Study on Energy Exchange of Dry-Land Spring Maize Field in Loess Plateau

2013 ◽  
Vol 726-731 ◽  
pp. 3771-3779
Author(s):  
Jia Xuan Guo ◽  
Xu Rong Mei ◽  
Yu Zhong Li
Keyword(s):  
Loess Plateau ◽  
Energy Exchange ◽  
Growth Period ◽  
Bowen Ratio ◽  
Heat Consumption ◽  
Field Energy ◽  
Growth Stages ◽  
Dry Land ◽  
North West ◽  
Spring Maize

Dry-land spring maize is a main cultivated crop in North-West China. To explore the mechanism for changes of evapotranspiration and heat consumption in dry-land spring maize, eddy covariance technique was used to monitor the energy-exchange characteristics of the crop in Eastern Loess Plateau field. The results showed that the field-energy-balance ratio of dry-land spring maize is in the 0.75 - 1.0 range during non-rainfall daily noon (12:00 - 14:00). The Bowen ratio exhibited "L-type" trend during the total growth stages, namely, the highest Bowen ratio was at seedling stage with phase average 4.85 ± 1.42. The evaporation fraction showed a single peak trend in August, and the higher evaporation ratio met with more precipitation with average values 0.55 ± 0.06. The Bowen ratio and average evaporation fraction at the entire growth period were 1.78 ± 1.71 and 0.40 ± 0.18, respectively. About 40% of surface energy obtained from drought agro-ecosystem was used for evapotranspiration and heat consumption.

scholarly journals Response of Soil Temperature, Moisture, and Spring Maize (Zea mays L.) Root/Shoot Growth to Different Mulching Materials in Semi-Arid Areas of Northwest China

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 453
Author(s):  
Haidong Lu ◽  
Zhenqing Xia ◽  
Yafang Fu ◽  
Qi Wang ◽  
Jiquan Xue ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Soil Water ◽  
Leaf Area ◽  
Growth Period ◽  
Soil Water Storage ◽  
Shoot Biomass ◽  
Growth Stages ◽  
Plastic Film ◽  
Area Index ◽  
Spring Maize

Adaptive highly efficient mulching technologies for use on dryland agricultural ecosystems are crucial to improving crop productivity and water-use efficiency (WUE) under climate change. Little information is available on the effect of using different types of mulch on soil water thermal conditions, or on root/shoot trait, leaf area index (LAI), leaf area duration (LAD), yield, and WUE of spring maize. Hence, in this study, white transparent plastic film (WF), black plastic film (BF), and maize straw (MS) was used, and the results were compared with a non-mulched control (CK). The results showed that the mean soil temperature throughout the whole growth period of maize at the 5–15 cm depth under WF and BF was higher than under MS and CK, but under BF, it was 0.6 °C lower than WF. Compared with CK, the average soil water storage (0–200 cm) over the whole growth period of maize was significantly increased under WF, BF, and MS. WF and BF increased the soil water and temperature during the early growth stages of maize and significantly increased root/shoot biomass, root volume, LAI, LAD, and yield compared with MS. Higher soil temperatures under WF obviously reduced the duration of maize reproductive growth and accelerated root and leaf senescence, leading to small root/shoot biomass accumulation post-tasseling and to losses in yield compared with BF

Long-term vegetation restoration promotes the stability of the soil micro-food web in the Loess Plateau in North-west China

CATENA ◽  
2021 ◽  
Vol 202 ◽  
pp. 105293
Author(s):  
Yang Wu ◽  
WenJing Chen ◽  
Wulan Entemake ◽  
Jie Wang ◽  
HongFei Liu ◽  
...  
Keyword(s):  
Food Web ◽  
Loess Plateau ◽  
Vegetation Restoration ◽  
The Loess Plateau ◽  
West China ◽  
North West ◽  
The Stability

scholarly journals Vegetation Response to Goats Grazing Intensity in Semiarid Hilly Grassland of the Loess Plateau, Lanzhou, China

2021 ◽  
Vol 13 (6) ◽  
pp. 3569
Author(s):  
Hua Cheng ◽  
Baocheng Jin ◽  
Kai Luo ◽  
Jiuying Pei ◽  
Xueli Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Community Structure ◽  
Plant Growth ◽  
Loess Plateau ◽  
Grazing Intensity ◽  
Gps Tracking ◽  
Growth Stages ◽  
The Loess Plateau ◽  
Vegetation Community ◽  
Natural Grasslands

