The impact of climate change on agricultural production

Agricultural climate refers to the climatic conditions closely related to agricultural production and crop growth and development, including indispensable factors for crop growth and development, such as light, heat and water, as well as unfavorable climatic conditions such as drought, waterlogging, frost and gale. These conditions affect not only the geographical distribution of agricultural production, but also the yield and quality of crops.

Present situation and trend of Grain production in China

In the past 40 years, there has been a general trend of warming and drying in China, especially in the north, with the exception of the middle and lower reaches of the Yangtze River and the northeast, the precipitation in the eastern agricultural region continues to decrease. If the climate continues to develop according to the above trend in the future, it will have an adverse impact on China's agriculture. Although climate change will not shake the self-supply capacity of grain in our country, it will increase the difficulties for our country to achieve the future goal of grain production, and the requirements for material input and technical management of agricultural production will be higher, and the additional investment in agriculture will increase.

Effects of climate change on crop yield

To study the impact of climate change on agricultural crop yield, it is necessary to establish a crop growth model related to crop and climate factors. At present, the most commonly used model to evaluate the impact of climate change on agriculture is the DSSAT-CERES model. The data needed by the model include crop growth agronomic character parameters, field management data, soil data, genetic parameters and daily weather data. However, there is still lack of sufficient research evidence for the future changes of these factors.

Effects of climate change on crop growth

Climate warming will increase crop yield due to the extension of growth period, but if there is no new adaptation technology, the growth period of major crops will be generally shortened, which will have a negative effect on material accumulation and grain yield. At the same time, the effect of the increase of heat resources on the growth and development of crops is largely restricted by the change of precipitation. If the precipitation can not increase accordingly, it will adversely affect the growth of crops.

Effects of climate change on crop quality

The increase of carbon dioxide concentration will lead to the decline of crop quality. In this way, the per capita food demand of human beings may have to increase in order to meet their own nutrition.

Effects of climate change on agrometeorological disasters

Extreme climatic conditions, such as drought, storm, heat wave and frost, have the greatest impact on agriculture. Little is known about the impact of climate change on the frequency and intensity of these climate disasters, and it is difficult to accurately estimate the extent of these impacts.

Effects of climate change on crop diseases and insect pests

According to statistics, the loss of agricultural output value caused by diseases and insect pests in China is about 20-25% of the total agricultural output value. Climate warming will change the distribution area of agricultural diseases and insect pests. Low temperature often limits the distribution of some diseases and insect pests, and when the temperature increases, the distribution area of these diseases and insect pests may expand, thus affecting the growth of crops. At the same time, Greenhouse Effect also prolongs the growing season of some diseases and insect pests, increases the reproductive algebra of insect pests, prolongs the damage time of the year, and the damage to crops may be aggravated.

Effect of Climate change on the use of Chemical Fertilizer and Pesticide

Fertilizer effect is very sensitive to the change of environmental temperature, especially nitrogen fertilizer. If the temperature increases by 1 ℃, the release amount of available nitrogen that can be directly absorbed and utilized by plants will increase by about 4%, and the release period will be shortened by 3.6 days. Therefore, if the original fertilizer effect is to be maintained, the amount of fertilizer applied each time will be increased by about 4%. Climate warming will also change the application of pesticides, with the warming of the climate and the extension of crop growing season, the generations of insect reproduction in spring, summer and autumn will increase, and higher winter temperatures will also help larvae survive the winter safely, and the scope of various diseases and insect pests will be expanded. aggravate the prevalence of diseases and insect pests and the spread of weeds, which means that a large number of pesticides and herbicides will have to be applied in these areas.

Conclusion: agricultural production is a typical process of the interaction of natural and social factors, so the final impact assessment should be considered from these two aspects at the same time, because the same natural change process will produce different results in different economic levels of society. For a developing country like China, it is very important to consider the impact of socio-economic factors on climate change adaptation.