321. Changes in time of sowing, flowering and maturity of cereals in Europe under climate change.

• Authors:
  • Asselt, E.
  • Eitzinger, J.
  • Brisson, N.
  • Siebert, S.
  • Ewert, F.
  • Trnka, M.
  • Borjesson, T.
  • Peltonen-Sainio, P.
  • Skjelvag, A.
  • Rotter, R.
  • Palosuo, T.
  • Elsgaard, L.
  • Borgesen, C.
  • Olesen, J.
  • Oberforster, M.
  • Fels-Klerx, H.
• Source: Food Additives and Contaminants Part A-Chemistry Analysis Control Exposure & Risk Assessment
• Volume: 29
• Issue: 10
• Year: 2012
• Summary: The phenological development of cereal crops from emergence through flowering to maturity is largely controlled by temperature, but also affected by day length and potential physiological stresses. Responses may vary between species and varieties. Climate change will affect the timing of cereal crop development, but exact changes will also depend on changes in varieties as affected by plant breeding and variety choices. This study aimed to assess changes in timing of major phenological stages of cereal crops in Northern and Central Europe under climate change. Records on dates of sowing, flowering, and maturity of wheat, oats and maize were collected from field experiments conducted during the period 1985-2009. Data for spring wheat and spring oats covered latitudes from 46 to 64°N, winter wheat from 46 to 61°N, and maize from 47 to 58°N. The number of observations (site-year-variety combinations) varied with phenological phase, but exceeded 2190, 227, 2076 and 1506 for winter wheat, spring wheat, spring oats and maize, respectively. The data were used to fit simple crop development models, assuming that the duration of the period until flowering depends on temperature and day length for wheat and oats, and on temperature for maize, and that the duration of the period from flowering to maturity in all species depends on temperature only. Species-specific base temperatures were used. Sowing date of spring cereals was estimated using a threshold temperature for the mean air temperature during 10 days prior to sowing. The mean estimated temperature thresholds for sowing were 6.1, 7.1 and 10.1°C for oats, wheat and maize, respectively. For spring oats and wheat the temperature threshold increased with latitude. The effective temperature sums required for both flowering and maturity increased with increasing mean annual temperature of the location, indicating that varieties are well adapted to given conditions. The responses of wheat and oats were largest for the period from flowering to maturity. Changes in timing of cereal phenology by 2040 were assessed for two climate model projections according to the observed dependencies on temperature and day length. The results showed advancements of sowing date of spring cereals by 1-3 weeks depending on climate model and region within Europe. The changes were largest in Northern Europe. Timing of flowering and maturity were projected to advance by 1-3 weeks. The changes were largest for grain maize and smallest for winter wheat, and they were generally largest in the western and northern part of the domain. There were considerable differences in predicted timing of sowing, flowering and maturity between the two climate model projections applied.

322. Influence of winter cover crop on the physical attributes of soil in no-tillage farms cultivated to soybean and corn.; Influencia da cobertur a de inverno nos atributos fisicos do solo em culturas de milho e soja sob plantio direto.

• Authors:
  • Konopatzki, M. R. S.
  • Lima, G. P. de
  • Nobrega, L. H. P.
  • Pickler, E. P.
  • Pacheco, F. P.
• Source: Engenharia na Agricultura
• Volume: 20
• Issue: 1
• Year: 2012
• Summary: The increased mechanization, without adequate management, contributes to changes in soil structure, which facilitate erosive processes and soil degradation. The cover crops help protect soil surface, enhance physical, chemical, biological and productive potential of a soil and minimize degradation. This trial was done to analyze the influence of winter cover crop on the soil density, water content, macro and microporosity of soil cultivated to soybean and corn under no-tillage system. The experiment was conducted in a field with 24 plots, having six treatments of cover crops (forage turnip, pearl millet, oilseed rape, black oat, wheat and fallow) with four replications. After cover crop management, twelve plots were planted with corn and the other twelve with soybeans. It was observed that the soil under corn had better macroporosity, porosity and density compared to the soil cultivated to soybean. The crop cover with forage turnip increased soil macroporosity. However, cover crops did not influence water content, density, microporosity and porosity.

