APSIM model performance in simulating Piatã palisade grass growth and soil water in different positions of a silvopastoral system with eucalyptus

The European Space Agency Climate Change Initiative Soil Moisture (ESA CCI SM) product provides soil moisture estimates from radar satellite data with a daily temporal resolution. Despite validation exercises with ground data that have been performed since the product’s launch, SM has not yet been consistently related to soil water storage, which is a key step for its application for prediction purposes. This study aimed to analyse the relationship between soil water storage (S), which was obtained from soil water balance computations with ground meteorological data, and soil moisture, which was obtained from radar data, as affected by soil water storage capacity (Smax). As a case study, a 14-year monthly series of soil water storage, produced via soil water balance computations using ground meteorological data from northeast Portugal and Smax from 25 mm to 150 mm, were matched with the corresponding monthly averaged SM product. Linear (I) and logistic (II) regression models relating S with SM were compared. Model performance (r2 in the 0.8–0.9 range) varied non-monotonically with Smax, with it being the highest at an Smax of 50 mm. The logistic model (II) performed better than the linear model (I) in the lower range of Smax. Improvements in model performance obtained with segregation of the data series in two subsets, representing soil water recharge and depletion phases throughout the year, outlined the hysteresis in the relationship between S and SM.

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Hydrological effects of land use change on small catchments at the Narayen research station, Queensland

Soil Research ◽

10.1071/sr9880231 ◽

1988 ◽

Vol 26 (1) ◽

pp. 231 ◽

Cited By ~ 10

Author(s):

RE Prebble ◽

GB Stirk

Keyword(s):

Land Use ◽

Soil Water ◽

Ground Level ◽

Annual Runoff ◽

Balance Model ◽

Soil Water Storage ◽

Research Station ◽

Rainfall Runoff ◽

Grass Growth ◽

Small Catchments

The hydrological effect of a change in land use, where trees were killed and improved pasture was established, was examined in an open grassy woodland on duplex soil derived from granite. Two pairs of small catchments at the Narayen Research Station, Queensland, were instrumented to measure rainfall, runoff, soil water and meteorological variables. The treated catchments stored up to 26 mm more soil water in the 0-1 m depth than those in their original condition. Evapotranspiration over a period, calculated from rainfall, runoff and soil water storage change, was similar for both treated and untreated catchments. This result was attributed to compensating factors following death of the trees which removed interception of rain and solar radiation, caused an increase in wind velocity at ground level, and allowed enhanced grass growth in the areas previously under tree canopies. A water balance model did not provide a satisfactory calibration for the detection of runoff changes resulting from the treatment. The ratios of the annual runoff from catchment pairs, although variable, did not show drastic changes as a result of treatment. So, provided a good grass cover was maintained, it seems unlikely that the treatment would greatly alter runoff. The chloride balance in the undisturbed woodland under the present climate suggests that any changes due to treatment are unlikely, but indicates that in these soils soluble ions are readily lost from the system.

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CROPGRO-Perennial Forage model parameterization for simulating Piatã palisade grass growth in monoculture and in a silvopastoral system

Agricultural Systems ◽

10.1016/j.agsy.2019.102724 ◽

2020 ◽

Vol 177 ◽

pp. 102724 ◽

Cited By ~ 3

Author(s):

Cristiam Bosi ◽

Paulo Cesar Sentelhas ◽

José Ricardo Macedo Pezzopane ◽

Patricia Menezes Santos

Keyword(s):

Silvopastoral System ◽

Model Parameterization ◽

Grass Growth

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Simulating soil-plant-atmosphere interactions for sub-daily in situ observations of stable isotopes in soil and xylem water to assess two-pore domain model hypothesis

10.5194/egusphere-egu2020-17975 ◽

2020 ◽

Author(s):

Fabian Bernhard ◽

Stefan Seeger ◽

Markus Weiler ◽

Arthur Gessler ◽

Katrin Meusburger

Keyword(s):

