Spring Wheat Production Research Articles

The content of available mineral phosphorus compounds in chestnut soils of Northern Mongolia upon application of different forms of phosphorite

The effect of different forms of phosphorite (activated and crude ground) of the Burenkhansk deposit on the phosphate status of chestnut soils and the productivity of spring wheat was studied in Northern Mongolia. It was found that the transformation of mineral soil phosphates upon the application of activated phosphorite (together with NK) is similar to that upon superphosphate application, and the available phosphorus concentration is even a gradation higher. The application of crude ground phosphorite helped to preserve the content of mineral phosphates in the soil at the initial level. Optimum concentrations of available phosphorus and the sum of loosely bound and calcium phosphates in the plow horizon were estimated 33–35 mg/kg) and 16–18 mg/100 g, respectively. Under these concentrations, high and sustainable yields of spring wheat were obtained upon application of activated phosphorite.

西北旱地春小麦不同覆盖措施的温度和产量效应

PDF HTML阅读 XML下载 导出引用 引用提醒 西北旱地春小麦不同覆盖措施的温度和产量效应 DOI: 10.5846/stxb201403050373 作者: 作者单位: 甘肃农业大学生命科学与技术学院 甘肃干旱生境国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 公益性行业(农业)科研专项(20130314);现代农业产业技术体系建设专项(CARS-3-2-49) Effect of mulching method on soil temperature and grain yield of spring wheat in rainfed agricultural areas of northwestern China Author: Affiliation: College of bioscience and technology, Gansu Provincial Key Lab of Aridland Crop Science Gansu Agricultural University, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在西北半干旱雨养条件下,以春小麦为材料,研究了夏季覆膜(T1)、秋季覆膜(T2)、春季覆膜(T3)、小麦碎秆覆盖(T4)、小麦整秆覆盖(T5)、夏季覆膜+麦秆还田 (T6)和无覆盖对照(CK)7个处理间0-20 cm土壤温度、产量和重要农艺指标的差异。结果表明:处理间在不同生育时期、不同土层的土壤温度存在显著差异。生育时期间比较,处理间土壤温度差异以播种期-分蘖期最大、蜡熟期-成熟期次之、拔节期-灌浆中期较小;土层间比较,处理间土壤5 cm处的温度差异依次大于10 cm、15 cm、20 cm处。T6在各时期、各土层均表现出突出的增温效应,全生育期土壤平均温度较CK高0.57 ℃,以成熟期、播种期及分蘖期增温效果较大;其它覆盖处理存在增温和降温的双重效应,增温效应覆膜 > 秸秆覆盖,而降温效应则秸秆覆盖 > 覆膜,各处理的32个土壤温度测试点中,增温点次以T4最少(仅有9个),降温点次为23个,且T4降温幅度最大,全生育期0-20 cm土壤平均温度较CK低0.63 ℃,降温效果在播种期和分蘖期尤为突出。覆盖处理全生育期土壤平均温度表现为覆膜 > CK > 秸秆覆盖。温差最高值出现在分蘖期土壤5 cm处的T6与T4间,T6高出T4 4.23 ℃。T6可以平抑生育期间土壤温度的变化,其它5个覆盖处理则加剧土壤温度的波动,以T4处理的土壤温度波动最明显(CV为32.4%)。处理间产量、单位面积穗数、穗粒数间差异显著,而千粒重差异不显著。无论覆膜还是秸秆覆盖,都较CK穗粒数显著增加(17.4%-36.3%)。除T5较CK显著减产14.1%外,其它覆盖处理均较CK显著增产21.7%-37.3%,其中以全膜覆土穴播基础上的秋季覆膜 (T2)增产最显著,适宜在西北旱地春小麦产区推广应用。土壤温度主要影响营养生长,拔节-开花期0-20 cm的土壤温度与株高高度正相关(0.77*-0.92**),但覆盖引起土壤温度的变化最终对西北旱地春小麦产量没有关键影响。 Abstract:This study determined the effects of mulching method on soil temperatures in the 0-20 cm soil layer, and grain yield of spring wheat (Triticum aestivum L.) in a semiarid rainfed agricultural area of northwestern China. The experiment was conducted at Tongwei Research Station, Gansu Agricultural University (34°55'N, 104°57'E) in 2012. The following 7 treatments were evaluated: plastic film mulch applied in summer (T1), plastic film mulch applied in autumn (T2), plastic film mulch applied in spring (T3), mulching with chopped wheat straw (5 cm in length) on the soil surface in summer (T4), mulching with whole wheat straw in summer (T5), T1 in combination with harvested wheat straw returned to the field (T6), and control (no mulching, CK). Soil temperatures were measured and recorded at 32 points in each treatment. Soil temperatures differed significantly among mulching treatments, growth stages and soil layers. The largest difference in soil temperature occurred from the sowing to tillering period, followed by the dough stage to maturation period, whereas the smallest differences in soil temperature were in the jointing-middle filling stage. Soil temperature decreased with soil depth in the order 5 cm > 10 cm > 15 cm > 20 cm. Soil temperature in the T6 plots was significantly (0.57 ℃) higher than, and this effect was more pronounced in the sowing, tillering, and maturing stages than in the other growth stages. The other five treatments either increased or decreased soil temperatures depending on growth stage and soil layer. Soil temperature was consistently increased by plastic film mulch but consistently decreased by straw mulching. The T4 treatment had 9 points with soil temperatures higher than the CK, and 23 points lower than the CK. Mean soil temperature over the whole growth period was 0.63℃ lower in the T4 treatment than in the CK, with the difference being more obvious at the time of sowing and the tillering stage. Average soil temperatures over the whole growth period were in the order: plastic film mulch > CK > straw mulching. The highest difference occurred between T6 and T4 in the 5 cm soil layer at the tillering stage, with T6 being 4.23 ℃ higher than T4. The largest variation soil temperature among growth stages was found in the T4 treatment, with a coefficient of variation of 32.4%. Mulching increased the number of kernels per spike by 17.4% to 36.3% compared with the CK. Mulching increased wheat grain yield by 21.7% to 37.3% compared to the CK, with the maximum yield increase being with plastic film mulch applied in the autumn (T2). The exception was the T5 treatment which decreased grain yield by 14.1% compared to the CK. It appears that the T2 mulching method is the most suitable for spring wheat production in rainfed agricultural regions of northwestern China. There were highly positive correlations (r = 0.77*-0.92**) between soil temperature and plant height at jointing-flowering, but mulching method did not have a significant impact on spring wheat grain yield in the study area. 参考文献 相似文献 引证文献

