scholarly journals Modeling Soil Water–Heat Dynamic Changes in Seed-Maize Fields under Film Mulching and Deficit Irrigation Conditions

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1330 ◽  
Author(s):  
Yin Zhao ◽  
Xiaomin Mao ◽  
Manoj K. Shukla ◽  
Sien Li
Keyword(s):  
Soil Temperature ◽  
Soil Water ◽  
Crop Growth ◽  
Future Climate ◽  
Soil Water Storage ◽  
Future Climate Change ◽  
Model Parameters ◽  
Area Index ◽  
Swap Model ◽  
Film Mulching

The Soil–Water–Atmosphere–Plant (SWAP) model does not have a mulching module to simulate the effect of film mulching on soil water, heat dynamics and crop growth. In this study, SWAP model parameters were selected to simulate the soil water–heat process and crop growth, taking into account the effect of film mulching on soil evaporation, temperature, and crop growth, in order to predict the influence of future climate change on crop growth and evapotranspiration (ET). A most suitable scheme for high yield and water use efficiency (WUE) was studied by an experiment conducted in the Shiyang River Basin of Northwest China during 2017 and 2018. The experiment included mulching (M1) and non-mulching (M0) under three drip irrigation treatments, including full (WF), medium (WM), low (WL) water irrigation. Results demonstrated that SWAP simulated soil water storage (SWS) well, soil temperature at various depths, leaf area index (LAI) and aboveground dry biomass (ADB) with the normalized root mean square error (NRMSE) of 16.2%, 7.5%, 16.1% and 16.4%, respectively; and yield, ET, and WUE with the mean relative error (MRE) of 10.5%, 12.4% and 14.8%, respectively, under different treatments on average. The measured and simulated results showed film mulching could increase soil temperature, promote LAI during the early growth period, and ultimately improve ADB, yield and WUE. Among the treatments, M1WM treatment with moderate water deficit and film mulching could achieve the target of more WUE, higher yield, less irrigation water. Changes in atmospheric temperature, precipitation, and CO2 concentration are of worldwide concern. Three Representative Concentration Pathway (RCP) scenarios (RCP2.6, RCP4.5, RCP8.5) showed a negative effect on LAI, ADB and yield of seed-maize. The yield of seed-maize on an average decreased by 33.2%, 13.9% under the three RCPs scenarios for film mulching and non-mulching, respectively. Predicted yields under film mulching were lower than that under non-mulching for the next 30 years demonstrating that current film mulching management might not be suitable for this area to improve crop production under the future climate scenarios.

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

scholarly journals A Coupled Model for Simulating Water and Heat Transfer in Soil-Plant-Atmosphere Continuum with Crop Growth

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 47 ◽  
Author(s):  
Weicai Yang ◽  
Xiaomin Mao ◽  
Jian Yang ◽  
Mengmeng Ji ◽  
Adebayo J. Adeloye
Keyword(s):  
Heat Transfer ◽  
Soil Moisture ◽  
Winter Wheat ◽  
Soil Water ◽  
Coupled Model ◽  
Crop Growth ◽  
Soil Water Storage ◽  
Area Index ◽  
Moisture Condition ◽  
Soil Moisture Condition

Crop growth is influenced by the energy partition and water–heat transfer in the soil and canopy, while crop growth affects the land surface energy distribution and soil water-heat dynamics. In order to simulate the above processes and their interactions, a new model, named CropSPAC, was developed considering both the growth of winter wheat and the water–heat transfer in Soil-Plant-Atmosphere Continuum (SPAC). In CropSPAC, the crop module depicts the dynamic changes of leaf area index (LAI), crop height, and the root distribution and outputs them to the SPAC module, while the latter outputs soil moisture conditions for the crop module. CropSPAC was calibrated and validated by field experiment of winter wheat in Yongledian, Beijing, with five levels of irrigation treatments, namely W0 (0 mm), W1 (60 mm), W2 (110 mm), W3 (170 mm), and W4 (230 mm). Results show that CropSPAC could predict the soil water and temperature distribution, and winter wheat growth with acceptable accuracy. For example, for the 0–1 m soil water storage, the R2 for W0, W1, W2, W3, and W4 is 0.90, 0.88, 0.90, 0.91, and 0.79, and the root mean square error (RMSE) is 17.24 mm, 27.65 mm, 20.47 mm, 22.35 mm, and 12.88 mm, respectively. For soil temperature along the soil profile, the R2 ranges between 0.96 and 0.98, and the RMSE between 1.22 °C and 1.94 °C. For LAI, the R2 varied from 0.76 to 0.96, and the RMSE from 0.52 to 0.67. We further compared the simulation results by CropSPAC and its two detached modules, i.e., crop and the SPAC modules. Results demonstrate that the coupled model could better reflect the interactions between crop growth and soil moisture condition, more suitable to be used under deficit irrigation conditions.

