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ARS Home Plains Area Fort Collins, Colorado Center for Agricultural Resources Research Rangeland Resources & Systems Research People







Liwang  Ma    Research Soil Scientist /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@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.  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 GPFARM. Dr. Ma also maintains the USDA-ARS Root Zone Water Quality Model (RZWQM). **Publications:** Li, L.,**Ma, L.**, Qi, Z., Fang, Q., Harmel, R.D., Schmer, M.R. and Jin, V.L. 2023.Measured and simulated effects of residue removal and amelioration practices in no-till irrigated corn (*Zea mays*L.). *European Journal of Agronomy*146: 126807.  https://doi.org/10.1016/j.eja.2023.126807 Pan, P., Qi, Z., Zhang, T. and**Ma, L.**2023.Modeling phosphorus losses to subsurface drainage under tillage and compost management. *Soil and Tillage Research*227: 105587.https://doi.org/10.1016/j.still.2022.105587 Pan, P., Qi, Z., Koehn, A., Leytem, A., Bjorneberg, D. and**Ma, L.**2023.Modification of the RZWQM2-P model to simulate labile and total phosphorus in an irrigated and manure-amended cropland soil.*Computers and Electronics in Agriculture*206: 107672.https://doi.org/10.1016/j.compag.2023.107672 Fang, Q.X., Harmel, R.D.,**Ma, L.**, Bartling, P.N.S., Derner, J.D.,Jeong, J., Williams, J.R. and Boone, R.B. 2022. Evaluating the APEX model for alternative cow-calf grazing management strategies in Central Texas.*Agricultural Systems*195: 103287.  https://doi.org/10.1016/j.agsy.2021.103287 Chu, X., Flerchinger, G.N.,**Ma, L.**, Fang, Q., Malone, R.W., Yu, Q., He, J., Wang, N., Feng, H. and Zou, Y. 2022. Development of RZ-SHAW for simulating plastic mulch effects on soil water, soil temperature, and surface energy balance in a maize field.*Agricultural Water Management*269: 107666. https://doi.org/10.1016/j.agwat.2022.107666 Cheng, G., Harmel, R.D., **Ma, L.**, Derner, J.D., Augustine, D.J., Bartling, P.N.S., Fang, Q.X., Williams, J.R., Zilverberg, C.J., Boone, R.B. and Yu, Q., 2022. Evaluation of the APEX cattle weight gain component for grazing decision-support in the Western Great Plains.*Rangeland Ecology & Management*82, 1-11. Koehn A. C., D. L. Bjorneberg, R.W. Malone, A. B. Leytem, A. Moore, **L. Ma**, P.N.S. Bartling. 2021. Simulating soil nitrogen fate in irrigated crop production with manure applications. *Science of the Total Environment 793: 148510* Anar, M. J. Lin, Z., **Ma, L**., Chatterjee, A. 2021. Modeling the effects of crop rotation and tillage operations on sugarbeet yield and soil nitrate using RZWQM2. *Transactions* American Society of Agricultural and Biological Engineers, 2021. 64:461-474. Cheng, H., Shu, K., Qi, Z., **Ma, L.**, Jin, V. L., Li, Y., Schemer, M. R., Weinhold, B. J., and Feng, S. 2021. Simulated effects of residue removal and tillage on CO2 and N2O emissions in continuous corn systems with RZWQM2.  J. Environ. Manage. 285, 112097. **Ma, L**., Fang, Q. X., Sima, M. W., Burkey, K. O., and Harmel, R. D. 2021. Simulated climate change effects on soybean production using two crop modules in RZWQM2. *Agronomy*Journal113:1349-1365. Cheng, G.,  R.D. Harmel , **L. Ma,**J.D. Derner,  D.J. Augustine, P.N.S. Bartling, Q. X. Fang, J.R. Williams, C.J. Zilverberg, R.B. Boone, D. Hoover, Q. Yu. 2021.Evaluation of APEX modifications to simulate forage production for grazing management decision-support in the Western US Great Plains.*Agricultural Systems* 191:103139, doi.org/10.1016/j.agsy.2021.103139 Zhang, H., **Ma, L**., Douglas-Mankin, K., Han, M., and Trout, T. J. 2021. Modelling Maize Production under Growth Stage-Based Deficit Irrigation Management with RZQWM2. *Agricultural Water Management* 248: 106767. Malone, R. W., Garbrecht, J., Busteed, P., Hatfield, J. L., Todey, D., Gerlitz, J., Fang, Q. X., Sima, M., Radke, A., **Ma, L.**, Qi, Z., Wu, H., Jaynes, D., and Kaspar, T. 2020. Drainage N Loads Under Climate Change with Winter Rye Cover Crop in a Northern Mississippi River Basin Corn-Soybean Rotation. Sustainability. 