Stable Isotopes ◽

Soil Water ◽

Vadose Zone ◽

Model Performance ◽

Root Water Uptake ◽

In Situ Observations ◽

Pore Domain ◽

Model Structures ◽

Isotope Measurements

Recent advances in stable isotope measurements within the soil-plant-atmosphere continuum have paved the way to high-resolution sub-daily observations of plant water supply (Stumpp et al. 2018, Volkmann et al. 2016a, 2016b). It seems time is ripe for in-depth assessments of long-standing yet much-debated assumptions such as complete, homogenous mixing of water in the vadose zone (&#8220;one water world&#8221; versus "two water world") or absence of fractionation during root water uptake and vascular transport in plants.Information on the nature of these processes contained in high-resolution data sets needs to be exploited. One way to test hypotheses and thereby advance our understanding of soil-plant water interactions is by analysing observations with numerical simulations of the system dynamics &#8211; a method also known as inverse modelling. By evaluating the model performance and parameter identifiability of different model structures, conclusions can be drawn regarding the relevance of the modelled processes for reproduction of the observations. Testing two different models allows thus to assess the impact of the difference.We develop a framework for numerical simulation and model-based analysis of observations from soil-plant-atmosphere systems with a focus on isotopic fractionation. A central objective is to facilitate the evaluation of different model structures and thus test model hypotheses. This can assist development of models specifically tailored to the intended purpose and available data. The framework will first be tested with the "SWIS" model presented by Sprenger et al. (2018).As an illustration of the framework, we will test the model performance on a dataset of continuous, in situ observations of stable isotopes in xylem water of beech trees and soil water in four depths combined with observations of soil water content. The model assumes one-dimensional soil water flow taking place in one or two separate flow domains for tightly and weakly bound pore water. These two water pools are separated by a matrix potential threshold and isotopic exchange is modelled only through the vapour phase. Root water uptake is parametrised using the Feddes-Jarvis model. First results allow to assess the relevance of the two-pore domain hypothesis for the different soil depths and xylem water.&#160;Sprenger, M., D. Tetzlaff, J. Buttle, H. Laudon, H. Leistert, C.P.J. Mitchell, J. Snelgrove, M. Weiler, and C. Soulsby. 2018. Measuring and modeling stable isotopes of mobile and bulk soil water. Vadose Zone J. 17:170149. doi:10.2136/vzj2017.08.0149Stumpp, C., N. Br&#252;ggemann, and L. Wingate. 2018. Stable isotope approaches in vadose zone research. Vadose Zone J. 17:180096. Doi: 10.2136/vzj2018.05.0096Volkmann, T.H., K. Haberer, A. Gessler, and M. Weiler. 2016a. High&#8208;resolution isotope measurements resolve rapid ecohydrological dynamics at the soil&#8211;plant interface. New Phytologist, 210(3), 839-849.Volkmann, T.H., K. Haberer, A. Gessler, and M. Weiler. 2016a. High&#8208;resolution isotope measurements resolve rapid ecohydrological dynamics at the soil&#8211;plant interface. New Phytologist, 210(3), 839-849.

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Microbial-N supply and milk yield cows in a silvopastoral system with and without access to the forage tree and energy supplementation during the dry season

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200020342 ◽

2007 ◽

Vol 2007 ◽

pp. 131-131

Author(s):

V. Valdivia ◽

C.A. Sandoval-Castro ◽

K. Otaduy ◽

J.C. Ku-Vera

Keyword(s):

Milk Yield ◽

Dry Season ◽

Silvopastoral Systems ◽

Silvopastoral System ◽

Dual Purpose ◽

Lactating Cows ◽

N Supply ◽

Energy Supplementation ◽

Grass Growth ◽

Microbial N

Supplementation with legume fodder during the dry season is a strategy to improve animal performance. The results obtained in silvopastoral systems has been explained either by their ingestion of a higher quality grass (Hernandez et al., 2001, Iglesias, 1998) resulting from the inclusion of a legume in the system which provide N for grass growth or due to the intake of the legume itself, which in turn is also of higher quality than grass (Kakengi et al., 2001), and provides a higher microbial-N supply (Karda and Dryden, 2001). The objective of the present work was to discriminate, in a silvopastoral system, the effect of improved grass quality and legume intake (L. leucocephala) on rumen fermentation, microbial N supply, milk yield and composition of dual purpose lactating cows.