323. Ammonia volatilization from urea as affected by tillage systems and winter cover crops in the South-Central region of Parana.; Volatilizacao de amonia da ureia alterada por sistemas de preparo de solo e plantas de cobertura invernais no Centro-Sul do Parana.

• Authors:
  • Fontoura, S. M. V.
  • Bayer, C.
  • Rojas, C. A. L.
  • Weber, M. A.
  • Vieiro, F.
• Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
• Volume: 36
• Issue: 1
• Year: 2012
• Summary: Nitrogen losses from urea by ammonia volatilization are higher from no-tillage than from conventional tillage. The objective of this study was to evaluate the magnitude of this process under cool and wet spring conditions in the South-Central region of the State of Parana and to evaluate the influence of two winter cover crops (black oat and common vetch) on ammonia volatilization in no-tillage. The tillage systems were compared in a long-term tillage experiment (28 years) and the cover crops tested separately in a long-term (>15 yr) no-tillage area. Maize was grown in both experiments. Urea was applied at rates of 0, 80 and 160 kg ha -1 N in a single application in the tillage experiment and at rates of 0, 100 and 200 kg ha -1 N, split in two applications, in the cover crop experiment. Volatilization of NH 3 was measured for 20 days after urea application in a semi-open static system. Urease activity was evaluated in both experiments. The NH 3 loss rates were highest 5 days after urea application. Cumulative ammonia losses reached 18% of the applied N in no-tillage and 3% in conventional tillage. The higher losses from no-tillage may be partially related to the greatest urease activity in the soil surface layer. Ammonia volatilization was not affected by cover crops. As an isolated practice, split surface N fertilization does not ensure a decrease of NH 3 losses, which are primarily related to rain events immediately after urea application.

324. Wheat-barley-rye- or corn-fed growing pigs respond differently to dietary supplementation with a carbohydrase complex.

• Authors:
  • Torrallardona, D.
  • Geraert, P.
  • Devillard, E.
  • Badiola, I.
  • Willamil, J.
• Source: Journal of Animal Science
• Volume: 90
• Issue: 3
• Year: 2012
• Summary: Thirty-six pigs (22 kg of BW) were used to evaluate a carbohydrase preparation, with xylanase and beta-glucanase as main activities, added to either wheat-barley-rye- (WBR) or corn-based diets on performance, intestinal environment, and nutrient digestibility. Pigs were offered 1 of 4 different dietary treatments for 27 d according to a factorial arrangement of treatments (a 2*2) with 2 cereal types (WBR or corn) and 2 levels of supplemental carbohydrase (0 or 0.01%). Pig growth and feed intake were individually measured every week until the end of the experiment when pigs were slaughtered to obtain samples of digesta and tissues. Cereal type affected performance only during wk 1, in which WBR improved ADG (590 vs. 440 g/d; P=0.008) and G:F (0.61 vs. 0.43; P=0.045) compared with corn. The WBR also increased the viscosity of the digestive contents in stomach (1.95 vs. 1.23 mPa.s; P=0.001) and ileum (6.53 vs. 2.80 mPa.s; P=0.001) and resulted in greater cecal starch digestibility (95.7 vs. 93.9%; P=0.012). However, trends for a reduction in digestibility were observed for glucose in the nonstarch polysaccharide (NSP) fraction in the ileum (64.4 vs. 75.8%; P=0.074) and galactose in the NSP fraction in the cecum (1.4 vs. 1.8%; P=0.055). The use of the enzyme preparation increased ADFI during wk 2 (1,328 vs. 1,215 g/d; P=0.028), and increased villus height (423 vs. 390 m; P=0.045) and tended to reduce relative pancreas weight (0.16 vs. 0.17% BW; P=0.079) at d 27. The enzyme also improved cecal starch digestibility (95.5 vs. 94.1%; P=0.043) and tended to improve ileal energy digestibility (61.3 vs. 53.7%; P=0.090) and cecal glucose digestibility in the NSP fraction (76.0 vs. 54.5%; P=0.055). However, it reduced the cecal digestibility of mannose in the NSP fraction (27.0 vs. 50.5%; P=0.016). Interactions ( P

