oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Soil nitrogen mineralization and its prediction in winter wheat-summer maize rotation system
冬小麦/夏玉米轮作体系中土壤氮素矿化及预测

JU Xiaotang,LIU Xuejun,ZHANG Fusuo,
巨晓棠
,刘学军,张福锁

应用生态学报 , 2003,
Abstract: The mineralization of soil nitrogen in winter wheat-summer maize growth season was studied with field experiment, and its prediction was made by interval leached aerial incubation combined with first-order dynamic model. The results showed that the amount of soil mineralized nitrogen had a large variation among years and crops. The soil nitrogen mineralization was lower in winter wheat growth season than in summer maize growth season, resulted in the yield increment of summer maize being not significant with increasing nitrogen fertilization rate. The amount of soil mineralized nitrogen occupied 31%-60% of the total nitrogen uptake by winter wheat and 62%-108% by summer maize. It was understandable why crop yield (especially summer maize) was not significantly response to applied nitrogen fertilizer. The amount of soil mineralized nitrogen decreased with increasing soil nitrogen supply. The mineralization was positive in normal nitrogen supply range(0-300 kg N.hm-2). The first order dynamic model could only predict the whole trend of mineralization in growth season, but could not reflect its variation in some growth stages. The role of the model was still important in view of the prediction of nitrogen mineralization before sowing.
华北平原夏玉米各生育阶段农业气候要素变化特征
Analyses of variations in agro-climatic elements during summer maize growing season in North China Plain
 [PDF]

胡洵瑀,王靖
- , 2015, DOI: 10.7606/j.issn.1000-7601.2015.04.38
Abstract: 基于华北平原6个农业气象试验站1981—2009年夏玉米生育期资料,以及同期48个气象站平均、最高和最低温度,降水、日照时数等逐日气象资料,采用线性倾向估计的方法,分析了华北平原近30年夏玉米各生育阶段农业气候要素的变化趋势。结果表明:(1) 夏玉米出苗~拔节期的温度升高,其中平均温度、平均最高温度、平均最低温度的增幅分别为0.42℃·10a-1、0.36℃·10a-1和0.58℃·10a-1(P<0.05),平均最低温度显著增加的站点多于平均最高温度显著增加的站点,温度日较差降幅为0.22℃·10a-1(P<0.05);夏玉米拔节~抽雄期的温度变化不明显,温度日较差降幅为0.22℃·10a-1(P<0.05);夏玉米抽雄~成熟期的平均温度、平均最高温度、平均最低温度均下降,降幅分别为0.16℃·10a-1(P<0.05),0.15℃·10a-1(P<0.05)和0.06℃·10a-1,其中下降显著的站点位于山东省。(2) 各生育阶段降水量变化不明显,全区仅山东南部和河南中部出苗~拔节期的降水量增加显著。(3) 除播种~出苗期外,各生育阶段的总辐射量均显著下降,其中出苗~拔节、拔节~抽雄、抽雄~成熟和全生育期的日均总辐射降幅分别0.83、1.10、0.87 MJ·m-2·10a-1和0.89 MJ·m-2·10a-1(P<0.05),且大部分站点下降显著。
Based on phenological data of summer maize at from typical agro-meteorological experimental stations and parallel daily meteorological data from 48 meteorological stations in the North China Plain (NCP) from 1981 to 2009, we analyzed the variations of agro-climatic elements during summer maize growing season in recent 30 years by using the method of liner regression. The results showed that mean temperature, mean maximum temperature and mean minimum temperature during the period from emergence to jointing were increased by 0.42℃·10a-1, 0.36℃·10a-1 and 0.58℃·10a-1(P<0.05), respectively. There were more stations where mean minimal temperature became increased statistically significantly than those where mean maximum temperature was increased significantly. Mean daily temperature range became decreased by 0.22℃·10a-1(P<0.05) during the period from emergence to jointing. There was no significant changing trend in the temperature during the period from jointing to tasseling. However, mean daily temperature range was decreased by 0.22℃·10a-1(P<0.05) from jointing to tasseling. Mean temperature, mean maximum temperature and mean minimum temperature during the period from tasseling to maturity were decreased by 0.16℃·10a-1(P<0.05), 0.15℃·10a-1(P<0.05) and 0.06℃·10a-1, respectively. The stations where the temperature became decreased significantly in statistics were located in Shandong province. Also, precipitation was changed little during all the development stages of summer maize, except for the south area of Shandong and the middle regions of Henan where precipitation during the period from the emergence to jointing had been increased significantly. Additionally, mean daily radiation was decreased by 0.83 MJ·m-2·10a-1, 1.10 MJ·m-2·10a-1, 0.87 MJ·m-2·10a-1 and 0.89 MJ·m-2·10a-1(P<0.05), respectively, during the periods from emergence to jointing, from jointing to tasseling, from tasseling to maturity and from sowing to maturity. The
Appropriate soil nitrate N content for a winter wheat/summer maize rotation system in North China Plain
华北平原冬小麦/夏玉米轮作体系土壤硝态氮的适宜含量

