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United States Department of Agriculture

Agricultural Research Service

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Liwang Ma

Research Soil Scientist


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 /ARSUserFiles/3495/Liawang_Macropped.jpg

Liwang Ma

Research Soil Scientist

USDA-ARS Rangeland Resources and Systems Research Unit

2150 Centre Avenue, Bldg. D.

Fort Collins, CO 80526

Phone: (970)492-7339

Email: liwang.ma@ars.usda.gov  
           

Education:

B.S. China Agricultural University, 1984

M.S. China Agricultural University, 1987

Ph. D. Louisiana State University, 1993

Research Interest:

Dr. Ma’s research interests include the use of system ecological and biophysical models to quantify agricultural production and environmental impacts at multiple spatiotemporal scales in rangelands and croplands. His current research involves assessing sustainable intensification of agriculture by comparing outcomes of business as usual vs. aspirational management strategies for rangelands, pasturelands and croplands of the Long-Term Agro-ecosystem Research (LTAR) network (hyperlink to this here).  Initial efforts are evaluating grazing management strategies at the semiarid Central Plains Experimental Range (CPER) in Nunn, Colorado and subhumid Riesel Watershed in Riesel, Texas (Texas Gulf Research Partnership LTAR) through collaborative efforts involving system models: APEX (Agricultural Policy/Environmental eXtender) and IFSM (Integrated Farm System Model).

Publications:

Fang, Q. L. Ma, L. R. Ahuja, T. J. Trout, R. W. Malone, H. Zhang, D. Gui, Q. Yu. 2017. Long-term simulation of growth stage-based irrigation scheduling in maize under various water constraints in Colorado, USA. Frontiers Agricultural Science and Engineering 4: 172–184

Kisekka, I., A. Schlegel, L. Ma, P.H. Gowda, P.V.V. Prasad. 2017. Optimizing preplant irrigation for maize under limited water in the High Plains. Agricultural Water Management 187:154–163

Gillette, K. L., Ma, L., Malone, R. W., Fang, Q. X., Halvorson, A. D., Hatfield, J. L., and Ahuja, L. R. 2017. Simulating N2O emissions in different tillage systems using RZWQM2. Soil and Tillage Research 165:268-278.

Ma, L., Ahuja, L. R., A. Islam, T. J. Trout, S. A. Saseendran, and Malone, R.W. 2017. Modeling Yield and Biomass Responses of Maize Cultivars to Climate Change under Full and Deficit Irrigation. Agriculture Water Management 180:88-98.

Malone, R. W., Kersebaum, K. C., Kaspar, T. C., Ma, L., Jaynes, D. B., and Gillette, K. 2017. Winter rye as a cover crop reduces nitrate loss to subsurface drainage in central Iowa as simulated by HERMES. Agriculture Water Management 184:156-169.

Kisekka, I., Schlegel, A., Vanderveer, M., and Ma, L. 2017. Effect of preplanitng irrigation on corn yield, evapotranspiration, and profitability under limited water in semi-arid climate. Agriculture Water Management 187:154-163.

Ma, L., Ahuja, L. R., Trout, T. J., Nolan, B. T., and Malone, R. W. 2016. Simulating maize yield and biomass with spatial variability of soil field capacity. Agronomy J. 108:171-184.

Qi, Z., Ma, L., W. C. Bausch, T. J. Trout, L. R. Ahuja, G. N. Flerchinger, and Q. X. Fang,. 2016. Simulating maize production, water and surface energy balance, and canopy temperature, and water stress under full and deficit irrigation. Trans. ASABE. 59:623-633.

Saseendran, S. A., L. R. Ahuja , P. H. Gowda, L. Ma, G. Marek, S. Evett, and T. Howell. 2016. Simulation of crop evapotranspiration and crop coefficients with data in weighing lysimeters. Agriculture Water Management 177:274-283.

Saseendran, S. A., W. T. Pettigrew, K. N. Reddy, L. Ma, D. K. Fisher, and R. Sui. 2016. Climate Optimized planting windows for cotton in the lower Mississippi Delta region. Agronomy 6(4), 46. doi: 10.3390/agronomy6040046.

Nolan, B. T., Malone, R. W., Barbash, J. E., Ma, L., and Shaner, D. L. 2015. Unsaturated zone transport and fate of metolachlor and degrades in agricultural settings of the United States. Pesticide Management Science DOI 10.1002/ps.3875. 71:972-985.