12, 7630; doi:10.3390/su12187630. Sohoulande, C. D. D., **L. Ma**, A. A. Szogi, G. C. Sigua, K. C. Stone, R. W. Malone. 2020. Evaluating nitrogen management for corn production with supplemental irrigation on sandy soils of the Southeastern Coastal Plain Region of the U.S. *American Society of Agricultural and Biological Engineers,* 63(3): 731-740, doi.org/10.13031/trans.13885 Zhang, H., Han, M., Comas, L., DeJonge, K., Gleason, S., Trout, T. J., and **Ma, L.** 2019. Response of maize yield components to growth stage-based deficit irrigation. *Agronomy* *Journal* 111:3244-3252. 2019. Chen, X., Z. Qi , D. Gui , Z. Gu, **L. Ma**, F. Zeng, L. Li  and M. W. Sima. 2019. A model-based real-time decision support system for irrigation scheduling to improve water productivity. *Agronomy*, 9, 686; doi:10.3390/agronomy9110686 Fang, Q. X., **Ma, L.**, Harmel, R. D., Yu, Q., Sima, M. W., Bartling, P. N. S., Malone, R. W., Nolan, B. T., and Doherty, J.  2019. Uncertainty of model calibration using the PEST optimization algorithm. *Agronomy* 9, 241; doi:10.3390/agronomy9050241. **Ma, L.**, Derner, J. D., Harmel, R. D., Tatarko, J., Moore, A. D., Rotz, C. A., Augustine, D. J., Boone, R. B., Coughenour, M. B., Beukes, P. C., van Wijk, M. T., Bellocchi, G., Cullen, B. R., and Wilmer. H. 2019. Application of Grazing Land Models in Ecosystem Management: Current Status and Next Frontiers. *Advances in  Agronomy* 158:173-216. Chen, X., Qi, Z., Gui, D., Gu, Z., **Ma, L.,** Zeng, F., and Li, L. 2019. Simulating the impacts of climate change on cotton yield and water requirement using RZWQM2. *Agricultural Water Management.* 222:231-241. Sadhukhan, D., Qi, Z., Zhang, T. Q., Tan, C. S., and **Ma, L.** 2019.Modeling and mitigating phosphorus losses in a tile-drained field with manure application using RZWQM2-P.. *Journal of Environmental Quality*. 48:995-1005. Zhang, H., Malone, R. W., **Ma, L.**, Ahuja, L. R., Anapalli, S. S., Marek, G., Gowda, P. H., Evett, S., and Howell, T.  2019. Modeling evapotranspiration and crop growth of irrigated and non-irrigated corn in the Texas High Plains using RZWQM. *Transactions*American Society of Agricultural and Biological Engineers**. 61:1653-1666. Sadhukhan, D., Qi, Z., Zhang, T. Q., Tan, C. S., **Ma, L.**, and Andales, A. A. 2019. Development and evaluation of a phosphorus (P) module in RZWQM2 for P management in agricultural field. *Environmental Modelling Software* 113:48-58. 2019. Malone, R. W., Herbstritt, S., **Ma, L.**, Richard, T. L., Cibin, R., Gassman, P. W., Zhang, H., Karlen, D. L., Hatfield, J. L., Obrycki, J. F., Helmers, M. J., Jaynes, D. B., Kaspar, T. C, Parkin, T. B., and Fang. Q. X.  2019. Corn stover harvest and N losses in central Iowa. *Science of Total Environment*. 663:776-792. Sima, N. Q., Andales, A. A., Harmel, R. D., **Ma**, **L.,**and Trout, T. J. 2019. Evaluating RZWQM-CERES-Maize and water production functions for predicting irrigated maize yield and biomass in eastern Colorado. *Transactions**American Society of Agricultural and Biological Engineers*. 62:213-223. *Robertson, A. D*., Zhang, Y., Sherrod, L. A., Rosenzweig, S. T., **Ma, L**., Ahuja, L. R., and Schipanski, M. E. 2018. Climate change impacts on yields and soil carbon below dryland agriculture. *Journal of Environmental Quality.* 47:684-694.  doi:10.2134/jeq2017.08.0309. Shuai, X. **Ma, L**., and Wendroth, O., 2018 Unified weak and strong soil tests to estimate latent plant available phosphorus pools. *Agronomy  Journal*  110:859-867. Sima, N. Q., Harmel, R. D., Fang, Q. X., **Ma**, **L.,**and Andales, A. A. 2018. A modified F-test for evaluating model performance by considering both experimental and simulation uncertainties. *Environmental Modelling & Software* 104:236-248 Han, M., Zhang, H. H., Chavez, J. L., **Ma, L**., Trout, T. J., and DeJonge, K. C.  2018.  Improved soil water deficit estimation through the integration of crop canopy temperature measurements into a soil water balance model. *Irrigation Science* 36:187–201, doi.org/10.1007/s00271-018-0574-z R. W. Malone, J. F. Obrycki, D. L. Karlen**, L. Ma**, T. C. Kaspar, D. B. Jaynes, T. B. Parkin, S. H. Lence, G. W. Feyereisen, Q. X. Fang, T. L. Richard, and K. Gillette. 