The difference of greenhouse gas fluxes was related with the chemical properties and crop growth after long-term fertilization. Soil CO2 emissions were in the increasing order of CK,NK,PK,NP and NPK. There was no significant difference of CH4 fluxes among different treatments.
A combined soil water-heat-nitrogen and crop growth simulation model was established and validated based on the field data. It's found that the simulated values on soil water and nitrogen content fit well with the observed ones.
On the slight sandy loam with its thickness of being over 40 cm and when the amount of precipitation is over 200mm, and soil moisture is over 8% in the crop growth and development stage, applying chemical fertilizer to the fields can have a good effect of yield increase.
When wind speed increases in 20% of crop growth season(from April to October),ET_0 will vary in a range of 2.9% ～ 8.0%. Value added of ET_0 from April to June takes the 61.9% of all crop growth season.
GM(1,1)differential equation of the precipitation time series of crop growth period was attained based on grey theory. The self-memory grey model for predicting precipitation of crop growth period was established;
The integration between remote sensing data and crop growth simulation model is an important trend for yield estimation and prediction, since remote sensing can provide information on the actual status of the agricultural crop.
Potential growth of two widely-grown hybrid rice varieties in the Jinhua district of Zhejiang Province, Shanyou63 for mid-rice and Xieyou46 for late rice, was simulated using a crop growth model of WOFOST.
The implemented system can be used for evaluating individual and comprehensive management strategies based on the results of crop growth simulation under various environments and different genotypes.
These GMDSSCM systems have realized dynamic prediction of crop growth and decision making on cultural management, and thus should be helpful for the construction and application of informational and digital farming system.
Where crop growth is adversely affected by diseases, competition from weeds or poor management, the full benefit of insecticide spray programmes cannot be realised.