Saseendran, S. A., Trout, T. J., Ahuja, L. R., Ma, L., McMaster, G. S., Andales, A. A., Chaves, J., and Ham, J. 2015. Quantification of crop water stress factors in limited irrigation experiments. Agricultural System 137:191-205.

Saseendran, S. A. Trout, T. J., Ahuja, L. R., Ma, L., McMaster, G. S., Andales, A. A., Chaves, J., and Ham, J. , 2015. Developing and normalizing average corn crop water production functions across years and locations using a system model. Agricultural Water Management 157:65-77.

Shipitalo, M. J., R. W. Malone, L. Ma, D. L. Shaner, B. T. Nolan, and R. S. Kanwar. 2015. Effect of corn stover harvest on herbicide movement to subsurface drains – RZWQM simulations. Pesticide Management Science DOI 10.1002/ps.4087.

Fang, Q. X., Ma, L., Halvorson, A. D., Malone, R. W., Ahuja, L. R., Del Grosso, S. and Hatfield, J. L. 2015. Evaluating four nitrous oxide emission algorithms in response to N rate on an irrigated corn field. Environmental Modeling & Software 72:56-70.

Feng, G., H. Tewolde, L. Ma, K. R. Sistani, A. Adeli, and J. Jenkins. 2015. Simulating management of poultry litter on corn production and soil nitrogen balance in the Mid-Southern United States. Soil Science Society America Journal 79:1804-1814.

Saseendran, S. A., Ahuja, L. R., Ma, L., Nielsen, D. C., Trout, T. J., Andales, A. A., Chaves, J., and Ham, J. Enhancing the water stress factors for simulation of corn (Zea mays L.) in RZWQM2. Agronomy J. 106:81-94.

Malone, R. W., Nolan, B. T., Ma, L., Kanwar, R. S., Peterson, C., and Heilman, P. 2014. Effects of tillage and application rate affects atrazine transport to subsurface drainage with macropore flow: evaluation of RZWQM using a long-term field study. Agriculture Water Management 132:10-22. 2014.

Fang, Q. X., Ma, L., Flerchinger, G. N., Qi, Z., Ahuja, L. R., Xing, H. T., Li, J., and Yu, Q. 2014. Modelling evapotranspiration and energy balance in a wheat-maize cropping system using the revised RZ-SHAW model. Agricultural Forest Meteorology 194:218-229.

Malone, R.W., Jaynes, D.B., Kaspar, T.C., Thorp, K.R., Kladivko, E., Ma, L., James, D.E., Singer, J., Morin, X., Searchinger, T.  2014. Cover crops in the upper Midwestern United State: Simulated effect on nitrate leaching with artificial drainage. Journal Soil Water Conservation. 69:(4):292-305.

Fang, Q. X., Andales, A. A., Derner, J., Ahuja, L.R., Ma, L., Bartling, P. N. S., J. L. Reeves, and Z. Qi. 2014. Quantifying stocking density and weather effects on forage and steer production on the Northern Mixed-Grass Prairie. Agricultural Systems 129:103-114.

Cameira, M. R., A. Pereira, Ahuja, L. R., and Ma, L. 2014. Sustainability and Environmental Assessment of Fertigation in an Intensive Olive Grove under Mediterranean Conditions. Agriculture Water Management 146:346-360,

Fang, Q.X., A.A. Andales, J.D. Derner, L.R. Ahuja, L. Ma, P.N.S. Bartling , J.L. Reeves, Z. Qi. 2014. Modeling weather and stocking rate effects on forage and steer production in northern mixed-grass prairie. Agricultural Systems 129:103–114.

Nolan, B.T., R.W. Malone, J.E. Doherty, J. E. Barbash, L. Ma and D. L. Shaner. 2014. Data worth and prediction uncertainty for pesticide transport and fate models in Nebraska and Maryland, United States. DOI 10.1002/ps.3875

Saseendran S.A., Nielsen, D. C., Ahuja, L. R., Ma, L., and Lyon, D. 2013. Simulated yield and profitability of five potential crops for intensifying the dryland wheat-fallow production system. Agriculture Water Management

Qi, Z., Bartling, P. N. S., Jabro, J. D., Lensen, A.W., Ahuja, L. R., Ma, L. Allen, B. L. and Evans, R. G. 2013. Simulating dryland water availability and spring wheat production in the Northern Great Plains. Agronomy Journal 105:37-50.