scholarly journals Daily and seasonal patterns of CO2 fluxes and evapotranspiration in maize-grass intercropping

2016 ◽  
Vol 20 (9) ◽  
pp. 777-782 ◽  
Author(s):  
Cássia B. Machado ◽  
José R. de S. Lima ◽  
Antonio C. D. Antonino ◽  
Eduardo S. de Souza ◽  
Rodolfo M. S. Souza ◽  
...  
Keyword(s):  
Soil Water ◽  
Climate Changes ◽  
Carbon Sink ◽  
Soil Water Storage ◽  
Co2 Uptake ◽  
Co2 Fluxes ◽  
Area Index ◽  
Available Energy ◽  
Atmospheric Carbon ◽  
Main Consumer

ABSTRACT Studies that investigate the relationships between CO2 fluxes and evapotranspiration (ET) are important for predicting how agricultural ecosystems will respond to climate changes. However, none was made on the maize-grass intercropping system in Brazil. The aim of this study was to determine the ET and CO2 fluxes in a signal grass pasture intercropped with maize, in São João, Pernambuco, Brazil, in a drought year. Furthermore, the soil water storage (SWS) and leaf area index (LAI) were determined. The latent heat flux was the main consumer of the available energy and the daily and seasonal ET and CO2 variations were mainly controlled by rainfall, through the changes in soil water content and consequently in SWS. The agroecosystem acted as an atmospheric carbon source, during drier periods and lower LAI, and as an atmospheric carbon sink, during wetter periods and higher LAI values. In a dry year, the intercropping sequestered 2.9 t C ha-1, which was equivalent to 8.0 kg C ha-1 d-1. This study showed strong seasonal fluctuations in maize-grass intercropping CO2 fluxes, due to seasonality of rainfall, and that this agroecosystem is vulnerable to low SWS, with significant reduction in CO2 uptake during these periods.

scholarly journals Vegetation–climate feedbacks modulate rainfall patterns in Africa under future climate change

2016 ◽  
Vol 7 (3) ◽  
pp. 627-647 ◽  
Author(s):  
Minchao Wu ◽  
Guy Schurgers ◽  
Markku Rummukainen ◽  
Benjamin Smith ◽  
Patrick Samuelsson ◽  
...  
Keyword(s):  
Surface Energy ◽  
General Circulation ◽  
Hydrological Cycle ◽  
Regional Climate ◽  
Circulation Model ◽  
Future Climate ◽  
Tree Cover ◽  
Future Climate Change ◽  
Climate Projections ◽  
Area Index

Abstract. Africa has been undergoing significant changes in climate and vegetation in recent decades, and continued changes may be expected over this century. Vegetation cover and composition impose important influences on the regional climate in Africa. Climate-driven changes in vegetation structure and the distribution of forests versus savannah and grassland may feed back to climate via shifts in the surface energy balance, hydrological cycle and resultant effects on surface pressure and larger-scale atmospheric circulation. We used a regional Earth system model incorporating interactive vegetation–atmosphere coupling to investigate the potential role of vegetation-mediated biophysical feedbacks on climate dynamics in Africa in an RCP8.5-based future climate scenario. The model was applied at high resolution (0.44 × 0.44°) for the CORDEX-Africa domain with boundary conditions from the CanESM2 general circulation model. We found that increased tree cover and leaf-area index (LAI) associated with a CO2 and climate-driven increase in net primary productivity, particularly over subtropical savannah areas, not only imposed important local effect on the regional climate by altering surface energy fluxes but also resulted in remote effects over central Africa by modulating the land–ocean temperature contrast, Atlantic Walker circulation and moisture inflow feeding the central African tropical rainforest region with precipitation. The vegetation-mediated feedbacks were in general negative with respect to temperature, dampening the warming trend simulated in the absence of feedbacks, and positive with respect to precipitation, enhancing rainfall reduction over the rainforest areas. Our results highlight the importance of accounting for vegetation–atmosphere interactions in climate projections for tropical and subtropical Africa.

