in a split-plot design with four replications, and it was carried out during the first occurrence of maize in winter wheat-winter wheat-maize-maize rotation. Maize was sown on 10 May 2006; the weed survey was carried out using Balazs-Ujvarosi coenological method on 5 June 2006, after which weed control was implemented. Maize biomass of plants at the three to four leaf stage was determined at the same time. Sixteen weed species were identified in the no-till treatment, and 14 each in the in the conventional and the disk tillage treatments. Cultivation systems had a profound effect on the weediness of maize, with the lowest weediness occurring in the conventional tillage treatment. There was a strong interaction between N application and weed biomass that favored increased yield of maize over all cultivation treatments at higher N rates. The N content of weeds decreased as follows: conventional tillage < disc tillage < no-till.
  • Authors:
    • Hunt, T. E.
    • Magalhaes, L. C.
    • Siegfried, B. D.
  • Source: Journal of Economic Entomology
  • Volume: 102
  • Issue: 1
  • Year: 2009
  • Summary: The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is native to Asia and was recently (2000) detected in North America. Since then, it has become a significant threat to U.S. soybean production. Although neonicotinoid insecticide seed treatments, imidacloprid and thiamethoxam, have been suggested as a method of control, the season-long efficacy is still uncertain. Therefore, the use of imidacloprid and thiamethoxam seed treatments to control soybean aphid in Nebraska were examined. Soybean aphid populations were monitored weekly in an irrigated field study planted during the later half of the typical Nebraska planting window during 2005 and 2006. Imidacloprid and thiamethoxam were quantified by leaves through time, and leaf specific bioassays were conducted. In 2005, aphid populations were very low; however, in 2006 aphid numbers were significantly higher than 2005, reaching ~1,200 aphids per plant in the untreated plots. Aphid injury significantly reduced yield and individual seed size in 2006. Imidacloprid significantly reduced aphid densities in 2006 but not below the economic threshold. In 2006, thiamethoxam held aphid densities below the economic threshold. Leaf specific bioassays and leaf specific imidacloprid and thiamethoxam quantification indicated that thiamethoxam was present in the plant at higher concentrations and for a longer period.
  • Authors:
    • Marinov-Serafimov, P.
  • Source: Selskostopanska Nauka (Agricultural Science)
  • Volume: 42
  • Issue: 5
  • Year: 2009
  • Summary: During the period 2006-2008 in the experimental field of the Experimental station of soybean - Pavlikeni is displayed field trial in non-irrigated conditions for establishing the efficacy and selectivity of the herbicide Diflufenikan - 500 g/l (Pelican 50 KS) in soybean agrocenosis background in natural mixed type weediness. Results obtained may be generalized in the following more important conclusions: Herbicides Diflufenikan - 500 g/l (Pelican 50SC) has relatively high selectivity (EWRS 2-3 ball) and is suitable for treatment of soybean crops after germination before sowing at a dose of culture 125 ml/ha. Herbicide effectiveness Diflufenikan - 500 g/l (Pelican 50 KS) varies from 73 to 89% on annual dicotyledonous weeds ( S. nigrum; Amaranthus spp.). Less herbicide effect (from 25 to 50%) is established under Ch. album and the least (from 8 to 52%) in the group of weeds annual Monocotyledon ( Setaria spp., Eh. crus-galli). The increase in grain yield of soybean varies from 11.3 to 106.0% compared to the control variant (control - zero) and is in direct relation to the effect achieved in the fight against weeds.
  • Authors:
    • Rosculete, E.
    • Gheorghe, D.
    • Matei, G.
    • Imbrea, F.
    • Cojocaru, I.
  • Source: Research Journal of Agricultural Science
  • Volume: 41
  • Issue: 1
  • Year: 2009
  • Summary: Field studies were conducted in Romania, from 2006 to 2008, to determine the effect of rotations and fertilizer applications on the yield and quality of maize in irrigated sandy soils. The treatments comprised 3 years rotation (wheat, maize and soyabeans), 4 years rotation (wheat, lucerne, maize and soyabeans), wheat monoculture, maize monoculture, 2 years rotation (maize and wheat), 5 years rotation (wheat, lucerne, potato, maize and wheat), 3 years rotation (wheat, maize and groundnut), 6 years rotation (maize, groundnuts, wheat, sunflower, potato and wheat) and 4 years rotation (bean, wheat, maize and wheat) and fertilizer applications, i.e. 160 kg N and 80 kg P/ha, 80 kg N and 80 kg P/ha and control. Results showed that maize gave good seed yields, which varied between 4.5 q/ha on unfertilized variant and 38.5 q/ha in the 6 years rotation on 160 kg N and 80 kg P/ha. The most valuable rotations for maize were beans, soyabean, groundnuts or lucerne. Applying fertilizers in monoculture resulted only in small increases in production. The best variant with fertilizers was the 80 kg N and 80 kg P/ha, which increased the yields of all rotations used compared to the control. On all the rotations studied, the nitrogen fertilizer application improved the N content of maize seeds and directly increased the protein content, while other macro- and microelements in maize seeds registered small fluctuations, some of which were considered as constant no matter what kind of rotation was used.