325. Production and N nutrient performance of wheat-maize-soybean relay strip intercropping system and evaluation of interspecies competition.

• Authors:
  • Wan, Y.
  • Chen, X.
  • Xiang, D.
  • Yang, W.
  • Yong, T.
• Source: Acta Prataculturae Sinica
• Volume: 21
• Issue: 1
• Year: 2012
• Summary: The aim of this paper was to study the variation of interspecies competitiveness in two relay strip intercropping system; wheat-maize-soybean and wheat-maize-sweet potato. The character of biomass accumulation and nitrogen uptake were examined for five cropping systems using years of field experiment. The cropping systems included three sole cropping systems (wheat-soybean, wheat-sweet potato and maize) and two relay strip intercropping systems (wheat/maize/soybean and wheat/maize/sweet potato). Land equivalent ratio (LER), aggressiveness (A), and nutrition competition ratio (NCR) were introduced as indexes to evaluate the interspecies competitiveness in each treatment. The results showed that there was obvious relay strip intercropping advantage ( LER >1, Awc 1) in the wheat-maize-soybean relay strip intercropping system, maize occupied the dominant niche for the whole growing stage in the relay strip intercropping systems, and the interspecies competitiveness of wheat and soybean were lower than that of the maize. Comparing with the sole cropping systems and wheat-maize-sweet potato relay strip intercropping system, the grain yield and nitrogen uptake, total biomass and total nitrogen uptake above ground of crops were increased significantly at both flowering (or spinning) and maturity stages in the wheat-maize-soybean relay strip intercropping system. The values of biomass and nitrogen uptake for the relay strip intercropping system were greater than the sole cropping systems, and that of soybean stubble were greater than sweet potato stubble. The total economic returns of crops in the wheat/maize/soybean relay strip intercropping system was higher 28.02% than those of crops in the wheat/maize/sweet potato relay strip intercropping system.

326. Effect of wheat/maize/soybean and wheat/maize/sweet potato relay strip intercropping on bacterial community diversity of rhizosphere soil and nitrogen uptake of crops.

• Authors:
  • Zhu, Z.
  • Xiang, D.
  • Yang, W.
  • Yong, T.
• Source: Acta Agronomica Sinica
• Volume: 38
• Issue: 2
• Year: 2012
• Summary: The aim of this study was to understand the relationship between diversity of rhizosphere bacterial community and nitrogen uptake of crops in two relay strip intercropping systems: wheat/maize/soybean and wheat/maize/sweet potato. We analyzed the diversities of rhizosphere bacterial community in five cropping systems using denaturing gradient gel electrophoresis (DGGE) based on 16S rDNA. The cropping systems included wheat-soybean (A1), wheat-sweet potato (A2), maize single cropping (A3), wheat/maize/soybean (A4), and wheat/maize/sweet potato (A5). Compared to the sole cropping systems (A1, A2, and A3 treatments), the A4 treatment showed increases in grain nitrogen uptake and total nitrogen uptake amounts of aboveground of crops at both flowering (or silking) and maturity stages, and the Shannon-Weiner indices for rhizosphere bacterial community diversity was also increased significantly. The values of nitrogen uptake and the Shannon-Weiner index in the relay strip intercropping systems were greater than those in sole cropping systems, and the values in the treatment with soybean stubble were greater than those in the treatment with sweet potato stubble. The number and strength of the DNA bands from DGGE profiles varied with the cropping systems, especially for the distinguished bands. The comparability of rhizosphere bacterial community composition was low among different cropping systems. The similarity coefficient ( Cs) was higher between two relay strip intercropping systems than between relay strip intercropping system and sole cropping system, but the Cs value was low between A4 and A5 treatments. However, there was obvious difference of rhizosphere bacterial community composition between A4 and A5 treatments, and the A4 treatment was propitious to enhancing rhizosphere bacterial community diversity and increasing nitrogen uptakes of crops.

