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Fields experiments in North China show no decrease in winter wheat yields with night temperature increased by 2.0-2.5°C

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Science China Earth Sciences 2012年第6期55卷 1021-1027页

作者： FANG ShiBo TAN KaiYan REN SanXue ZHANG XinShi ZHAO JunFang Chinese Academy of Meteorological Sciences Beijing 100081 China Institute of Botany Chinese Academy of Sciences Beijing 100093 China

The trends of daily maximum and minimum temperature in global warming indicated that the daily minimum temperature （Tmin） has risen more than twice as fast as the daily maximum temperature （Tmax） during the 20th century. Most researchers have focused on how the crops respond to daily mean temperature, whereas few controlled experiments were carried out to in- vestigate how the crops respond to the Train rise. In particular, no experiment research has reported on how crops respond to the higher night temperature, which was the main trend in the climate warming. Taking winter wheat as the test crop, we investi- gated how the winter wheat growth and yields responded to the higher night temperature. In the field experiments, infrared heaters were used to increase higher night temperature （HNT） by about 2.5℃ in contrast to the normal night temperature （CK） in two whole growth durations of winter wheat in 2008-2009 and 2009-2010 in North China. The results indicated that, com- pared to the CK treatment, winter wheat yield did not decline in HNT treatment, which increased temperatures by 2.0-2.5℃ in both Wanner year （WY） and Colder year （CY）. Furthermore, winter wheat yield in CY increased significantly in HNT treatment. HNT treatment in CY could significantly promote tillering and increase the effective panicles, which increased grain yield significantly （by more than 30% compared with CK）. HNT treatment in CY contributed to an increase in the effective panicles and Kernels significantly, although making a significant reduction in 1000-grain weight, but did not lead to the yield decline. Under the HNT treatment, the whole growth duration of the winter wheat was shortened and the phenological dates were earlier except for the beginning of overwintering; the beginnings of the overwintering phase were postponed substantially and the ends of the overwintering phase were ahead of date compared to CK, which shortened the duration of overwintering considerably. We draw on our ow

关键词： climate change higher night temperature winter wheat yields adaptation

Contributions of climate change to cereal yields in Tibet, 1993–2017

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Journal of Geographical Sciences 2022年第1期32卷 101-116页

作者： DING Rui SHI Wenjiao Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Climate change is a global environmental crisis, but there have been few studies of the effects of climate change on cereal yields on the Tibetan Plateau. We used data from meteorological stations and statistical yearbooks to assess the impacts of climate change on cereal yields in Tibet. Three types of statistical models were selected: fixed-effects model, first-difference models, and linear detrending models. We analyzed the impacts of climate change(including the minimum temperature, precipitation, growing degree days and solar radiation) on cereal yields in Tibet from 1993 to 2017 at the county, prefecture-level city, and autonomous region scales. The results showed that the sensitivity of cereal yields in Tibet to temperature(minimum temperature and growing degree days) was greater than their sensitivity to precipitation and solar radiation. The joint impacts of climate variables were positive, but the sensitivity and significance varied in different regions. The impacts of minimum temperature, precipitation, and solar radiation were positive in all cities, apart from the negative impacts of growing degree days on cereal yields in Lhasa. The impacts of climate trends on cereal yields in Tibet were positive and the results were in the range of 1.5%–4.8%. Among the three types of model, the fixed-effects model was the most robust and the linear detrending model performed better than the first-difference model. The robustness of the first-difference model decreased after adding the interaction terms between different climate variables. Our findings will help in implementing more spatially targeted agricultural adaptations to cope with the impacts of climate change on the agro-ecosystem of the Tibetan Plateau.

