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Management Options for Organic Winter Wheat Production under Climate Change النص الكامل
2016
Ralf Bloch | Jürgen Heß | Johann Bachinger
Management Options for Organic Winter Wheat Production under Climate Change النص الكامل
2016
Ralf Bloch | Jürgen Heß | Johann Bachinger
An effective adaptive strategy for reducing climate change risks and increasing agro-system resiliency is broadening cropping system diversity, heightening the flexibility of cultivation and tillage methods. Climate change impacts on standard cultivation practices such as mineralisation and nitrate leaching due to mild and rainy winters, as well as frequent drought or water saturation, not only limiting fieldwork days, but also restricting ploughing. This calls for alternative methods to counteract these propensities. From 2010 to 2013, a farming system experiment was conducted on a distinctly heterogeneous organic farm in Brandenburg, Germany. With the intention of devising a more varied and flexible winter wheat cultivation method, standard organic farming practices (winter wheat cultivation after two years of alfalfa-clover-grass and ploughing in mid-October) were compared to four alternative test methods, which were then evaluated for their robustness and suitability as adaptive strategies. Two of the alternative methods, <em>early sowing</em> and <em>catch crop</em>, entailed moving up the date for alfalfa-clover-grass tilling to July. Instead of a plough, a ring-cutter was used to shallowly (8 cm) cut through and mix the topsoil. In the <em>early sowing</em> test method, winter wheat was sown at the end of August, after repeated ring-cutter processing. With the <em>catch crop</em> method, winter wheat seeding followed a summer <em>catch crop</em> and October tillage. The two <em>oat</em> methods (<em>oat/plough</em>; <em>oat/ring-cutter</em>) entailed sowing winter wheat in September, following oat cultivation. Overall, the cultivation methods demonstrated the following robustness gradation: standard practice = <em>catch crop</em> ≥ <em>early sowing</em> > <em>oat/plough</em> > <em>oat/ring-cutter</em>. When compared to standard procedures, the<em> catch crop</em> and <em>early sowing </em>test methods showed no remarkable difference in grain yields. Measured against <em>early sowing</em>, the <em>catch crop</em> test method was significantly more robust when it came to winterkill, quality loss, and weed infestation (40% lower weed-cover). High N<sub>min- </sub>values (up to 116 kg N ha<sup>-1</sup>) in autumn could have caused the chamomile and thistle infestation in both <em>oat/plough</em><em>oat/ring-cutter</em> test methods, which led to crop failure in the hollows. Compared to standard practices, the <em>oat ring-cutter</em> test method brought in over 50% less grain yield. This was attributed to ring-cutter processing, which reduced N mineralisation and caused high weed infestation. However, the ring-cutter effectively regulated alfalfa-clover-grass fields in both exceedingly wet and very dry weather; a temporal flexibility which increases the number of fieldwork days. The <em>catch crop</em> and <em>early sowing</em> test methods contributed most to boosting future agronomic diversity.
اظهر المزيد [+] اقل [-]Management Options for Organic Winter Wheat Production under Climate Change النص الكامل
2016
Bloch, R. (Ralf) | Hess, Jürgen | Bachinger, Johann
An effective adaptive strategy for reducing climate change risks and increasing agro-system resiliency is broadening cropping system diversity, heightening the flexibility of cultivation and tillage methods. Climate change impacts on standard cultivation practices such as mineralisation and nitrate leaching due to mild and rainy winters, as well as frequent drought or water saturation, not only limiting fieldwork days, but also restricting ploughing. This calls for alternative methods to counteract these propensities. From 2010 to 2013, a farming system experiment was conducted on a distinctly heterogeneous organic farm in Brandenburg, Germany. With the intention of devising a more varied and flexible winter wheat cultivation method, standard organic farming practices (winter wheat cultivation after two years of alfalfa-clover-grass and ploughing in mid-October) were compared to four alternative test methods, which were then evaluated for their robustness and suitability as adaptive strategies. Two of the alternative methods, <em>early sowing</em> and <em>catch crop</em>, entailed moving up the date for alfalfa-clover-grass tilling to July. Instead of a plough, a ring-cutter was used to shallowly (8 cm) cut through and mix the topsoil. In the <em>early sowing</em> test method, winter wheat was sown at the end of August, after repeated ring-cutter processing. With the <em>catch crop</em> method, winter wheat seeding followed a summer <em>catch crop</em> and October tillage. The two <em>oat</em> methods (<em>oat/plough</em>; <em>oat/ring-cutter</em>) entailed sowing winter wheat in September, following oat cultivation. Overall, the cultivation methods demonstrated the following robustness gradation: standard practice = <em>catch crop</em> ≥ <em>early sowing</em> > <em>oat/plough</em> > <em>oat/ring-cutter</em>. When compared to standard procedures, the<em> catch crop</em> and <em>early sowing </em>test methods showed no remarkable difference in grain yields. Measured against <em>early sowing</em>, the <em>catch crop</em> test method was significantly more robust when it came to winterkill, quality loss, and weed infestation (40% lower weed-cover). High N<sub>min- </sub>values (up to 116 kg N ha<sup>-1</sup>) in autumn could have caused the chamomile and thistle infestation in both <em>oat/plough</em><em>oat/ring-cutter</em> test methods, which led to crop failure in the hollows. Compared to standard practices, the <em>oat ring-cutter</em> test method brought in over 50% less grain yield. This was attributed to ring-cutter processing, which reduced N mineralisation and caused high weed infestation. However, the ring-cutter effectively regulated alfalfa-clover-grass fields in both exceedingly wet and very dry weather; a temporal flexibility which increases the number of fieldwork days. The <em>catch crop</em> and <em>early sowing</em> test methods contributed most to boosting future agronomic diversity.