327. Classification of intact cereal flours by front-face synchronous fluorescence spectroscopy.

• Authors:
  • Dramicanin, T.
  • Lenhardt, L.
  • Zekovic, I.
  • Dramicanin, M.
• Source: Food Analytical Methods
• Volume: 5
• Issue: 5
• Year: 2012
• Summary: Synchronous fluorescence spectroscopy, a technique that measures both the absorption and the emission properties of a sample in a single measurement, was used for the analysis and classification of intact cereal flours (wheat, corn, rye, buckwheat, rice, and barley). Total synchronous fluorescence spectra recorded in constant wavelength mode show clear differences in the emission spectra of different flours due to variances in intrinsic fluorophore concentrations and their microenvironments. Principal component analysis, cluster analysis, and partial least squares discriminant analysis are used to assess the ability of synchronous fluorescence measurements to differentiate and classify intact samples of different flour types. The flour specimens were obtained directly from a market in Belgrade and had different expiration dates to provide a more representative set of samples. The results of the current analysis suggest that chemometric methods applied on synchronous fluorescence data can discriminate and classify flour types and that the best results are achieved using a combination of synchronous fluorescence measurements at synchronous intervals of 7 and 20 nm. The quality of results, the high speed of measurements, and the avoidance of extensive sample preparation make synchronous fluorescence spectroscopy a promising technique for cereal research.

328. Influence of no-tillage and frequency of a green manure legume in crop rotations for balancing N outputs and preserving soil organic C stocks.

• Authors:
  • Franchini, J.
  • Jantalia, C.
  • Urquiaga, S.
  • Boddey, R.
  • Zatorre, N.
  • Zotarelli, L.
  • Alves, B.
• Source: Field Crops Research
• Volume: 132
• Year: 2012
• Summary: The sustainability of crop production systems depends on the adoption of practices that allow the balancing of nutrient output and the preservation of soil organic matter. In Brazil, no-tillage (NT) is widely adopted for soybean-based cropping systems. In the Southern region, soybean alternates with maize in the summer and black-oats or wheat in the winter. Green-manure legumes are occasionally introduced in the crop rotation to break the continuous use of wheat in the winter. The objective of the present study was to evaluate if NT adoption would increase biological nitrogen fixation to soybean and other legumes. The hypothesis that a system richer in N would bring about positive effects on soil C stocks, was also tested. The study was carried out in Londrina, Parana State, in Southern Brazil on a clayey Ferralsol that was cropped under NT with soybean as the main crop for more than 25 years. In 1997, three different crop rotations under both NT and conventional plough tillage (CT) were introduced. The crop rotations were composed of soybean, maize, wheat, black-oats and white lupins, but differed from each other in the frequency that each crop appeared in the rotation. Crop yields and the biomass of lupins and black-oats were quantified at every harvest during the 12 years of this study. Conversion factors of measured yield and biomass into C and biologically fixed N inputs to the crop system were developed from whole plant measurements performed in four of the twelve years of the study. The contribution of biological N 2 fixation (BNF) to the legumes was determined using the ureide abundance and the 15N natural abundance techniques in 1998, 1999, 2005 and 2007. From these data, the calculation of N balance for each rotation (input N minus output N in harvested grain) was carried out. Soil C and N stocks to 80 cm depth were quantified in 1997, 2003 and 2009. Grain yields were higher under NT for soybean and under CT for maize, in the rotation with the lowest frequency of legume crops. Soybean reliance on BNF was higher under NT (76%) than under CT (68%) whilst for lupins the reliance was 68% under NT and 60% under CT. The use of lupins as a green manure represented an extra contribution to soil N of approximately 300 kg N ha -1 and this was essential to maintain a positive N balance for the system. The comparison of soil C stocks between 1997 and 2009 revealed almost no gain in soil C under NT, but a C loss of 19 Mg C ha -1 after 12 years of CT. Significant soil C and N losses were recorded in the rotation where lupins were planted more frequently and fertilizer N application to maize was suspended, which resulted in a very negative N balance for the system. The results highlight the importance of NT to enhance BNF inputs to the system and the need to recognize the N balance as a key driver of C stock changes in the soil. In addition, it suggests NT in this study had the consequence of avoiding soil C loss rather than increasing soil C stocks.

