Using datasets of 1991-2004 meteorological and soil data as well as field management from 8 stations in the
summer-sown maize zone over the Huang-Huai River Basin, North China, study is performed of the water deficit in
various phases of growth of the crop impacting on the final yield by means of CERES-Maize of DSSAT Version 4.0,
whose parameters are adjusted for local conditions. Results show that 1) in the jointing stage of vegetative growth and
the filling stage (especially its earlier part) of the reproduction growth, field moisture acts as a key factor affecting the
yield; 2) deficient moisture in the 7-leaf and jointing periods would cause maximum leaf area index to significantly drop,
keeping dry matter from accumulation, leading to appreciable diminution of weight of dry stem and leaves; 3) water
deficit in the earlier (middle) filling stage would result in reduced number of grains per cob (decrease substantially the
weight of 100 grains). The findings in conjunction with measured moisture can be used to implement the "efficient
irrigation with less water" practice in this vast region.
Using 1994-2006 typical-station agricultural data of the Huang-Huai winter wheat zone for the adjustment and
validation of the DSSAT-CERES Wheat model, which is then used with the IPCC SRES climate scenarios (A2 and B2)
through a stochastic weather generator, simulation is undertaken of effects of the 2050s climate regime on winter wheat
yield, growth/development and water requirement in the Huang-Huai plain. Results suggest that of the two emission
schemes, A2 gives higher negative influence compared to B2; the wheat growth/development period is shortened by 18
days, on average, for the region due to global warming leading to the accelerated growth, the flowering occurring ~20
days in advance, the span from flowering to maturity shortened 1~2 days, and the regional yield reducing by ~10%, on
the average. Enough irrigation will be needed to alleviate the yield decline but the wheat productivity per unit water
volume is to reduce.
Drought is the serious agrometeorological disaster influences the growth of winter wheat in Henan Province, China.
The main causes of drought formation in the province was preliminarily described based on factors such as
geographical, monsoon circulation and the global climate background and then drought patterns that happened during
last more than 40 years were analyzed in terms of negative departure percentage from averaged precipitation as
indicators. Results show that heavy droughts are centralized in northeast part of the province and light droughts
centralized in southwest part. The light ones took place every 3 years, medium ones did every 7 years and heavy ones
every 10 years. This study is beneficial to winter wheat cropping planning and drought-prevention in Henan Province.