关键词： Tibetan Plateau climate change statistical model cereal yields

Potential energy surfaces and fission fragment mass yields of even-even superheavy nuclei

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Chinese Physics C 2021年第12期45卷 155-174页

作者： Pavel V.Kostryukov Artur Dobrowolski Bozena Nerlo-Pomorska Michal Warda Zhigang Xiao Yongjing Chen Lile Liu Jun-Long Tian Krzysztof Pomorski Institute of Physics Maria Curie Sklodowska University20-031 LublinPoland Department of Physics Tsinghua UniversityBeijing 100084China Institute of Atomic Energy Beijing 102413China School of Physics and Electrical Engineering Anyang Normal UniversityAnyang 455000China

Potential energy surfaces and fission barriers of superheavy nuclei are analyzed in a macroscopic-microscopic *** Lublin-Strasbourg Drop(LSD)model is used to obtain the macroscopic part of the energy,whereas the shell and pairing energy corrections are evaluated using the Yukawa-folded potential;a standard flooding technique is utilized to determine barrier heights.A Fourier shape parametrization containing only three deformation parameters is shown to effectively reproduce the nuclear shapes of nuclei approaching *** addition,a non-axial degree of freedom is taken into account to better describe the structure of nuclei around the ground state and in the saddle *** addition to the symmetric fission valley,a new highly asymmetric fission mode is predicted in most superheavy *** fission fragment mass distributions of the considered nuclei are obtained by solving 3D Langevin equations.

关键词： nuclear fission mac-mic model fission barrier heights fragment mass yields

Rice breeding for low methane and high yields

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Plant Communications 2024年第5期5卷 94-96页

作者： Suvendu Das Pil Joo Kim Institute of Agriculture and Life Sciences Gyeongsang National UniversityJinju 660-701South Korea Division of Applied Life Science Gyeongsang National UniversityJinju 660-701South Korea

Rice is the staple food for more than half of the world’s population,and the demand for rice is expected to increase by 28%by 2050(Jiang et al.,2017).However,rice production is one of the largest anthropogenic sources of the potent greenhouse gas methane(CH4),accounting for 22%of total agricultural CH4 emissions(Qian et al.,2023).Therefore,to achieve sustainable intensification of rice cultivation,it is necessary to increase yields while reducing CH4 *** management techniques to reduce CH4 emissions while maintaining high yields have been studied extensively over the past few decades,but crop breeding to reduce CH4 emissions without compromising yields has received less attention(Kwon et al.,2023).

关键词： breeding methane yields

yields and Agronomic Characters of New Rice Hybrids Performed at Pine Bluff, Arkansas

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American Journal of Plant Sciences 2018年第9期9卷 1911-1921页

作者： Bihu Huang Zongbu Yan University of Arkansas at Pine Bluff Pine Bluff AR USA AgriLife Research at Beaumont Texas A&M University College Station USA

yields and agronomic characters of 35 new hybrids were tested at Pine Bluff, Arkansas in 2013. These hybrids were developed from 7 female parent sterile lines, UP-1s, UP-3s, 100s, 101s, 105s, 111s, and 113A, and 5 male parent restorer lines, PB2, PB5, PB12, PB13, and PB18. The inbred variety Francis, which is a popular variety in the rice production, was used as the check (CK). Results showed that the yields of 10 hybrids were 20.3% - 31.7% higher than that of CKFrancis. The yields of other 18 hybrids were 10.1% - 19.4% higher than CK, and the yields of rest of the hybrids were 2.5% - 9.2% higher than CK. Hybrid UP-3s/PB5 had the highest yield, 12,983.8 kg/hectare and over check by 31.7%. The yield of hybrid UP-3s/PB18 and 115A/PB18 were 12,333.7 kg/hectare and over check 25%. The yields of hybrid UP-1s/PB12 was 12,324.6 kg//hectare and over check 24.9%. The sterile lines UP-3s, 113A, 105s, and 101s have good combinability and the average grain yields of their hybrids were over CKby 21.5%, 20.34%, 17.2% and 16.2%, respectively. The restorer lines PB18, PB5, and PB12 have good combinability and the average grain yields of their hybrids were over CKby 19.9%, 18.4% and 16.2%, respectively. These results indicated that these top hybrids and their parents of the sterile lines and restorer lines might be used in the hybrid rice breeding and production in the future.