Probabilistic model for determining possible yield level

On the basis of the methodology for stochastic modeling and long-term statistical data about spring wheat productivity obtained in comparative precision farming tests on the bioground of the Agrophysical RI, an approach to establishing the law of distribution of the actual possible yield of the farm crop in particular soil climatic conditions is considered. The knowledge of this law will make it possible to objectively determine the potential yield level on a given field and develop, on reasonable grounds, the respective individual technology with regard to yield value.

Современные вопросы лесоустройства Республики Татарстан

The article examines the possibility of forecasting the spring wheat the productivity according to the content of mobile forms of phosphorus, potassium, applied amount of mineral and organic fertilizers. Deviation of the projected yield from actual comes to 31%, and the forecasting yield of the moving average drops to 4.6%. During the observation period the spring wheat productivity increased from 11.6 to 18.7 kilogram per hectare, an increase was 7.1 tons per hectare with an average yield of 17.4 tons per hectare. The productivity of spring wheat exhibits a very unstable value, which is evidenced by the high variation coefficient - 43.3%. There is a positive correlation between security soil by phosphorus, potassium and spring wheat yield. It is positive according to phosphorus for the actual and derivative wheat yield, the higher rates of coefficients was according U11. Potassium also has a positive association with yield. However, the correlation coefficients of potassium are higher (0.57-0.0.94), than of phosphorus (0.50-0.84). This fact suggests, that potassium in macroelement is more scarce, than phosphorus. Apparently, this feature of mobile potassium is manifested by solubility characteristics of the potassium compounds in aqueous medium, despite a sufficient amount of its gross shapes in soils. Studies prove once again, that the basis of of productivity formation is security by nutrient macroelements and peculiarities of economic activities. In addition to more accurately actual spring wheat yield it is necessary to attract agro-climatic indicators. The projections data are also a good tool for assessing the economic activity of individual districts, regions, and land users of different levels.