  • Authors:
    • Walker, A. M.
    • McKinnon, J. J.
  • Source: Canadian Journal of Animal Science
  • Volume: 89
  • Issue: 3
  • Year: 2009
  • Summary: McKinnon, J. J. and Walker, A. M. 2009. Comparison of canola and mustard presscake from biodiesel production as protein sources for growing cattle. Can. J. Anim. Sci. 89: 401-408. Two studies were conducted to examine in situ rumen degradation kinetics of biodiesel presscake from canola (CPC) (Brassica napa) and mustard (MPC) (Brassica hirta) relative to regular canola meal (CM) and to compare the performance of cattle fed these meals as protein supplements in backgrounding diets. In the in situ trial CPC and MPC had similar (P > 0.05) rates of DM, CP, fibre and crude fat disappearance relative to canola meal. However, CPC and MPC exhibited greater (P 0.05) in effective degradability of crude fat were observed. The feedlot trial involved 391 steers (323 +/- 24 kg) that were fed one of three experimental diets: a control diet consisting of barley silage (213 g kg(-1)) oat hulls (306 g kg(-1)), chopped straw (63 g kg(-1)), rolled barley (255 g kg(-1)) and CM (101 g kg(-1)), ora diet containing either CPC or MPC in place of CM as the protein supplement. Backgrounding performance was unaffected by treatment as no differences in DMI (P = 0.127), ADG (P = 0.679) or feed:gain (P = 0.792) were observed. Composition of gain estimated by ultrasound measurement of longissimus dorsi area and subcutaneous fat depth was unaffected by dietary treatment. It is concluded that biodiesel presscake from both canola and mustard seed provides a superior source of rumen degradable nutrients relative to CM and can be used as a protein supplement for growing cattle without any adverse affects on performance at levels up to 10% of the diet DM.
  • Authors:
    • Jauhiainen, L.
    • Peltonen-Sainio, P.
    • Hakala, K.
  • Source: Agricultural and Food Science
  • Volume: 18
  • Issue: 3-4
  • Year: 2009
  • Summary: As the northern hemisphere will experience the greatest increases in temperature and indications of climatic change are already visible in the north (in the 2000s average temperatures exceeded the long-term mean), we sought to establish if there are already signs of increased variability in yield and quality of the major field crops grown under the northernmost European growing conditions: spring and winter cereals (barley Hordeum vulgare L., oat Avena saliva L., wheat Triticum aestivum L., rye Secale cereale L.), spring rapeseed (turnip rape Brassica rapa L., oilseed rape B. napus L.), pea (Piston sativum L.) and potato (Solanum tuberosum L.). We used long-term yield datasets of FAO for Finland (1960s to date) and MTT Agrifood Research Finland (MTT) Official Variety Trial datasets on yield and quality of major field crops in Finland since the 1970s. Yield variability was exceptionally high in the 1980s and 1990s, but previously and subsequently national yields were clearly more stable. No progressive increase in yield variability was recorded. No marked and systematic changes in variability of quality traits were recorded, except for rapeseed, which exhibited reduced variability in seed chlorophyll content. This may at least partly attribute to the differences in intensity of input use and thereby responsiveness of the crops before and after 1980 and 1990 decades. We also noted that in the 2000s average temperatures were higher than in earlier decades and this was the case for all months of the growing season except June, which represents, however, the most critical phase for yield determination in most of the field crops in Finland. Also in the 2000s precipitation increased in the first three months of the growing season and thereafter decreased, but without signs of significantly increased numbers of heavy showers (extreme rain events). Hence, in general constant, increased average temperatures during the growing seasons of the 2000s were identified, but with reduced yield variability, which was partly attributable to the diminished use of inputs, especially fertilisers.
  • Authors:
    • Deen, W.
    • Earl, H.
    • Queen, A.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 6
  • Year: 2009
  • Summary: Red clover (Trifolium pratense L.) use as an underseeded cover crop in winter cereals has declined due to inability of growers to consistently establish uniform stands. The objective of this study was to assess the effect of light and soil moisture competition on underseeded red clover establishment and end of season dry matter production. Field trials were conducted at multiple locations in 2005 and 2006 in Ontario, Canada. Wheat (Triticum aestivum L.) N rate (67 and 135 kg N ha(-1)) and row thinning treatments (19-cm rows, every third 19-cm row removed at the 4-5 leaf stage) were used to alter light penetration and soil moisture competition. The high N rate and row thinning treatments consistently reduced light penetration, beginning as early as wheat stem elongation initiation, but had no effect on soil gravimetric moisture content. Soil moisture was primarily affected by location and year. Red clover dry weight in 2005, a relatively dry year, ranged from 688 to 1184 kg ha(-1), and in 2006, a relatively wet year, ranged from 2336 to 2805 kg ha(-1). Average final red clover stand count was 23 plants m(-2) in 2005 and 55 plants m(-2) in 2006. In 2005, plant mortality occurred before wheat anthesis. In both years, and at most locations, red clover final dry weight was positively correlated with light penetration, again beginning as early as initiation of wheat stem elongation. Final red clover dry weight in both years and red clover stand count in 2005 were correlated with soil gravimetric water content during wheat anthesis, but this was primarily due to location and year effects. Although both light penetration through the wheat canopy and soil moisture influence biomass production of underseeded red Clover, soil moisture has the greater influence and is altered very little by wheat management.