Fang, Q. X., Ma, L., Yu, Q., Hu, C. S., X. X. Li, R. W. Malone, and Ahuja, L. R. 2013. Quantifying climate and management effects on regional N leaching and crop yield in the North China Plain. Journal Environmental Quality 42:1466-1479.

Ko, J., Ahuja, L. R., Saseendran, S. A., Green, T. R., Ma, L., Nielsen, D. C., and Walthall, C. 2012. Climate change impacts on dryland cropping systems in the central Great Plains, USA. Climatic Change 111:445-472.

Ma, L., Trout, T. J., Ahuja, L. R., Bausch, W., Saseendran, S. A., Malone, R. W., and Nielsen, D. C. 2012. Calibrating RZWQM2 model for maize responses to deficit irrigation. Agriculture Water Management 103:140-149.

Fang, Q. X., Malone, R. W., Ma, L., Jaynes, D. B., Green, T. R., and Ahuja, L. R. 2012. Modeling the effects of controlled drainage, N rate and weather on nitrate loss to subsurface drainage. Agriculture Water Management. 103:150-161.

Heilman, P., Malone, R. W., Ma, L., Hatfield, J. L., Ahuja, L. R., Boyle, K., and Kanwar, R. S. 2012. Getting the most from intensively monitored data for water quality decision support. Agriculture Systems. 106:69-71.

Ma, L., Flerchinger, G. N., Ahuja, L. R., Sauer, T., Prueger, J. H., Malone, R. W., and Hatfield, J. L. 2012. Simulation of the surface energy balances in a soybean canopy using SHAW and RZ-SHAW. Trans. ASABE. 55:175-179.

Qi, Z., Ma, L., Helmers, M. J., Ahuja, L. R., and Malone, R. W. 2012. Simulating NO3-N concentration in tile drainage at various nitrogen application rates using RZWQM2. Journal Environmental Quality. 41:289-295.

Qi., Z., Bartling, P. N. S., Ahuja, L. R., Derner, J. D., Dunn, G. H., and Ma, L. 2012. Development and evaluation of the carbon-nitrogen cycle module for the GPFARM-Range model. Computers and Electronics in Agriculture. 83:1-10.

Nolan, B. T., Malone, R. W., Gronberg, J. A., Thorp, K. R. and Ma, L. 2012. Verifiable metamodels for predicting N and water fluxes in the Corn Belt, USA. Environmental Science & Technology 46:901-908.

Islam, Adlul, Ahuja, L. R., Garcia, L. A. Ma, L., Saseendran, S. A. and Trout, T. J. 2012. Modelling the impact of climate change on corn yield using multi-model ensemble climate change scenarios. Agriculture Water Management 110:94-108.

Nielsen, D. C., Saseendran, S. A., Ma, L., and Ahuja, L. R., 2012. Simulating the production potential of dryland spring canola in the central Great Plains. Agronomy Journal. 104:1182-1188.

Li, Z., Ma, L., Flerchinger, G. N., Ahuja, L. R., Wang, H., and Li, Z. 2012. Simulation of over-winter soil water and soil temperature with SHAW and RZ-SHAW. Soil Science Society American Journal. 76:1548-1563.

Ma, L., Ahuja, L. R., B. T. Nolan, Malone, R. W., Trout, T. J., and Qi, Z. 2012. Root Zone Water Quality Model (RZWQM2): Model use, calibration and validation. Trans. ASABE. 55:1425-1446.

Heilman, P., R. S. Kanwar, R. W. Malone, L. Ma, J. L. Hatfield and K. Boyle. 2012. The Nashua agronomic, water quality, and economic dataset. Journal Soil Water Conservation. 67:502-512.

Islam, Adlul, Ahuja, L. R., Garcia, L. A. Ma, L., Saseendran, S. A. 2012. Modeling the effect of elevated co2 and climate change on reference evapotranspiration in the semi-arid central Great Plains. Trans. ASABE. 55:2135-2146.

Singer, J., Malone, R. W., Jaynes, D. B., and Ma, L. 2011. Cover crop effects on nitrogen load in tile drainage from Walnut Creek Iowa using RZWQM. Agriculture Water Management. 98:1622-1628.