Crop growth and soil water fluxes at erosion-affected arable sites: A model inter-comparison based on weighing-lysimeter observations

2020 ◽  
Author(s):  
Jannis Groh ◽  
Keyword(s):  
Soil Water ◽  
Crop Growth ◽  
Water Dynamics ◽  
Water Fluxes ◽  
Ecosystem Models ◽  
Phenological Stages ◽  
Soil System ◽  
Area Index ◽  
Individual Model ◽  
Crop Development

<p>Agro-ecosystem models have been developed to study effects of agricultural management on crop production, mostly from an agronomic point of view. Based on a biophysical process representation, their most prominent advantage is the coupled modelling of crop development and yield formation, as well as water and nutrients fluxes in the plant-soil system. Crop models have previously been calibrated based on experimental data with a focus on plant observations. Less attention has been given to soil water and solute dynamics despite the importance of plant nutrient availability and chemical leaching, particularly for arable soils often affected by erosion. The question was whether the description of soil processes and properties play an important role in the crop simulations.</p><p>The aim of this study was to compare the ability of agro-ecosystem models to predict crop development and water fluxes under changing environmental conditions. Observations on crop growth and soil water dynamics were obtained from four weighable lysimeter of the TERENO-SOILCan lysimeter network in the northeast of Germany (Dedelow). The intact soil monoliths are representative for the spatial soil variability of erosion-affected hummocky agricultural landscape. Twelve agro-ecosystem models (AgroC; DailyDayCent; Daisy; HERMES; MONICA; Theseus, Theseus-HydroGeoSphere; Theseus-Hydrus-1D; Expert-N coupled to CERES, GECROS, SPASS, and SUCROS) were tested. Crop development stages were used to calibrate the agro-ecosystem models. The model performance was tested against observed grain yield, aboveground biomass, leaf area index, actual evapotranspiration, drainage, and soil water content.</p><p>Model descriptions were highly diverse for both crop development and water fluxes. Crop growth and soil water fluxes were better predicted by the Multi Model Mean simulations than by any individual model. Results demonstrate that i) the hydraulic properties of erosion-affected soil profiles controlled the observed interactions between crop yield, plant development, and water fluxes, ii) data on phenological stages contained insufficient information content to calibrated agro-ecosystem models for soils affected by erosion, and iii) neither an individual model nor the Multi Model Mean could describe the observation on crop development and water dynamics, when using phenological stages only for model calibration. The results suggest that soil does matter in agro-ecosystem models and that weighable lysimeter can provide such soil related observation.</p>

Modeling of a forested study site with the Community Land Model version 5 using climate projections for the 21st century.

2020 ◽  
Author(s):  
Lukas Strebel ◽  
Klaus Goergen ◽  
Bibi S. Naz ◽  
Heye Bogena ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Land Surface ◽  
Model Parameters ◽  
Climate Projections ◽  
Modeling Framework ◽  
Area Index ◽  
Community Land Model

<p>Modeling forest ecosystems is important to facilitate adaptations in forest management approaches necessary to address the challenges of climate change, particularly of interest are ecohydrological states and fluxes such as soil water content, biomass, leaf area index, and evapotranspiration.</p><p>The community land model in its current version 5 (CLM5) simulates a broad collection of important land-surface processes; from moisture and energy partitioning, through biogeophysical processes, to surface and subsurface runoff. Additionally, CLM5 contains a biogeochemistry model (CLM5-BGC) which includes prognostic computation of vegetation states and carbon and nitrogen pools. However, CLM5 predictions are affected by uncertainty related to uncertain model forcings and parameters. Here, we use data assimilation methods to improve model performance by assimilating soil water content observations into CLM5 using the parallel data assimilation framework (PDAF).</p><p> </p><p>The coupled modeling framework was applied to the small (38.5 ha) forested catchment Wüstebach located in the Eifel National Park near the German-Belgian border. As part of the terrestrial environmental observatories (TERENO) network, the SoilNet sensors at the study site provide soil water content and soil temperature measurements since 2009.</p><p>CLM5 simulations for the period 2009-2100 were made, using local atmospheric observations for the period of 2009-2018 and an ensemble of regional climate model projections for 2019-2100. Simulations illustrate that data assimilation of soil water content improves the characterization of past model states, and that estimated model parameters and default model parameters result in different trajectories of ecohydrological states for 2019-2100. The simulations also illustrate that this site is hardly affected by increased water stress in the future.</p><p>The developed framework will be extended and applied for both ecosystem reanalysis as well as further simulations using climate projections across forested sites over Europe.</p>

