Agricultural Climate Resources Change Characteristics of Beijing and Related Impacts on Maize Planted in Different Zones and Different Growth Periods
2010, 25 (8):
This paper aims to research the potential impacts resulted by the agricultural climate change by analyzing agricultural climate resources of heat, precipitation and sunshine for maize, including mountain spring maize, plain spring maize and plain summer maize, in sowing to elongation growth period, elongation to anthesis growth period, anthesis to silking growth period, silking to mature growth period, and the whole growth period. Statistic regression was used to reveal the time series characteristics of different kinds of maize during key growth period. Besides, we adopted Mann-Kendall and Pettitt methods in classical abrupt change theory to analyze trends and detect abrupt change characteristics of agricultural climate resources. On the basis of data analysis, we discussed the potential impacts on maize resulted from climate change according to relative research of other scholars and proposed corresponding solutions to it. The results are as follows: In recent 50 years, for Beijing, the annual active accumulated temperature and effective accumulated temperature ≥10 ℃ for maize in the whole growth period, showed no significant increasing trend without abrupt change point; while precipitation in sowing to elongation growth period got an increasing trend, precipitation of plain summer maize in elongation to anthesis growth period, plain spring maize in silking to mature growth period, hold a significant descending trend, and the other growth period showed no significant descending trend, with all growth periods having no significant abrupt change points; moreover, except for anthesis to silking growth period, sunshine resources in all the other growth periods showed significant descending trends with significant abrupt change points occurring between the mid 1980s and mid 1990s. And it concluded that according to international relative research on climate change, agricultural climate resources changing trends of Beijing may produce both positive and negative impacts on maize. In response to the increasing trend of accumulated temperature, measures should be taken to prolong grain-filling growth period. As to the descending trends of precipitation, maize variety of drought-resistance and effective drought fighting technique should be introduced; solutions for solving the descending trend of sunshine hours, maize of strong shade tolerance should be selected and attention should be paid to planting at proper intervals in order to improve ventilation and light transmission conditions.
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