Обеспеченность макроэлементами питания и прогнозирование урожайности яровой пшеницы в Республике Татарстан

The article examines the possibility of forecasting the spring wheat the productivity according to the content of mobile forms of phosphorus, potassium, applied amount of mineral and organic fertilizers. Deviation of the projected yield from actual comes to 31%, and the forecasting yield of the moving average drops to 4.6%. During the observation period the spring wheat productivity increased from 11.6 to 18.7 kilogram per hectare, an increase was 7.1 tons per hectare with an average yield of 17.4 tons per hectare. The productivity of spring wheat exhibits a very unstable value, which is evidenced by the high variation coefficient - 43.3%. There is a positive correlation between security soil by phosphorus, potassium and spring wheat yield. It is positive according to phosphorus for the actual and derivative wheat yield, the higher rates of coefficients was according U11. Potassium also has a positive association with yield. However, the correlation coefficients of potassium are higher (0.57-0.0.94), than of phosphorus (0.50-0.84). This fact suggests, that potassium in macroelement is more scarce, than phosphorus. Apparently, this feature of mobile potassium is manifested by solubility characteristics of the potassium compounds in aqueous medium, despite a sufficient amount of its gross shapes in soils. Studies prove once again, that the basis of of productivity formation is security by nutrient macroelements and peculiarities of economic activities. In addition to more accurately actual spring wheat yield it is necessary to attract agro-climatic indicators. The projections data are also a good tool for assessing the economic activity of individual districts, regions, and land users of different levels.

Продуктивность яровой пшеницы сорта Экада 66 в зависимости от систем удобрения при различных способах основной обработки серой лесной почвы

One of the important issues of increasing productivity and improving the quality of the grain is the correct application of fertilizers. The the quantity and quality of the final product depends on the right balance and the level of availability of nutrients in fertilizers. The results, presented in this article, demonstrate the relevance and significance of this research. We studied the issue of increasing technological qualities of grain and productivity of spring wheat. Using organomineral fertilizers by cash and balance method on the background of subsurface tillage can improve grain quality indicators. In the variant when treating organic fertilizers in amount of 7 tons per hectare of arable land per year with the addition of NPK fertilizer on the background subsurface loosening, the protein content was 14.8%, gluten - 32.7%, with the gluten deformation index 75 (I group), which corresponds to I class of grain quality. Not less important is the conservation the resources and reduction of fertilizers load on the soil in order to greening agriculture. So, the introduction of organomineral fertilizers will not only increase the crop by 1.5-2 times, compared to the control one without fertilizer, but also improve the payback of NPK fertilizer by grain to 50%, compared with mineral fertilizer system, by reducing fertilizer rates up to 40%.

A modelling approach to evaluate the long-term effect of soil texture on spring wheat productivity under a rain-fed condition.

Soil surface texture is an important environmental factor that influences crop productivity because of its direct effect on soil water and complex interactions with other environmental factors. Using 30-year data, an agricultural system model (DSSAT-CERES-Wheat) was calibrated and validated. After validation, the modelled yield and water use (WU) of spring wheat (Triticum aestivum L.) from two soil textures (silt loam and clay) under rain-fed condition were analyzed. Regression analysis showed that wheat grown in silt loam soil is more sensitive to WU than wheat grown in clay soil, indicating that the wheat grown in clay soil has higher drought tolerance than that grown in silt loam. Yield variation can be explained by WU other than by precipitation use (PU). These results demonstrated that the DSSAT-CERES-Wheat model can be used to evaluate the WU of different soil textures and assess the feasibility of wheat production under various conditions. These outcomes can improve our understanding of the long-term effect of soil texture on spring wheat productivity in rain-fed condition.

