Evaluation of water movement and water losses in a direct-seeded-rice field experiment using Hydrus-1D

ABSTRACT: The Clearfield® rice production system is an effective management tool for weedy rice and other weeds in the direct-seeded rice culture. However, if farmers cultivating the Clearfield® rice disregard stewardship recommendations, the industry could face a problem of herbicide-resistant weedy rice which would occur through the selection of outcrosses. This study aimed to confirm imidazolinone-resistant weedy rice in Malaysia. The resistant weedy rice (R-WR) was found to be 67 fold more resistant to OnDuty® (premix of imazapic and imazapyr) than the susceptible weedy rice (S-WR) based on the GR50 values (rate that causes 50% inhibition of shoot growth). The Clearfield® rice cultivar was 32-fold more tolerant to OnDuty® than the S-WR. Furthermore, the R-WR was 54 and 89 fold more resistant to imazapic and imazapyr applied separately than the S-WR, respectively. The Clearfield® rice was 140- and 40-fold more tolerant to imazapic and imazapyr, respectively than the S-WR. The R-WR biotype was susceptible to non-selective herbicides glyphosate and glufosinate, as well as the selective graminicide quizalofop. Oxadiazon controlled the R-WR biotype, but pretilachlor was ineffective. The present study documented the first case of weedy rice that was cross-resistant to imazapic and imazapyr in Malaysian Clearfield® rice field.

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Modelling Transport of 14 C-Labelled Natural Organic Matter (NOM) in Boom Clay

MRS Proceedings ◽

10.1557/proc-1107-629 ◽

2008 ◽

Vol 1107 ◽

Author(s):

Alice Ionescu ◽

Norbert Maes ◽

Dirk Mallants

Keyword(s):

Organic Matter ◽

Natural Organic Matter ◽

Water Movement ◽

Numerical Code ◽

Migration Behavior ◽

Colloidal Transport ◽

Boom Clay ◽

Kinetically Controlled ◽

Clay Formation ◽

Hydrus 1D

AbstractIn Belgium, the Boom Clay formation is considered to be the reference formation for HLW disposal R&D. Assessments to date have shown that the host clay layer is a very efficient barrier for the containment of the disposed radionuclides. Due to absence of significant water movement), diffusion - the dominant transport mechanism, combined with generally high retardation of radionuclides, leads to extremely slow radionuclide migration. However, trivalent lanthanides and actinides form easily complexes with the fulvic and humic acids which occur in Boom Clay and in its interstitial water. Colloidal transport may possibly result in enhanced radionuclide mobility, therefore the mechanisms of colloidal transport must be better understood. Numerical modeling of colloidal facilitated radionuclide transport is regarded an important means for evaluating its importance for long-term safety.The paper presents results from modeling experimental data obtained in the framework of the EC TRANCOM-II project, and addresses the migration behavior of relevant radionuclides in a reducing clay environment, with special emphasis on the role of the Natural Organic Matter (NOM) [1]. Percolation type experiments, using stable 14C-labelled NOM, have been interpreted by means of the numerical code HYDRUS-1D [2]. Tracer solution collected at regular intervals was used for inverse modeling with the HYDRUS-1D numerical code to identify the most likely migration processes and the associated parameters. Typical colloid transport submodels tested included kinetically controlled attachment/detachment and kinetically controlled straining and liberation.

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Numerical Study of Macropore Impact on Ponded Infiltration in Clay Soils

Soil and Water Research ◽

10.17221/6501-swr ◽

2013 ◽

Vol 1 (No. 1) ◽

pp. 16-22

Author(s):

Kodešova Radka ◽

Šimůnek Josef Kozak and Jiři

Keyword(s):

Numerical Simulations ◽

Preferential Flow ◽

Water Movement ◽

Numerical Study ◽

Water Infiltration ◽

Clay Soils ◽

Saturated Water ◽

Water Recharge ◽

Considerable Impact ◽

Hydrus 1D

The single-porosity and dual-permeability models in HYDRUS-1D (&Scaron;imůnek et al. 1998, 2003) were used to simulate variably-saturated water movement in clay soils with and without macropores. Numerical simulations of water flow for several scenarios of probable macropore compositions show a considerable impact of preferential flow on water infiltration in such soils. Preferential flow must be considered to predict water recharge in clay soils.

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Effect of the herbicide butachlor on methane emission and ebullition flux from a direct-seeded flooded rice field

Biology and Fertility of Soils ◽

10.1007/s003740000301 ◽

2001 ◽

Vol 33 (3) ◽

pp. 175-180 ◽

Cited By ~ 17

Author(s):

S. R. Mohanty ◽

K. Bharati ◽

B. T. S. Moorthy ◽

B. Ramakrishnan ◽

V. R. Rao ◽

...

Keyword(s):

Methane Emission ◽

Rice Field ◽

Flooded Rice ◽

Direct Seeded ◽

Flooded Rice Field

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Modeling of Soil Water Regime and Water Balance in a Transplanted Rice Field Experiment with Reduced Irrigation

Water ◽

10.3390/w9040248 ◽

2017 ◽

Vol 9 (4) ◽

pp. 248 ◽

Cited By ~ 11

Author(s):

Yong Li ◽

Jirka Šimůnek ◽

Shuang Wang ◽

Jiahui Yuan ◽

Weiwei Zhang

Keyword(s):

Water Balance ◽

Field Experiment ◽

Soil Water ◽

Water Regime ◽

Rice Field ◽

Soil Water Regime ◽

Transplanted Rice

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Lack of Response of Some Food Crops to the Application of Synthetic Soil Conditioners to A Clay Soil in Lajas Valley

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v41i3.12615 ◽

1969 ◽

Vol 41 (3) ◽

pp. 167-172

Author(s):

M. A. Lugo-López ◽

J. A. Bonnet ◽

M. Rico-Ballester ◽

G. Acevedo

Keyword(s):

Field Experiment ◽

Physical Properties ◽

Clay Soil ◽

Water Movement ◽

Soil Aggregates ◽

Soil Physical Properties ◽

Food Crops ◽

Dry Powder ◽

Soil Conditioners ◽

The Stability

Data are presented here from a field experiment where Krilium 6 and 9, Aerotil, and Goodrite (dry powder of the first three and flakes of the fourth) were applied to the uppermost 6 inches of a Santa Isabel clay soil at the Lajas Valley, each at rates of 900, 1,800, and 3,600 pounds to the acre. Three crops: Tomatoes, white beans, and sweetpotatoes, were grown in the sequence following the establishment of the treatment differentials. None of the crops showed any response to the soil-conditioning chemicals. The stability of the soil aggregates of Santa Isabel clay, which is naturally high, was not affected by the treatment. The data presented show also that the water movement and retention and other soil physical properties remain unaffected by treatment. The lack of response is discussed and compared with other problem soils where crop responses have been measured.

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