CUI Zhen-ling,CHEN Xin-ping,ZHANG Fu-suo,XU Jiu-fei,SHI Li-wei,LI Jun-liang,
崔振岭
,陈新平,张福锁,徐久飞,石立委,李俊良

应用生态学报 , 2007,
Abstract: A field experiment with 12-level N fertilization in winter wheat growth season and zero-N in summer maize growth season was conducted to study the appropriate soil nitrate N content for a winter wheat/summer maize rotation system in North China Plain. The results showed that when the soil mineral N content before sowing was higher, a split application of 150 kg N x hm(-2) in winter wheat growth season could meet the N demand of both winter wheat and summer maize in the rotation system. The N use efficiency of winter wheat in different N treatments was only from 11% to 23%, while the residual N use efficiency of summer maize ranged from 30% to 52%. When the nitrate N content in top 90 cm soil layer before maize sowing was up to 82 and 151 kg x hm(-2), respectively, the N demand of summer maize at its ten-leaf stage and in its whole growth season could be met with no N application. However, when the nitrate N content in top 90 cm soil layer was less than 46 and 65 kg x hm(-2) at maize ten-leaf stage and after harvest, respectively, no N application could impact maize growth, and decrease its grain yield. With the maize yield and environmental protection considered comprehensively, the nitrate N content in top 90 cm soil layer should be maintained at an appropriate level from 65 to 151 kg x hm(-2) during maize growth season.
Effects of Controlled-Release Fertiliser on Nitrogen Use Efficiency in Summer Maize  [PDF]
Bin Zhao, Shuting Dong, Jiwang Zhang, Peng Liu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0070569
Abstract: Nitrogen (N) is a nutrient element necessary for plant growth and development. However, excessive inputs of N will lead to inefficient use and large N losses to the environment, which can adversely affect air and water quality, biodiversity and human health. To examine the effects of controlled-release fertilisers (CRF) on yield, we measured ammonia volatilisation, N use efficiency (NUE) and photosynthetic rate after anthesis in summer maize hybrid cultivar Zhengdan958. Maize was grown using common compound fertiliser (CCF), the same amount of resin-coated controlled release fertiliser (CRFIII), the same amount of sulphur-coated controlled release fertiliser (SCFIII) as CCF, 75% CRF (CRFII) and SCF (SCFII), 50% CRF (CRFI) and SCF (SCFI), and no fertiliser. We found that treatments CRFIII, SCFIII, CRFII and SCFII produced grain yields that were 13.15%, 14.15%, 9.69% and 10.04% higher than CCF. There were no significant differences in grain yield among CRFI, SCFI and CCF. We also found that the ammonia volatilisation rates of CRF were significantly lower than those of CCF. The CRF treatments reduced the emission of ammonia by 51.34% to 91.34% compared to CCF. In addition, after treatment with CRF, maize exhibited a higher net photosynthetic rate than CCF after anthesis. Agronomic NUE and apparent N recovery were higher in the CRF treatment than in the CCF treatment. The N uptake and physiological NUE of the four yield-enhanced CRF treatments were higher than those of CCF. These results suggest that the increase in NUE in the CRF treatments was generally attributable to the higher photosynthetic rate and lower ammonia volatilisation compared to CCF-treated maize.
Soil nitrate leaching and control methods in the piedmont of North China Plain
华北山前平原农田土壤硝态氮淋失与调控研究

