What impact will it have on agriculture if precipitation increases and the precipitation line moves northward?

First of all, it is emphasized that the northward shift of the isoprecipitation line is not as exaggerated as we thought. In fact, there is no detailed official data to interpret the northward shift of the isoprecipitation line mentioned on the Internet in recent years. We think that the northward shift of the isohyet is only because more and more rain has passed through the Qinling Mountains in recent years. The meteorological data and precipitation data of China always take Qinling Mountain as the dividing line. The south is wet and warm, and the north is dry and cold. We have seen that in recent years, there have been repeated large-scale precipitation in the north of Qinling Mountains, especially in Henan, Shanxi, Shandong and even Xinjiang deserts this year, and the precipitation has been obvious in recent years. So we generally think that the precipitation line has moved northward, but I personally prefer the cause of global warming.

Closer to home, the increase in precipitation in the north has both advantages and disadvantages. On the one hand, it can effectively replenish crops and vegetation in the arid areas in the north, comprehensively improve forest coverage and crop yield per mu, effectively replenish some dry rivers and lakes, and more importantly, it can fully alleviate the groundwater funnel area, which is conducive to the development of surrounding agriculture. After all, the adequacy of water conservancy irrigation has a great influence on grain yield per mu. Taking Shandong, where I live, as an example, the increase of rainfall in recent two years has also played a great role in helping some cash crops, especially apple planting in Jiaodong area. Rainfall changed the situation of "grabbing water seepage" irrigation and greatly saved the cost of mechanical irrigation.

Besides, the disadvantages, the rivers in the north can withstand the general rainstorm, but few rivers can withstand the continuous rainstorm. The river exceeds the bearing water level, and the surrounding farmland suffers. Dryland agriculture in the north has lasted for thousands of years, and traditional crops such as peanuts, corn, soybeans and wheat are not waterlogged, which extends from seedlings to harvest. As mentioned earlier, there have been large-scale precipitation in Shandong, Shanxi and Henan this year, which not only brought benefits, but also caused a large area of farmland to be flooded and lost. Take Shandong as an example. In addition to traditional crop cultivation, Shandong is also a big province of fruits and vegetables. However, the large-scale rainfall this spring caused cracks in the big cherry in Jiaodong area, and the yield reduction of fruit farmers was very obvious.

Finally, the long-lasting increase in the price of 202 1 vegetables is actually related to the increase in rainfall in North China. Although it is not an extreme rainstorm, the continuous rainy weather has also caused many vegetables to rot roots and stems, which has affected the vegetable supply cycle. If you want to recover completely, you can't solve it in one crop. To sum up, the increase in rainfall has both advantages and disadvantages for the north.