Performance evaluation of a maize growth simulation model

Abstract

Maize is an important cereal and it has a large potential for a high yield production in China. Therefore, improved management practices aimed to increase the production in regional level are in demand. Consequently, the regional level accurate yield estimation of maize has become important and, in fact, a big challenge. Therefore, a region-specific maize model will have a great value in yield simulation in a particular region. Therefore, a maize growth simulation model was developed by analyzing the quantitative growth of maize on daily basis and emphasizing the potential yield prediction with special focus on Northwest region, China. Daily maize growth and development, total dry matter accumulation and final grain yield for one cropping cycle were considered for the simulation of the model. Seven major stages of the crop were considered: sowing date, germination and emergence, three-leaf unfolding, jointing, booting, spinning and harvesting. Model development was based on the Growing Degree Days. Validation was done with five cropping cycles’ observation data (2005, 2006, 2007, 2009 and 2011). The common maize variety in the area, ‘Zhengdan958’ was used and the experimental field was supplied with 40m3/ha of water, 300 kg/ha of Nitrogen and 225kg/ha of Phosphorus to avoid water and nutrient stresses in order to ensure a potential maize yield. Simulated and observed data were statistically analyzed and compared. The grain yield was slightly over estimated for three cropping cycles (2006, 2007 and 2011). However, the coefficient of determination (R2=0.94) has shown a positive agreement. The obtained results have shown a fair agreement between simulated and observed values for both development and growth variables. Based on the results, the model can be used as a prediction tool and as an economic management tool in economic planning at regional level for maize cultivation.