Quantitatively estimating the grazing intensity (GI) effects on vegetation in semiarid hilly grassland of the Loess Plateau can help to develop safe utilization levels for natural grasslands, which is a necessity of maintaining livestock production and sustainable development of grasslands. Normalized difference vegetation index (NDVI), field vegetation data, and 181 days (one goat per day) of GPS tracking were combined to quantify the spatial pattern of GI, and its effects on the vegetation community structure. The spatial distribution of GI was uneven, with a mean value of 0.50 goats/ha, and 95% of the study area had less than 1.30 goats/ha. The areas with utilization rates of rangeland (July) lower than 45% and 20% made up about 95% and 60% of the study area, respectively. Grazing significantly reduced monthly aboveground biomass, but the grazing effects on plant growth rate were complex across the different plant growth stages. Grazing impaired plant growth in general, but the intermediate GI appeared to facilitate plant growth rate at the end of the growing seasons. Grazing had minimal relationship with vegetation community structure characteristics, though Importance Value of forbs increased with increasing GI. Flexibility in the number of goats and conservatively defining utilization rate, according to the inter-annual variation of utilization biomass, would be beneficial to achieve ecologically healthy and economically sustainable GI.

scholarly journals Different Drought Legacies of Rain-Fed and Irrigated Croplands in a Typical Russian Agricultural Region

2020 ◽  
Vol 12 (11) ◽  
pp. 1700
Author(s):  
Yuanhuizi He ◽  
Fang Chen ◽  
Huicong Jia ◽  
Lei Wang ◽  
Valery G. Bondur
Keyword(s):  
Surface Temperature ◽  
Drought Index ◽  
Growth Period ◽  
Meteorological Drought ◽  
Agricultural Drought ◽  
Drought Monitoring ◽  
Growth Stages ◽  
Drought Conditions ◽  
Irrigated Lands ◽  
Meteorological Droughts

Droughts are one of the primary natural disasters that affect agricultural economies, as well as the fire hazards of territories. Monitoring and researching droughts is of great importance for agricultural disaster prevention and reduction. The research significance of investigating the hysteresis of agricultural to meteorological droughts is to provide an important reference for agricultural drought monitoring and early warnings. Remote sensing drought monitoring indices can be employed for rapid and accurate drought monitoring at regional scales. In this paper, the Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices and the surface temperature product are used as the data sources. Calculating the temperature vegetation drought index (TVDI) and constructing a comprehensive drought disaster index (CDDI) based on the crop growth period allowed drought conditions and spatiotemporal evolution patterns in the Volgograd region in 2010 and 2012 to be effectively monitored. The causes of the drought were then analyzed based on the sensitivity of a drought to meteorological factors in rain-fed and irrigated lands. Finally, the lag time of agricultural to meteorological droughts and the hysteresis in different growth periods were analyzed using statistical analyses. The research shows that (1) the main drought patterns in 2010 were spring droughts from April to May and summer droughts from June to August, and the primary drought patterns in 2012 were spring droughts from April to June, with an affected area that reached 3.33% during the growth period; (2) local drought conditions are dominated by the average surface temperature factor. Rain-fed lands are sensitive to the temperature and are therefore prone to summer droughts. Irrigated lands are more sensitive to water shortages in the spring and less sensitive to extremely high temperature conditions; (3) there is a certain lag between meteorological and agricultural droughts during the different growth stages. The strongest lag relationship was found in the planting stage and the weakest one was found in the dormancy stage. Therefore, the meteorological drought index in the growth period has a better predictive ability for agricultural droughts during the appropriately selected growth stages.

Light and Water Use Efficiency as Influenced by Clouds and/or Aerosols in a Rainfed Spring Maize Cropland on the Loess Plateau

Crop Science ◽  
2018 ◽  
Vol 58 (2) ◽  
pp. 853-862 ◽  
Author(s):  
Xiang Gao ◽  
Fengxue Gu ◽  
Xurong Mei ◽  
Weiping Hao ◽  
Haoru Li ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Loess Plateau ◽  
The Loess Plateau ◽  
Spring Maize ◽  
Use Efficiency

scholarly journals Crop Mapping in the Sanjiang Plain Using an Improved Object-Oriented Method Based on Google Earth Engine and Combined Growth Period Attributes

2022 ◽  
Vol 14 (2) ◽  
pp. 273
Author(s):  
Mengyao Li ◽  
Rui Zhang ◽  
Hongxia Luo ◽  
Songwei Gu ◽  
Zili Qin
Keyword(s):  
Large Scale ◽  
Vegetation Index ◽  
Object Oriented ◽  
Growth Period ◽  
Sanjiang Plain ◽  
Google Earth ◽  
Utilization Rate ◽  
Growth Stages ◽  
The Sanjiang Plain ◽  
Growth Method