LI Xiao-Xin,MA Hong-Bin,HU Chun-Sheng,ZHANG Gui-Jie,
李晓欣
,马洪斌,胡春胜,张桂杰

中国生态农业学报 , 2011,
Abstract: Soil core and soil water samples were collected in a long-term field experiments to study soil nitrate nitrogen (NO3--N) accumulation and leaching in winter wheat/summer maize double-cropping system under different agricultural management practices in the North China Plain (NCP). The results showed that NO3--N accumulation in the soil profile and NO3--N leaching through the root zone increased with increasing N fertilizer application (P<0.05). Application of P and K fertilizers improved the grain yield and harvested more N in grains. P and K inputs increased the amounts of harvested N in grains by 123 kg·hm-2·a-1 and 31 kg·hm-2·a-1, respectively. Based on the experiment, the amount of irrigation also affected NO3--N accumulation and distribution in the soil profile. The amounts of accumulated NO3--N in the 0~400 cm soil profile significantly decreased with increasing irrigation frequency. Arid irrigation treatment (i.e., no irrigation and one irrigation during winter wheat and summer maize seasons, respectively) produced 1 698 kg(N)·hm-2 of accumulated NO3--N in the 0~400 cm soil profile. This was significantly higher (P < 0.05) than those of deficient irrigation (i.e., 2~3 irrigations during winter wheat season, irrigation when needed during summer maize season) and sufficient irrigation (i.e., 4~5 irrigations during winter wheat season, irrigation when needed during summer maize season) with accumulated NO3--N in the 0~400 cm soil profile of 1 148 kg(N)·hm-2 and 961 kg(N)·hm-2, respectively. Compared with deficient and sufficient irrigation treatments, accumulated NO3--N in the 100~200 cm soil layer was higher than in the other soil layers under arid irrigation treatment. From 2003~2005, increases in NO3--N in the 0~400 cm soil profile were different among different irrigation treatments. The amounts of fertilizer N left in the soil under arid irrigation, deficient irrigation and sufficient irrigation were 23%, 22% and 47%, respectively. No-tillage decreased grain yield, changed soil water movement and increased water storage in deep soils, which in turn increased the risk of NO3--N leaching. Based on the results, 200 kg·hm-2·a-1 N input with less irrigation and balanced fertilization were the most effective mode that protected groundwater from nitrate pollution in NCP.
Multiscale characteristics of the rainy season rainfall and interdecadal decaying of summer monsoon in North China
Xingang Dai,Ping Wang,Jifan Chou
Chinese Science Bulletin , 2003, DOI: 10.1007/BF02901765
Abstract: This paper focuses on the rainfall spectrum and its evolution of North China in rainy season with summer monsoon decaying in interdecadal time scale. The interannual component of the rainfall is the dominant part, accounting for 85% of the total variance, and has been changed significantly during the last 30 years. According to wavelet analysis its 5a periodic spectrum suddenly disappeared in the late 1960s, and its biennial oscillation gradually become weaker and weaker since 1970, accompanied by the summer monsoon decaying. Contrarily, the interdecadal component is principal in the summer monsoon over North China and is very similar to the counterpart of the rainfall. Their interdecadal parts are significantly correlated, and the correlation coefficient is nearly equal to the one of the original sequences. Besides, the dry and wet climate alternated with the monsoon abrupt changes in the 1960s and the 1970s over East Asia, apart from North China, climate drifted from a light drought to a severe drought during the past 30 years.
Methane, Carbon Dioxide and Nitrous Oxide Fluxes in Soil Profile under a Winter Wheat-Summer Maize Rotation in the North China Plain  [PDF]
Yuying Wang, Chunsheng Hu, Hua Ming, Oene Oenema, Douglas A. Schaefer, Wenxu Dong, Yuming Zhang, Xiaoxin Li
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0098445
Abstract: The production and consumption of the greenhouse gases (GHGs) methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) in soil profile are poorly understood. This work sought to quantify the GHG production and consumption at seven depths (0–30, 30–60, 60–90, 90–150, 150–200, 200–250 and 250–300 cm) in a long-term field experiment with a winter wheat-summer maize rotation system, and four N application rates (0; 200; 400 and 600 kg N ha?1 year?1) in the North China Plain. The gas samples were taken twice a week and analyzed by gas chromatography. GHG production and consumption in soil layers were inferred using Fick’s law. Results showed nitrogen application significantly increased N2O fluxes in soil down to 90 cm but did not affect CH4 and CO2 fluxes. Soil moisture played an important role in soil profile GHG fluxes; both CH4 consumption and CO2 fluxes in and from soil tended to decrease with increasing soil water filled pore space (WFPS). The top 0–60 cm of soil was a sink of atmospheric CH4, and a source of both CO2 and N2O, more than 90% of the annual cumulative GHG fluxes originated at depths shallower than 90 cm; the subsoil (>90 cm) was not a major source or sink of GHG, rather it acted as a ‘reservoir’. This study provides quantitative evidence for the production and consumption of CH4, CO2 and N2O in the soil profile.
Yield prediction and nitrogen recommendation in maize using normalized difference vegetation index  [PDF]
TB Karki
Agronomy Journal of Nepal , 2013, DOI: 10.3126/ajn.v3i0.9009
Abstract: A study was carried out using three maize genotypes with three levels of nitrogen (30 kg, 60 kg and 120 kg per hectare) during the summer season of 2010 and 2011with the aim of predicting maize (Zea mays L.) yield through the Normalized difference vegetation index (NDVI). The NDVI was recorded at different times throughout the growing season using a Greenseeker? handheld sensor. Significant effect of genotypes and nutrient levels on the NDVI was observed at different growth stages of maize. There was positive correlation between the NDVI and grain yield. In the first season, the correlation coefficients were 0.90, 0.92, 0.76 and 0.73, respectively at 15, 45, 75 and 110 days after seeding. In the second season, the correlation coefficients were 0.80, 0.92, 0.77 and 0.75 respectively at 15, 45, 75 and 110 days after seeding. The NDVI based N calculator showed that irrespective of genotypes, yield potentials under farmers' levels of nutrient management were almost half of the recommended doses of nitrogen. The amount of N to be top dressed decreased with increased crop duration. Grain yield varied significantly due to season, genotypes and nutrient levels. NDVI was affected due to season, stages of the crop (DAS), genotypes and nutrient levels. Interaction effects were significant for season x genotype, growth stage x genotype, growth stage x nutrient levels, genotype x nutrient levels and genotype x growth stage x nutrient levels. There was a strong positive correlation between NDVI and grain yields of hybrid maize at 15 and 45 DAS, but this correlation declined thereafter. This means that N top-dressed at or after 75 days of seed sowing will not increase grain yield as significantly as N applied earlier in the season. In contrast, topdressed N was producing significant effects on the open pollinated Rampur Composite even after 75 days of seed sowing. Further confirmation of the finding could be useful for top dressing N in the maize crop.
Life cycle environmental assessment of summer maize in a North China high-yield region
华北高产粮区夏玉米生命周期环境影响评价

