Verification And Applied Simulation Of Developing AquaCrop Model For Maize Growing And Water Using On Mulching

Agricultural water-saving technology represented by film mulching and straw mulching has become increasingly vital technology in arid and semi-arid regions. However, as the lack of the soil temperature parameter in crop model, model application of film mulching and straw mulching for improving water-saving and the yield of crop is not reported yet. The present investigation conducted at Fuxin agricultural test station of Liaoning Agricultural Academy, which based upon data of maize rainfed and irrigation in the background of the process of regional drought, was to study that by adjusting temperature parameter, applied AquaCrop model developed by FAO to simulate to film mulching of maize rainfed, straw mulching and process of maize drip irrigation under film, and validate the improved methods and applicability of AquaCrop model in the Northeastern semi-arid regions based on data of maize canopy cover and yield in 2011-2013, and simulate to crop yield under conditions of maize rainfed, straw mulching and maize drip irrigation, and analyze function relationship between crop yield and water for application of optimal regional water management. The main contents are as follows:1.Reference crop evapotranspiration (ETo) at growing stage calculated by Penman-Monteith equation is increasing per year, and EToaero has the same trend as ETo; applied M-K method to test annual surface wetting index and the co-effect of temperature increasing over the period 1960 to 2013, and showed a significant downward trend of drought process starting 1996.2. Under condition of keeping constant temperature of maize growing based upon principle of effective cumulative temperature, we have constructed the linear relationship between air temperature and soil temperature under plastic film mulching, straw mulching and non-mulching, and cleared the relation between maize air cumulative temperature and soil cumulative temperature under mulching and straw mulching of maize field, and transform soil accumulated temperature to air accumulated temperature for making a air temperature parameter of plastic film mulching and straw mulching.3. We adjusted the AquaCrop model parameter of crop and management of mulching and straw mulching using data of 2011a, and validated the goodness of mulching, straw mulching and non-mulching under rainfed and drip irrigation below film mulching using data from 2011a to 2013a. Furthermore, R2 RRMSE and CE was 0.98、0.042 and 0.91 under rainfed, respectively; R2、RRMSE and CE was 0.96、0.04 and 0.96 under drip irrigation below plastic film mulching, respectively. It indicated that AquaCrop model can apply to simulate the process of maize production under mulching and straw mulching in semi-arid region in western of Liaonning province.4. We constructed a functional relationship between crop production and rainfall under mulching and straw mulching using simulated data from 1960 to 2013, and built a water productive formula of drip irrigation under plastic mulching in different hydrological years. Finally, based upon the change point formed in process of drought, we analyzed the effect of the drought on maize production, which loss of maize grain yield is 1505kghm-2 (-15.6%)、1202 kghm-2 (-11.2%) and 1282 kghm-2 (-11.8%) under non-mulching, film mulching and straw mulching, respectively, and CV is 0.45,0.40 and 0.38, respectively, increasing CV fluctuated the maize yield.