Ko, J., L. Ahuja, B. Kimball, S. Anapalli, L. Ma,T. R. Green, A. C. Ruane, G. W. Wall, P. Pinter, D. A. Bader. 2010. Simulation of free air CO2 enriched wheat growth and interactions with water, nitrogen, and temperature. Agricultural and Forest Meteorology 150:1331–1346

Li, L., D.C. Nielsen, Q. Yu, L. Ma, L.R. Ahuja. 2010. Evaluating the Crop Water Stress Index and its correlation with latent heat and CO2 fluxes over winter wheat and maize in the North China plain. Agricultural Water Management 97: 1146–1155

Li, L., Nielsen, D. C., Yu, Q., Ma, L., and Ahuja, L. R., 2010. Seasonal variations of CWSI and its correlation with soil moisture, CO2 flux, and canopy water use efficiency in the North China Plain. Agriculture Water Management. 97:1145-1155.

Fang, Q., Ma, L., Yu, Q., Ahuja, L. R., Malone, R. W., and Hoogenboom, G.. 2010. Irrigation strategies to improve the water use efficiency of wheat-maize double cropping systems in North China Plain. Agricultural Water Management. 97:1165-1174.

Fang, Q. Ma, L., Green, T. R., Yu, Q., Wang, T. D., and Ahuja, L. R.. 2010. Water resources and agricultural water use in the North China Plain: current status and management options. Agricultural Water Management. 97:1102-1116.

Nolan, B. T., Puckett, L. J., Ma, L., Green, C. T., Bayless, E. R., and Malone, R. W., 2010. Predicting unsaturated zone nitrogen mass balances in diverse agricultural settings of the United States. Journal Environmental Quality. 39:1051-1065.

Saseendran S. A., Nielsen, D. C., Ma, L., Ahuja, L. R., and Vigil, M. F. 2010. Simulating alternative dryland rotational cropping systems in the central Great Plains with RZWQM2. Agronomy Journal. 102:1521-1534.

Ahuja, L. R., Ma, L., and Green, T. R. 2010. Effective soil properties of heterogeneous areas for modeling infiltration and redistribution. Soil Science Society American Journal. 74:1469-1482.

Ko, J., Ahuja, L. R., Kimball, B., Saseendran, S. A., Ma, L., Green, T. R., Wall, G., and Pinter, P. 2010. Simulation of climate change impacts on wheat-fallow cropping systems. Agriculture and Forest Meteorology. 150:1331-1346.

Fang, Q. X., Green, T. R., Ma, L., Malone, R. W., Erskine, R. H., and Ahuja, L. R 2010. Optimizing soil hydraulic parameters in RZWQM2 under fallow conditions.  Soil Science Society America Journal. 74:1897-1913.

Malone, R. W., Jaynes, D. B., Ma, L., Nolan, B. T., Meek, D., Karlen, D. 2010. Soil test N recommendation augmented with PEST-optimized RZWQM simulations. Journal Environmental Quality. 39:1711-1723.

Saseendran S. A., Nielsen, D. C., Ma, L., and Ahuja, L. R. 2010. Adapting CROPGRO for simulating spring canola growth with both RZWQM2 and DSSAT4.0. Agronomy. J. 102:1606-1621.

Malone, R. W., Meek, D. W., Hatfield, J. L., Jaquis, R. J., and Ma, L. 2009. Quasi-biennial corn yield cycles. Agricultural and Forest Meteorology. 149:1087-1094.

Ma, L., Hoogenboom, G., Saseendran, S. A., Bartling, P. N. S., Ahuja, L. R., Green, T. R. 2009. Effects of estimating soil hydraulic properties and root growth factor on soil water balance and crop production. Agronomy Journal. 101:572-583.

Sophocleous, M., Townsend, M. A., Vocasek, F., Ma, L., and Ashok, K. C. 2009. Soil nitrogen balance under wastewater management: field measurements and simulation results. Journal Environmental Quality. 38:1286-1301.

Saseendran, S. A., Nielsen, D. C., Lyon, D, Ma, L., Felter, D. G., Baltensperger, D. D., Hoogenboom, G., and Ahuja, L. R. 2009. Modeling responses of dryland spring triticale, proso millet, and foxtail millet to initial soil water in the High Plains. Field Crop Research. 113:48-63.

Thorp, K.R., Youssef, M.A., Jaynes, D.B., Malone, R.W., and Ma, L. 2009. DRAINMOD-N II: Evaluated for an agricultural system in Iowa and compared to RZWQM-DSSAT. Trans. ASABE. 52:1557-1573.