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Effects of white clover and fertilizer nitrogen on herbage production and chemical composition and soil water

The Journal of Agricultural Science ◽

10.1017/s0021859600044166 ◽

1985 ◽

Vol 104 (2) ◽

pp. 453-467 ◽

Cited By ~ 13

Author(s):

D. Wilman ◽

P. A. Hollington

Keyword(s):

Soil Water ◽

Sea Level ◽

Perennial Ryegrass ◽

White Clover ◽

The Other ◽

Deep Soil ◽

N Content ◽

Nitrate N ◽

Grass Growth ◽

Grass Sward

SummaryEffects of seven levels of N application and three seeds mixtures were studied on two sites for 4 years. One seeds mixture comprised perennial ryegrass (Lolium perenne L.) and two comprised perennial ryegrass with white clover (Trifolium repens L.). One site (Trefloyne) was 24 m above sea level on deep soil and the other (Pwllpeiran) was 328 m above sea level on relatively shallow soil. The plots were cut seven times per year.White clover grew very strongly at Trefloyne in the first 2 years, fixing 350 kg N/ha/year where no N was applied; the clover declined very markedly during the 3rd year and there was very little in the sward in the 4th year; quite large quantities of clover were harvested in the 1st year even where 600 kg N/ha were applied. At Pwllpeiran the yields of clover were never high, but the clover persisted well where no N was applied. At Trefloyne the indirect contribution of the clover (in increasing the yield of grass) was greater in the first than in the second half of the year; clover was later than grass to grow strongly in the spring, but the extra grass growth compensated for this, so that the seasonal distribution of total herbage yield was similar on a grass-clover sward receiving no fertilizer N to that on a grass sward receiving six applications of N per year. At Pwllpeiran, on the other hand, the indirect contribution of the clover tended to be greater in the second than in the first half of the year where no N was applied.The olover was similar to grass in phosphorus and potassium content and higher than grass in calcium and nitrogen. The clover was higher in nitrate-N content than grass grown without clover, at low levels of applied N, and increased the nitrate-N content of the grass growing with it.Water consumption at Trefloyne was greatest on swards which contained olover and on the swards without clover which received at least 400 kg N/ha/year. The effect of clover on soil water was apparent particularly in the lower horizons of the soil.

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Estimating soil organic carbon changes in managed temperate moist grasslands with RothC

PLoS ONE ◽

10.1371/journal.pone.0256219 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0256219

Author(s):

Asma Jebari ◽

Jorge Álvaro-Fuentes ◽

Guillermo Pardo ◽

María Almagro ◽

Agustin del Prado

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Water ◽

Model Performance ◽

Climatic Conditions ◽

Livestock Grazing ◽

Plant Residue ◽

Plant Residues ◽

Organic C ◽

Rothc Model

Temperate grassland soils store significant amounts of carbon (C). Estimating how much livestock grazing and manuring can influence grassland soil organic carbon (SOC) is key to improve greenhouse gas grassland budgets. The Rothamsted Carbon (RothC) model, although originally developed and parameterized to model the turnover of organic C in arable topsoil, has been widely used, with varied success, to estimate SOC changes in grassland under different climates, soils, and management conditions. In this paper, we hypothesise that RothC-based SOC predictions in managed grasslands under temperate moist climatic conditions can be improved by incorporating small modifications to the model based on existing field data from diverse experimental locations in Europe. For this, we described and evaluated changes at the level of: (1) the soil water function of RothC, (2) entry pools accounting for the degradability of the exogenous organic matter (EOM) applied (e.g., ruminant excreta), (3) the month-on-month change in the quality of C inputs coming from plant residues (i.e above-, below-ground plant residue and rhizodeposits), and (4) the livestock trampling effect (i.e., poaching damage) as a common problem in areas with higher annual precipitation. In order to evaluate the potential utility of these changes, we performed a simple sensitivity analysis and tested the model predictions against averaged data from four grassland experiments in Europe. Our evaluation showed that the default model’s performance was 78% and whereas some of the modifications seemed to improve RothC SOC predictions (model performance of 95% and 86% for soil water function and plant residues, respectively), others did not lead to any/or almost any improvement (model performance of 80 and 46% for the change in the C input quality and livestock trampling, respectively). We concluded that, whereas adding more complexity to the RothC model by adding the livestock trampling would actually not improve the model, adding the modified soil water function and plant residue components, and at a lesser extent residues quality, could improve predictability of the RothC in managed grasslands under temperate moist climatic conditions.