2018. Harvesting fertilized rye cover crop: simulated revenue, net energy, and drainage nitrogen loss.*Agricultural & Environmental Letters* 3:170041 doi:10.2134/ael2017.11.0041 Gillette, K., **L. Ma**, R. W. Malone, Q.X. Fang, A. D. Halvorson, J. L. Hatfield, L.R. Ahuja. 2017. Simulating N2O emissions under different tillage systems of irrigated corn using RZ-SHAW model. *Soil & Tillage Research* 165: 268–278 Q. X. Fang, **L. Ma**, T. J. Trout, L. H. Comas, K. C. Dejonge, L. R. Ahuja, L. A. Sherrod, R. W. Malone. 2017. Modeling N concentration and uptake for maize hybrids under growth stage-based deficit irrigations. *Transactions**American Society of Agricultural and Biological Engineers.*** 60(6): 2067-2081 Fang, Q. X., **L. Ma**, Z. Qi, Y. J. Shen, L. He, S. H. Xu, I. Kisekka, M. Sima, R. W. Malone, Q. Yu. 2017. Optimizing et-based irrigation scheduling for wheat and maize with water constraints.  *Transactions**American Society of Agricultural and Biological Engineers.***60(6):2053-2065 Anar, M. J., Z. Lin, **L. Ma**, P. N. S. Bartling, J. M. Teboh, M. Ostlie. 2017. Analysis of parameter sensitivity and identifiability of root zone water quality model (RZWQM) for dryland sugarbeet modeling. *Transactions**American Society of Agricultural and Biological Engineers.*60(6):1995-2010. 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. Gu, Z., Z. Qi,**L. Ma**, D. Gui, J. Xu, Q. Fang, S. Yuan, G. Feng. 2017. Development of an irrigation scheduling software based on model predicted crop water stress. *Computers and Electronics in Agriculture* 143: 208–221 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. Anapalli ,S. S., 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: 46; doi:10.3390/agronomy6040046 Saseendran, S.A., T.J. Trout , L.R. Ahuja , **L. Ma** , G.S. McMaster , D.C. Nielsen , A.A. Andales , J.L. Chavez, J. Ham . 2016. Quantifying crop water stress factors from soil water measurements in a limited irrigation experiment. *Agricultural Water Management* 177: 274–283 **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. *Transactions**American Society of Agricultural and Biological Engineers*. 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. Feng, G., H. Tewolde**, L. Ma**, A. Adeli, K. R. Sistani, J. N. Jenkins. 2015. Simulating the Fate of Fall- and Spring-applied poultry Litter Nitrogen in Corn Production. *Soil Science Society America Journal*,  79:1804–1814 doi:10.2136/sssaj2015.06.0211 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. S.A. Saseendran,  L. R. Ahuja,**L. Ma**, T. J. Trout, G.  S. McMaster, D. C. Nielsen, J. M. Ham, A. A. Andales, A. D. Halvorson,  J. L. Chávez, Q. X. Fang. 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. 2014. Enhancing the water stress factors for simulation of corn in RZWQM2. *Agronomy* Journal. 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. *Transactions**American Society of Agricultural and Biological Engineers* 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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. *Transactions**American Society of Agricultural and Biological Engineers* 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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 Journal*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 Journal* 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 Journal,* *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. *Transactions**American Society of Agricultural and Biological Engineers*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. *Transactions**American Society of Agricultural and Biological Engineers*. 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.*Transactions**American Society of Agricultural and Biological Engineers*. 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. *Transactions**American Society of Agricultural and Biological Engineers*. 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*J*ournal,***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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