Simulation and validation of CERES Maize and CERES Barley models

Abstract

newline Investigations were carried out for determination of genotypic co-efficients of important varieties of maize and barley, simulation and validation of CERES-Maize and CERES- Barley crop models for growth, yield and yield attributes, and working out simulation-guided management practices for yield maximization of both the crops. Field experiments comprising of four dates of sowing (June 1, June 10, June 20 and June 30) and four varieties (KH 9451, KH 5991, early composite and local) of maize and four dates of sowing (October 10, November 1, November 20 and December 10) and three varieties (Dolma, Sonu and HBL-113) of barley were conducted during Kharif 2002 to Rabi 2004-05 in split plot design. Observations on development stages, dry matter accumulation (leaves, stem and grains) at 15 days interval, yield attributes, yield (grains, stover/straw and biological), nitrogen content and uptake were recorded. Genotypic coefficients of important recommended varieties of maize and barley were worked out. CERES-Maize model successfully simulated phenological stages, yield attributes (except test weight), yield and also N uptake, but failed to simulate accurately dry matter accumulation in different plant parts at different growth periods. CERES-Barley model also successfully simulated phenological stages, yield attributes and grain yield, but failed to simulate straw yield, dry matter accumulation in different plant parts at different growth periods and N content and uptake. Both the models were validated with fair degree of accuracy. Simulation guided management practices were worked out under potential production and resource limiting situations. In case of maize, best time of sowing of both hybrids(KH 9451, KH 5991) was worked out to be last week of April. While for early composite, first week of May proved advantageous and for local second fortnight of April. The best schedule of N application was 60 kg /ha at sowing time and 30 kg/ha at knee high stage for all varieties except for local where it was 60 k