关键词： New Hybrid Rice Sterile Line Restore Line yields Miller Rice and Head Rice

Effect of Mineral Fertilization and Irrigation on Sunflower yields

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American Journal of Plant Sciences 2015年第7期6卷 870-879页

作者： Lucia Helena Garófalo Chaves Danila Lima Araujo Hugo Orlando Carvallo Guerra Walter Esfrain Pereira Federal University of Campina Grande Avenue Aprigio Veloso Campina Grande Brazil Federal University of Paraiba Campus II Areia Brazil

Among the cultures used for the production of biofuels, the sunflower is one of the most important. Although some information exists, the water and nutritional needs of sunflower in the north east of Brazil are not well known. To fill knowledge gaps, an experiment was carried out to evaluate the effect of nitrogen (N), phosphorus (P), potassium (K) fertilization and available soil water (ASW) on sunflower yields. The sunflower cultivar Embrapa 122-V2000 was subjected to 44 treatments on a completely randomized design generated by the Baconian Matrix with four rates of N (0, 60, 80 and 100 kg·ha-1), four rates of P2O5 (0, 80, 100 and 120 kg·ha-1), four rates of K2O (0, 80, 100 and 120 kg·ha-1), and four available soil water (ASW) levels (55%, 70%, 85% and 100%) replicated three times. Urea was used as a source of N, triple super phosphate as P and potassium chloride as K. In all the experimental units was applied 2 kg·B·ha-1 as boric acid. The components of production evaluated were dry matter of the head, total number of achenes, total achenes’ weight and 1000 achenes’ weight. The results of this research showed that nitrogen had a significant effect on the dry matter of the head, total number of achenes and total achenes’ weight. Phosphorus affected all production components and potassium affected the total number and the weight of achenes. With the exception of the 1000 achenes’ weight, all the production components of the sunflower increased with the increased ASW level influenced significantly at 0.01 level of probably the total number of achenes. The highest rates of N, P and K (100, 120 and 120 kg·ha-1, respectively) and 100% of available soil water produced the highest production.

关键词： Water Fertilizers yields Oil Plants Seeds

Genotype and Environment Interactions of yields and Yield Components of Tea (Camellia sinensis) Cultivars in Kenya

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American Journal of Plant Sciences 2016年第6期7卷 855-869页

作者： Karl W. Nyabundi P. Okinda Owuor Godfrey W. Netondo John K. Bore Tea Research Institute Kenya Agricultural and Livestock Research Organization Kericho Kenya Department of Chemistry School of Physical and Biological Sciences Maseno University Maseno Kenya Department of Botany School of Physical and Biological Sciences Maseno University Maseno Kenya

The tea crop provides income and employment to rural populations in many countries. In Kenya, tea, which is the leading export commodity crop, is grown in highlands east and west of the Rift Valley at altitudes ranging from 1300 m to 2700 m above mean sea level. Variable responses of tea genotypes to different environments have been demonstrated. This affects the growth, productivity, and quality of tea. However, most tea husbandry practices are uniform across tea growing regions leading to variations in yields and quality in the different environments. Understanding causes of variations in tea growth parameters and yields to varying environments is vital to optimizing husbandry practices for maximization of productivity. The responses in growth and yield parameters of clonal tea to locations of production and their contribution to yields were compared. A genotype × environment trial was conducted in three sites (Kangaita, Timbilil and Kipkebe). At each site, a trial comprising 20 cultivars was laid in a randomized complete design replicated 3 times. yields, yield components and climatic data were collected then subjected to analysis of variance and regression analysis. There were significant (p ≤ 0.05) yield variations between clones and locations. yields ranged from 5162 kg mt/ha on clone TRFK 303/577 at Kipkebe to 935 kg mt/ha/year on clone TRFK 7/3 in Kangaita, surpassing the maximum variation possible postulated in earlier studies. The responses of the tea yield components to weather parameters varied with genotypes and environments. Shoot growth rates in Timbilil (r = 0.476)) and shoot density (Kangaita (r = 0.652) significantly (p ≤ 0.05)) correlated with yields. Yield components and weather parameters contribution to the total yield also varied with locations. The variations demonstrated that not all yield components can be used universally as yield indicators for clonal selection in different locations. For optimal production, selected tea clones should the

关键词： Genotype Environment Weather Parameters yields Yield Components

Validation of PSIAC Model for Sediment yields Estimation in Ungauged Catchments of Tanzania

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International Journal of Geosciences 2013年第7期4卷 1101-1115页