Crop Diversification, Tillage, and Management System Influence Spring Wheat Yield and Water Use

Depleted soil quality, decreased water availability, and increased weed competition constrain spring wheat production in the northern Great Plains. New management systems are necessary for improved crop productivity. The objective of our study was to compare productivity and soil water use of spring wheat (Triticum aestivum L.) in four crop rotations (continuous wheat, wheat–pea [Pisum sativum L.], wheat–forage barley [Hordeum vulgaris L.]–pea, and wheat–forage barley–corn [Zea mays L.]–pea) in two tillage (tilled and no‐till) and management systems (conventional and ecological). Conventional management included recommended seed rates, early planting date, and broadcast N fertilization. Ecological management included variable seed rates, delayed planting, banded N fertilization, and increased stubble height. Spring wheat in diversified rotations averaged 35 mm greater preplant soil water content, 37 mm greater water use, 0.8 kg ha−1 mm−1 greater water use efficiency, and 473 kg ha−1 and 817 kg ha−1 greater grain and biomass yields than continuous wheat. Wheat in conventional management averaged 28 fewer heads m−2, 4 additional seed head−1, and 2 mg seed−1 heavier seed weight than wheat under ecological management, resulting in 644 kg ha−1 greater yield. Wheat under ecological management used 8 mm more water, but water use efficiency was 2.6 kg ha−1 mm−1 greater under conventional management. Postharvest soil water content was similar among rotations, tillage, and management systems, suggesting that wheat uses most available soil water. Spring wheat in diversified rotations planted early in the season is more resilient and should confer greater production stability than continuous wheat systems planted late.

Estimating the local effect of weather on field crop production with unobserved producer behavior: a bioeconomic modeling framework

The role of weather in crop production at field is central to understanding the impact of climate change on agriculture and its implications for food security. In this study, we developed a bioeconomic modeling framework for estimating the field effect of weather on crop production at the regional scale with unobserved producer behavior. We took a systematic perspective for model development, explicitly considering crop production as a coupled human–nature system dominated by management adapted to local environmental and economic conditions. We drew on economics to characterize producer management behavior and crop yield consistent with the process of field production. We integrated scientific findings on plant growth and production economics to parameterize the yield function of crop that can be statistically estimated with observed data. An empirical application of our approach to spring wheat production found spatially heterogeneous effect of weather and climate change impact. Our modeling approach can be applied to different crops or regions to develop locally specific understandings of the management adjusted, production effect of weather and climate change impact, with implications on cropping system resilience and for adaptation.

Use of NBPT and ammonium thiosulphate as urease inhibitors with varying surface placement of urea and urea ammonium nitrate in production of hard red spring wheat under reduced tillage management

Grant, C. A. 2014. Use of NBPT and ammonium thiosulphate as urease inhibitors with varying surface placement of urea and urea ammonium nitrate in production of hard red spring wheat under reduced tillage management. Can. J. Plant Sci. 94: 329–335. Field studies were conducted at two locations over 3 yr to evaluate the effect of surface placement of urea ammonium nitrate (UAN) and urea fertilizers, with and without the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) on straw and grain yield of hard red spring wheat (Triticum aestivum L.) grown under reduced tillage management. Ammonium thiosulphate (ATS) was also evaluated as a urease inhibitor with UAN. Surface sprayed applications of UAN were frequently less effective than dribble-banded UAN applications or broadcast or dribble-banded urea in increasing grain or straw yield of hard red spring wheat. Use of NBPT with the sprayed UAN increased its effectiveness, so that grain and straw yields were similar to those with urea or with surface dribble-banded UAN. Addition of NBPT to broadcast or banded urea did not increase straw or grain yield under the conditions of this study. While there was some indication that use of ATS with UAN may have had a limited effect on fertilizer efficiency, it did not increase final grain yield as compared with dribble-banded or spray UAN applied alone or with NBPT. If surface nitrogen (N) applications are used in reduced tillage systems, spray applications of UAN should be avoided in favour of dribble-band applications, or the use of urea. Alternately, NBPT may be effective in improving the efficacy of spray UAN.

