Simulating soybean–wheat cropping system: APSIM model parameterization and validation

• Published in: Agriculture, ecosystems & environment ecosystems & environment, 2012-05, Vol.152, p.68-78
• Main Authors: Mohanty, M., Probert, M.E., Reddy, K. Sammi, Dalal, R.C., Mishra, A.K., Subba Rao, A., Singh, M., Menzies, N.W.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; animal manures; APSIM; Biological and medical sciences; carbon; Central India; cropping systems; Cropping systems. Cultivation. Soil tillage; cultivars; Fundamental and applied biological sciences. Psychology; FYM; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; Generalities. Agricultural and farming systems. Agricultural development; Generalities. Cropping systems and patterns; grain yield; growing season; growth models; irrigation rates; irrigation water; long term experiments; management systems; model validation; N management; nutrient management; nutrients; rain; soil organic carbon; Soybean; soybeans; tropical and subtropical crops; Wheat
• ISSN: 0167-8809; 1873-2305
• DOI: 10.1016/j.agee.2012.02.013

► The APSIM model has been parameterized and validated for soybean–wheat cropping system of central India. ► Data on water, N uptake, grain yield and soil organic C from an ongoing long-term experiment was used for validation. ► The model was parameterized for FYM by specifying the N mineralized from the manure in the laboratory incubation. ► The model predicted successfully grain yield and N uptake under FYM treatment under field condition. In recent years, nutrient management of soybean–wheat systems in central India has become a cause for concern because of stagnation of grain yields of soybean and wheat. The reduction in grain yield was mainly attributed to a suboptimal supply of nutrients to both the crops, use of poor quality farmyard manures and erratic distribution of rainfall during soybean's growing season and unavailability of irrigation water during wheat season. In this connection, the crop growth simulation models are handy in identifying the constraints to yield and recommending appropriate management practices to optimize the productivity of soybean–wheat system. To achieve this, the APSIM model was parameterized and validated for soybean and wheat crop of subtropical central India. Independent data set was used to parameterize soybean cultivar (JS 335) and wheat cultivar (Sujata) to be used for APSIM simulation. Genetic coefficient generated from this study was used for subsequent model validation. The data on water use, N uptake, grain yield and soil organic C from an ongoing long-term experiment was used for validation purpose. Three nutrient treatments, viz., control (no nutrient), inorganic (recommended rate) and FYM (8tha−1 to soybean and 16tha−1 to wheat) were used to validate the APSIM model. For organic treatments, we simulated N management using the FYM as the source of plant available N under field condition. The model was parameterized by specifying the N mineralized from the manure in the laboratory incubation. The model predicted successfully grain yield and N uptake under FYM treatments in soybean and wheat. For other treatments, model prediction was satisfactory in most of the cases in simulating water and organic carbon, grain yield and N uptake by both the crops. The discrepancy observed between the observed and predicted yield in the control under soybean was due to the P limiting condition of the treatment rather than the model. The predicted variability of crop yield was also due to the variation of weather during soybe