As the fourth major staple crop after rice, wheat and corn, potato is of great significance for ensuring the national food security. In order to explore the response characteristics of potato (Solanum tuberosum L.) yield, leaf photosynthetic physiology, dry matter accumulation characteristics to water stress in the semi-arid region of the Loess Plateau, the soil water stress experiment was conducted in 2021 by using the main potato variety “Xindaping” as the test material. The soil water was controlled during the critical period of tuber enlargement (August). Field water capacity was set at 40%±5% (moderate water stress, T1 treatment) and 55%±5% (mild water stress, T2 treatment), and 75%±5% (full water treatment, T3) was used as the control for analysis. The results show that under water stress, the maximum tuber weight per plant, tuber weight per plant and yield all decreased, the number of tubers decreased, the weight and the number of pellet potato increased significantly (P<0.05), and compared with T3 the yield of potato under T1 and T2 treatments decreased by 30% and 13%, respectively. The net photosynthetic rate (P_n), stomatal conductance (G_s) and intercellular CO₂ concentration (C_i) of potato leaves decreased significantly, among them the G_s decreased by 59%, and the water use efficiency (WUE) of T1 treatment was 31% higher than that of T3. In the weak light area, the effect of moderate and mild water stress on P_n is not obvious (P>0.05), when the light intensity was higher than 300 μmol·m^-2·s^-1, the differences between treatments increased, and P_n under T1 and T2 treatments decreased by 42% and 32% on average compared with T3. Under the influence of water stress, the maximum net photosynthetic rate (P_nmax), light compensation point (LCP) and dark respiration rate (R_d) decreased significantly (P<0.05), and light saturation point (LSP) under mild water stress was the highest (893.32 μmol·m^-2·s^-1). The range of available photosynthetically active radiation (PAR) of leaves decreased under moderate water stress, and the ability to use strong light decreased. The dry matter weight of roots, stems, leaves and petioles decreased under water stress, and under moderate water stress, the petiole decreased the most (63%), followed by leaves (57%) and roots (50%). This study can provide theoretical basis for potato drought damage assessment and soil water efficient utilization in semi-arid area of Loess Plateau.

Drought is a major meteorological disaster with the highest frequency, the longest duration and the widest scope of harm in the world today, which has a huge and extensive impact on agriculture, ecology, social development and national economy all over the world. The drought is an important factor affecting agricultural production which determines the stability of crop production, further relates to the national food security. China is a large agricultural country, and also is a country with frequent drought disaster. Therefore, to improve the monitoring, forecasting and warning level of agricultural drought disaster, it is necessary to deeply understand its formation, influence characteristics, drought intensity, severity and physiological process and mechanism of crop victimization. It is also an important scientific problem to reduce and prevent drought disaster losses and improve national food security production. This paper comprehensively reviews the recent internal and overseas research progress of agricultural drought with different degrees and its impact on crop production, and explores the influence characteristics and mechanism of drought from the aspects of crop morphology, physiology, cellular and molecular levels, etc. The main indicators, indexes, methods and early warning systems in current agricultural drought monitoring are reviewed around food production to cope effectively agriculture drought. According to the new characteristics of agricultural sustainable development and drought, the current situation of drought disaster prevention and mitigation and agricultural drought coping are discussed. A series of drought coping measures both adaptation and mitigation are emphasized. On this basis, combining with the needs of national, regional and industrial development, the paper puts forward the important scientific problems, research countermeasures and the prospect of discipline development which should be emphasized in the future.

Drought is one of the natural disasters with the widest impact and the most serious economic losses in China, which directly threatens the country’s food security and socio-economic development. The understanding and research on drought will help to improve the national capacity of drought prevention and mitigation. Since 1949, China’s research on drought meteorology has achieved fruitful results. Based on the research results of the scientific research project group related to drought meteorology carried out by the Key Open Laboratory of Arid Climate Change and Disaster Reduction of China Meteorological Administration since the 21st century, through the achievement retrieval, this paper summarizes the new progress in drought monitoring technology, drought temporal and spatial distribution, drought disaster-causing characteristics, drought disaster risk and its response to climate warming, as well as drought disaster risk management and defense technology. At the same time, based on the frontier development trend of drought meteorology research, on the basis of strengthening the comprehensive drought observation test in drought prone areas under the background of climate change, this paper puts forward that China’s drought meteorology research in future should study quantitatively the formation mechanism of drought from different dimensions and scales, build a new comprehensive drought monitoring method of multi-source data fusion and multi-method combination, reveal the mechanism of drought disaster-causing and evaluate scientifically the drought disaster risk, putting forward the executable risk management strategies. This work is of positive significance to promoting drought meteorological research in China.

Considering the different disaster-pregnant environment, population density and economic condition, the drought disaster chain models in southwest and south China were constructed respectively by using history data and record of references. Here, the disaster-pregnant environment includes climate background, underlying surface, landforms, soil and river network. And on this basis that the transmission characteristics of disaster on separate disaster chains were analyzed. The results show that the drought disaster chain structure is similar in southwest and south China, but their transfer process of disaster on the two chain is different. There are obvious regional characteristics of disaster transfer on their chain. The incipient drought can cause crop drought in southwest China, while moderate drought can cause crop drought in south China. In southwest China, the moderate drought can lead to some problems such as people and livestock drinking water difficult and livestock forage shortage, but these corresponding problems can be generated by the severe drought in south China. Being the difference in disaster-pregnant environment, the rock desertification phenomenon appears in southwest China under the severe drought condition, but the probability of rock desertification is small in south China except for north Guangxi. In the same region, as far as the various disaster-affected bodies are concerned, the threshold of drought degree transmitting is different. For example, shipping problems usually result from the moderate drought, and forest fire and pest disaster are often led by the severe drought, while soil degradations appear in the extreme drought.