Modelling the effects of climate variability on spring wheat productivity in the steppe zone of Russia and Kazakhstan

Spring wheat is the principal crop in the steppe zone of Russia and Kazakhstan, but wheat productivity levels are currently low and susceptible to weather and climate anomalies. Water scarcity during the growing season represents a major stress factor and is expected to negatively affect wheat production in the future as well. In this paper we present a simple mechanistic model for assessing the impact of climate variability on spring wheat productivity in the steppe zone of Russia and Kazakhstan. The novel aspect of the model development is represented by the adoption of an adaptive approach for the formulation of growth partitioning. In spite of simplifying assumptions the model is shown to satisfactorily reproduce yield levels observed both at the local scale under controlled conditions as well as at the regional scale. The model is able to capture a significant percentage of the observed year-to-year variability of wheat yields. Results of the model application indicate that, for the steppe zone of Russia and Kazakhstan, seasonal water shortage is likely to cause yield deficits of 20–25%, with deficits of up to 40% in extreme years, and an increase in the coefficient of variation of yields.

Прогнозирование урожайности яровой пшеницы в лесостепной зоне Среднего Поволжья по методу наименьших квадратов

The efficient use of arable land is based on the prediction of crop yields. In extensive farming system the productivity forecasting was carried out by scores of soil fertility, where the level of soil fertility was associated with soil type, and crop yields depended on the leading basic and sustained properties - humus content, cation-exchange capacity, particle size distribution. The system of intensive farming is based on the use of mineral and organic fertilizers. The leading factor in the formation of crop yield is the soil security by mobile soil nutrients on the background of optimal soil parameters. Nowadays, crop yield forecasting is made with the use of the available to plants macro nutrition content. The article presents the results of spring wheat yield prognosis in the Laishevo municipal district with the use of MatLab (matrix operations). The matrix was made according to the data over the last 43 years, it’s moving averages with steps of 11 and 22 years, the content of mobile phosphorus and potassium, determined by the method of Kirsanov. The predictive ability is confirmed by correlation analysis, for the actual number of crop coefficients of correlation with phosphorus and potassium are 0.52 and 0.61, respectively, for the moving average yields are equal to 0.94 and 0.95. A comparison of the actual spring wheat yield (УФ) with the calculated data (the model 1 and the model 2) shows the average deviation of 30%. Similar calculations for the derived series of the moving average of crop yield for the step length of 11 years gives a marked decrease in the deviation of 5-6 %. This convergence of data with the calculated У11 (the model 1 and the model 2, in the left part of the table) indicates for the elimination of weather factor for У11, which influences the overall level of productivity of spring wheat in the forest-steppe zone. The conclusion of the article is the inclusion of agro-climatic conditions (precipitation and temperature) for further calculation of crop yields forecasting.

Impact of Climate Variability on Yield of Spring Wheat in North Dakota

Agricultural production is highly dependent on the climatic variability of the specific regions. Differential climatic and soil conditions bring about changes in yield, quality of crops thus affecting the economy. This study evaluated the impact of variability in different climatic factors keeping the other factors constant on spring wheat production in North Dakota from 2007 to 2011. The spring wheat yield mainly depends on the climatic changes during growing periods April to September. Average maximum air temperature was significantly different from April to September except June from 2007 to 2011. High average minimum and maximum air temperatures during planting time increase yield and planting area for 2010. In 2011, low mean soil temperature, excess rainfall in April caused low yield of spring wheat. The unmitigated climate variability will result in declines in yields. So, adoption of sustainable agriculture practices helps the farmers to develop the different practices for their farms.

In vitro culture for doubled haploids: tools for molecular breeding.

Doubled haploid (DH) techniques using immature microspores or embryos rescued in vitro following interspecific hybridization are important tools for breeding wheat and barley and for generating populations for gene mapping purposes. Here, we describe methods being used for the successful production of spring wheat and barley DHs in Australia.