Saseendran, S. A., Ahuja, L. R., Nielsen, D. C., Trout, T., and Ma, L,. 2008. Use of crop simulation models to evaluate limited irrigation management options for corn in a semiarid environment. Water Resources Reseach. 44, W00E02, doi:10.1029/2007WR006181.

Ma, L., Malone, R. W., Jaynes, D. B., Thorp, K., and Ahuja, L. R. 2008. Simulated effects of nitrogen management and soil microbes on soil nitrogen balance and crop production. Soil Science Society America Journal. 72:1594-1603.

Fang, Q., Ma, L., Yu, Q., Malone, R. W., Saseendran, S. A., and Ahuja, L. R. 2008. Modeling nitrogen and water management effects in a wheat-maize double-cropping system. Journal Environmental Quality. 37:2232-2242.

Li, L. Malone, R. W., Ma, L., Kaspar, T. C., Jaynes, D. B., Saseendran, S. A., Yu, Q., and Ahuja, L. R. 2008. Winter cover crop effects on nitrate leaching in subsurface drainage as simulated by RZWQM-DSSAT. Trans. ASABE 51(5):1575-1583.

Kozak, J., Ahuja, L. R., Green, T. R. and Ma, L. 2007. Modeling crop canopy and residue rainfall interception effects on soil hydrological components for semi-arid agriculture. Hydrological Processes. 21:229-241.

Ahuja, L. R., Andales, A. A., Ma, L., and Saseendran, S. A., 2007. Whole system integration and modeling essential to agricultural science and technology for the 21st century. Journal Crop Improvement. 19:73-103.

Sabbagh, G. J., Fox, G. A., Ma, L., Malone, R. W., Arthur, E. L., and Dyer, D. G. 2007. Modeling pesticide fate and nonideal transport from seeds treated with a slow-release pesticide in a laboratory soil column. Trans. ASABE. 50:523-532.

Cameira, M. R., Fernando, R. M., Ahuja, L. R., and Ma, L. 2007. Using RZWQM to simulate the fate of nitrogen in field soil – crop environment in the Mediterranean region. Agricultural Water Management. 90:121-136.

Ma, L., Malone, R. W., Heilman, P., Ahuja, L. R., Meade, T., Saseendran, S. A., Ascough II, J. C., and Kanwar, R. S. 2007. Sensitivity of tile drainage flow and crop yield on measured and calibrated soil hydraulic properties. Geoderma.140:284-296.

Ma, L. Malone, R. W., Heilman, P., Jaynes, D., Ahuja, L. R., Saseendran, S. A., Kanwar, R. S., and Ascough II, J. C. 2007. RZWQM simulated effects of crop rotation, tillage, and controlled drainage on crop production and nitrate-N loss in drain flow. Geoderma, 140:260-271.

Ma, L., Malone, R. W., Heilman, P., Karlen, D. L., Kanwar, R. S., Cambardella, C. A., Saseendran, S. A., and Ahuja, L. R. 2007. RZWQM simulation of long-term crop production, water and nitrogen balances in Northeast Iowa. Geoderma, 140:247-259.

Malone, R. W., Ma, L., Karlen, D. L., Meade, T., Meek, D., Heilman, P., Kanwar, R. S., Hatfield, J. L. 2007. Empirical analysis and prediction of nitrate loading and crop yield for corn-soybean rotations. Geoderma. 140:223-234.

Malone, R. W., Ma, L., Heilman, P., Karlen, D. L., Kanwar, R. S. and Hatfield, J. L. 2007. Simulated N management effects on corn yield and tile-drainage nitrate loss. Geoderma, 140:272-283.

Saseendran, S. A., Ma, L., Malone, R. W., Heilman, P., Ahuja, L. R., Kanwar, R. S., Karlen, D. L., Hoogenboom, G., 2007. Simulating management effects on crop production, tile drainage, and water quality using RZWQM-DSSAT. Geoderma, 140:297-309.

Malone, R. W., Huth, N., Carberry, P. S., Ma, L., Kaspar, T., Karlen, D. L., Meade, T., Kanwar, R. S., and Heilman, P., 2007. Evaluating and predicting agricultural management effects under tile drainage using modified APSIM. Geoderma. 140:310-322.

Kozak, J. A., Aiken, R., Flerchinger, G. N., Nielsen, D. C., Ma, L., and Ahuja, L. R. 2007. Comparison of modeling approaches to quantify residue architecture effects on soil temperature and water. Soil & Tillage Research. 95:84-96.

