Modeling effects of plastic mulching on crop yields and water productivity in the middle Heihe River Basin

2020 ◽  
Author(s):  
Wang Zhang ◽  
Chunmiao Zheng
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Global Sensitivity Analysis ◽  
Water Productivity ◽  
Regional Scale ◽  
Canopy Cover ◽  
Heihe River ◽  
Aquacrop Model ◽  
Plastic Mulching

<p>Plastic mulching is an effective field practice to improve crop water productivity (WP), especially widely used in arid and semi-arid areas. The positive effects of soil mulching on crop yield and WP have been studied through numerous field experiments and simulations at the site scale. However, few studies have focused on the mulching effects at the regional scale. Zhangye oasis, a typical arid region in the middle Heihe River Basin, was chosen as the study area. Global sensitivity analysis was applied to determine the most sensitive parameters in AquaCrop model. Based on the results of global sensitivity analysis, soil and crop parameters of AquaCrop model were calibrated and validated using field observations from three stations. The normalized root mean square error (NRMSE) values for soil water content, seed maize canopy cover, aboveground biomass, yield, spring wheat canopy cover, aboveground biomass and yield were 18.7%, 6.7%, 23.5%, 12.5%, 10.7%, 24.2% and 15.0% during the calibration period, and the corresponding values during the validation period were 25.1%, 7.0%, 22.2%, 17.7%, 9.1%, 23.6% and 11.7%, respectively. These values indicated the calibrated model performed well to simulate the soil water content and crop growth. Compared with no-mulching, the average soil water content during the growth period, seed maize yield and WP under mulching had been increased by 8.8%, 3.0% and 3.0%, respectively. The results demonstrated that plastic mulching could effectively improve the yield and WP of seed maize, which not significantly on spring wheat. This study offers a quantitatively analysis for plastic mulching applications at the regional scale.</p>

Simulation of crop production in weed-infested fields for data-scarce regions

2016 ◽  
Vol 154 (6) ◽  
pp. 1026-1039 ◽  
Author(s):  
H. VAN GAELEN ◽  
N. DELBECQUE ◽  
B. ABRHA ◽  
A. TSEGAY ◽  
D. RAES
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Productivity ◽  
Canopy Cover ◽  
Simple Approach ◽  
Crop Water ◽  
Crop Water Productivity ◽  
Aquacrop Model ◽  
Weed Infestation

SUMMARYWeed infestation is a major yield-reducing factor that also decreases crop water productivity. Yet weeds are often neglected in crop productivity simulation studies, because existing empirical equations and mechanistic models are not widely applicable or have a high demand for input data and calibration. For that reason, AquaCrop, a widely applicable crop water productivity model, was expanded with a weed management module which requires only two easily obtainable input variables: (i) relative leaf cover of weeds, and (ii) weed-induced increase of total canopy cover. Using these inputs, AquaCrop directly simulates soil water content, crop canopy development and production as it is observed in weed-infested fields. Despite this simple approach, AquaCrop performed well to simulate soil water content in the root zone (relative root-mean-square error (RRMSE) of 5–13%), canopy cover (RRMSE of 15–22%), dry above-ground crop biomass during the season (RRMSE of 21–39%) and at maturity (RRMSE of 5–6%) and yield (RRMSE of 11–25%) of barley and wheat grown under different weed infestation levels and environments. The current study illustrates that the AquaCrop model can be used to assess the effect of weed infestation on crop growth and production, using a simple approach that is applicable to diverse environmental and agronomic conditions, even in data-scarce regions.

Simulation of Canopy Cover, Soil Water Content and Yield Using FAO-AquaCrop Model under Deficit Irrigation Strategies

2020 ◽  
Vol 46 (3) ◽  
pp. 279-288
Author(s):  
Mohmed A. M. Abdalhi ◽  
Zhonghua Jia ◽  
Wan Luo ◽  
Osama O. Ali ◽  
Cheng Chen
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Deficit Irrigation ◽  
Canopy Cover ◽  
Cover Soil ◽  
Aquacrop Model

scholarly journals A semi-quantitative approach for modelling crop response to soil fertility: evaluation of the AquaCrop procedure

2014 ◽  
Vol 153 (7) ◽  
pp. 1218-1233 ◽  
Author(s):  
H. VAN GAELEN ◽  
A. TSEGAY ◽  
N. DELBECQUE ◽  
N. SHRESTHA ◽  
M. GARCIA ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Grain Yield ◽  
Soil Water ◽  
Crop Production ◽  
Water Productivity ◽  
Canopy Cover ◽  
Quantitative Approach ◽  
Fertility Level ◽  
Crop Response ◽  
Aquacrop Model