اظهر المزيد [+] اقل [-]On-farm evaluation of an active optical sensor performance for variable nitrogen application in winter wheat النص الكامل
2016
Samborski, Stanisław M. | Gozdowski, Dariusz | Stępień, Michał | Walsh, Olga S. | Leszczyńska, Elżbieta
Winter wheat (Triticum aestivum L.) represents almost 50% of total cereal production in the European Union, accounting for approximately 25% of total mineral nitrogen (N) fertilizer applied to all crops. Currently, several active optical sensor (AOS) based systems for optimizing variable N fertilization are commercially available for a variety of crops, including wheat. To ensure successful adoption of these systems, definitive measurable benefits must be demonstrated. Nitrogen management strategies developed based on small-scale plot research are not always meaningful for large-scale farm conditions. In 2010–2012 (5 site-years) on-farm study was implemented in northern Poland utilizing a strip-trial design. The objective was to evaluate the performance of AOS in combination with a built-in algorithm for variable N rate fertilization. In this study, the reference uniform N rates (farmer’s practice) were comparable to optimum variable N rate recommendations. Side-by-side comparisons of uniform and variable N application revealed inconsistent benefits in terms of grain yield, grain protein content (GPC), N use and N use efficiency (NUE). Anticipated yield increases and/or reduced N rates are typical drivers for AOS adoption. Significant yield increases are not easily attained on farms with winter wheat yields already close to maximum yield potential. Thus, sensor-based variable N rate recommendations for fields previously fertilized with relatively low uniform N rates would often entail more appropriate allocation (redistribution) of the same amount of total N. This would minimize N surplus in areas of lower productivity and to improve the sustainability of N management overall.
اظهر المزيد [+] اقل [-]Effects of meteorological factors on different grades of winter wheat growth in the Huang-Huai-Hai Plain, China النص الكامل
2016
Qing HUANG | Li-min WANG | Zhong-xin CHEN | Hang LIU
Effects of meteorological factors on different grades of winter wheat growth in the Huang-Huai-Hai Plain, China النص الكامل
2016
Qing HUANG | Li-min WANG | Zhong-xin CHEN | Hang LIU
The sown area of winter wheat in the Huang-Huai-Hai (HHH) Plain accounts for over 65% of the total sown area of winter wheat in China. Thus, it is important to monitor the winter wheat growth condition and reveal the main factors that influence its dynamics. This study assessed the winter wheat growth condition based on remote sensing data, and investigated the correlations between different grades of winter wheat growth and major meteorological factors corresponding. First, winter wheat growth condition from sowing until maturity stage during 2011–2012 were assessed based on moderate-resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) time-series dataset. Next, correlation analysis and geographical information system (GIS) spatial analysis methods were used to analyze the lag correlations between different grades of winter wheat growth in each phenophase and the meteorological factors that corresponded to the phenophases. The results showed that the winter wheat growth conditions varied over time and space in the study area. Irrespective of the grades of winter wheat growth, the correlation coefficients between the winter wheat growth condition and the cumulative precipitation were higher than zero lag (synchronous precipitation) and one lag (pre-phenophase precipitation) based on the average values of seven phenophases. This showed that the cumulative precipitation during the entire growing season had a greater effect on winter wheat growth than the synchronous precipitation and the pre-phenophase precipitation. The effects of temperature on winter wheat growth varied according to different grades of winter wheat growth based on the average values of seven phenophases. Winter wheat with a better-than-average growth condition had a stronger correlation with synchronous temperature, winter wheat with a normal growth condition had a stronger correlation with the cumulative temperature, and winter wheat with a worse-than-average growth condition had a stronger correlation with the pre-phenophase temperature. This study may facilitate a better understanding of the quantitative correlations between different grades of crop growth and meteorological factors, and the adjustment of field management measures to ensure a high crop yield.