Экономическая и агроэнергетическая оценка возделывания яровой пшеницы при использовании препарата Нано-гро в условиях темно-серых лесных почв Нижегородской области

The criterion of whether to apply a different technological methods in the cultivation of spring wheat is the economic assessment, which characterizes the change in the cost of production and other economic indicators. Today, the most effective cultivation methods of spring wheat are those, which provide higher yields and determine the food security of the population and industrial raw materials. In this regard, our paper considers the issues of economic and agroenergetic efficiency of spring wheat, using Nano-Gro seed treatment formulation instead of the traditional etching, depending on the varietal characteristics of dark gray forest soils of the Nizhniy Novgorod region. The study was carried out on varieties Margarita, Marusya and Sofia. The aim was to determine the economic feasibility of agroenergetic and cultivation of new varieties of spring wheat during treatment with Nano-Gro. Based on the analysis, it was revealed that in a dark gray forest soils of the Volga-Vyatka region the grain production of spring wheat economically is profitable. Seed treatment by Nano-Gro increases the profitability of wheat production in the studied varieties. The maximum net energy yield 41,57-48,42 G joules per hectare were obtained in the cultivation of wheat seed treatment with the Nano- Gro.

Projected climate impacts to South African maize and wheat production in 2055: a comparison of empirical and mechanistic modeling approaches

Crop model-specific biases are a key uncertainty affecting our understanding of climate change impacts to agriculture. There is increasing research focus on intermodel variation, but comparisons between mechanistic (MMs) and empirical models (EMs) are rare despite both being used widely in this field. We combined MMs and EMs to project future (2055) changes in the potential distribution (suitability) and productivity of maize and spring wheat in South Africa under 18 downscaled climate scenarios (9 models run under 2 emissions scenarios). EMs projected larger yield losses or smaller gains than MMs. The EMs' median-projected maize and wheat yield changes were -3.6% and 6.2%, respectively, compared to 6.5% and 15.2% for the MM. The EM projected a 10% reduction in the potential maize growing area, where the MM projected a 9% gain. Both models showed increases in the potential spring wheat production region (EM = 48%, MM = 20%), but these results were more equivocal because both models (particularly the EM) substantially overestimated the extent of current suitability. The substantial water-use efficiency gains simulated by the MMs under elevated CO2 accounted for much of the EM-MM difference, but EMs may have more accurately represented crop temperature sensitivities. Our results align with earlier studies showing that EMs may show larger climate change losses than MMs. Crop forecasting efforts should expand to include EM-MM comparisons to provide a fuller picture of crop-climate response uncertainties.

ПОРАЖЕНИЕ ЯРОВОЙ ПШЕНИЦЫ ВРЕДНЫМИ ОРГАНИЗМАМИ В УСЛОВИЯХ ПРЕДБАЙКАЛЬЯ В ЗАВИСИМОСТИ ОТ СРОКОВ СЕВА И ПРИМЕНЕНИЯ РЕГУЛЯТОРОВ РОСТА

The conditions of South Siberia region are favorable for the propagation of r-strategy harmful organisms. The authors investigated the influence of sowing time (early — April 26, and usual for this region — Mai 19), presowing seed treatment by the Vial preparation and Humate 80 and Krezacin growth regulators on the damage of spring wheat sowings of the Tulunskaya 12, Iren’, Novosibirskaya 29 by the root rot, wheat leaf bloch, cereal leaf beetle (larva phase), wheat thrips (larva phase), grey cereal noctuid (larva phase). The authors estimated the species composition of weeds, their number, an accumulation of green mass and wheat harvest. The investigations were made on experimental field of the Irkutsk State Agricultural Academy and in practical conditions in other zones of Pre-Baikal region. After early sowing without presowing treatment the authors observed the reduction of spreading of root rot (13.84 %) and ear bloch (13.33 %), also observed the decrease of leaves damages by cereal leaf beetle (2.3 times), corn damages by wheat thrips (6.5 times) and grey cereal noctuid (3.8 times). The weed’s biomass was decreased to 6-8 times. The productivity of spring wheat was raised by 15-40 %. The application of growth regulator-adaptogen (instead of seed treatment) permits to obtain the good and early sprouts, that also permit to increase the competitiveness of cultural plants and to weaken the harmful effect of phytopathogens, phytophages and weeds.