Yu, Q., Flerchinger, G. N., Xu, S., Kozak, J., Ma, L., and Ahuja, L. R., 2007. Energy balance simulation of a wheat canopy using RZ-SHAW Model. Trans. ASABE. 50:1507-1516.

Ahuja, L. R., Kozak, J. A., Andales, A. A., Ma, L. 2007. Scaling parameters of the Lewis-Kostiakov ponded-water infiltration equation across soil texture classes. Trans. ASABE. 50:1525-1541.

Ma, L., Ahuja, L. R., and Malone, R. W., 2007. Systems modeling for soil and water research and management: current status and further needs in the 21st century. Trans. ASABE. 50:1705-1713.

Ma, L., Hoogenboom, G., Ahuja, L. R., Ascough II, J. C., and Anapalli, S. S. 2006. Evaluation of RZWQM-CERES-maize hybrid model for maize production. Agricultural Systems. 87:274-295.

Ahuja, L. R., Ma, L., and Timlin, D. J. 2006. Trans-disciplinary soil physics research critical to synthesis and modeling of agricultural systems. Soil Science Society America Journal. 70:311-326.

Hu, C., Saseendran S. A., Green, T. R., Ma, L., Li, X. and Ahuja, L. R. 2006. Evaluating nitrogen and water management in a double-cropping system using RZWQM. Vadose Zone Journal. 5:493-505.

Yu, Q., Saseendran, S. A., Ma, L. Flerchinger, G. N., T. R. Green, and Ahuja, L. R. 2006. Modeling a wheat-maize double cropping system in China using two plant growth modules with RZWQM. Agricultural Systems. 89:457-477.

Kozak, J., Ma, L., Ahuja, L. R., Flerchinger, G. N., and Nielsen, D. C. 2006. Evaluating various water stress calculations in RZWQM and RZ-SHAW for corn and soybean production. Agronomy Journal. 98:1146-1155.

Hu, C., Delgado, J. A., Zhang, X., and Ma, L. 2005. Assessment of groundwater use by wheat (Triticum aestivum L.) in the Luancheng Xian region and potential implications for water conservation in the northwestern North China Plain. Journal Soil & Water Conservation. 60:80-88.

Saseendran, S. A., Ma, L., Nielsen, D. C., Vigil, M. F., and Ahuja, L. R. 2005. Simulating planting date effects on crop production using RZWQM and CERES-maize. Agronomy. J. 97:58-71.

Ma, L., Hoogenboom, G., Ahuja, L. R., Nielsen, D. C., and Ascough II, J. C. 2005. Development and evaluation of RZWQM-CROPGRO hybrid model for soybean production. Agronomy. J. 97:1172-1182.

Kozak, J., Ahuja, L. R., Ma, L., and Green, T. R. 2005. Scaling and estimation of evaporation and transpiration of water across soil texture classes. Vadose Zone Journal. 4:418-427.

Saseendran, S. A., Nielsen, D. C., Ma, L., L. R. Ahuja, M. F. Vigil, J. G. Benjamin, A. D. Harvorson. Effectiveness of RZWQM for simulating alternative Great Plains cropping systems. Agronomy. J. 97:1183-1193. 2005.

Bakhsh, A., Hatfield, J. L., Kanwar, R. S., Ma, L. and Ahuja, L. R. 2004. Simulating nitrate losses from Walnut Creek Watershed. Journal Environmental Quality. 33:114-123.

Malone, R. W., Ahuja, L. R., Ma, L., Wauchope, R. D., Ma, Q. L., and Rojas, K. W. 2004. Application of the Root Zone Water Quality Model (RZWQM) to pesticide fate and transport: an overview. Pest Management Science. 60:205-221.

Malone, R. W., Ma, L., Wauchope, R. D., Ahuja, L. R., Rojas, K. W., Ma, Q. L., Warner, R., and Byers, M. 2004. Modeling hydrology, metribuzin degradation and metribuzin transport in macroporous tilled and no-till silt loam soil using RZWQM. Pest Management Science. 60:253-266.

Malone, R. W., Weatherington-Rice, J., Shipitalo, M., Fausey, N., Ma, L., Ahuja, L. R., Wauchope, R. D., and Ma, Q. L. 2004. Herbicide leaching as affected by macropore flow and within-storm rainfall intensity variation: a RZWQM simulation. Pest Management Science. 60:277-285.

