| Field experiments were carried out in northeast region (Heilongjiang, Jilin, Liaoning), northcentral region (Hebei, Heinan, Shanxi) and northwest region (Shaanxi, Xinjiang, Gansu Zhenyuan, Gansu Wuwei) of China in 2006~2007. The same maize cultivar (Zhengdan 958) was used for all experimental sites in all three regions, although in northeast region and Xinjiang, Gansu Zhenyuan, Gansu Wuwei in northwest region, it was used for spring maize planting, and in northcentral region and Shaanxi in northwest region, it was used for summer maize planting. Nutrient absorption and dry matter accumulation, as well as the effect of climate condition on quantity and yield of maize in different regions of northern China were studied. Common treatments were used in all experimental sites. In 2006, the treatments included optimum treatment (OPT), farm practice (FP), no fertilize treatment (CK) and nutrition deficient treatment based on OPT and FP treatments (OPT-N, OPT-P, OPT-K; FP-N, FP-P, FP-K); in 2007, the treatments included OPT, FP, CK and nutrition deficient treatment of OPT (OPT-N, OPT-P, OPT-K). Plant samples were taken at seedling, tasselling, grain filling and maturity stages, respectively from OPT, FP and CK treatment. From other treatments, plant sampling was only taken at maturity stage. After air dry, the samples were used to analyze nitrogen (N), phosphorus (P), potassium (K) content. The results were showed as following:1. In all experimental sites, the total plant biomass was increasing with the growth of maize. Vegetative growth reached maximum in grain filling stage, and then decreased. OPT treatment always gave the highest vegetative growth and grain yield, followed by FP treatment, and with CK treatment gave the lowest growth and yield. Among the three major nutrients, N, P and K, N showed the greatest effects on vegetative growth and grain yield. In OPT treatment, grain yield was highest in spring maize experiment sites in northwest region (Xinjiang, Gansu Zhenyuan, Gansu Wuwei), followed by spring maize experiment sites in northeast region (Heilongjiang, Jilin, Liaoning), and then in summer maize experiment sites in northwest region (Shaanxi) and northcentral region (Hebei, Heinan, Shanxi).2. With the plant growth and development, the contents of N, P and K in maize vegetative parts were all increased first and then decreased. At all growth stages, there were no significant differences in nutrition content among different treatments. The maximum of N content in vegetative parts was higher in summer maize than that in spring maize. And in summer maize, N content changed more quickly, and the time of highest increase rate (HIR) appeared earlier. In all experiment sites, the maximum of P content of vegetative parts usually appeared in high temperature period during maize growth stage. Maize plants cultivated in northcentral region and northwest region, had highest K content in vegetative parts (3.14%～4.5%), higher than that in maize cultivated in northeast region (2.08%～2.82%). After K content of vegetative parts reached maximum, the content decreased, but the decrease rate was slow. In maturity, K content in maize plants was highest in straw in northwest region (2.6%～3.54%), followed by that in northcentral region, and with that from northeast region the lowest (0.51%～1.25%). 3. The change of total biomass and nutrition accumulation could be described by Logistic equation y=k/(1+ae-bx). According the first derivative of the equation, the rate of dry matter accumulation and nutrition absorption was calculated; according the second derivative of the equation, the appearance time of HIR (highest increase rate) was estimated. In all regions, comparing the appearance time of highest N, P and K absorption rate, the results showed that the appearance time of highest K absorption rate was earlier than that of P, with that of N was the latest. The time of highest biomass accumulation rate appeared later than the time of highest nutrition absorption rate. When cultivated as summer maize, the time of highest total biomass accumulation rate appeared earliest in CK, followed in FP, and with that of OPT the latest. When cultivated as spring maize, the time of highest biomass accumulation rate appeared earliest in OPT, and latest in CK.In all experiment sites, nutrition absorption rate of maize were higher in early growth stage, and reached maximum earlier than dry matter accumulation rate. In the later growth stages, the nutrition absorption rate decreased quickly, but dry matter accumulation rate decreased slowly. Climate condition could not influence the change tendency of nutrition and total biomass, but had some effect on the appeared time of maximum rate. When cultivated as spring maize, the time of maximum total biomass accumulation rate and maximum N, P and K accumulation rates were appeared later than that cultivated as summer maize. And the total biomass and N, P accumulation rates were lower than cultivated as summer maize. However, the maximum absorption rate of K has slight difference with N and P. In northwest region, either cultivated as spring maize or as summer maize, the maximum absorption rate of K was higher than the other two regions. Moreover, the maximum absorption rate of K was lowest in northeast region where cultivated as spring maize.4. When Zhengdan 958 was cultivated as spring maize in northeast region, compared with that in other two regions, the total accumulation of N and P in vegetative parts before grain filling stage in northeastern region was obviously higher, while the total accumulation of K was lower. There is no significant difference in the transfer efficiency of N and P from vegetative parts to grain in different regions. But the amount of K transferred from vegetative parts to grain in sites in northwest region was higher that from northcentral and northeastern regions.5. The highest agronomic efficiency of N was found from the two spring maize sites in Gansu province in northwest region with 25.40 kg grain/kg N and 22.92 kg grain/kg N, followed by that from spring maize sites from northeast region with range of 13.50～19.36 kg grain/kg N, with the lowest agronomic efficiency of N found from summer maize sites in northcentral region with range of 3.98～11.63 kg grain/kg N, The N recovery efficiency from spring maize from northeast with 30.72～50.11% were higher than that from summer maize from northcentral region with 7.17～25.28%. The N recovery efficiency from northwest spring maize was similar with that of spring maize from northwest region. Balanced fertilization improved N fertilizer use efficiency.6. The yield of maize is positively correlated with the accumulated temperature, the average hours of sunshine, the mean temperature during the growing season, especially the hours of sunshine after the tasselling stage.7. Clustering analysis of maize seed qualities and its relationship with climatic factors indicated that the eight experimental sites could be divided into two ecologic regions. One ecologic region included Heilongjiang, Jilin, Liaoning and Xinjiang, the others included Hebei, Henan, Shandong and Shaanxi. Soluble sugar and starch in the first ecological region were higher than the from the second ecological region.
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