329. Relationships between farm size and operational performances in irrigated cropping systems under contrasted governance systems in Punjab (Pakistan)

• Authors:
  • Shivakoti, G.
  • Nawaz, R.
  • Perret, S.
  • Ahmad, S.
• Source: Journal of Food Agriculture & Environment
• Volume: 10
• Issue: 2
• Year: 2012
• Summary: This paper investigated the farm level diversity in operation and farm performances under two different governance situations in irrigation systems of Punjab Province of Pakistan: Farmer-Managed (FMIS) and Government-Managed Irrigation Scheme (GMIS). Questionnaire surveys and multivariate analyses were conducted. Farms typology was developed based on farm size. Results reveal a water-land-farming strategy nexus. Larger farms perform better in both schemes. Wheat cropping is a strategic choice, specialized, and exclusive, with low input, and low income. Conversely, maize and rice cropping tit well in diversification and intensification strategies, leading to higher farm income. Also poor financial basis and extension services for smaller farms do not support intensification and diversification. The paper shows that productivity of production factors, level of intensification, farm size are closely interlocked, in a general context of poor performances and institutional reforms. Groundwater access is also a key to success, since canal irrigation only cannot sustain an intensification-diversification process. The paper concludes that transfer of canal irrigation management to farmers will not solve all issues, and yet remains probably the only long-term solution. Areas for public intervention on, inter alia, land, finance, extension, markets remain necessary in FMIS and towards smaller farms.

330. Irrigation management, nitrogen fertilization and nitrogen losses in the return flows of La Violada irrigation district (Spain).

• Authors:
  • Aragues, R.
  • Isidoro, D.
  • Barros, R.
• Source: Agriculture, Ecosystems & Environment
• Volume: 155
• Year: 2012
• Summary: Nitrogen (N) pollution induced by irrigated agriculture is a significant environmental problem. The main N inputs and outputs were measured or estimated in the semi-arid La Violada irrigation district (Spain). Data on two periods (1995-1998 and 2006-2008) were compared and related to observed changes during the decade in cropping patterns and N fertilization and irrigation management. N fertilization exceeded crop N uptake due to over-fertilization of corn (426 kg N/ha in 1995-1998 and 332 kg N/ha in 2006-2008) and alfalfa (62 kg N/ha). Between the two periods, N fertilization decreased by 56%, primarily due to a change from corn to alfalfa and barley. Accordingly, N losses in the irrigation return flows (IRF) diminished from 31% of the applied fertilizer in 1995-1998 to 20% in 2006-2008. NO 3- concentrations and NO 3-N loads in the IRF decreased from 40 mg/L and 106 kg N/ha in 1995-1998 to 21 mg/L and 22 kg N/ha in 2006-2008, due to lower N fertilization, lower corn area and improved irrigation efficiency. N contamination in the IRF will be minimized by increasing the irrigation efficiency and decreasing the corn area and its N fertilization rates, particularly when supplemental organic N is applied at pre-sowing.