The growth and development of Townsville lucerne (Stylosanthes humilis) in ungrazed swards at Katherine, N.T

1969 ◽  
Vol 9 (37) ◽  
pp. 196 ◽  
Author(s):  
MJ Fisher
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Growth Rates ◽  
Dry Matter ◽  
Water Storage ◽  
Subterranean Clover ◽  
Crop Growth ◽  
Soil Water Storage ◽  
Nitrogen And Phosphorus ◽  
Stylosanthes Humilis

At Katherine, N.T., swards of Townsville lucerne (Stylosanthes humilis H.B.K.) were sown in late November and late December, 1964, and sampled every two weeks during the growing season. At each harvest the dry matter, nitrogen, and phosphorus yields of stem, leaf and petiole, inflorescence, unshed pods, shed leaf, and shed pods were determined. Crop growth rates and net assimilation rates (leaf weight basis, ELW), were derived for both plantings and compared with calculated soil water storage. Drought in January and February restricted growth during the vegetative phase, but rapid growth resumed when water stress was relieved by rain in March. Maximum dry matter yield (5400 lb an acre) and mean crop growth rate (42.3 lb an acre a day) for the November sowing were similar to those measured for Townsville lucerne at Katherine and elsewhere. Maximum crop growth rates (250 and 110 lb an acre a day for the November and December sowings respectively) appear to be about the same as those recorded in the field for subterranean clover. The strong influence of water stress on growth was emphasized by the close relationship demonstrated between ELW and calculated soil water storage. Uptake of nitrogen and phosphorus was restricted during water stress and both were redistributed to reproductive parts of the plant during flowering and seeding, nitrogen more readily than phosphorus. Nitrogen and phosphorus contents (1.9-2.0 per cent N and 0.70-0.75 per cent P) were lower than those recorded for other tropical and temperate pasture legumes. The implications of the low phosphorus contents of Townsville lucerne as cattle feed are discussed.

The combined effect of sowing methods, and nitrogen application rates on photosynthetic characteristics, and soil water consumption of wheat

2021 ◽  
Author(s):  
HAFEEZ NOOR ◽  
Min Sun ◽  
Wen Lin ◽  
Zhiq-iang Gao
Keyword(s):  
Soil Water ◽  
Sugar Content ◽  
Wheat Yield ◽  
Photosynthetic Characteristics ◽  
Soil Water Storage ◽  
High Yield ◽  
Area Index ◽  
Application Rates ◽  
Nitrogen Treatments ◽  
Nitrogen Rates

Abstract Sustainability of winter wheat yield under dryland conditions depends on Improvements in crop photosynthetic characteristics and, crop yield. Study the effects of sowing method and N-nitrogen rates on yield, selected sowing, and soil water storage, nitrogen translocation. Experiment comprised of three sowing methods: wide-space sowing (WSS), furrow sowing (FS), and drill sowing (DS) and seven nitrogen treatments: 0 kg ha− 1, 90 kg ha− 1, 180 kg ha− 1, 210 kg ha− 1, 240 kg ha− 1, 270 kg ha− 1 and 300 kg ha− 1.The results indicated that the sowing methods significantly affected the yield, and grain. The increase in grain yield was 25%, respectively. The photosynthetic traits, and leaf area index were highest under WS followed by FS. The plant height was highest under DS. I (WSS), and (II) (DS). Sowing method WSS with N level N240 significantly enhanced the Photosynthesis Rate, intercellular CO2, and transpiration rate .Our results indicated that implication of a proper sowing method coupled with enhanced nitrogen doses resulted in an increase in yield. WSS 240 kg ha− 1 enhances photosynthetic characteristics of flag leaves, and promotes to achieve high yield. The plants were improved, which ware beneficial to the improvement of sugar content.