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Comparison of the Roles of Optimizing Root Distribution and the Water Uptake Function in Simulating Water and Heat Fluxes within a Maize Agroecosystem

Water ◽

10.3390/w10081090 ◽

2018 ◽

Vol 10 (8) ◽

pp. 1090 ◽

Cited By ~ 2

Author(s):

Fu Cai ◽

Yushu Zhang ◽

Huiqing Ming ◽

Na Mi ◽

Shujie Zhang ◽

...

Keyword(s):

Soil Water ◽

Water Uptake ◽

Land Surface ◽

Root Distribution ◽

Model Performance ◽

Heat Fluxes ◽

Land Surface Models ◽

Field Station ◽

Common Land Model ◽

Surface Models

Roots are an important water transport pathway between soil and plant. Root water uptake (RWU) plays a key role in water and heat exchange between plants and the atmosphere. Inaccurate RWU schemes in land surface models are one crucial reason for decreased model performance. Despite some types of RWU functions being adopted in land surface models, none have been certified as suitable for maize farmland ecosystems. Based on 2007–2009 data observed at the maize agroecosystem field station in Jinzhou, China, the RWU function and root distribution (RD) in the Common Land Model (CoLM) were optimized and the effects of the optimizations on model performance were compared. Results showed that RD parameters calculated with root length density were more practical relative to root biomass in reflecting soil water availability, and they improved the simulation accuracy for water and heat fluxes. The modified RWU function also played a significant role in optimizing the simulation of water and heat fluxes. Similarly, the respective and integrated roles of two optimization schemes in improving CoLM performance were significant during continuous non-precipitation days, especially during the key water requirement period of maize. Notably, the improvements were restrained within a threshold of soil water content, and the optimizations were inoperative outside this threshold. Thus, the optimized RWU function and the revised RD introduced into the CoLM model are applicable for simulation of water and heat fluxes for maize farmland ecosystems in arid areas.

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Forage intake, milk yield and composition of cows in a silvopastoral system with and without access to the forage tree and energy supplementation during the rainy season

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200021025 ◽

2007 ◽

Vol 2007 ◽

pp. 199-199

Author(s):

V. Valdivia ◽

C.A. Sandoval-Castro ◽

K. Otaduy ◽

J.C. Ku-Vera

Keyword(s):

Milk Yield ◽

Rainy Season ◽

Silvopastoral Systems ◽

Animal Performance ◽

Silvopastoral System ◽

Dual Purpose ◽

Lactating Cows ◽

Forage Intake ◽

Energy Supplementation ◽

Grass Growth

The improvement in animal performance obtained in silvopastoral systems has been explained either by their ingestion of a higher quality grass (Hernandez et al., 2001, Iglesias, 1998) resulting from the inclusion of a legume in the system which provide N for grass growth or due to the intake of the legume itself, which in turn is also of higher quality than grass. During the rainy season, animals might be able to increase selectivity and intake due to the higher availability of biomass hence possibly reducing the advantage of including a legume in the system. The objective of the present work was to discriminate in a silvopastoral system the effect of improved grass quality and legume intake on dual purpose lactating cows milk yield and composition.

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Soil water availability in a full sun pasture and in a silvopastoral system with eucalyptus

Agroforestry Systems ◽

10.1007/s10457-019-00402-7 ◽

2019 ◽

Vol 94 (2) ◽

pp. 429-440 ◽

Cited By ~ 3

Author(s):

Cristiam Bosi ◽

José Ricardo Macedo Pezzopane ◽

Paulo Cesar Sentelhas

Keyword(s):

Soil Water ◽

Water Availability ◽

Soil Water Availability ◽

Silvopastoral System

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