To do agrometeorological servicework, the basic situation, characteristics ofclimate, meteorologicaldisasterand condition of occurrence ofpests, ecology characteristics ofplant, and crop ecological climate adaptability should be known. We should also do serviceworkwith flexible forms and have service productswith strong pointand strengthen the fourbasic constructions and four system construction work.
The heavy precipitationwas analyzed based on the data from 1943 to 2008 in 6 representativemeteorological stations in Linxiawhich is located in the northeast side ofQinghai-TibetPlateau. At first, the spatial and temporaldistribution ofheavy precipitation in this region was analyzed, and then, the return periods ofheavy precipitationwas assessed by Pearson-III dis ributionmethod. Results show that the days ofheavy precipitation increased conspicuously since the 1980s. The return periodwas calculated abouta heavy precipitation event in this region occurred on August20, 2008, and the result accorded with the artificial-assessment.
This paper summarizes the results on high temperature and heatwave researches in eight aspects, including damage types,standard, climatic characteristics, causes of formation, response to globalwarming, monitoring and warning technology, disastermitigation strategies and techniques. Although heatwave and high temperature is a relatively short time weather disaster, it can result in evere damages to agriculture, and its basic weather characteristic is high temperature and low humidity. It occurred in many parts of hina from June toAugust. Atmospheric circulation anomaly is the directcause for its formation, and climatewarming and drying is the mportant reason for its frequentoccurrence. A deep understanding on characteristics ofhigh temperature and heatwave damage is important, and itwill provide some guidance for isastersmonitoring and predicting and secure agriculture production.
Water or drought stress is one of the most important factors limiting crop growth world - wide. Some changes would be observed in p lant growth, physiologicalmechanisms and hormone level under soil drying stress. In arid or semi - arid region, water deficit in soil evidently inhibit the root and the shoot growth, and decrease biomass, yields and harvest index. Usually, water stress during the grain - filling period would decrease photosynthesis, shorten the grain - filling period, decline the grain - filling rate and induce early senescence, however, itwould increase the remetabolism of non - structural carbohydrate (NSC) from the vegetative tissues to the grain. Grain filling is an intensive transportation p rocess regulated by soil drying and p lant hormones. The concentration ofABA, which is generally regarded as an inhibitory growth hormone, would increase markedly in leaves, floral organs and develop ing grains in responses to soil drying. Some of the adap tive responses to drought are due to physiological and morphological changes, such as changes in p lant structure, dry matter accumulation, tissue osmotic potential and stomatal conductance. Soil drying is unfavorable to p lant growth butmay be favourable to the critical point of p roducing stress. So it is possible to take advantage of soil drying to induce whole - p lant senescence and better carbon remetabolism to imp rove grain yield during the slow grain filling period. If mild soil drying is p roperly controlled during the later grain - filling period in some crop s such as rice (Oryza sativa) and wheat ( Triticum aestivum) , it could enhance yield and harvest index, and might contribute to water saving, which is imminently needed to develop sustainable agriculture in many parts of the world.
An observation and analysis on microclimate in greenhouse were carried out in semi一arid region which lies in Loess Plateau. "hhc results show that the temperature and the relative humidity in different height in greenhouses were different, that is to say, the temperature at 1.5 m height was higher than that at() .> m，and the relative humidity at 1.5 m height was lower than that at() .> m，thus, there was a microcnvironment of the lower temperature and higher RH at() .5 m height compared with that at 1. 5 m. IW ring cucumbers growth period，the temperature in greenhouses maintained around 12一23. 5 C，R H ex- cccdcd 77. 3%in lower layer. Additionally, the survey shows that downy mildew occurred in every growth stage from seeding to bearing period，and the degree of disease in under part of the plant was more serious. So the conclusion on optimum climate condition of occurring and spreading of disease was the lower temperature and higher RH. At last, we brought forward the in- tegrated control measure.
Based on analysis of eco-climatic applicability for soybean in Gansn province, the climatic yield model was established The planting division analysis, and the way index was given with EOF method, the 5 types of suitable planting division were presented by fuzzy clustering to enhance utilizing efficiency of eco-climatic resource for soybean was put forward.
Based on an analysis of ecoclimatic applicability for millet, the climatic yield model was established in different climatic re- gion. The key meteorological factors affecting yield were confirmed,which included≥10℃accumulated temperature, average temper- ature from Aug to Sep, precipitation in July, altitude, the rate between investment and yield and so on.An integrated index system of suitable planting division was given,and the eco-climatic planting division was divided into 5 grades.At the same time,the way to enhance utilizing efficiency of ecoclimate resources was brought forward.
Based on analysis of phenological features and metorological conditions during the growing period of prosomillet in Gansu province，the main agrometeorological facts that influence on the growth of prosomillet have been found out and discussed.The influences of meterological factors on the yield of prosomillet has been analyzed with statistical methods.The complex in dices system of ecoclimate regionalzation for planting prosomillet in Gansu province has been given，and the suitable regions have been pointed out，the fit and unfit conditions in different regions have been commented.