Evapotranspiration of Safflower at three densities of sowing

1965 ◽  
Vol 16 (6) ◽  
pp. 961 ◽  
Author(s):  
WR Stern
Keyword(s):  
Soil Water ◽  
Transition Period ◽  
Root Zone ◽  
Free Water ◽  
Soil Water Storage ◽  
Water Evaporation ◽  
Low Latitude ◽  
Type Curve ◽  
Area Index ◽  
Irrigated Crops

In a low latitude environment, evapotranspiration from irrigated crops of safflower growing at low, middle, and high densities was determined from changes in soil water storage. Evapotranspiration was related to potential free water evaporation as calculated by the Penman formula. Except at the rosette stage and during the transition period leading to elongation, there was no measurable difference in evapotranspiration between densities. The ratio of evapotranspiration to free water evaporation was 1.57 during elongation and 1.25 between elongation and flowering, falling to less than 1 before the last irrigation and before any marked depletion of soil water in the root zone. Average evapotranspiration over the cropping period was 3.1 mm day-l and the transpiration ratio 342. Leaf area index and evapotranspiration rates were related by a Mitscherlich type curve with an evapotranspiration plateau of 4.2 mm day-1. The high ratios of evapotranspiration to potential evaporation were due to bulk advective conditions in this environment. The observed evapotranspiration is discussed in relation to the growth of the crop and the variations observed in the field.

scholarly journals Interannual Variation of Transpiration and Its Modeling of a Larch Plantation in Semiarid Northwest China

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1303
Author(s):  
Yanbing Wang ◽  
Yanhui Wang ◽  
Zhenhua Li ◽  
Pengtao Yu ◽  
Xinsheng Han
Keyword(s):  
Soil Water ◽  
Forest Canopy ◽  
Potential Evapotranspiration ◽  
Northwest China ◽  
Measured Data ◽  
Model Parameters ◽  
Individual Factor ◽  
Area Index ◽  
Continuous Multiplication ◽  
The Individual

Quantifying the variation of forest transpiration (T) is important not only for understanding the water and energy budget of forest ecosystems but also for the prediction, evaluation, and management of hydrological effects as well as many other ecosystem services of forests under the changes of climate, vegetation, and anthropological impacts. The accurate prediction of T, a key component of water used by forests, requires mechanism-based models describing the T response to environmental and canopy conditions. The daily T of a larch (Larix principis-rupprechtti) plantation was measured through monitoring the sap flow in the growing season (from May to September) of a dry year (2010), a normal year (2012), and a wet year (2014) at a shady slope in the semi-arid area of Liupan Mountains in northwest China. Meanwhile, the meteorological conditions, soil moisture, and forest canopy leaf area index (LAI) were monitored. To get a simple and easily applicable T model, the numerous influencing parameters were grouped into three factors: the atmospheric evapotranspiration demand indicated by the potential evapotranspiration (PET), the soil water supply ability indicated by the relative extractable soil water content (REW), and the vegetation transpiration capacity indicated by the forest canopy LAI. The T model was established as a continuous multiplication of the T response equations to individual factors, which were determined using the upper boundary lines of measured data. The effect of each factor on the T in a dry year (2010) or normal year (2012) was assessed by comparing the measured T in the baseline of the wet year (2014) and the model predicted T, which was calculated through inputting the actual data of the factor (i.e., PET) to be assessed in the dry or normal year and the measured data of other two factors (i.e., REW, LAI) in the baseline of the wet year. The results showed that the mean daily T was 0.92, 1.05, and 1.02 mm; and the maximum daily T was 1.78, 1.92, and 1.89 mm in 2010, 2012, and 2014, respectively. The T response follows a parabolic equation to PET, but a saturated exponential equation to REW and LAI. The T model parameters were calibrated using measured data in 2010 and 2012 (R2 = 0.89, Nash coefficient = 0.88) and validated using measured data in 2014 satisfactorily (R2 = 0.89, Nash coefficient = 0.79). It showed a T limitation in the dry year 2010 for all factors (18.5 mm by PET, 11.5 mm by REW, and 17.8 mm by LAI); while a promotion for PET (1.4 mm) and a limitation for REW (4.2 mm) and LAI (14.3 mm) in the normal year 2012. The daily T model established in this study can be helpful to assess the individual factor impact on T and improve the daily T prediction under changing environmental and canopy conditions.

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