scholarly journals Intercropping Simulation Using the SWAP Model: Development of a 2×1D Algorithm

Agriculture ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 126 ◽  
Author(s):  
Victor Meriguetti Pinto ◽  
Jos C. van Dam ◽  
Quirijn de Jong van Lier ◽  
Klaus Reichardt

Intercropping is a common cultivation system in sustainable agriculture, allowing crop diversity and better soil surface exploitation. Simulation of intercropped plants with integrated soil–plant–atmosphere models is a challenging procedure due to the requirement of a second spatial dimension for calculating the soil water lateral flux. Evaluations of more straightforward approaches for intercrop modeling are, therefore, mandatory. An adaptation of the 1D model Soil, Water, Atmosphere and Plant coupled to the World Food Studies (SWAP/WOFOST) to simulate intercropping (SWAP 2×1D) based on solar radiation and water partitioning between plant strips was developed and the outcomes are presented. An application of SWAP 2×1D to maize–soybean (MS) strip intercropping was evaluated against the monocropping maize (M) and soybean (S) simulated with the 1D model SWAP/WOFOST, and a sensitivity analysis of SWAP 2×1D was carried out for the intercropping MS. SWAP 2×1D was able to simulate the radiation interception by both crops in the intercropping MS and also to determine the effect of the radiation attenuation by maize on soybean plants. Intercropped plants presented higher transpiration and resulted in lower soil evaporation when compared to their equivalent monocropping cultivation. A numerical issue involving model instability caused by the simulated lateral water flux in the soil from one strip to the other was solved. The most sensitive plant parameters were those related to the taller plant strips in the intercropping, and soil retention curve parameters were overall all significantly sensitive for the water balance simulation. This implementation of the SWAP model presents an opportunity to simulate strip intercropping with a limited number of parameters, including the partitioning of radiation by a well-validated radiation sharing model and of soil water by simulating the lateral soil water fluxes between strips in the 2×1D environment.

1994 ◽  
Vol 40 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Shuichi Hasegawa ◽  
Seiko Osozawa ◽  
Hideto Ueno

1997 ◽  
Vol 195 (1-4) ◽  
pp. 312-334 ◽  
Author(s):  
M.B. McGechan ◽  
R. Graham ◽  
A.J.A. Vinten ◽  
J.T. Douglas ◽  
P.S. Hooda

Géotechnique ◽  
2021 ◽  
pp. 1-41
Author(s):  
Mohammad Hassan Baziar ◽  
Alireza Ghadamgahi ◽  
Andrew John Brennan

Seismic design of soil-nailed walls requires demonstrations of tolerable ranges of wall movements, especially when a surcharge load exists near the wall. In this study, the effect of surcharge location on seismically induced wall movements was investigated using four centrifuge tests. The axial tensile forces, developed along the soil nails during the seismic loadings, were also measured during the tests. At 50g centrifugal acceleration, model tests represented a 12-m-high prototype wall reinforced with five rows of soil nails. To apply a surcharge stress of 30 kPa at the specified location relative to the wall for each model test, a rigid footing was placed on the soil surface. The model soil-nailed walls were subjected to three successive earthquake motions. Surprisingly, it was found that the model wall with the footing located behind the soil-nailed region experienced the largest seismic movements, even more than when the footing was directly behind the wall. Further, the tests showed that the lower soil nails played a key role in the wall stability during earthquake shaking, acting as a pivot for the pre-collapse cases tested, whereas the upper soil nails needed to be sufficiently extended to properly contribute to the seismic stability of the wall.


2010 ◽  
Vol 53 (10) ◽  
pp. 1527-1532 ◽  
Author(s):  
YuanJun Zhu ◽  
YunQiang Wang ◽  
MingAn Shao

Irriga ◽  
2005 ◽  
Vol 10 (2) ◽  
pp. 135-145
Author(s):  
Jocelito Saccol de Sá ◽  
Décio Eugênio Cruciani ◽  
Sérgio Nascimento Duarte ◽  
José Roberto Brito Pereira