  • Authors:
    • Yang, Y.
    • Reddy, N.
  • Source: Bioresource Technology
  • Volume: 100
  • Issue: 14
  • Year: 2009
  • Summary: This paper reports the development of natural cellulose technical fibers from soybean straw with properties similar to the natural cellulose fibers in current use. About 220 million tons of soybean straw available in the world every year could complement the byproducts of other major food crops as inexpensive, abundant and annually renewable sources for natural cellulose fibers. Using the agricultural byproducts as sources for fibers could help to address the concerns on the future price and availability of both the natural and synthetic fibers in current use and also help to add value to the food crops. A simple alkaline extraction was used to obtain technical fibers from soybean straw and the composition, structure and properties of the fibers was studied. Technical fibers obtained from soybean straw have high cellulose content (85%) but low% crystallinity (47%). The technical fibers have breaking tenacity (2.7 g/den) and breaking elongation (3.9%) higher than those of fibers obtained from wheat straw and sorghum stalk and leaves but lower than that of cotton. Overall, the structure and properties of the technical fibers obtained from soybean straw indicates that the fibers could be suitable for use in textile, composite and other industrial applications.
  • Authors:
    • Sandor, M.
    • Domuta, C.
    • Samuel, A. D.
    • Vuscan, A.
  • Source: Research Journal of Agricultural Science
  • Volume: 41
  • Issue: 2
  • Year: 2009
  • Summary: Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for preluvosoil. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can provide information on how soil management affects the soil potential to perform processes, such as decomposition and nutrient cycling. Soil enzyme activities (actual and potential dehydrogenase, catalase, acid and alkaline phosphatase) were determined in the 0-20-, 20-40- and 40-60-cm layers of a preluvosoil submitted to a complex tillage (no-till and conventional tillage) and crop rotation (2- and 6-crop rotations) experiment. Each activity in both non-tilled and conventionally tilled soil under all crops of both rotations decreased with increasing sampling depth. No-till - in comparison with conventional tillage - resulted in significantly higher soil enzymatic activities in the 0-20- and in significantly lower activities in the deeper layers. The soil under maize or wheat was more enzyme-active in the 6- than in the 2-crop rotation. In the 2-crop rotation, higher enzymatic activities were recorded under wheat than under maize. The enzymatic indicators of soil quality were calculated from the values of enzymatic activities determined in the plots of the 6-crop rotation. The results obtained show that the different hierarchies of the six plots as registered in 2008 may be related to the different nature of crops and kind of fertilisers. This means that by determination of enzymatic activities, valuable information can be obtained regarding fertility status of soils.
  • Authors:
    • Singh, R. K.
    • Irmak, A.
  • Source: Journal of Irrigation and Drainage Engineering
  • Volume: 135
  • Issue: 5
  • Year: 2009
  • Summary: Crop coefficient (Kc) based estimation of crop evapotranspiration (ETc) is one of the most commonly used methods for irrigation water management. The standardized FAO56 Penman-Monteith approach for estimating ETc from reference evapotranspiration and tabulated generalized Kc values has been widely adopted worldwide to estimate ETc . In this study, we presented a modified approach toward estimating Kc values from remotely sensed data. The surface energy balance algorithm for land model was used for estimating the spatial distribution of ETc for major agronomic crops during the 2005 growing season in southcentral Nebraska. The alfalfa-based reference evapotranspiration (ETr) was calculated using data from multiple automatic weather stations with geostatistical analysis. The Kc values were estimated based on ET c and ETr (i.e., Kc = ETc / ETr ). A land use map was used for sampling and profiling the Kc values from the satellite overpass for the major crops grown in southcentral Nebraska. Finally, a regression model was developed to establish the relationship between the normalized difference vegetation index (NDVI) and the ETr -based crop coefficients ( Kcr ) for corn, soybeans, sorghum, and alfalfa. We found that the coefficients of variation (CV) for NDVI, as well as for Kcr of crops were lower during the midseason as compared to the early and late growing seasons. High CV values during the early growing season can be attributed to differences in planting dates between the fields, whereas high CVs during the late season can be attributed to differences in maturity dates of the crops, variety, and management practices. There was a good relationship between Kcr and NDVI for all the crops except alfalfa. Validation of the developed model for irrigated corn showed very promising results. There was a good correlation between the NDVI-estimated Kcr and the Bowen ratio energy balance system based Kcr with a R2 of 0.74 and a low root mean square difference of 0.21. This approach can be a very useful tool for a large (watershed or regional) scale estimation of evapotranspiration using the crop coefficient and reference evapotranspiration approach.