SUMMARYMost crop models make use of a nutrient-balance approach for modelling crop response to soil fertility. To counter the vast input data requirements that are typical of these models, the crop water productivity model AquaCrop adopts a semi-quantitative approach. Instead of providing nutrient levels, users of the model provide the soil fertility level as a model input. This level is expressed in terms of the expected impact on crop biomass production, which can be observed in the field or obtained from statistics of agricultural production. The present study is the first to describe extensively, and to calibrate and evaluate, the semi-quantitative approach of the AquaCrop model, which simulates the effect of soil fertility stress on crop production as a combination of slower canopy expansion, reduced maximum canopy cover, early decline in canopy cover and lower biomass water productivity. AquaCrop's fertility response algorithms are evaluated here against field experiments with tef (Eragrostis tef (Zucc.) Trotter) in Ethiopia, with maize (Zea mays L.) and wheat (Triticum aestivum L.) in Nepal, and with quinoa (Chenopodium quinoa Willd.) in Bolivia. It is demonstrated that AquaCrop is able to simulate the soil water content in the root zone, and the crop's canopy development, dry above-ground biomass development, final biomass and grain yield, under different soil fertility levels, for all four crops. Under combined soil water stress and soil fertility stress, the model predicts final grain yield with a relative root-mean-square error of only 11–13% for maize, wheat and quinoa, and 34% for tef. The present study shows that the semi-quantitative soil fertility approach of the AquaCrop model performs well and that the model can be applied, after case-specific calibration, to the simulation of crop production under different levels of soil fertility stress for various environmental conditions, without requiring detailed field observations on soil nutrient content.

scholarly journals Overstory–Understory Vegetation Cover and Soil Water Content Observations in Western Juniper Woodlands: A Paired Watershed Study in Central Oregon, USA

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 151 ◽  
Author(s):  
Grace Ray ◽  
Carlos G. Ochoa ◽  
Tim Deboodt ◽  
Ricardo Mata-Gonzalez
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Texture ◽  
Canopy Cover ◽  
Understory Vegetation ◽  
Watershed Scale ◽  
Shrub Cover ◽  
Western Juniper ◽  
Tree Canopy Cover

The effects of western juniper (Juniperus occidentalis) control on understory vegetation and soil water content were studied at the watershed-scale. Seasonal differences in topsoil (12 cm) water content, as affected by vegetation structure and soil texture, were evaluated in a 96-ha untreated watershed and in a 116-ha watershed where 90% juniper was removed in 2005. A watershed-scale characterization of vegetation canopy cover and soil texture was completed to determine some of the potential driving factors influencing topsoil water content fluctuations throughout dry and wet seasons for approximately one year (2014–2015). We found greater perennial grass, annual grass, and shrub cover in the treated watershed. Forb cover was no different between watersheds, and as expected, tree canopy cover was greater in the untreated watershed. Results also show that on average, topsoil water content was 1% to 3% greater in the treated watershed. The exception was during one of the wettest months (March) evaluated, when soil water content in the untreated watershed exceeded that of the treated by <2%. It was noted that soil water content levels that accumulated in areas near valley bottoms and streams were greater in the treated watershed than in the untreated toward the end of the study in late spring. This is consistent with results obtained from a more recent study where we documented an increase in subsurface flow residence time in the treated watershed. Overall, even though average soil water content differences between watersheds were not starkly different, the fact that more herbaceous vegetation and shrub cover were found in the treated watershed led us to conclude that the long-term effects of juniper removal on soil water content redistribution throughout the landscape may be beneficial towards restoring important ecohydrologic connections in these semiarid ecosystems of central Oregon.

On-farm measurement of the water use and productivity of maize

2008 ◽  
Vol 48 (3) ◽  
pp. 274 ◽  
Author(s):  
K. L. Greenwood ◽  
G. N. Mundy ◽  
K. B. Kelly
Keyword(s):  
Dairy Cows ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
Water Productivity ◽  
Weather Data ◽  
Local Conditions ◽  
High Yields ◽  
Crop Coefficients

Maize, as a C4 species, is likely to use water more productively than the perennial ryegrass and white clover pastures typically grown for dairy cows in northern Victoria. However, only estimates of water use by irrigated maize crops are available for this region. We measured the growth and water use of three commercial maize crops used for silage in northern Victoria. Crops under centre pivot irrigation were monitored in 2003–04 (Spray 1) and 2004–05 (Spray 2). A border-check irrigated crop (Border-check) was monitored in 2004–05. The Spray 1 crop was irrigated 30 times and received 782 mm of rainfall and irrigation. The crop yielded 22 t DM/ha, giving a water productivity of 28 kg DM/ha.mm (including irrigation, rainfall and change in soil water content). In the cooler, wetter summer of 2004–05, the water productivity was 34 kg DM/ha.mm for the Spray 2 crop and 30 kg DM/ha.mm for the Border-check crop. Crop evapotranspiration was estimated from weather data and a daily soil water balance was computed according to FAO 56. The estimated and measured changes in soil water content were in good agreement and indicated that the basal crop coefficients in the model (Kcb = 1.15 during the mid-season, before correction for non-standard humidity and wind speed) were appropriate to local conditions. Maize grown for silage in northern Victoria has higher water productivity than pastures. However, high yields are required to make it economically viable compared with alternative forages for dairy cows. These data will assist dairy farmers to select the optimum forage mix for their enterprises.