作者： P. M. Ndomba Department of Water Resources Engineering University of Dar es Salaam Dar es Salaam Tanzania

The main objective of this paper is to report on preliminary validation results of the newly applied sediment yields estimation model in Tanzania, the Pacific Southwest Inter-Agency Committee (PSIAC). This is a follow-up research on the call to customize simple and/or multi-processes sediment yields estimation models such as PSIAC in the region. The PSIAC approach is based on a sediment yield classification scheme employing individual drainage basin characteristics: surface geology, soils, climate, runoff, topography, ground cover, land use, upland erosion, channel erosion, and sediment transport. In this study, PSIAC model is built from readily available environmental variables sourced from Government ministries/agencies and public domain global spatial data. The sediment classification exercise was verified with field observations. The set up model was then validated by 31 small dams’ siltation surveys and previous sedimentation study findings. PSIAC model performance for major part of central Tanzania was good during calibration (BIAS = 7.88%) and validation (BIAS = 18.12%). Another observation was that uncalibrated model performs fairly well, though performance improves with calibration. The extension of the uncalibrated PSIAC model to 3 selected large basins of Tanzania, with drainage areas size up to 223,000 km2, registered a satisfactory performance in one of them with fair performance in the rest. For large basins, the performance seems to correlate with general ground slope. The higher the slope, the better the performance. It is, however, not apparent from this study on the threshold drainage area and slope requirements for better performance of the model. Notwithstanding, the PSIAC model has improved previous sediment yields estimates based on simple regressive models. Finally, the paper proposes two main further research works: use of high resolution geospatial data and additional validation dams siltation data even beyond the central part of Tanzania, a

关键词： Calibration PSIAC Model Sediment yields Tanzania Validation

Impact of Seasons on Soil Physico-Chemical Properties and Tea yields Based on Enriched Sheep Manure Used in Kericho, Kenya

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Journal of Agricultural Chemistry and Environment 2019年第3期8卷 184-199页

作者： Rhoda Ruto Syphline Kebeney John K. Bore David Chemei Tea Research Institute Kenya Agricultural and Livestock Research Organization Kericho Kenya Department of Soil Science The University of Eldoret Eldoret Kenya

Tea (Camellia sinensis (L) O. Kuntze) is a perennial crop grown for beverage consumption. Its production is the leading foreign exchange earner in Kenya contributing about 26% foreign exchange and 4% GDP. Nitrogen (N), Phosphorus (P) and potassium (K) are the recommended nutrients for tea production. However, their continuous use has been reported to have negative effect on soil physico-chemical properties and health. Sheep manure has been recommended in tea production for its soil pH buffering effect and increased tea yields. However, effects of sheep manure enriched with inorganic fertilizer on tea soils and yield have not been conclusively investigated. This study was established at KALRO—Tea Research Institute Kericho in Timbilil estate to determine the impact of seasonal variation on soil pysico-chemical properties and yields on enriched sheep manure used. Randomized complete block design (RCBD) experimental design was adopted with 14 treatments replicated thrice. The treatments were: control with no fertilizer use, NPK at 180 Kgs N/ha/yr, sheep manure only and two enriched sheep manure ratios of 4:1 and 8:1 which translates to a mixture of (4:1) 4 parts of sheep manure and 1 part of D.A.P inorganic fertilizer. Same applied to 8:1 ratio, respectively at rates of 60, 120, 180 and 240 Kgs N/ha once per year. Data were subjected to ANOVA in GenStat statistical package and means separated by Duncan’s multiple range tests at P ≤ 0.05 significance level. Results obtained showed that soil physico-chemical properties and tea yields were influenced significantly (P ≤ 0.05) by treatments applied. Soil available water and organic matter were higher on enriched sheep manure 4:1 at 240 rate used while soil porosity and bulk density were not significantly affected. Total N and P, increased with enriched sheep manure ratio of 4:1 at 240 rate while K+, Ca2+, Mg2+, Mn and pH increased with sole application of sheep manure at rate 180 and enriched sheep manure 8:1 at 180 rate. T

关键词： Seasons Soil Physic-Chemical Properties Enriched Sheep Manure Tea yields