王明新,吴文良,夏训峰
环境科学学报 , 2010,
Abstract: Life cycle assessment was used to establish an inventory of resource use and emissions and to assess life cycle environmental impacts of summer maize production system with different nitrogen fertilizer intensity in Huantai County, Shandong province. The assessment was conducted with per product as the functional unit and the life cycle of the summer maize production system was divided into three phases, including raw material mining & transportation, agricultural production & transportation and crop planting. The results revealed that the life cycle environmental impacts of summer maize production system show an exponential upward trend with the increase of nitrogen fertilizer application. The most significant environmental impact was water depletion because agriculture is a water\|intensive industry and water productivity in the study area was low. The most important pollution effect type was global warming at a low nitrogen application rate, but aquatic eutrophication with high nitrogen fertilizer input. As such, to reduce the nitrogen and water consumption as well as to increase their productivities are the key to control the life cycle environmental impacts of summer maize production system, which decrease resource consumption and emissions not only directly in the crop planting stage but also indirectly in the upstream production stage.
Zinc, Iron, Manganese and Copper Uptake Requirement in Response to Nitrogen Supply and the Increased Grain Yield of Summer Maize  [PDF]
Yanfang Xue, Shanchao Yue, Wei Zhang, Dunyi Liu, Zhenling Cui, Xinping Chen, Youliang Ye, Chunqin Zou
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0093895
Abstract: The relationships between grain yields and whole-plant accumulation of micronutrients such as zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) in maize (Zea mays L.) were investigated by studying their reciprocal internal efficiencies (RIEs, g of micronutrient requirement in plant dry matter per Mg of grain). Field experiments were conducted from 2008 to 2011 in North China to evaluate RIEs and shoot micronutrient accumulation dynamics during different growth stages under different yield and nitrogen (N) levels. Fe, Mn and Cu RIEs (average 64.4, 18.1and 5.3 g, respectively) were less affected by the yield and N levels. ZnRIE increased by 15% with an increased N supply but decreased from 36.3 to 18.0 g with increasing yield. The effect of cultivars on ZnRIE was similar to that of yield ranges. The substantial decrease in ZnRIE may be attributed to an increased Zn harvest index (from 41% to 60%) and decreased Zn concentrations in straw (a 56% decrease) and grain (decreased from 16.9 to 12.2 mg kg?1) rather than greater shoot Zn accumulation. Shoot Fe, Mn and Cu accumulation at maturity tended to increase but the proportions of pre-silking shoot Fe, Cu and Zn accumulation consistently decreased (from 95% to 59%, 90% to 71% and 91% to 66%, respectively). The decrease indicated the high reproductive-stage demands for Fe, Zn and Cu with the increasing yields. Optimized N supply achieved the highest yield and tended to increase grain concentrations of micronutrients compared to no or lower N supply. Excessive N supply did not result in any increases in yield or micronutrient nutrition for shoot or grain. These results indicate that optimized N management may be an economical method of improving micronutrient concentrations in maize grain with higher grain yield.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.