Evaluating Soil Water Content in a WRF-Noah Downscaling Experiment

2013 ◽  
Vol 52 (10) ◽  
pp. 2312-2327 ◽  
Author(s):  
Peter Greve ◽  
Kirsten Warrach-Sagi ◽  
Volker Wulfmeyer
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Land Surface ◽  
Root Zone ◽  
Regional Scale ◽  
Land Surface Model ◽  
Surface Model ◽  
Flux Partitioning

AbstractSoil water content (SWC) depends on and affects the energy flux partitioning at the land–atmosphere interface. Above all, the latent heat flux is limited by the SWC of the root zone on one hand and radiation on the other. Therefore, SWC is a key variable in the climate system. In this study, the performance of the Weather Research and Forecasting model coupled with the Noah land surface model (WRF-Noah) system in a climate hindcast simulation from 1990 to 2008 is evaluated with respect to SWC versus two reanalysis datasets for Europe during 2007 and 2008 with in situ soil moisture observations from southern France. When compared with the in situ observations, WRF-Noah generally reproduces the SWC annual cycle while the reanalysis SWCs do not. The biases in areal mean WRF-Noah SWCs relate to biases in precipitation and evapotranspiration in a cropland environment. The spatial patterns and temporal variability of the seasonal mean SWCs from the WRF-Noah simulations and from the two reanalyses correspond well, while absolute values differ significantly, especially at the regional scale.

scholarly journals Interactive Effects of Water and Fertilizer on Yield, Soil Water and Nitrate Dynamics of Young Apple Tree in Semiarid Region of Northwest China

Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 360 ◽  
Author(s):  
Hanmi Zhou ◽  
Xiaoli Niu ◽  
Hui Yan ◽  
Na Zhao ◽  
Fucang Zhang ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Apple Tree ◽  
Water Productivity ◽  
Interactive Effect ◽  
Field Capacity ◽  
Northwest China ◽  
Significant Difference ◽  
Young Apple

Exploring the interactive effect of water and fertilizer on yield, soil water and nitrate dynamics of young apple tree is of great importance to improve the management of irrigation and fertilization in the apple-growing region of semiarid northwest China. A two-year pot experiment was conducted in a mobile rainproof shelter of the water-saving irrigation experimental station in Northwest A&F University, and the investigation evaluated the response of soil water and fertilizer migration, crop water productivity (CWP), irrigation water use efficiency (IWUE), partial factor productivity (PFP) of young apple tree to different water and fertilizer regimes (four levels of soil water: 75%–85%, 65%–75%, 55%–65% and 45%–55% of field capacity, designated W1, W2, W3 and W4, respectively; three levels of N-P2O5-K2O fertilizer, 30-30-10, 20-20-10 and 10-10-10 g plant−1, designated F1, F2 and F3, respectively). Results showed that F1W1, F2W1 and F3W1 had the highest average soil water content at 0~90 cm compared with the other treatments. When fertilizer level was fixed, the average soil water content was gradually increased with increasing irrigation amount. For W1, W2, W3 and W4, high levels of water content were mainly distributed at 50~80 cm, 40~70 cm, 30~50 cm and 10~30 cm, respectively. There was no significant difference in soil water content at all fertilizer treatments. However, F1 and F2 significantly increased soil nitrate-N content by 146.3%~246.4% and 75.3%~151.5% compared with F3. The highest yield appeared at F1W1 treatment, but there was little difference between F1W1 and F2W2 treatment. F2W2 treatment decreased yield by 7.5%, but increased IWUE by 11.2% compared with F1W1 treatment. Meanwhile, the highest CWP appeared at F2W2 treatment in the two years. Thus, F2W2 treatment (soil moisture was controlled in 65–75% of field capacity, N-P2O5-K2O were controlled at 20-20-10 g·tree−1) reached the best water and fertilizer coupling mode and it was the optimum combinations of water and fertilizer saving.

Effects of Mini-ditch Planting with Plastic Mulching in Ridges on Soil Water Content, Temperature and Potato Yield in Rain-fed Semiarid Region

2015 ◽  
Vol 41 (10) ◽  
pp. 1582 ◽  
Author(s):  
Hui-Zhi HOU ◽  
Juan WANG ◽  
Xu-Cheng ZHANG ◽  
Yan-Jie FANG ◽  
Xian-Feng YU ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Potato Yield ◽  
Semiarid Region ◽  
Plastic Mulching
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