اظهر المزيد [+] اقل [-]Effects of meteorological factors on different grades of winter wheat growth in the Huang-Huai-Hai Plain, China النص الكامل
2016
Huang, Qing | Wang, Limin | CHEN, Zhong-xin | LIU, Hang
The sown area of winter wheat in the Huang-Huai-Hai (HHH) Plain accounts for over 65% of the total sown area of winter wheat in China. Thus, it is important to monitor the winter wheat growth condition and reveal the main factors that influence its dynamics. This study assessed the winter wheat growth condition based on remote sensing data, and investigated the correlations between different grades of winter wheat growth and major meteorological factors corresponding. First, winter wheat growth condition from sowing until maturity stage during 2011–2012 were assessed based on moderate-resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) time-series dataset. Next, correlation analysis and geographical information system (GIS) spatial analysis methods were used to analyze the lag correlations between different grades of winter wheat growth in each phenophase and the meteorological factors that corresponded to the phenophases. The results showed that the winter wheat growth conditions varied over time and space in the study area. Irrespective of the grades of winter wheat growth, the correlation coefficients between the winter wheat growth condition and the cumulative precipitation were higher than zero lag (synchronous precipitation) and one lag (pre-phenophase precipitation) based on the average values of seven phenophases. This showed that the cumulative precipitation during the entire growing season had a greater effect on winter wheat growth than the synchronous precipitation and the pre-phenophase precipitation. The effects of temperature on winter wheat growth varied according to different grades of winter wheat growth based on the average values of seven phenophases. Winter wheat with a better-than-average growth condition had a stronger correlation with synchronous temperature, winter wheat with a normal growth condition had a stronger correlation with the cumulative temperature, and winter wheat with a worse-than-average growth condition had a stronger correlation with the pre-phenophase temperature. This study may facilitate a better understanding of the quantitative correlations between different grades of crop growth and meteorological factors, and the adjustment of field management measures to ensure a high crop yield.
اظهر المزيد [+] اقل [-]Soil properties and yields of winter wheat after long-term growing of this crop in two contrasting rotations النص الكامل
2016
Smagacz J, Koziel M, Martyniuk S
Soil properties and yields of winter wheat after long-term growing of this crop in two contrasting rotations النص الكامل
2016
Smagacz J, Koziel M, Martyniuk S
This study was based on a long-term field experiment established in 1967 in which winter wheat is grown in two rotations consisting of: potato-winter wheat-fodder crops-winter wheat (rotation A) and oat-winter wheat-winter rye-winter wheat (rotation B). In the years 2010-2013 selected soil properties and winter wheat yields as influenced by these rotations were analysed. The soils under winter wheat grown in crop rotations A and B contained similar amounts of total organic carbon (C) (0.76% and 0.80%, respectively) and did not differ significantly with respect to biological characteristics (contents of microbial biomass C and nitrogen (N), dehydrogenase and acid phosphatase activities). Averaged for 3 years, the highest grain yields were obtained for winter wheat grown after potato in rotation A (7.94 t/ha) and the lowest (6.0 t/ha) for wheat following winter rye in rotation B. The highest take-all index and the lowest numbers of ears/m2 were the main factors influencing poor performance of winter wheat following rye.
اظهر المزيد [+] اقل [-]Soil properties and yields of winter wheat after long-term growing of this crop in two contrasting rotations النص الكامل
2016
J. Smagacz | M. Kozieł | S. Martyniuk
This study was based on a long-term field experiment established in 1967 in which winter wheat is grown in two rotations consisting of: potato-winter wheat-fodder crops-winter wheat (rotation A) and oat-winter wheat-winter rye-winter wheat (rotation B). In the years 2010-2013 selected soil properties and winter wheat yields as influenced by these rotations were analysed. The soils under winter wheat grown in crop rotations A and B contained similar amounts of total organic carbon (C) (0.76% and 0.80%, respectively) and did not differ significantly with respect to biological characteristics (contents of microbial biomass C and nitrogen (N), dehydrogenase and acid phosphatase activities). Averaged for 3 years, the highest grain yields were obtained for winter wheat grown after potato in rotation A (7.94 t/ha) and the lowest (6.0 t/ha) for wheat following winter rye in rotation B. The highest take-all index and the lowest numbers of ears/m2 were the main factors influencing poor performance of winter wheat following rye.