Ma, Q. L., Wauchope, R. D., Rojas, K. W., Ahuja, L. R., Ma, L., and Malone, R. W. 2004. The pesticide module of the Root Zone Water Quality Model (RZWQM): testing and sensitivity analysis of selected algorithms for pesticide fate and surface runoff. Pest Management Science. 60:240-252.

Ma, Q. L., Wauchope, R. D., Ma, L., Rojas, K. W., Malone, R. W., and Ahuja, L. R. 2004. Test of the Root Zone Water Quality Model (RZWQM) for predicting runoff of atrazine, alachlor and fenamiphos species from conventional-tillage corn mesoplots. Pesticide Management Science. 60:267-276.

Wauchope, R. D., Rojas, K. W., Ahuja, L. R., Ma, Q. L., Malone, R. W., and Ma, L. 2004. Documenting the pesticide processes module of the ARS RZWQM agroecosystem model. Pest Management Science. 60:222-239.

Saseendran, S. A., Nielsen, D. C., Ma, L., Ahuja, L. R. and Halvorson, A.D. 2004. Modeling nitrogen management effects on a winter wheat cropping system using RZWQM and CERES-wheat. Agronomy Journal. 96:615-630.

Bakhsh, A., Ma, L., Ahuja, L. R., Hatfield, J. L., and Kanwar, R. S. 2004. Using RZWQM to predict herbicide leaching losses in subsurface drainage water. Trans. ASAE 47:1415-1426.

Starks, P. J., Heathman, G. C., Ahuja, L. R., and Ma, L. 2003. Use of limited soil property data and modeling to estimate root zone soil water content. Journal Hydrology. 272:131-147.

Malone, R. W., Logsdon, S., Shipitalo, M. J., Weatherington-Rice, J., Ahuja, L. R., Ma, L. 2003. Tillage effect on macroporosity and herbicide transport in percolate. Geoderma. 116:191-215.

Ma, L., Nielsen, D. C., Ahuja, L. R., Malone, R. W., Anapalli, S. S., Rojas, K. W., Hanson, J. D., and Benjamin, J. G. 2003. Evaluation of RZWQM under varying irrigation levels in Eastern Colorado. Trans. ASAE. 46:39-49.

Heilman, P., Hatfield, J. L., Rojas, K. W., Ma, L., Huddleston, J., Ahuja, L. R., Adkins, M. 2002. How good is good enough? What information is needed for agricultural and how can it be provided most affordably? Journal Soil & Water Conservation. 57:98-105

Nielsen, D. C., Ma, L., Ahuja, L. R., and Hoogenboom, G. 2002. Simulating soybean water stress effects with RZWQM and CROPGRO models. Agronomy. J. 94:1234-1243.

Mansell, R. S., Ma, L., Ahuja, L. R., and Bloom, S. A. 2002. Adaptive grid refinement in numerical models for water flow and solute transport in soil: a review. Vadose Zone Journal. 1:222-238.

Malone, R. W., Shipitalo, M. J., Ma, L., Ahuja, L. R., and Rojas, K. W. 2001. Macropore component assessment of the Root Zone Water Quality Model (RZWQM) using no-till soil blocks. Trans. ASAE. 44:843–852.

Ma, L., Ahuja, L. R., Ascough II, J. C., Shaffer, M. J., Rojas, K. W., Malone, R. W., and Cameira, M. R. 2000. Integrating system modeling with field research in agriculture: applications of the Root Zone Water Quality Model (RZWQM). Advance Agronomy. 71:233-292.

Ma, L., Ascough II, J. C., Ahuja, L. R., Shaffer, M. J., Hanson, J. D., and Rojas, K. W. 2000. Root Zone Water Quality Model sensitivity analysis using the Monte Carlo simulation. Trans. ASAE. 43:883-895.

Ma, L., Peterson, G. A., Ahuja, L. R., Sherrod, L., Shaffer, M. J., and Rojas, K. W. 1999. Decomposition of surface crop residues in long-term studies of dryland agroecosystems. Agronomy Journal, 91:401-409.

Ma, L., Scott, H. D., Shaffer, M. J., and Ahuja, L. R. 1998. RZWQM simulations of water and nitrate movement in a manured tall fescue field. Soil Science. 163:259-270.

Ma, L., Shaffer, M. J., Boyd, J. K., Waskom, R., Ahuja, L. R., Rojas, K. W., and Xu, C. 1998. Manure management in an irrigated silage corn field: experiment and modeling. Soil Science Society America Journal. 62:1006-1017.

 

 


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