CAJ | 학술논문

采取等养分及土培试验方法，进行硅钾肥在不同施肥条件下对青菜产量、维生素含量、硝酸盐含量、重金属元素含量以及土壤养分含量影响的试验，分析施用硅钾肥对提高蔬菜产量品质和土壤养分的作用。结果显示：施用硅钾肥可以有效提高土壤有效氮和土壤有效磷含量，明显提高青菜的产量和青菜中维生素含量，减少青菜硝酸盐含量，降低青菜中重金属元素镉、铬、铅等的含量。
채취등양분급토배시험방법，진행규갑비재불동시비조건하대청채산량、유생소함량、초산염함량、중금속원소함량이급토양양분함량영향적시험，분석시용규갑비대제고소채산량품질화토양양분적작용。결과현시：시용규갑비가이유효제고토양유효담화토양유효린함량，명현제고청채적산량화청채중유생소함량，감소청채초산염함량，강저청채중중금속원소력、락、연등적함량。
Based on collecting, reorganizing and analyzing the history data about Shanxi in Ming Dynasty, this paper studied the grade series, stage changes, different grades＇ periodicity and reason of the frost-snow and low-temperature disasters in Shanxi. The statistical results showed that the disasters had 114 times, the disasters＇ grade may be divided into mild, moderate and severe disaster, and they were respectively 22, 66 and 26 times. The disasters can be divided into two stages. The first stage was from 1368 to 1519, the second stage was from 1520 to 1644. The first stage was that the disasters happen occasionally, and most of them were mild and moderate disasters. The second stage was that the disasters happen frequently, and most of them were moderate and the most serious. According to wavelets analysis, it was known that there were mainly 2 -3a period, 9 - 14a period and 45 55a period. There were four cold climate events from 1531 to 1533, from 1578 to 1588, from 1591 to 1607 and from 1631 to 1642. The cold weather events had occurred after 1520 and prescribed the climate of the middle and late Ming Dynasty was colder than that of the early Ming Dynasty.