SENSIBILIDADE DE PLANTAS DE SOJA AO REBAIXAMENTO DO NÍVEL FREÁTICO  Jocelito Saccol de Sá; Décio Eugênio Cruciani; Sérgio Nascimento Duarte; José Roberto Brito PereiraDepartamento de Engenharia Rural, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo,  Piracicaba - SP, [email protected].  1.      RESUMO A diversificação de culturas em terras baixas é de grande interesse em diversas regiões produtoras de arroz, no Brasil e no exterior. O cultivo de soja é uma opção economicamente viável para a ocupação dessas áreas em rotação e/ou em sucessão à orizicultura. Este trabalho foi realizado em casa de vegetação localizada em uma área experimental da ESALQ/USP, Piracicaba – SP, com o objetivo de avaliar os efeitos de rebaixamentos sucessivos do nível freático (NF) no desenvolvimento e na produtividade de plantas de soja, cv. BR-16, e identificar o estádio de desenvolvimento da cultura com maior sensibilidade à inundação do solo. O delineamento utilizado foi o inteiramente casualizado, em arranjo fatorial (2x5) com um tratamento adicional (testemunha), sendo os fatores estudados: período de desenvolvimento da cultura durante a inundação do solo (estádios V8 e R4) e rebaixamento do NF (10, 20, 30, 40 e 60 cm dia-1). As plantas de soja apresentaram maior suscetibilidade à inundação do solo durante o período vegetativo. As taxas de rebaixamento do NF influenciaram o desenvolvimento e a produtividade dessa cultura. O aumento da velocidade de drenagem reduziu os danos ocasionados às plantas pelo excesso de água no solo, principalmente no estádio menos tolerante a essa condição. UNITERMOS: inundação, coeficiente de drenagem.  SÁ, J. S.; CRUCIANI, D. E.; DUARTE, S. N. E PEREIRA, J. R. B. SENSITIVITY OF SOYBEAN PLANTS TO WATER TABLE DRAWDOWN   2 ABSTRACT Agricultural diversification in low lands is very important in several Brazilian regions and countries, especially in irrigated rice lands. Soybean is a viable economic option for low lands. This study was carried out in an experimental area at ESALQ/USP, Piracicaba, São Paulo – Brazil. The objectives were to estimate the effects of water table drawdown in the growth and crop yield of soybean cv. BR-16 and to identify the most sensitive crop stages to soil water logging. The statistical experimental design was a completely randomized one with factorial arrangement (2x5) one additional treatment (control) and four replications. The study was done in the V8 e R4 crop stages. The water table was lowered 10, 20, 30, 40 and 60cm per day, from initial level. Control plants where only irrigated without flooding. The soybean plants showed highest susceptibility to soil water logging in the vegetative stage. The water table drawdown rates influenced the development and productivity of soybean plants. The drainage rate increase reduced the damage caused to the plants by the water excess in the soil, mainly in the less tolerant stage. KEYWORDS: flooding, drainage coefficient.


Author(s):  
Łukasz Zawadzki ◽  
Dorota Wychowaniak ◽  
Mariusz Lech

Abstract Every single investment affects the natural environment, and that is why it is so important to eliminate nuisance it could cause. Extremely harmful effect on environment or human health could be expected from waste treatment facilities. One of the kinds of contamination which is a real threat to soil and water environment are leachates from landfills. They contain random chemical composition and can migrate from landfill through soil water flux leading to environmental pollution and degradation of groundwater. This paper focuses on the use of geophysical methods to assess migration of pollutants from the landfill through the subsoil. The laboratory tests of solute transport have been conducted on three soil samples from Łubna site to simulate the contamination flow. Migration of leachates through soil samples was controlled using the column test and electrical resistivity measurements which allow to com pare the results obtained with the standard column test method and electrical resistivity measurements. It leads to the conclusion that electrical resistivity methods for contamination transport monitoring in soil–water systems are suitable. Furthermore, field electrical resistivity tomography have been used for monitoring of the vertical sealing system in Łubna landfill.


2021 ◽  
Author(s):  
Thomas Weninger ◽  
Simon Scheper ◽  
Nathan King ◽  
Karl Gartner ◽  
Barbara Kitzler ◽  
...  

<p>Wind erosion of arable soil is considered a risk factor for Austrian fields, but direct measurements of soil loss are not available until now. Despite this uncertainty, vegetated windbreaks have been established to minimize adverse wind impacts on arable land. The study addresses these questions: i) How relevant is wind erosion as a factor of soil degradation? ii) How important is the protective effect of vegetated windbreaks? iii) Are systematic patterns of spatial and temporal variability of wind erosion rates detectable in response to weather conditions? </p><p>Two experimental fields adjacent to windbreaks were equipped with sediment traps, soil moisture sensors, and meteorological measurement equipment for microclimatic patterns. Sediment traps were arranged in high spatial resolution from next to the windbreak to a distance of ten times the windbreak height. Beginning in January 2020, the amount of trapped sediment was analyzed every three weeks. The highest wind erosion rates on bare soil were observed in June and July. For unprotected fields with bare soil, upscaled annual erosion rates were as high as 0.8 tons per hectare, and sediment trapped increased in a linear fashion with distance from the windbreak. Soil water content near the surface (5 cm depth) was three percent higher at a distance of two times the height of the windbreak than at a distance of six times the height. For the same respective distances from the windbreak, we observed 29 days of soil water contents below the wilting point compared with 60 days.</p><p>The preliminary outcomes confirmed the expected effects of windbreaks on soil erosion and microclimate in agricultural fields. Prospective results from multiple vegetation periods will be used in an upscaling approach to gain informations for the whole basin. That is meant to be done by a combination with a soil wind erosion model which was so far used for regional modelling of wind erosion susceptibility.</p>


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