اظهر المزيد [+] اقل [-]Brochure on irrigation scheduling for winter wheat in Fergana Valley النص الكامل
2016
Brochure on irrigation scheduling for winter wheat in Fergana Valley | (2015).Brochure on irrigation scheduling for winter wheat in Fergana Valley [Brochure]. Author
اظهر المزيد [+] اقل [-]Monitoring of winter wheat distribution and phenological phases based on MODIS time-series: A case study in the Yellow River Delta, China النص الكامل
2016
Lin CHU | Qing-sheng LIU | Chong HUANG | Gao-huan LIU
Accurate winter wheat identification and phenology extraction are essential for field management and agricultural policy making. Here, we present mechanisms of winter wheat discrimination and phenological detection in the Yellow River Delta (YRD) region using moderate resolution imaging spectroradiometer (MODIS) time-series data. The normalized difference vegetation index (NDVI) was obtained by calculating the surface reflectance in red and infrared. We used the Savitzky-Golay filter to smooth time series NDVI curves. We adopted a two-step classification to identify winter wheat. The first step was designed to mask out non-vegetation classes, and the second step aimed to identify winter wheat from other vegetation based on its phenological features. We used the double Gaussian model and the maximum curvature method to extract phenology. Due to the characteristics of the time-series profiles for winter wheat, a double Gaussian function method was selected to fit the temporal profile. A maximum curvature method was performed to extract phenological phases. Phenological phases such as the green-up, heading and harvesting phases were detected when the NDVI curvature exhibited local maximum values. The extracted phenological dates then were validated with records of the ground observations. The spatial patterns of phenological phases were investigated. This study concluded that, for winter wheat, the accuracy of classification is 87.07%, and the accuracy of planting acreage is 90.09%. The phenological result was comparable to the ground observation at the municipal level. The average green-up date for the whole region occurred on March 5, the average heading date occurred on May 9, and the average harvesting date occurred on June 5. The spatial distribution of the phenology for winter wheat showed a significant gradual delay from the southwest to the northeast. This study demonstrates the effectiveness of our proposed method for winter wheat classification and phenology detection.
اظهر المزيد [+] اقل [-]Image Analysis Approach to Understand the Differences in Flour Particle Surface and Shape Characteristics النص الكامل
2016
Siliveru, Kaliramesh | Kwek, Jin W. | Lau, Grace M. L. | Ambrose, R. P Kingsly
The separation efficiency of wheat flour particles based on size, with minimum bran contamination, is important for a flour mill. Separation of flour during fractionation depends on the surface characteristics and shape of flour particles. Wheat flour particle characteristics such as surface lipid content, roughness, and morphology with respect to particle size were studied to better understand the differences between hard and soft wheat flours. Fractal analysis using image analysis was used to ascertain surface roughness. That was in turn verified by atomic force microscopy measurements. Soft wheat flours (soft red winter and soft white) had a higher degree of surface roughness than the hard wheat flours (hard red spring, hard red winter, and hard white). The fractal dimension values ranged from 2.67 to 2.78 and from 2.28 to 2.55 for soft and hard wheat flours, respectively. The surface lipid content increased with particle size in hard wheat but decreased in soft wheat flours. The surface lipid levels ranged from 1.02 to 1.18 and from 2.55 to 2.58% (% of total area) for 45 μm particles in hard wheat flours (hard red spring, hard red winter, and hard white) and soft wheat flours (soft red winter and soft white), respectively. For the 90 μm particles the lipid levels ranged from 1.54 to 1.62 and from 1.70 to 1.83% (% of total area) for flour particles in hard wheat flours (hard red spring, hard red winter, and hard white) and soft wheat flours (soft red winter and soft white), respectively. Surface lipid content and roughness values showed that soft wheat flours will be more cohesive than hard wheat flours. The morphology values revealed the irregularity in flour particles, irrespective of wheat class and particle size, owing to nonuniform fragmentation of protein and starch matrix of the wheat endosperm.
اظهر المزيد [+] اقل [-]The impacts of surface ozone pollution on winter wheat productivity in China – An econometric approach النص الكامل
2016
Yi, Fujin | Jiang, Fei | Zhong, Funing | Zhou, Xun | Ding, Aijun
The impact of surface ozone pollution on winter wheat yield is empirically estimated by considering socio-economic and weather determinants. This research is the first to use an economic framework to estimate the ozone impact, and a unique county-level panel is employed to examine the impact of the increasing surface ozone concentration on the productivity of winter wheat in China. In general, the increment of surface ozone concentration during the ozone-sensitive period of winter wheat is determined to be harmful to its yield, and a conservative reduction of ozone pollution could significantly increase China's wheat supply.
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