In recent years, the scale of rural land transfer has gradually expanded, and the phenomenon of non-grain-oriented cultivated land has emerged. Obtaining crop planting information is of the utmost importance to guaranteeing national food security; however, the acquisition of the spatial distribution of crops in large-scale areas often has the disadvantages of excessive calculation and low accuracy. Therefore, the IO-Growth method, which takes the growth stage every 10 days as the index and combines the spectral features of crops to refine the effective interval of conventional wavebands for object-oriented classification, was proposed. The results were as follows: (1) the IO-Growth method obtained classification results with an overall accuracy and F1 score of 0.92, and both values increased by 6.98% compared to the method applied without growth stages; (2) the IO-Growth method reduced 288 features to only 5 features, namely Sentinel-2: Red Edge1, normalized difference vegetation index, Red, short-wave infrared2, and Aerosols, on the 261st to 270th days, which greatly improved the utilization rate of the wavebands; (3) the rise of geographic data processing platforms makes it simple to complete computations with massive data in a short time. The results showed that the IO-Growth method is suitable for large-scale vegetation mapping.

Predicting Physiological Growth Period based on Cumulative Climatic Suitability of Spring Maize

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhou B ◽  
◽  
Zhang Y ◽  
Li J ◽  
Wang T ◽  
...  
Keyword(s):  
Growth Stage ◽  
Reference Value ◽  
Growth Period ◽  
Absolute Error ◽  
Weight Coefficient ◽  
Liaoning Province ◽  
Observation Data ◽  
Climatic Suitability ◽  
Spring Maize ◽  
Physiological Stage

The growth period prediction at the various physiological stage of spring maize is an essential component in agricultural management decisions. An Improved Climate Suitability (ICS) model was established by integrating temperature, precipitation, sunshine and soil moisture and setting individual weight coefficient in each subordinate function according to the observation data of spring maize growth and meteorological factors of 14 agrometeorological stations in the Liaoning Province of northeast China from 1981 to 2010. The predicted value (Bjk) and reference value (Bk) of the cumulative climatic suitability index were calculated by the ICS model for arranging farming activities in advance when the Bjk > Bk at the various physiological growth stage of spring maize. The ICS model was further verified by the observation data at the whole and various physiological stages of spring maize. The result showed that the Bjk was linearly correlated with the observed days at each physiological growth stage of spring maize with R² of 0.75-0.88, P<0.001, Thus, the Bjk can be used to determine the growth period of the various physiological stage of spring maize. The prediction days were significantly correlated with the observed days at the whole and each physiological growth stage of spring maize (R² of 0.57-0.98, P<0.001) with the absolute error (ABSE) of 1.1-4.1 d. Thus, the precision of the ICS model is acceptable for forecasting the growth period and arranging farming activities in advance. Thus, the ICS model should be promoted further in the management of spring maize plantation.

Analyses of Aerosol Concentrations and Bacterial Community Structures for Closed Cage Broiler Houses at Different Broiler Growth Stages in Winter

2018 ◽  
Vol 81 (9) ◽  
pp. 1557-1564
Author(s):  
LINLIN JIANG ◽  
JIANLONG ZHANG ◽  
JINXIU TANG ◽  
MENG LI ◽  
XIAOYU ZHAO ◽  
...  
Keyword(s):  
Bacterial Community ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Total Concentration ◽  
Growth Period ◽  
Growth Cycle ◽  
Growth Stages ◽  
Community Structures ◽  
Dynamic Pattern ◽  
Different Growth Stages

ABSTRACT The aim of the present study was to analyze the aerosol concentrations and microbial community structures in closed cage broiler houses at different broiler growth stages to assess the dynamic pattern of microbial aerosols in closed cage systems. Our results revealed that the total concentration of bacterial aerosols gradually increased during the growth cycle of broilers. High-throughput sequencing of 16S rDNA revealed that microbial compositions differed tremendously during different growth stages, although Firmicutes and Proteobacteria were the dominant taxa in samples from all broiler growth stages. At the genus level, dominant phylotypes displayed great variation during different growth stages. Escherichia and Shigella were the most dominant taxa throughout the growth cycle, increasing from 4.3 to 12.4% as the broilers grew. The alpha index revealed that the microbial diversity displayed significant differences between the different growth stages and that the bacterial community had the highest diversity when broilers were 22 days old. High-throughput sequencing analyses revealed that environmental microbes and opportunistic pathogens had relatively high abundances during the winter growth period. The data revealed the composition and aerodynamic diameters of microbial aerosols in closed cage broiler houses at different broiler growth stages in winter. The results also enabled us to elucidate the dynamic pattern of microbial aerosols in broiler houses in response to bacterial communities. Our results may provide a basis for developing technologies for air quality control in caged poultry houses.

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