Irrigation scheduling based on CERES-Wheat model for spring wheat production in the Minqin Oasis in Northwest China

The Minqin County in Northwest China is known for its serious desertification and irrigation-dependent oasis farming that is mainly distributed along the Shiyang River. To answer some important hypothetical questions related to optimal irrigation scheduling for spring wheat (Triticum aestivum L.) production in the Minqin Oasis, the CERES-Wheat model in DSSAT V4.5 was used to simulate the spring wheat growth in irrigated farmland in this area. The results of model simulation indicate that if the soil water content is lower than 65% of field capacity (or about 190mm water) in the 1-m depth soil profile during the grain filling and milk ripe stages, the final grain yield can be remarkably reduced (e.g. more than 1000kgha−1 for some treatments in field experiment) even for a short period of water stress. The water stress in the early stages could be eliminated with luxurious water supply, but more nitrogen would be washed away from the soil profile and then the yield was impacted. The optimized irrigation dates played an important role in improving the water use efficiency of spring wheat. If there was only a single irrigation allowed by the limited water resources, the irrigation date should be at the end of booting or beginning of heading stage. If the second irrigation could be adjusted to the middle of heading stage, the 3-irrigation schedule (a total of three irrigations in the whole growth season, and so forth) could meet the water demand of spring wheat without losing too much yield (e.g. less than 20kgha−1 when compared with the 4-irrigation treatment). Furthermore, if the first irrigation of the 4-irrigation schedule could be delayed to the starting of jointing, the simulated yield could be increased from about 6500kgha−1 to the highest 7000kgha−1. Finally, the analysis of uncertainties of simulated dry yields across 58 years historical weather data showed that the schedules with fewer irrigation events cause larger uncertainties due to local weather variations. The 4-irrigation schedule seemed to be the best choice for spring wheat at the Minqin Oasis due to its relatively higher long-term average yields and lower uncertainties since it was under non-limited water conditions.

U.S. West: Foliar‐applied nitrogen fertilizers in spring wheat production

Crops & SoilsVolume 46, Issue 4 p. 26-32 Regional Roundup U.S. West: Foliar-applied nitrogen fertilizers in spring wheat production Olga S. Walsh, Olga S. Walsh Montana State University, Western Triangle Agricultural Research Center (WTARC), ConradSearch for more papers by this authorRobin J. Christiaens, Robin J. Christiaens Montana State University, Western Triangle Agricultural Research Center (WTARC), ConradSearch for more papers by this authorArjun Pandey, Arjun Pandey Montana State University, Western Triangle Agricultural Research Center (WTARC), ConradSearch for more papers by this author Olga S. Walsh, Olga S. Walsh Montana State University, Western Triangle Agricultural Research Center (WTARC), ConradSearch for more papers by this authorRobin J. Christiaens, Robin J. Christiaens Montana State University, Western Triangle Agricultural Research Center (WTARC), ConradSearch for more papers by this authorArjun Pandey, Arjun Pandey Montana State University, Western Triangle Agricultural Research Center (WTARC), ConradSearch for more papers by this author First published: 18 July 2013 https://doi.org/10.2134/cs2013-46-4-8Citations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume46, Issue4July‐August 2013Pages 26-32 RelatedInformation

Modelling population dynamics of Sinapis arvensis in organically grown spring wheat production systems

SummaryAlthough we know that alterations in crop density, crop spatial pattern and inclusion of more selective weed control can improve weed suppression for organic growers, it is unknown whether these result in changes to the weed seedbank that increase cropping system profitability over time. Data collected from field trials conducted in 2009 and 2010 in Maine, USA, comparing regional grower practices (Standard) with management that aimed to (i) facilitate better physical weed control through the use of wide row spacing and inter‐row cultivation (Wide) or (ii) enhance crop–weed competition through increased seeding rate and narrow inter‐row spacing (Narrow HD), were used to construct a matrix population model with an economic sub‐model. Using field measurements of grain yield and weed survival and fecundity, we investigated the lasting implications of employing alternative organic spring wheat (Triticum aestivum) production practices on Sinapis arvensis population dynamics. In most scenarios, the model indicated that regional production practices were not sufficient to prevent an increase in the weed seedbank, even with excellent weed control. The two alternative methods, on the other hand, were able to limit weed population growth when initial densities were low or cultivation efficacy was >80%. Due to higher seed costs in the Narrow HD system, net returns were still lower after 10 years of simulation in this system compared with wide rows with cultivation, despite a lower weed seedbank.